WO2023184903A1 - 电极组件、电池单体、电池、用电设备、卷绕设备及方法 - Google Patents

电极组件、电池单体、电池、用电设备、卷绕设备及方法 Download PDF

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Publication number
WO2023184903A1
WO2023184903A1 PCT/CN2022/121435 CN2022121435W WO2023184903A1 WO 2023184903 A1 WO2023184903 A1 WO 2023184903A1 CN 2022121435 W CN2022121435 W CN 2022121435W WO 2023184903 A1 WO2023184903 A1 WO 2023184903A1
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WIPO (PCT)
Prior art keywords
segment
active material
material layer
pole piece
electrode assembly
Prior art date
Application number
PCT/CN2022/121435
Other languages
English (en)
French (fr)
Inventor
赵万奎
陈耀金
林纲
王艺若
王培潮
黄国达
谢超
陈威
Original Assignee
宁德时代新能源科技股份有限公司
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Publication date
Application filed by 宁德时代新能源科技股份有限公司 filed Critical 宁德时代新能源科技股份有限公司
Priority to JP2023549062A priority Critical patent/JP2024515233A/ja
Priority to EP22925239.0A priority patent/EP4280312A1/en
Priority to KR1020237028448A priority patent/KR20230142518A/ko
Priority to US18/236,944 priority patent/US20240006649A1/en
Publication of WO2023184903A1 publication Critical patent/WO2023184903A1/zh

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H01M10/0431—Cells with wound or folded electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H18/00—Winding webs
    • B65H18/08—Web-winding mechanisms
    • B65H18/10—Mechanisms in which power is applied to web-roll spindle
    • B65H18/103—Reel-to-reel type web winding and unwinding mechanisms
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H01M10/0404—Machines for assembling batteries
    • H01M10/0409—Machines for assembling batteries for cells with wound electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H01M10/0587—Construction or manufacture of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/04—Processes of manufacture in general
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/04—Processes of manufacture in general
    • H01M4/0402—Methods of deposition of the material
    • H01M4/0404—Methods of deposition of the material by coating on electrode collectors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/46—Separators, membranes or diaphragms characterised by their combination with electrodes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H2701/00—Handled material; Storage means
    • B65H2701/10—Handled articles or webs
    • B65H2701/19—Specific article or web
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/021—Physical characteristics, e.g. porosity, surface area
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2220/00—Batteries for particular applications
    • H01M2220/20—Batteries in motive systems, e.g. vehicle, ship, plane
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present application relates to the field of battery technology, and in particular to an electrode assembly, a battery cell, a battery, an electrical equipment, a winding equipment and a method.
  • Electric vehicles have become an important part of the sustainable development of the automobile industry due to their advantages in energy conservation and environmental protection.
  • battery technology is an important factor related to their development.
  • the battery includes at least one battery cell.
  • the battery cell includes an electrode assembly.
  • the electrode assembly is usually wound by a positive electrode piece and a negative electrode piece.
  • the performance of the electrode piece determines the performance of the electrode assembly. In the related art, the performance of the electrode assembly is poor and cannot be differentiated.
  • the purpose of this application is to provide an electrode assembly, a battery cell, a battery, an electrical equipment, a winding equipment and a method.
  • the electrode assembly can be processed in sections according to performance requirements to meet different performance requirements.
  • the present application provides an electrode assembly, including a first pole piece and a second pole piece with opposite polarities.
  • the first pole piece and the second pole piece are stacked and wound along the winding direction to form The electrode assembly;
  • the first pole piece includes a first segment and a second segment, the first segment is provided with a first active material layer, and the second segment is provided with a second active material layer layer, in the winding direction from inside to outside, the first segment is located upstream of the second segment.
  • the first pole piece includes a first segment and a second segment.
  • the first segment is located upstream of the second segment by connecting the first pole
  • the fragment is divided into the first segment and the second segment.
  • the first segment in the inner circle and the second segment in the outer circle can be processed differently, so that the first segment and the second segment have different characteristics.
  • the physical or chemical properties of the electrode assembly can be better adjusted through differentiated internal and external configurations to meet different performance requirements.
  • the coating density of the first active material layer is different from the coating density of the second active material layer.
  • the coating density of the first active material layer is different from the coating density of the second active material layer, so that the energy density of the electrode assembly can be adjusted to meet different energy density requirements of the electrode assembly.
  • the coating density of the first active material layer is smaller than the coating density of the second active material layer.
  • the coating density of the first active material layer is less than the coating density of the second active material layer, and the fracture toughness of the first segment is greater than the fracture toughness of the second segment, so that the bending area of the first segment It is not easy to produce cracks or fractures, which reduces the probability of cracks or fractures in the first pole piece, thereby improving the safety of the battery cells composed of the electrode assembly.
  • a thickness ratio of the first active material layer to a thickness of the second active material layer is 1/2-3/2.
  • the ratio of the thickness of the first active material layer to the thickness of the second active material layer satisfies the above range, Ensure that there are no steps at the transition between the first segment and the second segment, to avoid active material falling off or causing indentations, and to ensure the quality of the electrode assembly.
  • the active material material of the first active material layer is the same as or different from the active material material of the second active material layer.
  • the active material material of the first active material layer is different from the active material material of the second active material layer, and the performance of the first segment and the second segment can be adjusted to meet the needs of electrode assemblies with different physical properties or chemical properties. performance.
  • the tail of the first segment is connected to the head of the second segment or the tail of the first segment is connected to the head of the second segment. There is a gap between the heads of the second segments.
  • the tail of the first segment is connected to the head of the second segment, it is easy to ensure the continuity of the first pole piece.
  • the first pole piece has more active material and ensures that the electrode
  • the component has a high energy density; in the embodiment where a gap is provided between the tail of the first segment and the head of the second segment, the processing of the first segment and the second segment can be facilitated and the first segment can be reduced. Difficulty in manufacturing pole pieces.
  • the first pole piece further includes a first current collector, and the first active material layer and the second active material layer are respectively provided on the first current collector.
  • the first pole piece further includes a first current collector segment and a second current collector segment, and the first active material layer is disposed on the first current collector segment to form The first segment and the second active material layer are disposed on the second current collector segment to form the second segment.
  • the first active material layer is disposed on the first current collector segment to form the first segment
  • the second active material layer is disposed on the second current collector segment to form the second segment, which facilitates the realization of the first segment. Processing and manufacturing of first and second segments.
  • the tail of the first segment and the head of the second segment are connected through a first connection part.
  • the first segment and the second segment are connected through the first connecting part to realize the positioning of the first segment and the second segment and limit the positional movement of the first segment and the second segment.
  • the first segment can drive the second segment through the first connecting portion to provide winding power for the second segment, thereby realizing the sequential winding of the first segment and the second segment. around.
  • the electrode assembly further includes a separator for separating the first pole piece and the second pole piece.
  • the first pole piece and the second pole piece are separated by a diaphragm to avoid contact short circuit between the first pole piece and the second pole piece and improve safety.
  • the head of the second segment is connected to the diaphragm.
  • the head of the second segment is connected to the diaphragm, and the head of the second segment is positioned through the diaphragm to limit the positional movement of the first segment and the second segment.
  • the diaphragm drives the head of the second segment to be rolled in, providing winding power for the second segment, so as to realize the sequential winding of the first segment and the second segment.
  • the second pole piece includes a third segment and a fourth segment; a third active material layer is disposed on the third segment; and a third active material layer is disposed on the fourth segment.
  • the third segment in the inner ring and the fourth segment in the outer ring can be processed differently respectively, so that the third segment in the inner ring and the fourth segment in the outer ring can be processed differently.
  • the third segment and the fourth segment have different physical or chemical properties, and are configured internally and externally to better adjust the performance of the electrode assembly.
  • the coating density of the third active material layer is different from the coating density of the fourth active material layer; and/or, the thickness of the third active material layer is different from that of the fourth active material layer.
