Battery monomer, battery device and electric device

Abstract

The utility model provides a battery monomer, a battery device and a power utilization device, the battery monomer comprises a shell and an electrode assembly, the polarities of a first pole piece and a second pole piece in the electrode assembly are opposite, the first pole piece and the second pole piece are separated by a separator, the first pole piece comprises a first current collector, a first active material layer and a first support layer, the first active material layer comprises a first main body part and a first thinned part arranged on one side of the first main body part, the thickness of the first thinned part is smaller than that of the first main body part, and at least part of the first supporting layer is located between the first current collector and the first thinned part. During rolling, the first supporting layer can prevent the material of the first active material layer from flowing from the center to the edge to a certain extent, so that the risk that the edge of the first pole piece is cracked and the like is reduced, the thinning thickness of the first thinning part can be correspondingly reduced and even the first thinning part does not need to be thinned, and the production efficiency is improved. The risk that active ions are separated out at the first pole piece is reduced.

Description

TECHNICAL FIELD

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

[0002] With the development of new energy technology, batteries are applied more and more widely, such as 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] In the development of battery technology, the performance of the battery monomer directly affects the overall performance of the battery device. However, the battery monomer is prone to active ion precipitation and other phenomena during use, which seriously affects its performance. INNOVATION CONTENT

[0004] In view of the above problems, the present application provides a battery monomer, a battery device and a power consumption device, which can improve the performance of the battery monomer.

[0005] In a first aspect, the embodiments of the present application provide a battery monomer, comprising a shell and an electrode assembly, the electrode assembly is arranged in the shell, the electrode assembly comprises a first electrode sheet, a second electrode sheet and a separator, the first electrode sheet and the second electrode sheet are opposite in polarity, the separator separates the first electrode sheet and the second electrode sheet, the first electrode sheet comprises a first current collector, a first active material layer and a first support layer, the first active material layer comprises a first main body part and a first thinning part arranged on one side of the first main body part, the first main body part is arranged on the first current collector, the thickness of the first thinning part is smaller than the thickness of the first main body part, and at least part of the first support layer is arranged between the first current collector and the first thinning part.

[0006] In the above scheme, the separator separates the first electrode sheet and the second electrode sheet which are opposite in polarity, which can prevent the first electrode sheet and the second electrode sheet from short-circuiting. The first electrode sheet comprises a first current collector, a first support layer and a first active material layer, the first active material layer comprises a first main body part and a first thinning part arranged on one side of the first main body part, the first main body part is arranged on the first current collector, the thickness of the first thinning part is smaller than the thickness of the first main body part, and at least part of the first support layer is arranged between the first thinning part and the first current collector. In the subsequent rolling process of the first electrode sheet, the first support layer can support the first active material layer, to a certain extent, to block the flow of the material of the first active material layer from the center to the edge, thereby reducing the risk of liquid accumulation and edge explosion of the edge of the first electrode sheet. By such arrangement, the thickness of the first thinning part during the thinning process can be reduced or even the first thinning part does not need to be thinned, thereby reducing the gap between the first thinning part and the separator or even eliminating the gap therebetween, to reduce the risk of active ion precipitation at the first electrode sheet and improve the performance of the battery monomer.

[0007] In some embodiments, the first support layer and the first active material layer comprise the same active material.

[0008] In the above scheme, in the charging and discharging process of the battery cell, the first support layer can be embedded and de-embedded with the first active material layer to reduce the impact of the first support layer on the energy density of the battery cell. Moreover, the first support layer and the first active material layer comprise the same active material, and when the first active material layer is prepared, the first active material layer can better wet the first support layer, improve the spreading ability, and further improve the thickness uniformity of the first active material layer.

[0009] In some embodiments, the first support layer comprises a conductive layer.

[0010] In the above scheme, in the charging and discharging process of the battery cell, the second tab and the first thinning part are embedded or de-embedded with active ions, and the active ions are transmitted between the second tab and the first thinning part. On this basis, the first support layer comprises a conductive layer, which can provide a transmission channel for ions on the one hand to shorten the ion transmission path and speed up the ion transmission efficiency, and on the other hand can collect and conduct electrons to realize power output together with the first current collector.

[0011] In some embodiments, the first main part and the first thinning part are arranged along a first direction, and the first direction is perpendicular to the thickness direction of the first main part; in the first direction, along the direction from the first main part to the first thinning part, the thickness of the first thinning part shows a decreasing trend, and the thickness of the first support layer shows an increasing trend.

[0012] In the above scheme, in the first direction, along the direction from the first main part to the first thinning part, the thickness of the first thinning part is arranged to show a decreasing trend, and the thickness of the first support layer is arranged to show an increasing trend, which can make the overall structure of the first thinning part and the first support layer relatively uniform in thickness with the first main part, reduce the risk of increasing the overall thickness of the electrode assembly due to the setting of the first support layer, and on the other hand, the thickness of the first support layer is arranged to show an increasing trend, which can make the surface of the first support layer for contacting the first active material layer be an inclined surface or an arc surface, thereby reducing the contact angle between the first active material layer and the first support layer when the first active material layer is prepared, so that the first active material layer can better wet the first support layer, improve the spreading ability of the first active material layer, and further improve the thickness uniformity of the first active material layer.

[0013] In some embodiments, the first current collector comprises a first current collecting main body and a first tab, the first current collecting main body and the first tab are arranged along a first direction, and the first direction is perpendicular to the thickness direction of the first main part; the first thinning part is located on the side of the first main part close to the first tab.

[0014] In the above scheme, the first thinning portion is arranged at the side of the first main body portion close to the first tab, and the first support layer is located at the side of the first main body portion close to the first tab. In subsequent processes such as rolling, the first support layer can block the material of the first active material layer from flowing along the first direction to the side close to the first tab to some extent, reduce the risk of the side of the first active material layer close to the first tab being extruded in subsequent processes to cause edge explosion, and reduce the influence of the first active material layer on the performance of the first tab.

[0015] In some embodiments, the second tab includes a second current collector, a second active material layer, and a second support layer. The second active material layer includes a second main body portion and a second thinning portion arranged at one side of the second main body portion. The second main body portion is arranged on the second current collector, and the thickness of the second thinning portion is less than that of the second main body portion. At least part of the second support layer is located between the second current collector and the second thinning portion.

[0016] In the above scheme, the second main body portion is arranged on the second current collector, and the second thinning portion is located at one side of the second main body portion and has a thickness less than that of the second main body portion. At this time, by arranging the second support layer between the second current collector and the second thinning portion, in subsequent processes such as rolling of the second tab, the second support layer can support the second active material layer and block the material of the second active material layer from flowing from the center to the edge to some extent, thereby reducing the risk of liquid accumulation and edge explosion at the edge of the second tab. By such arrangement, the thickness of the second thinning portion during the thinning process can be reduced or even eliminated, thereby reducing the gap between the second thinning portion and the separator or even eliminating the gap therebetween, to reduce the risk of active ion precipitation at the edge of the second tab and improve the performance of the battery cell.

[0017] In some embodiments, the first main body portion and the first thinning portion are arranged along a first direction, and the first direction is perpendicular to the thickness direction of the first main body portion. In the first direction, the second thinning portion is located at the side of the second main body portion close to the first thinning portion, or the second thinning portion is located at the side of the second main body portion away from the first thinning portion.

[0018] In the above scheme, the second thinning portion is arranged at the side of the second main body portion close to the first thinning portion, which is conducive to improving the balance of active ions between the first thinning portion and the second thinning portion and reducing the risk of active ion precipitation due to excess active ions between the first thinning portion and the second thinning portion. Alternatively, the second thinning portion is arranged at the side of the second main body portion away from the first thinning portion, which is helpful to balance the volume change of the first active material layer and the second active material layer during use and improve the stress distribution of the battery cell.

[0019] In some embodiments, the first main body portion has a thickness greater than a thickness of the first support layer, and the first support layer is located between the first thinned portion and the first current collector.

[0020] In the above solution, by setting the thickness of the first main body portion to be greater than the thickness of the first support layer, and the first support layer is located between the first thinned portion and the first current collector, on the one hand, the blocking effect of the first support layer on the material of the first active material layer can be improved, and the risk of the first active material layer flowing to the edge after being pressed to cause edge explosion and the like can be reduced, on the other hand, the influence of the setting of the first support layer on the performance of the first active material layer can be reduced, which is beneficial to improving the overall performance of the battery cell.

[0021] In some embodiments, the first support layer includes a first sub-portion disposed between the first thinned portion and the first current collector, a projection of the first sub-portion on the first current collector along the thickness direction of the first main body portion is located within a projection of the first thinned portion on the first current collector along the thickness direction of the first main body portion, and a ratio Z1 of the thickness of the first sub-portion to the thickness of the first main body portion satisfies: 0.08≤Z1≤0.15.

[0022] In the above solution, the first sub-portion is disposed between the first thinned portion and the first current collector, and by reasonably setting the ratio of the thickness of the first sub-portion to the thickness of the first main body portion, on the one hand, the blocking effect of the first sub-portion on the material of the first active material layer can be improved, and the risk of the first active material layer occurring edge explosion and the like when being rolled can be reduced, on the other hand, the influence of the setting of the first support layer on the performance of the first active material layer can be reduced.

[0023] In some embodiments, the first support layer further includes a second sub-portion disposed between the first thinned portion and the first current collector, the second sub-portion is located on a side of the first sub-portion close to the first main body portion, and a ratio Z2 of the thickness of the second sub-portion to the thickness of the first main body portion satisfies: 0.03≤Z2≤0.08.

[0024] In the above solution, the second sub-portion is disposed between the first thinned portion and the first current collector, and is located on a side of the first sub-portion close to the first main body portion, which can block the first active material layer from flowing from the center to the edge when being rolled, so as to further reduce the risk of the first electrode tab occurring edge explosion and the like, and on this basis, by optimizing the ratio of the thickness of the second sub-portion to the thickness of the first main body portion, the stress transition of the first sub-portion and the second sub-portion when being extruded in subsequent processes can be smoother, and the risk of stress concentration between the first sub-portion and the second sub-portion can be reduced.

[0025] In some embodiments, the first support layer further comprises a third sub-portion disposed between the first thinning portion and the first current collector, the third sub-portion is located at a side of the second sub-portion close to the first main portion, and a ratio Z3 of a thickness of the third sub-portion to a thickness of the first main portion satisfies: 0.01≤Z3≤0.03.

[0026] In the above scheme, the third sub-portion is disposed between the first thinning portion and the first current collector and is located at a side of the second sub-portion close to the first main portion, which can block the first active material layer from flowing from the center to the edge during rolling, thereby further reducing the risk of edge explosion of the first pole piece. On this basis, the ratio of the thickness of the third sub-portion to the thickness of the first main portion is optimized and designed, which can make the stress transition of the second sub-portion and the third sub-portion more smooth during subsequent processes, thereby reducing the risk of stress concentration between the second sub-portion and the third sub-portion.

[0027] In some embodiments, the first support layer comprises a first portion and a second portion, the second portion is located at a side of the first portion close to the first main portion, the thickness of the first portion is greater than or equal to the thickness of the first main portion, and the first portion is exposed relative to the first thinning portion along a surface of the first main portion away from the first current collector.

[0028] In the above scheme, the first support layer comprises a first portion and a second portion, the second portion is located at a side of the first portion close to the first main portion, and the thickness of the first portion is greater than or equal to the thickness of the first main portion, which can improve the blocking effect of the first support layer on the first active material layer to a certain extent, thereby further reducing the risk of edge explosion of the first active material layer. In this way, the thinning thickness of the first thinning portion can be further reduced or even the first thinning portion does not need to be thinned, thereby further reducing the gap between the first thinning portion and the isolation piece or even eliminating the gap therebetween, thereby further reducing the risk of active ion precipitation at the first pole piece.

[0029] In some embodiments, the first current collector is provided with the first active material layer and the first support layer on opposite sides in the thickness direction of the first main portion.

[0030] In the above scheme, the first active material layers are arranged on opposite sides of the first current collector, which can improve the energy density of the battery monomer. On this basis, the first support layers are arranged on opposite sides of the first current collector, and the corresponding first active material layers are supported by the first support layers on the two sides respectively, so as to block the flow of the materials of the corresponding first active material layers from the center to the edge to a certain extent, thereby further reducing the risk of liquid accumulation, edge explosion and the like of the edge of the first pole piece. By such arrangement, the thickness of the first thinning part of the first active material layer on the two sides of the first current collector can be reduced when the first thinning part is thinned, or even the first thinning part does not need to be thinned, thereby reducing the gap between the corresponding first thinning part and the corresponding isolation piece or even eliminating the gap therebetween, and further reducing the risk of active ion precipitation at the first pole piece.

[0031] In a second aspect, the embodiments of the present application provide a battery device, comprising a plurality of battery monomers as described in any one of the above.

[0032] In a third aspect, the embodiments of the present application provide a power consumption device, comprising the above battery device, and the battery device is used to provide electric energy.

[0033] The above description is only a summary of the technical solutions of the present application. In order to more clearly understand the technical means of the present application, the embodiments of the present application can be implemented according to the content of the specification, and in order to make the above and other purposes, characteristics and advantages of the present application more obvious and easy to understand, the following will specifically describe the embodiments of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creating any creative labor.

[0035] Figure 1 is a structural schematic diagram of a vehicle provided by some embodiments of the present application;

[0036] Figure 2 is an exploded view of a battery device provided by some embodiments of the present application;

[0037] Figure 3 is an exploded view of a battery monomer provided by some embodiments of the present application;

[0038] Figure 4 is a cross-sectional schematic diagram of an electrode assembly in a battery monomer provided by some embodiments of the present application;

[0039] Figure 5is a cross-sectional view of a first pole piece in a battery cell provided by some embodiments of the present application;

[0040] Figure 6 is a cross-sectional view of an electrode assembly in a battery cell provided by some embodiments of the present application;

[0041] Figure 7 is a cross-sectional view of an electrode assembly in a battery cell provided by some embodiments of the present application;

[0042] Figure 8 is a partial enlarged view of a first pole piece in a battery cell provided by some embodiments of the present application;

[0043] Figure 9 is a cross-sectional view of a first pole piece in a battery cell provided by some embodiments of the present application.

[0044] Label name:

[0045] Vehicle 1000; battery device 100; first box body 110; second box body 120; controller 200; motor 300;

[0046] Battery cell 1; shell 10; casing 11; end cover 12; electrode assembly 20; first pole piece 21; first current collector 211; first current collector body 2111; first pole tab 2112; first active material layer 212; first body part 2121; first thinning part 2122; first support layer 213; first subpart 2131; second subpart 2132; second pole piece 22; second current collector 221; second current collector body 2211; second pole tab 2212; second active material layer 222; second body part 2221; second thinning part 2222; second support layer 223; separator 23; third subpart 2333; first direction X. DETAILED DESCRIPTION

[0047] The 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.

[0048] 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.

[0049] In the description of the embodiments of the present application, the technical terms "first", "second" and the like 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 and specifically limited.

[0050] 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 independent or alternative embodiments 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.

[0051] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined to form new technical solutions.

[0052] Unless otherwise specified, all technical features and optional technical features of the present application can be combined to form new technical solutions.

[0053] Unless otherwise specified, all steps of the present application can be performed in sequence or randomly, preferably in sequence. For example, the method comprises steps (a) and (b), which means that the method can comprise steps (a) and (b) performed in sequence, or steps (b) and (a) performed in sequence. For example, it is mentioned that the method can further comprise step (c), which means that step (c) can be added to the method in any order, for example, the method can comprise steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0054] In the description of the embodiments of the present application, the term "and / or" is only used to describe 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 " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0055] 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).

[0056] In the description of the embodiments of the present application, the orientations or positional relationships indicated by the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientations or positional relationships 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.

[0057] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connection", "connecting", "fixing" and the like should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or can be integrated; can be mechanical connection, can also be electrical connection; can be direct connection, can also be indirect connection through an intermediate medium, can be internal communication of two elements or interaction relationship between two elements. For those skilled in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0058] 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.

[0059] 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. The embodiments of the present application are not limited thereto.

[0060] 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, in parallel or in a mixed manner through a busbar component.

[0061] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode and a separator, and the separator is arranged between the negative electrode and the positive electrode. During the charging and discharging process of the battery cell, active ions (such as lithium ions) are embedded and extracted between the positive electrode and the negative electrode. The separator arranged between the positive electrode and the negative electrode can prevent the positive electrode and the negative electrode from short-circuiting, and at the same time allow the active ions to pass through.

[0062] 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 arranged on at least one surface of the positive electrode current collector.

[0063] As an example, the positive electrode current collector has two surfaces opposite in the thickness direction thereof, and the positive electrode active material is disposed on either one or both of the two surfaces of the positive electrode current collector.

[0064] As an example, the positive electrode current collector can employ a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as the metal foil, a pure metal, an alloy, a surface-treated metal, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver, and the like can be employed. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, an aluminum alloy, nickel, a nickel alloy, titanium, a titanium alloy, silver, a silver alloy, and the like) on a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, and the like).