  • the four active material layers have different thicknesses; and/or the active material material of the third active material layer is the same as or different from the active material material of the fourth active material layer.
  • the physical properties or chemical properties of the third segment and the fourth segment can be changed by changing the coating density, thickness and active material material formula of the third active material layer and the fourth active material layer, so as to
  • the electrode assembly can meet different performance requirements and be suitable for different usage scenarios.
  • the ratio of the thickness of the third active material layer to the thickness of the fourth active material layer is 1/2-3/2.
  • the thickness ratio of the third active material layer to the thickness of the fourth active material layer satisfies the above range, Ensure that there are no steps at the transition between the third segment and the fourth segment to avoid active material falling off or causing indentations and ensuring the quality of the electrode assembly.
  • the tail of the third segment is connected to the head of the fourth segment or the tail of the third segment is connected to the head of the fourth segment. There is a gap between the heads of the fourth segments.
  • the tail of the third segment is connected to the head of the fourth segment, it is easy to ensure the continuity of the second pole piece.
  • the second pole piece has more active material and ensures that the electrode
  • the component has a high energy density; in the embodiment where a gap is provided between the tail of the third segment and the head of the fourth segment, the processing of the third segment and the fourth segment can be facilitated and the second segment can be reduced. Difficulty in manufacturing pole pieces.
  • the second pole piece further includes a second current collector, and the third active material layer and the fourth active material layer are respectively provided on the second current collector.
  • the second pole piece further includes a third current collector segment and a fourth current collector segment, and the third active material layer is disposed on the third current collector segment to form In the third segment, the fourth active material layer is disposed on the fourth current collector segment to form the fourth segment.
  • the third active material layer is disposed on the third current collector segment to form the third segment
  • the fourth active material layer is disposed on the fourth current collector segment to form the fourth segment, which facilitates the realization of the third segment. Processing and manufacturing of segments and fourth segments.
  • the tail of the third segment and the head of the fourth segment are connected through a second connection part.
  • the third segment and the fourth segment are connected through the second connection part to realize the positioning of the third segment and the fourth segment and limit the positional movement of the third segment and the fourth segment.
  • the third segment can drive the fourth segment through the second connection part to provide winding power for the fourth segment, thereby realizing the sequential winding of the third segment and the fourth segment. around.
  • the electrode assembly further includes a separator for separating the first pole piece and the second pole piece, and the head of the fourth segment is connected to the separator.
  • the head of the fourth segment is connected to the diaphragm, and the positioning of the head of the fourth segment is achieved through the diaphragm, limiting the positional movement of the third segment and the fourth segment.
  • the diaphragm drives the head of the fourth segment to be rolled in, providing winding power for the fourth segment to realize the sequential winding of the third and fourth segments.
  • the electrode assembly includes two diaphragms, the two diaphragms are located on both sides of the second pole piece, and the head of the second segment is connected to one of the diaphragms. Connect, the head of the fourth segment is connected to another of the diaphragms.
  • one diaphragm connects the head of the second segment
  • the other diaphragm connects the head of the fourth segment
  • one diaphragm limits the position of the second segment
  • the other diaphragm limits the position of the fourth segment.
  • the number of turns of the third segment is smaller than the number of turns of the fourth segment.
  • the number of turns of the third segment is less than the number of turns of the fourth segment.
  • the number of winding turns of the fourth active material layer is greater than the number of winding turns of the third active material layer. Since the fourth The coating density of the active material layer is less than that of the third active material layer. When the thickness of the electrode assembly is the same, the number of winding turns of the fourth active material layer is larger, which can ensure that the electrode assembly has higher energy. density.
  • the number of turns of the first segment is smaller than the number of turns of the second segment.
  • the number of turns of the first segment is smaller than the number of turns of the second segment to ensure that the electrode assembly has a higher energy density.
  • the coating density of the second active material layer is 10%-200% greater than the coating density of the first active material layer.
  • the coating density of the second active material layer is greater than that of the first active material layer, ensuring that the first pole piece has more active material, thereby ensuring that the battery composed of the electrode assembly has a larger Energy Density.
  • the present application provides a battery cell, which includes the electrode assembly in the above embodiment.
  • the present application provides a battery, which includes the battery cell in the above embodiment.
  • the present application provides an electrical device, which includes the battery in the above embodiment.
  • the present application provides a winding device.
  • the winding device includes: a first providing device for providing a first pole piece, the first pole piece including a first segment and a second segment. ;
  • the first segment is provided with a first active material layer;
  • the second segment is provided with a second active material layer;
  • a second providing device is used to provide a polarity opposite to that of the first pole piece the second pole piece;
  • the segments, the second segment, the separator and the second pole piece are rolled along the winding direction to form an electrode assembly; wherein the first providing device is configured to provide the first providing device in the following manner One pole piece: the first segment enters the winding mechanism first, and the second segment enters the winding mechanism after the first segment.
  • the winding mechanism winds the first segment, the second segment, the separator and the second pole piece to form an electrode assembly.
  • the first segment and the second segment can be configured differently.
  • the processing makes the first segment and the second segment have different physical properties or chemical properties, and the performance of the electrode assembly can be better adjusted through differentiated internal and external configurations.
  • the coating density of the first active material layer is different from the coating density of the second active material layer; and/or the thickness of the first active material layer is different from that of the second active material layer.
  • the active material layers have different thicknesses; and/or the active material material of the first active material layer is the same as or different from the active material material of the second active material layer.
  • the physical properties or chemical properties of the first segment and the second segment can be changed by changing the coating density, thickness and active material material combination of the first active material layer and the second active material layer, so as to
  • the electrode assembly can meet different performance requirements and be suitable for different usage scenarios.
  • the second pole piece includes a third segment and a fourth segment; a third active material layer is disposed on the third segment; and a third active material layer is disposed on the fourth segment.
  • the third segment and the fourth segment can be processed differently respectively, so that the third segment and the fourth segment have different physical properties or chemical properties, and can be better configured through internal and external differentiation. Adjust the performance of the electrode assembly.
  • the coating density of the third active material layer is different from the coating density of the fourth active material layer; and/or, the thickness of the third active material layer is different from that of the fourth active material layer.
  • the four active material layers have different thicknesses; and/or the active material material of the third active material layer is the same as or different from the active material material of the fourth active material layer.
  • the physical properties or chemical properties of the third segment and the fourth segment can be changed by changing the coating density, thickness and active material material formula of the third active material layer and the fourth active material layer, so as to
  • the electrode assembly can meet different performance requirements and be suitable for different usage scenarios.
  • the separator includes a first separator and a second separator, and the separator providing mechanism is used to provide the first separator and the second separator;
  • the winding device further includes a first composite mechanism, the first composite mechanism is located downstream of the first providing device and the diaphragm providing mechanism, and the first composite mechanism is used to combine the first diaphragm, the first pole piece and the second The diaphragm is composited into the first pole piece assembly;
  • the first providing device is configured to provide the first pole piece in the following manner: the first segment enters the first composite mechanism first, and the second segment The segments enter the first composite mechanism after the first segment;
  • the winding mechanism is provided downstream of the first composite mechanism for connecting the first pole piece assembly and the second The pole pieces are wound along the winding direction to form an electrode assembly.
  • the first diaphragm, the first pole piece and the second diaphragm are combined to form the first pole piece group.
  • the first diaphragm and the second diaphragm play a positioning role in positioning the first pole piece, and the first diaphragm and the second diaphragm are composed of the first diaphragm and the second diaphragm.
  • the diaphragm clamps the second segment and drives the second segment to be rolled in, providing winding power for the second segment, thereby realizing the sequential rolling of the first segment and the second segment.
  • the first providing device includes a first connection mechanism for connecting the tail of the first segment and the head of the second segment through a first The connecting parts are connected.
  • the first segment and the second segment are connected through the first connecting part.
  • the first segment can drive the second segment through the first connecting part, forming the second segment.
  • the segments provide winding power, thereby realizing the sequential winding of the first segment and the second segment.
  • the separator includes a first separator and a second separator
  • the winding device includes two separator providing mechanisms, one of the separator providing mechanisms is used to provide the first separator, and the other is used to provide the first separator.
  • the winding equipment also includes: a first compounding mechanism, located downstream of the first providing device and one of the membrane providing mechanisms, the first compounding mechanism A mechanism is used to compound the first pole piece and the first diaphragm into a first pole piece assembly; a second compounding mechanism is located downstream of the second providing device and the other diaphragm providing mechanism, and the third Two composite mechanisms are used to composite the second pole piece and the second diaphragm into a second pole piece assembly;
  • the first providing device is configured to provide the first pole piece in the following manner: making the third pole piece One segment enters the first composite mechanism first, so that the second segment enters the first composite mechanism after the first segment; the winding mechanism is provided between the first composite mechanism and the first composite mechanism. Downstream of the second composite mechanism, the first pole piece assembly and the second pole piece assembly are wound along the winding direction to form an electrode assembly.
  • the first pole piece and the first diaphragm are compounded into the first pole piece assembly through the first compounding mechanism, so that the first pole piece is positioned through the first diaphragm, and the second pole piece is combined through the second compounding mechanism.
  • the pole piece and the second diaphragm are combined to form the second pole piece assembly, so as to facilitate the positioning of the second pole piece through the second diaphragm, thereby ensuring that the first pole piece and the second pole piece in the rolled electrode assembly are first
  • the separator and the second separator are separated to prevent the first pole piece and the second pole piece from contacting and causing a short circuit, ensuring the safety of the battery cell composed of the electrode assembly.
  • the present application provides a winding method.
  • the winding method includes: providing a first pole piece, the first pole piece includes a first segment and a second segment, the first segment A first active material layer is provided on the second segment, and a second active material layer is provided on the second segment; a second pole piece is provided, and the polarity of the second pole piece is opposite to the polarity of the first pole piece. ; Provide a separator; wind the first segment, the second segment, the separator and the second pole piece along the winding direction to form an electrode assembly, wherein the first segment is first The second segment is wound with the separator and the second pole piece after the first segment.
  • the coating density of the first active material layer is different from the coating density of the second active material layer; and/or the thickness of the first active material layer is different from that of the second active material layer.
  • the active material layers have different thicknesses; and/or the active material material of the first active material layer is the same as or different from the active material material of the second active material layer.
  • Figure 1 is a schematic structural diagram of a vehicle provided by some embodiments of the present application.
  • Figure 2 is a schematic diagram of the exploded structure of a battery provided by some embodiments of the present application.
  • Figure 3 is a schematic diagram of the exploded structure of a battery cell provided by some embodiments of the present application.
  • FIG. 4 is a schematic structural diagram of an electrode assembly provided by some embodiments of the present application.
  • Figure 5 is a schematic structural diagram of the first pole piece provided by some embodiments of the present application.
  • Figure 6 is a schematic structural diagram of the first pole piece provided by other embodiments of the present application.
  • Figure 7 is a schematic diagram of a first segment and a second segment being connected through a first connection part according to some embodiments of the present application;
  • Figure 8 is a schematic diagram of the connection between the first segment and the second segment and the diaphragm provided by some embodiments of the present application;
  • Figure 9 is a schematic diagram of the connection between the first segment and the second segment and the diaphragm provided by other embodiments of the present application.
  • FIG. 10 is a schematic structural diagram of an electrode assembly provided by other embodiments of the present application.
  • Figure 11 is a schematic structural diagram of the second pole piece provided by some embodiments of the present application.
  • Figure 12 is a schematic structural diagram of a second pole piece provided by other embodiments of the present application.
  • Figure 13 is a schematic diagram of the third segment and the fourth segment being connected through a second connection part according to some embodiments of the present application;
  • Figure 14 is a schematic diagram of the connection between the first pole piece, the second pole piece and the diaphragm provided by some embodiments of the present application;
  • Figure 15 is a schematic structural diagram of the winding equipment provided by some embodiments of the present application.
  • Figure 16 is a schematic diagram of the first conveying mechanism in the first conveying position provided by some embodiments of the present application.
  • Figure 17 is a schematic diagram of the second conveying mechanism in the first conveying position provided by some embodiments of the present application.
  • Figure 18 is a schematic structural diagram of the winding equipment provided by other embodiments of the present application.
  • Figure 19 is a schematic diagram of the third conveying mechanism in the second conveying position provided by some embodiments of the present application.
  • Figure 20 is a schematic diagram of the fourth conveying mechanism in the second conveying position provided by some embodiments of the present application.
  • Figure 21 is a schematic flow chart of a winding method provided by some embodiments of the present application.
  • an embodiment means that a particular feature, structure or characteristic described in connection with the embodiment may be included in at least one embodiment of the application.
  • the appearances of this phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.
  • connection should be understood in a broad sense.
  • connection can be a fixed connection, It can also be detachably connected or integrally connected; it can be directly connected or indirectly connected through an intermediate medium; it can be internal communication between two components.
  • connection can be a fixed connection
  • connection can also be detachably connected or integrally connected; it can be directly connected or indirectly connected through an intermediate medium; it can be internal communication between two components.
  • connection can also be detachably connected or integrally connected; it can be directly connected or indirectly connected through an intermediate medium; it can be internal communication between two components.
  • Multiple appearing in this application refers to more than two (including two). Similarly, “multiple groups” refers to two or more groups (including two groups), and “multiple tablets” refers to two or more tablets. (Includes two pieces).
  • the battery mentioned refers to a single physical module including one or more battery cells to provide higher voltage and capacity.
  • the battery mentioned in this application may include a battery module or a battery pack.
  • the battery cell includes an electrode assembly and an electrolyte.
  • the electrode assembly consists of a positive electrode plate, a negative electrode plate and a separator. Battery cells mainly rely on the movement of metal ions between the positive and negative electrodes to work.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer.
  • the positive electrode active material layer is coated on the surface of the positive electrode current collector.
  • the current collector that is not coated with the positive electrode active material layer protrudes from the current collector that is coated with the positive electrode active material layer.
  • the current collector that is not coated with the positive electrode active material layer serves as the positive electrode tab.
  • the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganate, etc.
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer.
  • the negative electrode active material layer is coated on the surface of the negative electrode current collector.
  • the current collector that is not coated with the negative electrode active material layer protrudes from the current collector that is coated with the negative electrode active material layer.
  • the current collector that is not coated with the negative electrode active material layer serves as the negative electrode tab.
  • the material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon.
  • the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together.
  • the material of the separator can be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene), etc.
  • the separator has electronic insulation and is used to isolate adjacent positive and negative electrode pieces and prevent adjacent positive and negative electrode pieces from short circuiting.
  • the separator has a large number of penetrating micropores, which can ensure the free passage of electrolyte ions and has good permeability to lithium ions. Therefore, the separator basically cannot block the passage of lithium ions.
  • the negative electrode plate, positive electrode plate and separator in the electrode assembly of the lithium-ion battery cell can be rolled and then compacted.
  • the electrode assembly includes a straight area and bent areas located at both ends of the straight area.
  • the straight area refers to the area with a parallel structure in the electrode assembly, that is, the negative electrode piece, the positive electrode piece and the The surfaces of the diaphragm are all flat.
  • the bending area refers to the area with a bending structure in the electrode assembly, that is, the negative electrode tab, positive electrode tab and separator are all bent in the bending area, that is, each layer of the negative electrode tab in the bending area of the electrode assembly , the surfaces of the positive electrode plate and the separator are all curved surfaces.
  • the electrode assembly having a wound structure is taken as an example for introduction.
  • the number of separators is two.