[0065] As an example, the positive electrode active material can include at least one of a lithium-containing phosphate, a lithium transition metal oxide, and a modified compound of each thereof. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery positive electrode active material can also be used. These positive electrode active materials can be used alone only in one kind, or two or more kinds can be used in combination. Among them, examples of the lithium-containing phosphate can include, but are not limited to, at least one of lithium iron phosphate (such as LiFeP04 (which can also be referred to simply as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnP04), a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon. Examples of the lithium transition metal oxide can include, but are not limited to, lithium cobalt oxide (such as LiCo02), lithium nickel oxide (such as LiNi02), lithium manganese oxide (such as LiMn02, LiMn204), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 02 (which can also be referred to simply as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 02 (which can also be referred to simply as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 02 (which can also be referred to simply as NCM), LiNi 0.6 Co 0.2 Mn 0.2 02 (which can also be referred to simply as NCM6 22 ), LiNi 0.8 Co 0.1 Mn 0.1 02 (which can also be referred to simply as NCM811 ), lithium nickel cobalt aluminum oxide (e.g., LiNi 0.8 Co 0.15 Al 0.05 O2) and modified compounds thereof. Modified compounds refer to compounds obtained by modification means such as doping or coating on the basis of the above-mentioned substances.

[0066] In some embodiments, the negative electrode can be a negative electrode sheet, which can include a negative electrode current collector.

[0067] As an example, the negative electrode current collector can employ a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, a pure metal, an alloy, a surface-treated metal, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver, etc. can be employed. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base material (e.g., a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0068] 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.

[0069] As an example, the negative electrode current collector has two surfaces opposite 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.

[0070] As an example, the negative electrode active material can employ a negative electrode active material for a battery cell known in the art. As an example, the negative electrode active material can include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, a silicon-based material, a tin-based material, and lithium titanate, etc. The silicon-based material can be selected from at least one of elemental silicon, a silicon oxide compound, a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy. The tin-based material can be selected from at least one of elemental tin, a tin oxide compound, and a tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as a negative electrode active material for a battery cell can also be used. These negative electrode active materials can be used alone or in combination of two or more.

[0071] 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.

[0072] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0073] In some embodiments, the separator is a separator film. The type of the 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.

[0074] 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. The separator film can be a single layer film or a multi-layer composite film, and is not particularly limited. When the separator film is a multi-layer composite film, the materials of the respective layers can be the same or different, and are not particularly limited. The separator can be a separate component located between the positive and negative electrodes, or can be attached to the surface of the positive and negative electrodes. An inorganic particle coating, an organic particle coating, or an organic / inorganic composite coating can be applied to the surface of the separator film.

[0075] In some embodiments, the separator is a solid-state electrolyte. The solid-state electrolyte is disposed between the positive and negative electrodes, and functions to transport ions and separate the positive and negative electrodes.

[0076] In some embodiments, the battery cell further includes an electrolyte that functions to conduct ions between the positive and negative electrodes. The type of the 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.

[0077] The liquid electrolyte includes an electrolyte salt and a solvent.

[0078] The electrode assembly can have a jelly-roll structure, a stack structure, or a hybrid structure of the jelly-roll and stack structures.

[0079] In some embodiments, the electrode assembly has a jelly-roll structure. The positive electrode sheet and the negative electrode sheet are wound to form the jelly-roll structure.

[0080] In some embodiments, the electrode assembly has a stack structure.

[0081] For example, a plurality of positive electrode sheets and a plurality of negative electrode sheets can be alternately stacked.

[0082] For example, a plurality of positive electrode sheets can be provided, and the negative electrode sheet can be folded to form a plurality of folded sections that are stacked. One positive electrode sheet can be interposed between adjacent folded sections.

[0083] For example, the positive electrode sheet and the negative electrode sheet can each be folded to form a plurality of folded sections that are stacked.

[0084] For example, a plurality of separators can be provided, and each of the plurality of separators can be interposed between any adjacent positive electrode sheet or negative electrode sheet.

[0085] For example, the separators can be continuously provided and interposed between any adjacent positive electrode sheet or negative electrode sheet by folding or winding.

[0086] In some embodiments, the electrode assembly can have a cylindrical shape, a flat shape, or a multi-prism shape, etc.

[0087] In some embodiments, the electrode assembly can be provided with tabs, which can guide the current out of the electrode assembly. The tabs can include positive tabs and negative tabs.

[0088] In some embodiments, the battery cell can include a housing. 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. In some embodiments, the housing can be a sealed structure or a non-sealed structure. As an example, when the housing is a non-sealed structure, the housing serves to protect the electrode assembly, and a sealing bag is further included between the housing and the electrode assembly, which is used to encapsulate the electrode assembly and the electrolyte. Specifically, the sealing bag can be a bag-shaped insulating member or an aluminum-plastic film. When the housing is a sealed structure, it is used to encapsulate the electrode assembly and the electrolyte, etc.

[0089] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or other shapes of battery cells, including a square battery cell, a blade battery cell, a multi-prismatic battery cell (such as a hexagonal battery cell), etc., without specific limitations in the present application.

[0090] In some embodiments, the housing includes an end cap and a shell, the shell is provided with an opening, and the end cap is provided on the opening. The shell can be provided with one or more openings. The end cap can also be provided with one or more openings.

[0091] In the production process of the electrode sheet, it is usually necessary to roll the active material layer of the electrode sheet to compact the active material layer. However, during the rolling process, the active material layer in the middle of the electrode sheet may move to the edge of the electrode sheet under the action of pressure, resulting in the occurrence of edge explosion, edge bulging, etc. on the edge of the electrode sheet. In order to solve this problem, the edge of the electrode sheet can be thinned to reduce the thickness of the edge of the electrode sheet, which can alleviate the degree of edge explosion, edge bulging, etc. of the electrode sheet during rolling, or even avoid the occurrence of edge explosion or edge bulging, etc. of the electrode sheet.

[0092] However, in the electrode assembly, the positive electrode sheet and the negative electrode sheet are stacked, and when the edge of at least one of the positive electrode sheet and the negative electrode sheet is thinned, there will be a gap at the thinned area between the two. During the charging and discharging process of the battery cell, the transmission path of the active ions located between the positive and negative electrode sheets is lengthened, the transmission efficiency is reduced, the surface of the electrode sheet towards the gap is prone to ion precipitation, and the performance of the battery cell is affected.

[0093] In view of this, the battery cell provided in the embodiments of the present application includes a shell and an electrode assembly, the electrode assembly is arranged in the shell, the electrode assembly includes a first electrode plate, a second electrode plate and a separator, the first electrode plate and the second electrode plate are opposite in polarity, the separator separates the first electrode plate and the second electrode plate, the first electrode plate includes a first current collector, a first active material layer and a first support layer, the first active material layer includes a first main body part and a first thinned part arranged on one side of the first main body part, the first main body part is arranged on the first current collector, the thickness of the first thinned part is smaller than the thickness of the first main body part, and at least part of the first support layer is arranged between the first current collector and the first thinned part. By arranging at least part of the first support layer between the first thinned part and the first current collector, the first support layer can support the first active material layer in subsequent processes such as rolling of the first electrode plate, to a certain extent, block the flow of the material of the first active material layer from the center to the edge, thereby reducing the risk of liquid accumulation, edge explosion and the like of the edge of the first electrode plate. By such arrangement, the thickness of the first thinned part can be correspondingly reduced or even the first thinned part does not need to be thinned, thereby reducing the gap between the first thinned part and the separator or even eliminating the gap therebetween, to reduce the risk of active ion precipitation at the first electrode plate and improve the performance of the battery cell.

[0094] The technical solutions described in the embodiments of the present application are applicable to various electric devices using battery devices, for example, mobile phones, portable devices, notebook computers, electric vehicles, electric toys, electric tools, vehicles, ships and spacecraft, etc. For example, the spacecraft includes an airplane, a rocket, a space shuttle and a spaceship, etc.

[0095] The battery device described in the embodiments of the present application is not only limited to the above-described electric devices, but for the sake of brevity, the following embodiments are described by taking an electric vehicle as an example.

[0096] Please refer to Figure 1 , Figure 1 A simple schematic diagram of a vehicle 1000 is provided in the embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle or a range extended vehicle, etc. The vehicle 1000 can be provided with a battery device 100 inside, for example, the battery device 100 can be arranged at the bottom, the front or the rear of the vehicle 1000. The battery device 100 can be used for power supply of the vehicle 1000, for example, the battery device 100 can be used as the operating power source of the vehicle 1000. The vehicle 1000 can further include a controller 200 and a motor 300, and the controller 200 is used to control the power supply of the motor 300 by the battery. The battery device 100 can be used for starting, navigation and the like of the vehicle 1000, of course, the battery device 100 can also be used to drive the vehicle 1000 to run, to replace or partially replace the fuel or natural gas to provide driving for the vehicle 1000.​​​​​​​​

[0097] In some embodiments of the present application, the battery device 100 can not only serve as the operating power source of the vehicle 1000, but also serve as the driving power source of the vehicle 1000, replacing or partially replacing the fuel or natural gas to provide driving power for the vehicle 1000.