  • the electrode assembly may be a negative electrode sheet, a first separator, a positive electrode sheet and a second separator that are laminated and wound, or may be a first separator, a negative electrode sheet, a third separator. The two separators and the positive electrode sheet are stacked and wound.
  • the active material is coated on the surface of the current collector to form an active material layer.
  • the coating density of the active material layer refers to the coating weight of the active material per unit surface area.
  • the performance of the battery cell depends on the performance of the electrode assembly.
  • the electrode assembly is usually wound by a positive electrode piece and a negative electrode piece.
  • the performance of the electrode piece determines the performance of the electrode assembly.
  • the pole piece is usually a continuous strip structure, and the performance of each position of the pole piece is not much different.
  • the performance of the electrode assembly after the pole piece is wound is determined; depending on the performance of the electrode assembly, the performance of the electrode assembly is poor and cannot be differentiated.
  • the coating density of the active material layer of the pole piece is relatively high.
  • the fracture toughness of the pole piece is small and the pole piece is relatively brittle. It is easy to crack or even break when folded.
  • the bending area of the pole piece is prone to cracks or even fractures, resulting in insufficient space for lithium insertion in the bending area, prone to lithium precipitation, and lithium crystals can easily pierce the separator.
  • the broken pole piece can also easily pierce the separator, causing an internal short circuit, affecting the safety of the battery cell, making the battery cell composed of the electrode assembly unable to be used in environments with high safety requirements.
  • the electrode assembly includes a first pole piece and a second pole piece with opposite polarities.
  • the first pole piece and the second pole piece are stacked and wound along the winding direction to form an electrode assembly.
  • the first pole piece includes a first segment and a second segment.
  • a first active material layer is provided on the first segment.
  • a second active material layer is provided on the two segments.
  • the first segment is located upstream of the second segment.
  • the first segment in the inner ring and the second segment in the outer ring can be processed differently, so that the first segment and the second segment have different physical properties or chemical properties.
  • the first pole piece is divided into a first segment and a second segment.
  • the first segment and the second segment can be processed differently according to different needs to meet different performance requirements. .
  • the battery cells disclosed in the embodiments of the present application can be used in, but are not limited to, vehicles, ships, aircraft, and other electrical equipment.
  • the power supply system of the electrical equipment can be composed of battery cells, batteries, etc. disclosed in this application.
  • Embodiments of the present application provide an electrical device that uses a battery as a power source.
  • the electrical device can be, but is not limited to, a mobile phone, a tablet computer, a laptop, an electric toy, an electric tool, an electric bicycle, an electric motorcycle, an electric car, a ship, Spacecraft and more.
  • electric toys can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, electric airplane toys, etc.
  • spacecraft can include airplanes, rockets, space shuttles, spaceships, etc.
  • an electrical device is a vehicle 1000 as an example.
  • FIG. 1 is a schematic structural diagram of a vehicle 1000 provided by some embodiments of the present application.
  • the vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc.
  • the battery 100 is disposed inside the vehicle 1000 , and the battery 100 may be disposed at the bottom, head, or tail of the vehicle 1000 .
  • the battery 100 can be used to provide power for the vehicle 1000.
  • the battery 100 can be used as an operating power source for the vehicle 1000 and used for the vehicle's circuit system, such as for starting, navigating, and operating power requirements of the vehicle.
  • the vehicle 1000 may also include a controller 200 and a motor 300 .
  • the controller 200 is used to control the battery 100 to provide power to the motor 300 , for example, for starting, navigating and driving the vehicle 1000 .
  • the battery 100 can not only be used as an operating power source for the vehicle 1000 , but also can be used as a driving power source for the vehicle 1000 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000 .
  • FIG. 2 is a schematic diagram of an exploded structure of the battery 100 provided by some embodiments of the present application.
  • the battery 100 includes a case 10 and battery cells 20 , and the battery cells 20 are accommodated in the case 10 .
  • the box 10 is used to provide an accommodation space for the battery cells 20, and the box 10 can adopt a variety of structures.
  • the box 10 may include a first sub-box 11 and a second sub-box 12.
  • the first sub-box 11 and the second sub-box 12 cover each other.
  • the first sub-box 11 and the second sub-box 12 are The two sub-boxes 12 jointly define an accommodation space for accommodating the battery cells 20 .
  • the second sub-box 12 can be a hollow structure with one end open, and the first sub-box 11 can be a plate-like structure.
  • the first sub-box 11 is covered with the open side of the second sub-box 12 so that the first sub-box 11 can have a plate-like structure.
  • the box 11 and the second sub-box 12 jointly define an accommodation space; the first sub-box 11 and the second sub-box 12 can also be hollow structures with one side open, and the open side of the first sub-box 11 It is closed on the open side of the second sub-box 12 .
  • the box 10 formed by the first sub-box 11 and the second sub-box 12 can be in various shapes, such as a cylinder, a rectangular parallelepiped, etc.
  • the battery 100 there may be a plurality of battery cells 20, and the plurality of battery cells 20 may be connected in series, in parallel, or in mixed connection.
  • Mixed connection means that the plurality of battery cells 20 are connected in series and in parallel.
  • the plurality of battery cells 20 can be directly connected in series or in parallel or mixed together, and then the whole composed of the plurality of battery cells 20 can be accommodated in the box 10 ; of course, the battery 100 can also be a plurality of battery cells 20 First, the battery modules are connected in series, parallel, or mixed to form a battery module, and then multiple battery modules are connected in series, parallel, or mixed to form a whole, and are accommodated in the box 10 .
  • the battery 100 may also include other structures.
  • the battery 100 may further include a bus component for realizing electrical connections between multiple battery cells 20 .
  • Each battery cell 20 may be a secondary battery or a primary battery; it may also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited thereto.
  • the battery cell 20 may be in the shape of a cylinder, a flat body, a rectangular parallelepiped or other shapes.
  • FIG. 3 is an exploded structural diagram of a battery cell 20 provided in some embodiments of the present application.
  • the battery cell 20 refers to the smallest unit that constitutes the battery.
  • the battery cell 20 includes an end cover 21 , a case 22 , an electrode assembly 23 and other functional components.
  • the end cap 21 refers to a component that covers the opening of the case 22 to isolate the internal environment of the battery cell 20 from the external environment.
  • the shape of the end cap 21 can be adapted to the shape of the housing 22 to fit the housing 22 .
  • the end cap 21 can be made of a material with a certain hardness and strength (such as aluminum alloy). In this way, the end cap 21 is less likely to deform when subjected to extrusion and collision, so that the battery cell 20 can have higher durability. Structural strength and safety performance can also be improved.
  • Functional components such as electrode terminals 24 may be provided on the end cap 21 . The electrode terminal 24 may be used to electrically connect with the electrode assembly 23 for outputting or inputting electrical energy of the battery cell 20 .
  • the end cap 21 may also be provided with a pressure relief mechanism for releasing the internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold.
  • the end cap 21 can also be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which are not particularly limited in the embodiment of the present application.
  • an insulating member may also be provided inside the end cover 21 , and the insulating member may be used to isolate the electrical connection components in the housing 22 from the end cover 21 to reduce the risk of short circuit.
  • the insulating member may be plastic, rubber, etc.
  • the housing 22 is a component used to cooperate with the end cover 21 to form an internal environment of the battery cell 20 , wherein the formed internal environment can be used to accommodate the electrode assembly 23 , electrolyte, and other components.
  • the housing 22 and the end cover 21 may be independent components, and an opening may be provided on the housing 22.
  • the end cover 21 covers the opening at the opening to form the internal environment of the battery cell 20.
  • the end cover 21 and the housing 22 can also be integrated.
  • the end cover 21 and the housing 22 can form a common connection surface before other components are put into the housing. When it is necessary to encapsulate the inside of the housing 22 At this time, the end cover 21 covers the housing 22 again.
  • the housing 22 can be of various shapes and sizes, such as rectangular parallelepiped, cylinder, hexagonal prism, etc. Specifically, the shape of the housing 22 can be determined according to the specific shape and size of the electrode assembly 23 .
  • the housing 22 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which are not particularly limited in the embodiment of the present application.
  • the electrode assembly 23 is a component in the battery cell 20 where electrochemical reactions occur.
  • One or more electrode assemblies 23 may be contained within the housing 22 .
  • the electrode assembly 23 is mainly formed by winding a positive electrode piece and a negative electrode piece, and is usually provided with a separator between the positive electrode piece and the negative electrode piece. The separator is used to insulate the positive electrode piece and the negative electrode piece to avoid internal short circuit. .
  • the portions of the positive electrode piece and the negative electrode piece that contain active material constitute the main body of the battery cell assembly, and the portions of the positive electrode piece and the negative electrode piece that do not contain active material each constitute the tabs.
  • the positive electrode tab and the negative electrode tab can be located together at one end of the main body or respectively located at both ends of the main body. During the charging and discharging process of the battery, the positive active material and negative active material react with the electrolyte, and the tabs are connected to the electrode terminals to form a current loop.
  • Figure 4 is a schematic structural diagram of the electrode assembly 23 provided by some embodiments of the present application
  • Figure 5 is a schematic structural diagram of the first pole piece 231 provided by some embodiments of the present application
  • Figure 6 is a schematic structural diagram of the first pole piece 231 provided by other embodiments of the present application.
  • the present application provides an electrode assembly 23, which includes a first pole piece 231 and a second pole piece 232 with opposite polarities.
  • the first pole piece 231 and the second pole piece 232 are stacked and formed along the winding direction to form the electrode assembly 23 .
  • the first pole piece 231 includes a first segment 2311 and a second segment 2312.
  • the first segment 2311 is provided with a first active material layer 2311a
  • the second segment 2312 is provided with a second active material layer 2312a. In the winding direction from inside to outside, the first segment 2311 is located upstream of the second segment 2312.
  • the first pole piece 231 and the second pole piece 232 have opposite polarities.
  • the first pole piece 231 can be a negative pole piece
  • the second pole piece 232 can be a positive pole piece.
  • the first pole piece 231 can be a positive pole piece.
  • the second pole piece 232 may be a negative pole piece.
  • the embodiment of this application is introduced by taking the first pole piece 231 as a negative pole piece and the second pole piece 232 as a positive pole piece as an example.
  • the first segment 2311 and the second segment 2312 are two parts that constitute the first pole piece 231.
  • the first segment 2311 and the second segment 2312 are arranged along the winding direction from the inside to the outside.
  • the first segment 2311 and the second section 2312 can be integrally formed, or the first section 2311 and the second section 2312 can also be provided separately.
  • the first segment 2311 and the second segment 2312 may partially overlap, or, as shown in FIG. 5 , the tail of the first segment 2311 fits the head of the second segment 2312, or , as shown in Figures 4 and 6, there is a gap between the first segment 2311 and the second segment 2312.
  • the tail of the first segment 2311 and the head of the second segment 2312 fit together, or there is a gap between the first segment 2311 and the second segment 2312, but the gap is small; in this case below, the first segment 2311 and the second segment 2312 do not overlap, so as to avoid the overlapping area of the first segment 2311 and the second segment 2312 from increasing the thickness of the electrode assembly 23 and reducing space occupation.
  • first segment 2311 is located upstream of the second segment 2312 means that when the electrode assembly 23 is rolled to form the electrode assembly 23 , the first segment 2311 is wound before the second segment 2312 , so that the first segment 2311 is positioned relative to the second segment 2312 . Segment 2312 is close to the center of the winding.
  • the first segment 2311 is the portion of the first pole piece 231 located inside the electrode assembly 23 , that is, the portion of the first pole piece 231 close to the winding center; the second segment 2312 is the portion of the first pole piece 231 located inside the electrode assembly 23 .
  • the outer portion of the electrode assembly 23 that is, the portion of the first pole piece 231 away from the winding center.
  • the first segment 2311 has a winding structure, and the number of turns of the first segment 2311 is greater than or equal to one turn. That is, the first segment 2311 has at least two bending areas 235 .
  • the second segment 2312 has a winding structure, and the number of turns of the second segment 2312 is greater than one turn. That is, the second segment 2312 has a plurality of bending areas 235 .
  • the first pole piece 231 includes a first segment 2311 and a second segment 2312. Along the winding direction from the inside to the outside, the first segment 2311 is inside the second segment 2312. upstream, by dividing the first pole piece 231 into a first segment 2311 and a second segment 2312, different processes can be performed on the first segment 2311 in the inner ring and the second segment 2312 in the outer ring. , so that the first segment 2311 and the second segment 2312 have different physical properties or chemical properties, and can better adjust the performance of the electrode assembly 23 through internal and external differential configurations to meet different performance requirements.
  • the coating density of the first active material layer 2311a is different from the coating density of the second active material layer 2312a.
  • the coating density of the first active material layer 2311a refers to the coating weight of the active material of the first active material layer 2311a per unit surface area.
  • the coating density of the second active material layer 2312a refers to the coating weight of the active material of the second active material layer 2312a per unit surface area.
  • the coating density of the first active material layer 2311a is different from the coating density of the second active material layer 2312a.
  • the energy density of the electrode assembly 23 can be adjusted to meet different energy density requirements of the electrode assembly.
  • the coating density of the first active material layer 2311a is smaller than the coating density of the second active material layer 2312a.
  • the electrode assembly 23 includes a straight region 234 and bent regions 235 located at both ends of the straight region 234 .
  • the straight region 234 refers to a region with a parallel structure in the electrode assembly 23 , that is, the third region within the straight region 234 .
  • the surfaces of the first pole piece 231, the second pole piece 232 and the diaphragm are all flat.
  • the bending area 235 refers to an area with a bending structure in the electrode assembly 23 , that is, the first pole piece 231 , the second pole piece 232 and the separator are all bent in the bending area 235 , that is, the electrode assembly 23 is bent.
  • the surfaces of the first pole piece 231, the second pole piece 232 and the separator of each layer in the folding area 235 are all curved surfaces.
  • the coating density of the first active material layer 2311a is less than the coating density of the second active material layer 2312a, and the fracture toughness of the first segment 2311 is greater than the fracture toughness of the second segment 2312, so that the bending area of the first segment 2311 235 is not easy to crack or break, which reduces the probability of cracks or breakage of the first pole piece 231, thereby improving the safety of the battery cell 20 composed of the electrode assembly 23.
  • the coating density of the second active material layer 2312a is 10%-200% greater than the coating density of the first active material layer 2311a.
  • the coating density of the second active material layer 2312a is H2, and the coating density of the first active material layer 2311a is H1, which satisfies 0.1 ⁇ (H2-H1)/H1 ⁇ 2.
  • the coating density of the second active material layer 2312a is higher than the coating density of the first active material layer 2311a, ensuring that the first pole piece 231 has more active material, thereby ensuring that the battery cell 20 composed of the electrode assembly 23 has a greater Large energy density.
  • the coating density of the second active material layer 2312a is 20%-150% greater than the coating density of the first active material layer 2311a.
  • the coating density of the second active material layer 2312a is 40%-120% greater than the coating density of the first active material layer 2311a.
  • the coating density of the second active material layer 2312a is greater than the coating density of the first active material layer 2311a by 30%, 50%, 60%, 70%, 100%, 130%, 150% or 180%, etc. .
  • the ratio of the thickness of the first active material layer 2311a to the thickness of the second active material layer 2312a is 1/2-3/2.
  • the thickness of the first active material layer 2311a is D1
  • the thickness of the second active material layer 2312a is D2, which satisfies 1/2 ⁇ D1/D2 ⁇ 3/2.
  • the thickness of the first active material layer 2311a and the second active material layer 2311a is D2.
  • the thickness of layer 2312a is close to.
  • D1/D2 can be 5/8, 3/4, 7/8, 1, 9/8, 5/4, 11/8, etc.