[0098] Please refer to Figure 2 , Figure 2 An exploded view of the battery device provided in some embodiments of the present application is shown. The battery device 100 includes a battery box and a battery cell 1. In some embodiments, the battery box can include a first box 110 and a second box 120, the first box 110 and the second box 120 are covered with each other, and the first box 110 and the second box 120 together define a receiving cavity for accommodating the battery cell 1. The second box 120 can be a hollow structure with one end open, and the first box 110 can be a plate structure, which is covered on the open side of the second box 120 to make the first box 110 and the second box 120 together define the receiving cavity; the first box 110 and the second box 120 can also be hollow structures with one side open, and the open side of the first box 110 is covered on the open side of the second box 120. Of course, the battery box formed by the first box 110 and the second box 120 can have various shapes, such as a cylinder, a cuboid, etc.

[0099] In some embodiments, the battery cell assembly is usually formed by arranging a plurality of battery cells 1.

[0100] As an example, the battery cell assembly can be a battery module, which is formed by arranging and fixing a plurality of battery cells 1 into one independent module. As an example, the battery module can be formed by bundling a plurality of battery cells 1 with a cable tie.

[0101] In some embodiments, the battery device 100 can be a battery pack, which includes a battery box and one or more battery cell assemblies, and the battery cell assemblies are accommodated in the battery box.

[0102] As an example, the battery cell assembly can be a battery module, which can be accommodated in the battery box by fixing the battery module in the battery box.

[0103] As an example, the battery cell assembly can also be accommodated in the battery box by directly fixing a plurality of battery cells 1 in the battery box.

[0104] As an example, the battery box can include a first box 110 and a second box 120. The first box 110 and the second box 120 are buckled so that a closed space is formed inside the battery box to accommodate the battery cell assembly. Here, closed means covered or closed, which can be sealed or unsealed. The first box 110 can be a top cover or a bottom plate.

[0105] As an example, the battery box can include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected with the frame, so that an enclosed space is formed inside the battery box to accommodate the battery monomer assembly.

[0106] In some embodiments, the battery box can be part of the chassis structure of the vehicle. For example, part of the battery box can be at least part of the floor of the vehicle, or part of the battery box can be at least part of the cross beam and the longitudinal beam of the vehicle.

[0107] In some embodiments, the battery device 100 can be an energy storage device. The energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0108] Figure 3 The structural diagram of the battery monomer provided for some embodiments of the present application is shown. In the battery device 100, the battery monomer 1 can be multiple, and the multiple battery monomers 1 can be connected in series, in parallel, or in a mixed connection. The mixed connection means that there are both series and parallel connections among the multiple battery monomers 1. The multiple battery monomers 1 can be directly connected in series, in parallel, or in a mixed connection, and then the whole of the multiple battery monomers 1 is accommodated in the box; of course, the battery device 100 can also be that the multiple battery monomers 1 are first connected in series, in parallel, or in a mixed connection to form a battery module, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, which is accommodated in the box.

[0109] Among them, each battery monomer can be a secondary battery monomer or a primary battery monomer; it can also be a lithium-sulfur battery monomer, a sodium-ion battery monomer, or a magnesium-ion battery monomer, but is not limited thereto. The battery monomer can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, etc.

[0110] In some embodiments, the housing 10 includes a shell 11 having an opening and an end cap 12 connected to the shell 11 and covering the opening. The shell 11 is a component for cooperating with the end cap 12 to form an internal cavity of the battery cell 1, which can be used to accommodate the electrode assembly 20, electrolyte and other components. The shell 11 and the end cap 12 can be separate components. For example, the opening can be provided on the shell 11, and the end cap 12 is used to cover the opening to form the internal cavity of the battery cell 1. The shell 11 can be in various shapes and sizes, such as a cuboid. In particular, the shape of the shell 11 can be determined according to the specific shape and size of the electrode assembly 20. The shell 11 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc. The end cap 12 can be shaped to fit the shell 11. The material of the end cap 12 can be the same as or different from that of the shell 11. Optionally, the end cap 12 can be made of a material with certain hardness and strength (such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.), so that the end cap 12 is less likely to deform when subjected to extrusion and impact, and the battery cell 1 can have higher structural strength and improved reliability. The end cap 12 can be connected to the shell 11 by welding, bonding, clamping or other means. The shell 11 can be open at one end or both ends. In some examples, the shell 11 can be open at one side, and the end cap 12 is provided as one and covers the shell 11. In other examples, the shell 11 can be open at both ends, and the end cap 12 is provided as two and covers the two openings of the shell 11, respectively. The electrode assembly 20 is a component in which electrochemical reactions occur in the battery cell 1. The shell 11 can contain one or more electrode assemblies 20.

[0111] Next, the structure of the battery device 100 will be described in detail with reference to the accompanying drawings.

[0112] Please refer to Figure 3 and Figure 4In a first aspect, the embodiments of the present application provide a battery cell 1, comprising a housing 10 and an electrode assembly 20, the electrode assembly 20 is arranged in the housing 10, the electrode assembly 20 comprises a first electrode tab 21, a second electrode tab 22 and a separator 23, the first electrode tab 21 and the second electrode tab 22 are opposite in polarity, the separator 23 separates the first electrode tab 21 and the second electrode tab 22, the first electrode tab 21 comprises a first current collector 211, a first active material layer 212 and a first support layer 213, the first active material layer 212 comprises a first main body part 2121 and a first thinning part 2122 arranged on one side of the first main body part 2121, the first main body part 2121 is arranged on the first current collector 211, the thickness of the first thinning part 2122 is less than the thickness of the first main body part 2121, and at least part of the first support layer 213 is arranged between the first current collector 211 and the first thinning part 2122.

[0113] The housing 10 is a component for protecting the electrode assembly 20, and the housing 10 can be enclosed to form a containing cavity for containing the electrode assembly 20, and the electrode assembly 20 and the electrolyte are arranged in the containing cavity.

[0114] The electrode assembly 20 comprises the first electrode tab 21, the second electrode tab 22 and the separator 23, the first electrode tab 21 and the second electrode tab 22 are opposite in polarity, one of the first electrode tab 21 and the second electrode tab 22 can be a positive electrode tab, and the other can be a negative electrode tab, and the present application takes the first electrode tab 21 as a negative electrode tab and the second electrode tab 22 as a positive electrode tab as an example for description.

[0115] The first electrode tab 21 comprises the first current collector 211 and the first active material layer 212, and the first active material layer 212 can be arranged on one side surface or both side surfaces of the first current collector 211 along the thickness direction of the first current collector 211, the first current collector 211 can be used as a carrier of the first active material layer 212, and also as a collection and conduction body of corresponding electrons.

[0116] The first active material layer 212 includes a first main portion 2121 and a first thinning portion 2122, both of which can intercalate or deintercalate active ions during charging and discharging of the battery cell 1. In a direction parallel to the plane in which the first main portion 2121 is located, the first thinning portion 2122 can be connected to at least one side of the first main portion 2121, for example, the first thinning portion can be located on one side of the first main portion, on either two sides of the first main portion, or around the first main portion. The first thinning portion 2122 is provided at the edge of the first main portion 2121 and has a thickness smaller than that of the first main portion 2121. It should be noted that the "thickness" of the first thinning portion smaller than that of the first main portion can be the minimum thickness or the average thickness, for example, the average thickness of the first thinning portion is smaller than that of the first main portion, in which case, the thickness of the part of the first thinning portion used to connect to the first main portion can be equal to that of the first main portion, and the thickness of the remaining part is smaller than that of the first main portion.

[0117] The first support layer 213 is a component for supporting the first active material layer 212 and blocking the flow of the first active material layer 212 from the center to the edge. The first support layer 213 is provided on the first current collector 211, and a part of the first support layer can be located between the first thinning portion and the first current collector, and the remaining part is located outside the area between the first thinning portion and the first current collector, or the first support layer can be located entirely between the first thinning portion and the first current collector, so that the first support layer can block the flow of the material of the first thinning portion 2122 and the first main portion 2121 to the edge of the first current collector 211 when the first tab 21 is subjected to roller pressing.

[0118] The first support layer 213 can have various shapes, for example, the first support layer 213 can be approximately prismatic, or can be other regular or irregular shapes. The material of the first support layer 213 can be various, for example, the material of the first support layer 213 can be the same as that of the first active material layer 212, or can be the same as that of the first current collector 211, of course, the material of the first support layer 213 can also be different from the first active material layer 212 and the first current collector 211.

[0119] In the above scheme, the spacer 23 separates the first and second polar pieces 21 and 22 with opposite polarities, which can prevent the first and second polar pieces 21 and 22 from short circuiting. The first polar piece 21 includes a first current collector 211, a first support layer 213, and a first active material layer 212, the first active material layer 212 includes a first main body part 2121 and a first thinning part 2122 disposed on one side of the first main body part 2121, the first main body part 2121 is disposed on the first current collector 211, the thickness of the first thinning part 2122 is less than the thickness of the first main body part 2121, and by disposing the first support layer 213 between the first thinning part 2122 and the first current collector 211, the first support layer 213 can support the first active material layer 212 in subsequent processes such as rolling of the first polar piece 21, which can to some extent block the material of the first active material layer 212 from flowing from the center to the edge, thereby reducing the risk of liquid accumulation, edge explosion, and the like at the edge of the first polar piece 21. By such arrangement, the thickness of the first thinning part 2122 can be reduced or even eliminated during the thinning process, thereby reducing or even eliminating the gap between the first thinning part 2122 and the spacer 23, and reducing the risk of active ion precipitation at the first polar piece 21 and improving the performance of the battery monomer 1.

[0120] It should be noted that during the preparation of the first polar piece 21, the first support layer 213 can be formed on the first current collector 211 first, and then the first active material is further formed on the first current collector 211. After the first active material is leveled, part of the first active material can cover the first current collector 211 to form the first main body part 2121, and another part can cover at least part of the first support layer 213 to form the first thinning part 2122, so that the thickness of the first thinning part 2122 is less than the thickness of the first main body part 2121.

[0121] In some optional embodiments, along the thickness direction of the first main body part 2121, the side surface of the first thinning part 2122 away from the first current collector 211 can be further thinned to form a thinning region, to further reduce the risk of liquid accumulation, edge explosion, and the like at the edge of the first polar piece 21 during rolling.

[0122] In some embodiments, the first support layer 213 and the first active material layer 212 include the same active material.

[0123] In the preparation process of the first support layer 213 and the first active material layer 212, the first active material can be formed on the preset region of the first current collector 211 first, and the first support layer 213 is formed after the first active material is solidified. Then, the first active material is formed on the first current collector 211 again, so that the subsequently formed first active material covers at least part of the first support layer 213, and the preparation of the first active material layer 212 is completed.

[0124] In the above scheme, in the charging and discharging process of the battery monomer 1, the first support layer 213 can be embedded and de-embedded with the first active material layer 212 to reduce the risk of active ion precipitation at the first electrode sheet 21, and to reduce the influence of the setting of the first support layer 213 on the energy density of the battery monomer 1. Moreover, the first support layer 213 and the first active material layer 212 include the same active material, and in the preparation of the first active material layer 212, the first active material layer 212 can better wet the first support layer 213, improve its spreading ability, and thus improve the thickness uniformity of the first active material layer 212.

[0125] In some embodiments, the first support layer 213 includes a conductive layer.

[0126] The material of the first support layer 213 can be various, for example, the first support layer 213 can include the same conductive material as the first current collector 211, or the first support layer 213 can include other conductive materials different from the first current collector 211, and in addition to including a conductive layer, the first support layer can also include other materials.

[0127] In the above scheme, in the charging and discharging process of the battery monomer 1, the second electrode sheet 22 and the first thinning portion 2122 are embedded or de-embedded with active ions, and the active ions are transmitted between the second electrode sheet 22 and the first thinning portion 2122. On this basis, the first support layer 213 is set as a conductive layer, which can provide a transmission channel for ions on the one hand to shorten the ion transmission path and speed up the ion transmission efficiency, and on the other hand can also collect and conduct electrons to realize power output together with the first current collector 211.

[0128] Please continue to refer to Figure 4 In some embodiments, the first main portion 2121 and the first thinning portion 2122 are arranged along the first direction X, and the first direction X is perpendicular to the thickness direction of the first main portion 2121; in the first direction X, along the direction of the first main portion 2121 pointing to the first thinning portion 2122, the thickness of the first thinning portion 2122 shows a decreasing trend, and the thickness of the first support layer 213 shows an increasing trend.

[0129] The first direction X can be a length direction or a width direction of the first body part 2121, and the first body part 2121 and the first thinning part 2122 are sequentially arranged along the first direction X, that is, the first thinning part 2122 is arranged on at least one side of the first body part 2121 along the first direction X.

[0130] In the first direction X, the thickness of the first thinning part 2122 can decrease linearly or nonlinearly along a direction in which the first body part 2121 points to the first thinning part 2122. The surface of the first thinning part 2122 facing the first support layer 213 can be a slope or an arc, and the distance between the surface and the spacer 23 can gradually increase along the direction in which the first body part 2121 points to the first thinning part 2122.

[0131] The surface of the first support layer 213 facing the first thinning part 2122 can be in contact with the surface of the first thinning part 2122 facing the first support layer 213, and the shapes of the two surfaces are matched. That is, in the first direction X, the thickness of the first support layer 213 can increase linearly or nonlinearly along a direction in which the first body part 2121 points to the first thinning part 2122, and the surface of the first support layer 213 facing the first thinning part 2122 can be a slope or an arc.

[0132] In the above scheme, in the first direction X, the thickness of the first thinning part 2122 is arranged to decrease along a direction in which the first body part 2121 points to the first thinning part 2122, and the thickness of the first support layer 213 is arranged to increase. On the one hand, the overall structure formed by the first thinning part 2122 and the first support layer 213 can be relatively uniform in thickness with the first body part 2121, reducing the risk of increasing the overall thickness of the electrode assembly 20 due to the arrangement of the first support layer 213. On the other hand, the thickness of the first support layer 213 is arranged to increase, so that the surface of the first support layer 213 used to contact the first active material layer 212 is a slope or an arc, thereby reducing the contact angle between the first active material layer 212 and the first support layer 213 when the first active material layer 212 is prepared, so that the first active material layer 212 can better wet the first support layer 213, improve the spreading ability of the first active material layer 212, and further improve the thickness uniformity of the first active material layer 212.

[0133] Please refer to Figure 5 In some embodiments, the first current collector 211 includes a first current collector body 2111 and a first tab 2112, the first current collector body 2111 and the first tab 2112 are arranged along a first direction X, the first direction X is perpendicular to the thickness direction of the first body part 2121; the first thinning part 2122 is located on one side of the first body part 2121 close to the first tab 2112.

[0134] The first current collecting main body 2111 is a main component of the first current collector 211 for serving as a carrier of the first main body part 2121 and for serving as a collector and conductor of electrons. The first main body part 2121 can be arranged in a stacked manner on at least one surface of the first current collecting main body 2111 in the thickness direction thereof.

[0135] The first tab 2112 is a component of the first current collector 211 for electrically connecting with an external device to transmit current. The first tab 2112 is arranged on one side of the first current collecting main body 2111 along the first direction X and protrudes relative to the first active material layer 212 along the first direction X to facilitate electrical connection with the external device.

[0136] In the above scheme, the first thinning part 2122 is arranged on the side of the first main body part 2121 close to the first tab 2112, and the first support layer 213 is located on the side of the first main body part 2121 close to the first tab 2112. In subsequent processes such as rolling, the first support layer 213 can block the flow of the material of the first active material layer 212 along the first direction X to the side close to the first tab 2112 to some extent, thereby reducing the risk of the side of the first active material layer 212 close to the first tab 2112 being extruded and causing edge burst in subsequent processes, and reducing the influence of the first active material layer 212 on the performance of the first tab 21.

[0137] Please refer to Figure 6 In some embodiments, the second tab 22 includes a second current collector 221, a second active material layer 222, and a second support layer 223, the second active material layer 222 includes a second main body part 2221 and a second thinning part 2222 arranged on one side of the second main body part 2221, the second main body part 2221 is arranged on the second current collector 221, the thickness of the second thinning part 2222 is less than that of the second main body part 2221, and at least part of the second support layer 223 is located between the second current collector 221 and the second thinning part 2222.

[0138] The second main body part 2221 and the second thinning part 2222 can both embed or extract active ions during the charging and discharging process of the battery monomer 1.

[0139] The structure of the second thinning part 2222 can be the same as or different from that of the first thinning part 2122. For example, the structure of the second thinning part 2222 is the same as that of the first thinning part 2122, the second thinning part 2222 is arranged on one side of the second main body part 2221 along the first direction X, and the thickness of the second thinning part 2222 decreases in the direction of the second main body part 2221 pointing to the second thinning part 2222 along the first direction X.