  • the ratio of the thickness of the first active material layer 2311a to the thickness of the second active material layer 2312a satisfies the above range to ensure the first segmentation There will be no step at the transition point between 2311 and the second segment 2312, which prevents the active material from falling off or causing indentation, and ensures the quality of the electrode assembly 23.
  • the active material material of the first active material layer 2311a is the same as or different from the active material material of the second active material layer 2312a.
  • the active material material of the first active material layer 2311a is different from the active material material of the second active material layer 2312a, and the properties of the first segment 2311 and the second segment 2312 can be adjusted to satisfy the electrode assembly 23 with different physical properties or chemistry. performance.
  • the first active material layer 2311a and the second active material layer 2312a can use the same formula, for example, use the same kind of active material materials and the same ratio of active material materials; or, the first active material layer 2311a and the second active material layer 2311a can use the same formula.
  • the material layer 2312a may use different formulas, for example, the same type of active material material may be used, but the ratio of the active material materials may be different; or the first active material layer 2311a and the second active material layer 2312a may use different types of active materials. Materials, for example, different chemical systems.
  • the negative active material can be graphite (artificial graphite, natural graphite), amorphous carbon (soft At least one of carbon, hard carbon, other amorphous carbon) and lithium titanate.
  • the positive electrode active material may be lithium cobalt oxide, lithium manganate, lithium iron phosphate, or nickel cobalt manganese. At least one of lithium acid oxide, lithium-rich lithium manganese oxide, and lithium nickel cobalt aluminate.
  • the tail of the first segment 2311 and the head of the second segment 2312 are connected; or, as shown in Figures 4 and 6, the first There is a gap between the tail of segment 2311 and the head of second segment 2312.
  • the tail of the first segment 2311 refers to the end of the first segment 2311 along the winding direction. In other words, the tail of the first segment 2311 refers to the ending position of the first segment 2311; the second segment 2312 The head refers to the head end of the second segment 2312 along the winding direction. In other words, the head of the second segment 2312 refers to the starting position of the second segment 2312.
  • the first pole piece 231 has more active material and ensures that the electrode assembly 23 has a higher energy density; in an embodiment where a gap is provided between the tail of the first segment 2311 and the head of the second segment 2312, the processing of the first segment 2311 and the second segment 2312 can be facilitated. , reducing the manufacturing difficulty of the first pole piece 231.
  • the first pole piece 231 further includes a first current collector 2313 , and the first active material layer 2311 a and the second active material layer 2312 a are respectively provided on the first current collector 2313 .
  • the first current collector 2313 has a continuous strip structure, and the first active material layer 2311a and the second active material layer 2312a are respectively disposed on the first current collector 2313.
  • the first segment 2311 is a region where the active material layer of the first pole piece 231 has a lower coating density
  • the second segment 2312 is a region where the active material layer of the first pole piece 231 has a higher coating density. Area.
  • the active material layer when rolling the active material layer, by adjusting the distance between a pair of pressure rollers and changing the roller pressure of the pair of pressure rollers on the first pole piece 231, the active material layer The area with lower coating density forms the first segment 2311, and the area with higher coating density of the active material layer forms the second segment 2312.
  • the first pole piece 231 further includes a first current collector segment 2311b and a second current collector segment 2312b, and the first active material layer 2311a is disposed on the first current collector segment.
  • the first segment 2311 is formed on the segment 2311b, and the second active material layer 2312a is disposed on the second current collector segment 2312b to form the second segment 2312.
  • the first current collector section 2311b and the second current collector section 2312b are two different current collector sections. In this case, the first section 2311 and the second section 2312 are two disconnected parts.
  • the first active material layer 2311a is disposed on the first current collector segment 2311b to form the first segment 2311
  • the second active material layer 2312a is disposed on the second current collector segment 2312b to form the second segment 2312, which facilitates the realization of the first
  • the processing and manufacturing of the segment 2311 and the second segment 2312 reduce the manufacturing difficulty of the first pole piece 231.
  • FIG. 7 is a schematic diagram of a first segment 2311 and a second segment 2312 connected through a first connection part 2314 according to some embodiments of the present application.
  • the tail of the first segment 2311 and the head of the second segment 2312 are connected through the first connection part 2314.
  • the first connecting part 2314 is a connecting component used to connect the first segment 2311 and the second segment 2312.
  • the first connecting part 2314 may be an adhesive tape or a separator with a glue layer.
  • the first connecting part 2314 can be made of a material through which ions can pass, so that the active material covered by the first connecting part 2314 can function, which is beneficial to increasing the energy density.
  • the first connecting part 2314 may be located on one side of the first segment 2311 and the second segment 2312, or, as shown in FIG. 7 , the first connecting part 2314 may be located on both sides of the first segment 2311 and the second segment 2312. side.
  • the first segment 2311 and the second segment 2312 are connected through the first connection part to realize the positioning of the first segment 2311 and the second segment 2312 and limit the positional movement of the first segment 2311 and the second segment 2312,
  • the first segment 2311 can drive the second segment 2312 through the first connecting part 2314 to provide winding power for the second segment 2312, thereby realizing the first segment 2311 and
  • the second segment 2312 is wound sequentially.
  • FIG. 8 is a schematic diagram of the connection between the first segment 2311 and the second segment 2312 and the diaphragm 233 provided by some embodiments of the present application.
  • the electrode assembly 23 further includes a separator 233 , which is used to separate the first pole piece 231 and the second pole piece 232 .
  • the diaphragm 233 is disposed between the first pole piece 231 and the second pole piece 232.
  • the diaphragm 233 is an electrically insulating film-like structure that can insulate the first pole piece 231 and the second pole piece 232, thereby separating the first pole piece 231. and second pole piece 232.
  • the first pole piece 231 and the second pole piece 232 are separated by the diaphragm 233 to avoid contact short circuit between the first pole piece 231 and the second pole piece 232 and improve safety.
  • the head of the second segment 2312 is connected to the diaphragm 233 .
  • the head of the second segment 2312 is connected to the diaphragm 233.
  • the diaphragm 233 realizes the positioning of the head of the second segment 2312, restricting the positional movement of the first segment 2311 and the second segment 2312.
  • the diaphragm 233 can drive the head of the second segment 2312 to be rolled in, providing winding power for the second segment 2312, so as to realize the sequential winding of the first segment 2311 and the second segment 2312.
  • both the first segment 2311 and the second segment 2312 are connected to the diaphragm 233 .
  • the first segment 2311 and the second segment 2312 are connected to the diaphragm 233, and the first segment 2311 and the second segment 2312 are positioned through the diaphragm 233 to limit the positional movement of the first segment 2311 and the second segment 2312. , reduce the risk of short circuit between the first pole piece 231 and the second pole piece 232, and ensure the safety of the battery cell 20 composed of the electrode assembly 23.
  • FIG. 9 is a schematic diagram of the connection between the first segment 2311 and the second segment 2312 and the diaphragm 233 provided by other embodiments of the present application.
  • the electrode assembly 23 may include two diaphragms 233 , the two diaphragms 233 are respectively located on both sides of the first pole piece 231 , and the first pole piece 231 is connected to the two diaphragms 233 .
  • Diaphragm 233 connection In other words, the first segment 2311 and the second segment 2312 are connected through the two diaphragms 233 to achieve positioning of the first segment 2311 and the second segment 2312.
  • Figure 10 is a schematic structural diagram of the electrode assembly 23 provided by some embodiments of the present application.
  • Figure 11 is a schematic structural diagram of the second pole piece 232 provided by some embodiments of the present application.
  • Figure 12 is a schematic structural diagram of the electrode assembly 23 provided by some embodiments of the present application.
  • Other embodiments provide a schematic structural diagram of the second pole piece 232 .
  • the second pole piece 232 includes a third segment 2321 and a fourth segment 2322; the third segment 2321 is provided with a third active material layer 2321a; the fourth segment 2322 is provided with a third active material layer 2321a.