[0140] The second support layer 223 is a component for supporting the second active material layer 222 and preventing the second active material layer 222 from flowing along the center to the edge. The second support layer 223 is arranged on the second current collector 221 and at least partially located between the second current collector 221 and the second thinning portion 2222. The shape of the second support layer 223 can be the same as or different from that of the first support layer 213, for example, the second support layer 223 and the first support layer 213 can both be approximately prismatic. The material of the second support layer 223 can be the same as or different from that of the first support layer 213. Optionally, the second support layer 223 can comprise the same active material as the second active material layer 222, so as to be embedded or de-embedded with the second active material layer 222 during the charging and discharging process of the battery monomer 1.

[0141] In the above scheme, the second main portion 2221 is arranged on the second current collector 221, and the second thinning portion 2222 is located on one side of the second main portion 2221 and has a thickness smaller than that of the second main portion 2221. At this time, by arranging the second support layer 223 between the second current collector 221 and the second thinning portion 2222, the second support layer 223 can support the second active material layer 222 during subsequent processes such as rolling of the second tab 22, and to some extent, prevent the material of the second active material layer 222 from flowing along the center to the edge, thereby reducing the risk of liquid accumulation and edge explosion of the edge of the second tab 22. By such arrangement, the thickness of the second thinning portion 2222 during the thinning process can be reduced or even the second thinning portion 2222 does not need to be thinned, thereby reducing the gap between the second thinning portion 2222 and the separator 23 or even eliminating the gap therebetween, so as to reduce the risk of active ion precipitation at the edge of the second tab 22 and improve the performance of the battery monomer 1.

[0142] It should be noted that during the preparation of the second tab 22, the second support layer 223 can be formed on the second current collector 221 first, and then the second active material is further formed on the second current collector 221. After the second active material is leveled, a part of the second active material can cover the second current collector 221 to form the second main portion 2221, and another part can cover at least part of the second support layer 223 to form the second thinning portion 2222, so that the thickness of the second thinning portion 2222 is smaller than that of the second main portion 2221.

[0143] Please continue to refer to Figure 6In some optional embodiments, the second current collector 221 comprises a second current collector body 2211 and a second tab 2212 arranged on one side of the second current collector body 2211, and the second thinning portion 2222 can be arranged on the side of the second body portion 2221 close to the second tab 2212, so as to reduce the risk of the second active material layer 222 close to the second tab 2212 being extruded and causing edge burst in subsequent processes, and reduce the influence of the second active material layer 222 on the performance of the second tab 22.

[0144] It can be understood that when the first thinning portion 2122 is arranged on the side of the first body portion 2121 close to the first tab 2112, and the second thinning portion 2222 is arranged on the side of the second body portion 2221 close to the first thinning portion 2122, the second thinning portion 2222 is arranged on the side of the second body portion 2221 close to the first thinning portion 2122 along the first direction X, which is equivalent to arranging the first tab 2112 and the second tab 2212 on the same side of the separator 23 along the first direction X, so as to reduce the distance between the first tab 2112 and the second tab 2212, and facilitate the electrical connection between the first tab 2112 and the second tab 2212 and external devices.

[0145] In some embodiments, the first body portion 2121 and the first thinning portion 2122 are arranged along the first direction X, and the first direction X is perpendicular to the thickness direction of the first body portion 2121; as shown in Figure 6 , the second thinning portion 2222 is arranged on the side of the second body portion 2221 close to the first thinning portion 2122, or as shown in Figure 7 , the second thinning portion 2222 is arranged on the side of the second body portion 2221 away from the first thinning portion 2122.

[0146] Specifically, please refer to Figure 6The second thinning portion 2222 is arranged on the side of the second main body portion 2221 close to the first thinning portion 2122 along the first direction X. The projection of the first thinning portion 2122 on the spacer 23 along the thickness direction of the first main body portion 2121 and the projection of the second thinning portion 2222 on the spacer 23 along the thickness direction of the first main body portion 2121 can at least partially overlap. At this time, the second support layer 223 is correspondingly arranged on the side of the second main body portion 2221 close to the first thinning portion 2122 along the first direction X. The projection of the second support layer 223 on the spacer 23 along the thickness direction of the first main body portion 2121 and the projection of the first support layer 213 on the spacer 23 along the thickness direction of the first main body portion 2121 can at least partially overlap. In addition, when the first thinning portion 2122 is arranged on the side of the first main body portion 2121 close to the first tab 2112, and the second thinning portion 2222 is arranged on the side of the second main body portion 2221 close to the second tab 2212, the second tab 2212 is arranged on the side of the second current collecting main body 2211 close to the first tab 2112 along the first direction X.

[0147] Alternatively, please refer to Figure 7 The second thinning portion 2222 is arranged on the side of the second main body portion 2221 away from the first thinning portion 2122 along the first direction X. That is, the first thinning portion 2122 and the second thinning portion 2222 are arranged close to the two sides of the spacer 23 along the first direction X. At this time, the second support layer 223 is arranged on the side of the second main body portion 2221 away from the first support layer 213 along the first direction X. In addition, when the first thinning portion 2122 is arranged on the side of the first main body portion 2121 close to the first tab 2112, and the second thinning portion 2222 is arranged on the side of the second main body portion 2221 close to the second tab 2212, the second tab 2212 is arranged on the side of the second current collecting main body 2211 away from the first tab 2112 along the first direction X.

[0148] In the above scheme, the second thinning portion 2222 is arranged on the side of the second main body portion 2221 close to the first thinning portion 2122, which is conducive to balancing the active ions between the first thinning portion 2122 and the second thinning portion 2222, and reducing the risk of active ion precipitation due to excess active ions between the first thinning portion 2122 and the second thinning portion 2222. Alternatively, the second thinning portion 2222 is arranged on the side of the second main body portion 2221 away from the first thinning portion 2122, which is helpful to balance the volume change of the first active material layer 212 and the second active material layer 222 during use, and improve the stress distribution of the battery monomer 1.

[0149] Please refer to Figure 8 In some embodiments, the thickness of the first main body portion 2121 is greater than the thickness of the first support layer 213, and the first support layer 213 is arranged between the first thinning portion 2122 and the first current collector 211.

[0150] In the above scheme, by setting the thickness of the first main body part 2121 to be greater than the thickness of the first support layer 213, and locating the first support layer 213 between the first thinning part 2122 and the first current collector 211, on the one hand, the blocking effect of the first support layer 213 on the material of the first active material layer 212 can be improved, reducing the risk of the first active material layer 212 flowing to the edge after being pressed, leading to edge explosion and other situations, on the other hand, the performance of the first active material layer 212 can also be reduced. The influence of the setting of the first support layer 213 is beneficial to improve the overall performance of the battery monomer 1.

[0151] Please continue to refer to Figure 8 In some embodiments, the first support layer 213 includes a first sub-part 2131 disposed between the first thinning part 2122 and the first current collector 211, the projection of the first sub-part 2131 on the first current collector 211 along the thickness direction of the first main body part 2121 is located within the projection of the first thinning part 2122 on the first current collector 211 along the thickness direction of the first main body part 2121, and the ratio Z1 of the thickness of the first sub-part 2131 to the thickness of the first main body part 2121 satisfies: 0.08≤Z1≤0.15.

[0152] The first sub-part 2131 is disposed on the first current collector 211 and located between the first current collector 211 and the first thinning part 2122, which can block the flow of the first active material layer 212 to a certain extent. The edge of the first pole piece 21 has a risk of liquid accumulation, edge explosion and other situations. The first sub-part 2131 can be block-shaped or other regular or irregular shapes.

[0153] It can be understood that the first sub-part 2131 has a certain width in the direction in which the first main body part 2121 points to the first thinning part 2122, when the first support layer 213 increases in the direction in which the first main body part 2121 points to the first thinning part 2122, the thickness of each part of the first sub-part 2131 in the direction in which the first main body part 2121 points to the first thinning part 2122 gradually increases, and the thickness of each part is within the above range. The ratio of the thickness of the first sub-part 2131 to the thickness of the first main body part 2121 can be greater than or equal to 0.08 and less than or equal to 0.15, for example, the ratio can be 0.08, 0.09, 0.1, 0.12, 0.15, etc.

[0154] In the above scheme, the first sub portion 2131 is arranged between the first thinning portion 2122 and the first current collector 211. By reasonably setting the ratio of the thickness of the first sub portion 2131 to the thickness of the first main portion 2121, on the one hand, the blocking effect of the first sub portion 2131 on the material of the first active material layer 212 can be improved, and the risk of edge explosion of the first active material layer 212 during rolling can be reduced. On the other hand, the influence of the arrangement of the first support layer 213 on the performance of the first active material layer 212 can be reduced.

[0155] For further information Figure 8 In some embodiments, the first support layer 213 further includes a second sub portion 2132 arranged between the first thinning portion 2122 and the first current collector 211. The second sub portion 2132 is located on the side of the first sub portion 2131 close to the first main portion 2121. The ratio Z2 of the thickness of the second sub portion 2132 to the thickness of the first main portion 2121 satisfies: 0.03≤Z2≤0.08.

[0156] The second sub portion 2132 is arranged on the second current collector 221 and is located between the first current collector 211 and the first thinning portion 2122. The projection of the second sub portion 2132 on the first current collector 211 along the thickness direction of the first main portion 2121 can be located within the projection of the first thinning portion 2122 on the first current collector 211 along the thickness direction of the first main portion 2121. Therefore, the second sub portion 2132 can block the flow of the first active material layer 212 from the center to the edge to some extent, so as to further reduce the risk of liquid accumulation, edge explosion, etc. of the edge of the first pole piece 21.

[0157] The second sub portion 2132 is located on the side of the first sub portion 2131 close to the first main portion 2121. Therefore, by reasonably setting the thickness of the second sub portion 2132, a smooth transition can be formed between the first sub portion 2131 and the second sub portion 2132, so as to reduce the risk of stress concentration between the first sub portion 2131 and the second sub portion 2132.

[0158] It should be noted that the second sub portion 2132 is a component with a certain width in the direction in which the first main portion 2121 points to the first thinning portion 2122. When the first support layer 213 increases in the direction in which the first main portion 2121 points to the first thinning portion 2122, the thickness of each part of the second sub portion 2132 in the direction in which the first main portion 2121 points to the first thinning portion 2122 gradually increases, and the ratio of the thickness of each part to the thickness of the first main portion 2121 is within the above range. The ratio of the thickness of the second sub portion 2132 to the thickness of the first main portion 2121 can be greater than or equal to 0.03 and less than or equal to 0.08, for example, the ratio can be 0.03, 0.04, 0.05, 0.06, 0.08, etc.

[0159] In the above scheme, the second sub-section 2132 is arranged between the first thinning section 2122 and the first current collector 211 and is located on the side of the first sub-section 2131 close to the first main body section 2121. The second sub-section 2132 can block the flow of the first active material layer 212 from the center to the edge during rolling, thereby further reducing the risk of edge explosion of the first pole piece 21. On this basis, the ratio of the thickness of the second sub-section 2132 to the thickness of the first main body section 2121 is optimized and designed, so that the stress transition of the first sub-section 2131 and the second sub-section 2132 during subsequent processes is smoother, and the risk of stress concentration between the first sub-section 2131 and the second sub-section 2132 is reduced.

[0160] Please continue to refer to Figure 8 In some embodiments, the first support layer 213 further comprises a third sub-section 2333 arranged between the first thinning section 2122 and the first current collector 211. The third sub-section 2333 is located on the side of the second sub-section 2132 close to the first main body section 2121. The ratio Z3 of the thickness of the third sub-section 2333 to the thickness of the first main body section 2121 satisfies: 0.01≤Z3≤0.03.

[0161] The third sub-section 2333 is arranged on the second current collector 221 and is located between the first current collector 211 and the first thinning section 2122. The projection of the third sub-section 2333 on the first current collector 211 along the thickness direction of the first main body section 2121 can be located within the projection of the first thinning section 2122 on the first current collector 211 along the thickness direction of the first main body section 2121. The third sub-section 2333 can block the flow of the first active material layer 212 from the center to the edge to some extent, thereby further reducing the risk of liquid accumulation, edge explosion, and the like of the edge of the first pole piece 21.

[0162] The third sub-section 2333 is located on the side of the second sub-section 2132 close to the first main body section 2121. Therefore, by reasonably setting the thickness of the third sub-section 2333, a smooth transition can be formed between the second sub-section 2132 and the third sub-section 2333, thereby reducing the risk of stress concentration between the second sub-section 2132 and the third sub-section 2333.

[0163] It should be noted that the third sub-part 2333 is a component with a certain width in the direction in which the first main part 2121 points to the first thinning part 2122, when the first support layer 213 has a trend of increasing in the direction in which the first main part 2121 points to the first thinning part 2122, the thickness of each part of the third sub-part 2333 in the direction in which the first main part 2121 points to the first thinning part 2122 gradually increases, and the ratio of the thickness of each part to the thickness of the first main part 2121 is within the above range. The ratio of the thickness of the third sub-part 2333 to the thickness of the first main part 2121 can be greater than or equal to 0.01 and less than or equal to 0.03, for example, the ratio can be 0.01, 0.015, 0.02, 0.025, 0.03, etc.

[0164] In the above scheme, the third sub-part 2333 is arranged between the first thinning part 2122 and the first current collector 211, and is located on the side of the second sub-part 2132 close to the first main part 2121, which can block the flow of the first active material layer 212 from the center to the edge during rolling, thereby further reducing the risk of edge explosion of the first pole piece 21. On this basis, the ratio of the thickness of the third sub-part 2333 to the thickness of the first main part 2121 is optimized and designed, which can make the stress transition of the second sub-part 2132 and the third sub-part 2333 more smooth when they are extruded in the subsequent process, thereby reducing the risk of stress concentration between the second sub-part 2132 and the third sub-part 2333.

[0165] In some optional embodiments, the first support layer 213 can further include a fourth sub-part arranged between the first thinning part 2122 and the first current collector 211, the fourth sub-part is located on the side of the third sub-part 2333 close to the first main part 2121, the thickness of the fourth sub-part can be greater than 0 and less than the thickness of the third sub-part 2333, and the fourth sub-part can be a transition component between the third sub-part 2333 and the first main part 2121. By reasonably setting the thickness of the fourth sub-part, a smooth transition can be formed between the third sub-part 2333 and the first main part 2121, thereby reducing the risk of forming a large step between the first support layer 213 and the first main part 2121.

[0166] It should be noted that the overall structure formed by the first sub-part 2131, the second sub-part 2132, the third sub-part 2333 and the fourth sub-part can be adapted to the gap between the first thinning part 2122 and the first current collector 211, and the surface of each sub-part facing the first thinning part 2122 can be adapted to the shape of the side surface of the first thinning part 2122 facing the first current collector 211.

[0167] Optionally, in the first direction X, the width of the first support layer 213 can be greater than or equal to 3 mm and less than or equal to 15 mm, for example, the width of the first support layer 213 can be 3 mm, 5 mm, 7 mm, 10 mm, 15 mm, etc., to reasonably set the width of the first support layer 213 and improve the barrier effect of the first support layer 213 on the material of the first active material layer 212.

[0168] For example, taking the width of the first support layer 213 as 15 mm, in the direction in which the first thinning portion 2122 points to the first main body portion 2121, the first sub-portion 2131 can be a portion of the first support layer 213 with a width of about 3 mm, the second sub-portion 2132 can be a portion of the first support layer 213 with a width of about 5 mm, the third sub-portion 2333 can be a portion of the first support layer 213 with a width of about 5 mm, and the fourth sub-portion can be a portion of the first support layer 213 with a width of about 2 mm.

[0169] It should be noted that the "thickness" mentioned in the embodiments of the present application refers to the size of the corresponding component in the thickness direction of the first main body portion 2121.

[0170] Optionally, the thickness of the first support layer 213 can be greater than or equal to 5 microns and less than or equal to 15 microns, for example, the thickness of the first support layer 213 can be 5 microns, 7 microns, 10 microns, 13 microns, 15 microns, etc., to reasonably set the thickness of the first support layer 213, which on the one hand can improve the barrier effect of the first support layer 213 on the material of the first active material layer 212, and on the other hand can reduce the influence of the setting of the first support layer 213 on the performance of the first active material layer 212.

[0171] For example, taking the width of the first support layer 213 as 15 mm, in the direction in which the first thinning portion 2122 points to the first main body portion 2121, the first sub-portion 2131 can be a portion of the first support layer 213 with a width of about 3 mm, the second sub-portion 2132 can be a portion of the first support layer 213 with a width of about 5 mm, the third sub-portion 2333 can be a portion of the first support layer 213 with a width of about 5 mm, and the fourth sub-portion can be a portion of the first support layer 213 with a width of about 2 mm. Figure 9 In some embodiments, the first support layer 213 includes a first portion and a second portion, the second portion is located on one side of the first portion close to the first main body portion 2121, and the thickness of the first portion is greater than or equal to the thickness of the first main body portion 2121. The first portion is exposed relative to the first thinning portion 2122 along the surface of the first main body portion 2121 away from the first current collector 211.