  • Four active material layers 2322a; along the winding direction from the inside to the outside, the third segment 2321 is located upstream of the fourth segment 2322.
  • the third segment 2321 and the fourth segment 2322 are two parts that constitute the second pole piece 232.
  • the third segment 2321 and the fourth segment 2322 are arranged along the winding direction from the inside to the outside.
  • 2321 and the fourth section 2322 can be integrally formed, or the third section 2321 and the fourth section 2322 can also be provided separately.
  • the third segment 2321 and the fourth segment 2322 may overlap, or, as shown in Figure 11, the tail of the third segment 2321 and the head of the fourth segment 2322 may fit together, or, As shown in Figure 12, there is a gap between the third segment 2321 and the fourth segment 2322.
  • the tail of the third segment 2321 and the head of the fourth segment 2322 fit together, or there is a gap between the third segment 2321 and the fourth segment 2322, but the gap is small; in this case below, the third segment 2321 and the fourth segment 2322 do not overlap, so as to avoid the overlapping area of the third segment 2321 and the fourth segment 2322 from increasing the thickness of the electrode assembly 23 and reducing space occupation.
  • the fact that the third segment 2321 is located upstream of the fourth segment 2322 means that when the electrode assembly 23 is rolled to form, the third segment 2321 is wound before the fourth segment 2322 , so that the third segment 2321 is positioned relative to the fourth segment 2322 . Segment 2322 is close to the center of the winding.
  • the third segment 2321 is the portion of the second pole piece 232 located inside the electrode assembly 23 , that is, the portion of the second pole piece 232 close to the winding center; the fourth segment 2322 is the portion of the second pole piece 232 located inside the electrode assembly 23 .
  • the outer portion of the electrode assembly 23 that is, the portion of the second pole piece 232 away from the winding center.
  • the third section 2321 has a winding structure, and the number of turns of the third section 2321 is greater than or equal to one turn. That is, the third section 2321 has at least two bending areas 235 .
  • the fourth section 2322 is a winding mechanism, and the number of turns of the fourth section 2322 is greater than one turn. That is, the fourth section 2322 has a plurality of bending areas 235 .
  • the third segment 2321 in the inner ring and the fourth segment 2322 in the outer ring can be processed differently respectively, so that the third segment 2321 in the inner ring and the fourth segment 2322 in the outer ring can be processed differently.
  • the third segment 2321 and the fourth segment 2322 have different physical properties or chemical properties, and are configured internally and externally to better adjust the performance of the electrode assembly 23 and adapt to different usage environments.
  • the coating density of the third active material layer 2321a is different from the coating density of the fourth active material layer 2322a; and/or, the thickness of the third active material layer 2321a is different from that of the fourth active material layer 2322a. have different thicknesses; and/or, the active material material of the third active material layer 2321a is the same as or different from the active material material of the fourth active material layer 2322a.
  • the coating density of the third active material layer 2321a refers to the coating weight of the active material of the third active material layer 2321a per unit surface area.
  • the coating density of the fourth active material layer 2322a refers to the coating weight of the active material of the fourth active material layer 2322a per unit surface area.
  • the physical properties or chemical properties of the third segment 2321 and the fourth segment 2322 can be changed by changing the coating density, thickness and active material material formula of the third active material layer 2321a and the fourth active material layer 2322a, so that The electrode assembly 23 meets different performance requirements and is suitable for different usage scenarios.
  • the coating density of the third active material layer 2321a is smaller than the coating density of the fourth active material layer 2322a.
  • the coating density of the third active material layer 2321a is less than the coating density of the fourth active material layer 2322a, and the fracture toughness of the third segment 2321 is greater than the fracture toughness of the fourth segment 2322, so that the bending area of the third segment 2321 235 is not easy to crack or break, which reduces the probability of cracks or breakage of the second pole piece 232, thereby improving the safety of the battery cell 20 composed of the electrode assembly 23.
  • the coating density of the fourth active material layer 2322a is 10%-200% greater than the coating density of the third active material layer 2321a.
  • the coating density of the fourth active material layer 2322a is H4, and the coating density of the third active material layer 2321a is H3, which satisfies 0.1 ⁇ (H4-H3)/H3 ⁇ 2.
  • the coating density of the fourth active material layer 2322a is higher than that of the third active material layer 2321a, ensuring that the second pole piece 232 has more active material, thereby ensuring that the battery cell 20 composed of the electrode assembly 23 has a higher Large energy density.
  • the coating density of the fourth active material layer 2322a is 20%-150% greater than the coating density of the third active material layer 2321a.
  • the coating density of the fourth active material layer 2322a is 40%-120% greater than the coating density of the third active material layer 2321a.
  • the coating density of the fourth active material layer 2322a is greater than the coating density of the third active material layer 2321a by 30%, 50%, 60%, 70%, 100%, 130%, 150% or 180%, etc. .
  • the third active material layer 2321a and the fourth active material layer 2322a may use the same formula, for example, use the same type of active material materials and the same ratio of active material materials; or, the third active material layer 2321a may use the same formula.
  • the layer 2321a and the fourth active material layer 2322a may use different formulas, for example, the same type of active material material may be used, but the ratio of the active material materials may be different; or the third active material layer 2321a and the fourth active material layer 2322a may use different formulas.
  • Use different types of active material materials for example, different chemical systems.
  • the negative active material can be graphite (artificial graphite, natural graphite), amorphous carbon (soft At least one of carbon, hard carbon, other amorphous carbon) and lithium titanate.
  • the positive electrode active material can be lithium cobalt oxide, lithium manganate, lithium iron phosphate, or nickel cobalt manganese. At least one of lithium acid oxide, lithium-rich lithium manganese oxide, and lithium nickel cobalt aluminate.
  • the ratio of the thickness of the third active material layer 2321a to the thickness of the fourth active material layer 2322a is 1/2-3/2.
  • the thickness of the third active material layer 2321a is D3, and the thickness of the fourth active material layer 2322a is D4, which satisfies 1/2 ⁇ D3/D4 ⁇ 3/2. In other words, the thickness of the third active material layer 2321a and the fourth active material layer 2321a is D4. The thickness of layer 2322a is close to.
  • D1/D2 can be 5/8, 3/4, 7/8, 1, 9/8, 5/4, 11/8, etc.
  • the thickness ratio of the third active material layer 2321a to the thickness of the fourth active material layer 2322a satisfies the above range, ensuring that There will be no step at the transition between the third segment 2321 and the fourth segment 2322, which prevents the active material from falling off or causing indentation, and ensures the quality of the electrode assembly 23.
  • the tail of the third segment 2321 and the head of the fourth segment 2322 are connected, or, as shown in Figure 12, the third segment 2321 There is a gap between the tail and the head of the fourth segment 2322.
  • the tail of the third segment 2321 refers to the end of the third segment 2321 along the winding direction. In other words, the tail of the third segment 2321 refers to the ending position of the third segment 2321; the fourth segment 2322 The head refers to the head end of the fourth segment 2322 along the winding direction. In other words, the head of the fourth segment 2322 refers to the starting position of the fourth segment 2322.
  • the second pole piece 232 has more active material and ensures that the electrode assembly 23 has higher energy density; in the embodiment where a gap is provided between the tail of the third segment 2321 and the head of the fourth segment 2322, the processing of the third segment 2321 and the fourth segment 2322 can be facilitated. , reducing the manufacturing difficulty of the second pole piece 232.
  • the second pole piece 232 further includes a second current collector 2323, and the third active material layer 2321a and the fourth active material layer 2322a are respectively provided on the second current collector 2323.
  • the second current collector 2323 has a continuous strip structure, and the third active material layer 2321a and the fourth active material layer 2322a are respectively disposed on the second current collector 2323.