[0172] Specifically, the first portion and the second portion can be arranged in sequence along the first direction X, and the second portion is located on one side of the first portion close to the first main body portion 2121, wherein the thickness of the second portion can be less than the thickness of the first main body portion 2121, and the first thinning portion 2122 can cover the second portion. The thickness of the first portion is greater than or equal to the thickness of the first main body portion 2121, and the side of the first portion away from the surface of the first current collector 211 in the thickness direction of the first main body portion 2121 can be exposed relative to the first thinning portion 2122, that is, not covered by the first thinning portion 2122.

[0173] In the above scheme, the first support layer 213 includes a first part and a second part, the second part is located on one side of the first part close to the first main body part 2121, and the thickness of the first part is greater than or equal to the thickness of the first main body part 2121, which can improve the blocking effect of the first support layer 213 on the first active material layer 212 to a certain extent, and further reduce the risk of edge explosion of the first active material layer 212. In this way, the thickness reduction of the first thinning part 2122 can be further reduced or even the first thinning part 2122 does not need to be thinned, so as to further reduce the gap between the first thinning part 2122 and the isolation piece 23 or even no gap exists between them, thereby further reducing the risk of active ion precipitation at the first pole piece 21.

[0174] In some embodiments, the first current collector 211 is provided with the first active material layer 212 and the first support layer 213 on opposite sides along the thickness direction of the first main body part 2121.

[0175] In the above scheme, the first active material layer 212 is arranged on opposite sides of the first current collector 211, which can improve the energy density of the battery monomer 1. On this basis, the first support layer 213 is arranged on the opposite sides of the first current collector 211, and the first support layer 213 on the two sides supports the corresponding first active material layer 212 respectively, so as to block the material of the corresponding first active material layer 212 from flowing from the center to the edge to a certain extent, thereby further reducing the risk of liquid accumulation, edge explosion and the like at the edge of the first pole piece 21. In this way, the thickness reduction of the first thinning part 2122 of the first active material layer 212 on the two sides of the first current collector 211 can be reduced or even the corresponding first thinning part 2122 does not need to be thinned, thereby reducing the gap between the corresponding first thinning part 2122 and the corresponding isolation piece 23 or even no gap exists between them, and further reducing the risk of active ion precipitation at the first pole piece 21.

[0176] In a second aspect, the embodiments of the present application provide a battery device 100, which includes a plurality of battery monomers 1 as described in any one of the above.

[0177] In a third aspect, the embodiments of the present application provide a power consumption device, which includes the above battery device 100.

[0178] In some embodiments, the application provides a battery cell 1, comprising a housing 10 and an electrode assembly 20, the electrode assembly 20 is disposed in the housing 10, the electrode assembly 20 comprises a first electrode tab 21, a second electrode tab 22 and a separator 23, the first electrode tab 21 and the second electrode tab 22 are opposite in polarity, the separator 23 separates the first electrode tab 21 and the second electrode tab 22, the first electrode tab 21 comprises a first current collector 211, a first active material layer 212 and a first support layer 213, the first active material layer 212 comprises a first main body part 2121 and a first thinned part 2122 disposed on one side of the first main body part 2121, the first main body part 2121 is disposed on the first current collector 211, the thickness of the first thinned part 2122 is smaller than that of the first main body part 2121, and at least part of the first support layer 213 is disposed between the first current collector 211 and the first thinned part 2122. The first support layer 213 and the first active material layer 212 comprise the same active material. The first main body part 2121 and the first thinned part 2122 are arranged along a first direction X, the first direction X being perpendicular to the thickness direction of the first main body part 2121; in the first direction X, along the direction from the first main body part 2121 to the first thinned part 2122, the thickness of the first thinned part 2122 shows a decreasing trend, and the thickness of the first support layer 213 shows an increasing trend. The first current collector 211 comprises a first current collecting main body 2111 and a first tab 2112, the first current collecting main body 2111 and the first tab 2112 are arranged along the first direction X, the first direction X being perpendicular to the thickness direction of the first main body part 2121; the first thinned part 2122 is located on the side of the first main body part 2121 close to the first tab 2112. The second electrode tab 22 comprises a second current collector 221, a second active material layer 222 and a second support layer 223, the second active material layer 222 comprises a second main body part 2221 and a second thinned part 2222 disposed on one side of the second main body part 2221, the second main body part 2221 is disposed on the second current collector 221, the thickness of the second thinned part 2222 is smaller than that of the second main body part 2221, and at least part of the second support layer 223 is located between the second current collector 221 and the second thinned part 2222.

[0179] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some or all of the technical features can be replaced equivalently. Such modifications or replacements do not change the essence of the corresponding technical solutions, which should be covered in the scope of the claims and the specification of the present application. In particular, 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 by, The battery cell comprises: a housing; an electrode assembly disposed in the housing, the electrode assembly comprising a first electrode tab, a second electrode tab, and a separator, the first electrode tab and the second electrode tab being opposite in polarity, the separator separating the first electrode tab and the second electrode tab, the first electrode tab comprising a first current collector, a first active material layer, and a first support layer, the first active material layer comprising a first main body portion and a first thinned portion disposed on one side of the first main body portion, the first main body portion being disposed on the first current collector, the first thinned portion having a thickness smaller than that of the first main body portion, at least part of the first support layer being disposed between the first current collector and the first thinned portion.

2. The battery cell of claim 1, wherein, The first support layer and the first active material layer comprise the same active material.

3. The battery cell of claim 1, wherein, The first support layer comprises a conductive layer.

4. The battery cell of claim 1, wherein, The first main body portion and the first thinned portion are arranged along a first direction, the first direction being perpendicular to a thickness direction of the first main body portion. In the first direction, along a direction in which the first main body portion points to the first thinned portion, the thickness of the first thinned portion shows a decreasing trend, and the thickness of the first support layer shows an increasing trend.

5. The battery cell of claim 1, wherein, The first current collector comprises a first current collector main body and a first tab, the first current collector main body and the first tab being arranged along a first direction, the first direction being perpendicular to a thickness direction of the first main body portion. The first thinned portion is located on a side of the first main body portion close to the first tab.

6. The battery cell of claim 4, wherein, The second electrode tab comprises a second current collector, a second active material layer, and a second support layer, the second active material layer comprising a second main body portion and a second thinned portion disposed on one side of the second main body portion, the second main body portion being disposed on the second current collector, the second thinned portion having a thickness smaller than that of the second main body portion, at least part of the second support layer being disposed between the second current collector and the second thinned portion.

7. The battery cell according to claim 6, wherein In the first direction, the second thinned portion is located on a side of the second main body portion close to the first thinned portion, or the second thinned portion is located on a side of the second main body portion away from the first thinned portion.

8. The battery cell of any one of claims 1-5, wherein, The thickness of the first main body portion is greater than that of the first support layer, and the first support layer is located between the first thinned portion and the first current collector.

9. The battery cell of claim 8, wherein, The first support layer comprises a first sub-portion disposed between the first thinned portion and the first current collector, a projection of the first sub-portion on the first current collector along the thickness direction of the first main body portion is located within a projection of the first thinned portion on the first current collector along the thickness direction of the first main body portion, and a ratio Z1 of the thickness of the first sub-portion to the thickness of the first main body portion satisfies: 0.08≤Z1≤0.

15.

10. The battery cell of claim 9, wherein, The first support layer further comprises a second sub-portion disposed between the first thinned portion and the first current collector, the second sub-portion is located on a side of the first sub-portion close to the first main body portion, and a ratio Z2 of the thickness of the second sub-portion to the thickness of the first main body portion satisfies: 0.03≤Z2≤0.

08.

11. The battery cell of claim 10, wherein, The first support layer further includes a third sub-portion disposed between the first thinning portion and the first current collector, the third sub-portion is located on a side of the second sub-portion close to the first main portion, and a ratio Z3 of a thickness of the third sub-portion to a thickness of the first main portion satisfies 0.01≤Z3≤0.

03.

12. The battery cell of any one of claims 1-5, wherein, The first support layer includes a first portion and a second portion, the second portion is located on a side of the first portion close to the first main portion, a thickness of the first portion is greater than or equal to a thickness of the first main portion, and the first portion is exposed relative to the first thinning portion along a surface of the first main portion away from the first current collector.

13. The battery cell of any one of claims 1-5, wherein, Along a thickness direction of the first main portion, the first active material layer and the first support layer are provided on opposite sides of the first current collector.

14. A battery device characterized by comprising: A plurality of battery cells as claimed in any one of claims 1-13.

15. An electrical device, comprising: A battery device as claimed in claim 14, the battery device being used to provide electrical energy.

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