  • the third segment 2321 is the area where the active material layer of the second pole piece 232 has a lower coating density
  • the fourth segment 2322 is the area where the active material layer of the second pole piece 232 has a higher coating density. Area.
  • the active material layer when the active material layer is rolled, by adjusting the distance between a pair of pressure rollers and changing the roller pressure of the pair of pressure rollers on the second pole piece 232, the active material layer
  • the area with lower coating density forms the third segment 2321
  • the area with higher coating density of the active material layer forms the fourth segment 2322.
  • the second pole piece 232 also includes a third current collector segment 2321b and a fourth current collector segment 2322b, and the third active material layer 2321a is disposed on the third current collector segment.
  • the third segment 2321 is formed on the segment 2321b, and the fourth active material layer 2322a is disposed on the fourth current collector segment 2322b to form the fourth segment 2322.
  • the third current collector segment 2321b and the fourth current collector segment 2322b are two different current collector segments. In this case, the third current collector segment 2321b and the fourth current collector segment 2322b are two disconnected current collector segments. part.
  • the third active material layer 2321a is disposed on the third current collector segment 2321b to form the third segment 2321
  • the fourth active material layer 2322a is disposed on the fourth current collector segment 2322b to form the fourth segment 2322, which facilitates the realization of the third segment 2321.
  • the processing and manufacturing of the segment 2321 and the fourth segment 2322 reduce the manufacturing difficulty of the second pole piece 232.
  • FIG. 13 is a schematic diagram of the third section 2321 and the fourth section 2322 connected through the second connection part 2324 according to some embodiments of the present application.
  • the tail of the third segment 2321 and the head of the fourth segment 2322 are connected through the second connection part 2324.
  • the second connecting part 2324 is a connecting component used to connect the third segment 2321 and the fourth segment 2322.
  • the second connecting part 2324 may be an adhesive tape or a separator with a glue layer.
  • the second connecting part 2324 can be made of a material through which ions can pass, so that the active material covered by the second connecting part 2324 can function, which is beneficial to increasing the energy density.
  • the second connection part 2324 may be located on one side of the third section 2321 and the fourth section 2322, or, as shown in FIG. 13, the second connection part 2324 may be located on both sides of the third section 2321 and the fourth section 2322. side.
  • the third segment 2321 and the fourth segment 2322 are connected through the second connecting part 2324 to realize the positioning of the third segment 2321 and the fourth segment 2322 and limit the position movement of the third segment 2321 and the fourth segment 2322.
  • the third segment 2321 can drive the fourth segment 2322 through the second connecting part 2324 to provide winding power for the fourth segment 2322, thereby realizing the third segment 2321 and the sequential winding of the fourth segment 2322.
  • the electrode assembly further includes a separator 233, which is used to separate the first pole piece 231 and the second pole piece 232, and the head of the fourth segment 2322 is connected to the separator 233.
  • the head of the fourth segment 2322 is connected to the diaphragm 233, and the fourth segment 2322 is positioned through the diaphragm 233 to limit the positional movement of the third segment 2321 and the fourth segment 2322.
  • the diaphragm 233 can The head of the fourth segment 2322 is driven to be rolled in, providing winding power for the fourth segment 2322, so as to realize the sequential winding of the third segment 2321 and the fourth segment 2322.
  • the electrode assembly 23 includes two diaphragms 233.
  • the two diaphragms 233 are respectively located on both sides of the second pole piece 232.
  • the head of the second segment 2312 is connected to one diaphragm 233, and the fourth segment The head of 2322 is connected to another diaphragm 233.
  • One diaphragm 233 connects the head of the second segment 2312, the other diaphragm 233 connects the head of the fourth segment 2322, one diaphragm 233 limits the position of the second segment 2312, and the other diaphragm 233 limits the position of the fourth segment 2322.
  • a diaphragm 233 can drive the head of the second segment 2312 to be rolled in, providing winding power for the second segment 2312 to realize the first segment 2311 and the second segment 2312
  • the other diaphragm 233 can drive the head of the fourth segment 2322 to be rolled in, providing winding power for the fourth segment 2322 to realize the sequential winding of the third segment 2321 and the fourth segment 2322. around.
  • FIG. 14 is a schematic diagram of the connection between the first pole piece 231 , the second pole piece 232 and the diaphragm 233 provided by some embodiments of the present application.
  • the electrode assembly 23 further includes a separator 233 , which is used to separate the first pole piece 231 and the second pole piece 232 , the third segment 2321 and the fourth pole piece 232 . Segments 2322 are each connected to diaphragm 233.
  • the diaphragm 233 is disposed between the first pole piece 231 and the second pole piece 232.
  • the diaphragm 233 is an electrically insulating film-like structure to separate the first pole piece 231 and the second pole piece 232.
  • the third segment 2321 and the fourth segment 2322 are connected to the diaphragm 233, and the third segment 2321 and the fourth segment 2322 are positioned through the diaphragm 233 to limit the positional movement of the third segment 2321 and the fourth segment 2322. , reduce the risk of short circuit between the first pole piece 231 and the second pole piece 232, and ensure the safety of the battery cell 20 composed of the electrode assembly 23.
  • the electrode assembly 23 includes two diaphragms 233 , the two diaphragms 233 are respectively located on both sides of the second pole piece 232 , the first segment 2311 and the second segment 231 .
  • the segments 2312 are each connected to one membrane 233
  • the third segment 2321 and the fourth segment 2322 are each connected to the other membrane 233 .
  • the two separators 233 and the first pole piece 231 and the second pole piece 232 may be stacked in the following manner: the separator 233, the first pole piece 231, the separator 233, and the second pole piece 232, or It can be the first pole piece 231, the diaphragm 233, the second pole piece 232 and the diaphragm 233.
  • One diaphragm 233 connects the first segment 2311 and the second segment 2312, and the other diaphragm 233 connects the third segment 2321 and the fourth segment 2322, ensuring that the first segment 2311 and the second segment 2312 are positioned by one diaphragm 233.
  • the third segment 2321 and the fourth segment 2322 are positioned by another diaphragm 233.
  • One diaphragm 233 limits the position of the first segment 2311 and the second segment 2312.
  • the other diaphragm 233 limits the third segment 2321 and the fourth segment.
  • the position of the segment 2322 reduces the risk of short circuit between the first pole piece 231 and the second pole piece 232 and ensures the safety of the battery cell 20 composed of the electrode assembly 23.
  • the number of turns of the third segment 2321 is less than the number of turns of the fourth segment 2322.
  • the number of turns of the third segment 2321 refers to the number of winding turns of the third segment 2321.
  • One circle refers to starting from a certain point on the third segment 2321, and the third segment 2321 is wound along the winding direction.
  • the part wound by the third segment 2321 is one circle.
  • the number of turns of the fourth segment 2322 refers to the number of winding turns of the fourth segment 2322.
  • One circle refers to starting from a certain point on the fourth segment 2322, and the fourth segment 2322 moves along the winding direction. Winding, when the fourth segment 2322 covers the starting point for the first time, the wound part of the fourth segment 2322 is one circle.
  • the number of turns of the third segment 2321 is less than the number of turns of the fourth segment 2322. In other words, the number of winding turns of the fourth segment 2322 is greater than the number of winding turns of the third segment 2321. Since the fourth active material layer The coating density of 2322a is greater than that of the third active material layer 2321a. When the thickness of the electrode assembly 23 is the same, the number of winding turns of the fourth segment 2322 is greater, which can ensure that the electrode assembly 23 has a higher Energy Density.
  • the number of turns of the third segment 2321 is 1-5 turns.
  • the number of turns of the third segment 2321 is between 1 and 5, which can not only reduce the probability of cracks or breaks in the area of the second pole piece 232 close to the winding center, but also ensure the durability of the battery cell 20 composed of the electrode assembly 23 Energy Density. If the number of turns of the third segment 2321 is too small, the bending area 235 of the second pole piece 232 close to the winding center is likely to crack or break, affecting the safety of the battery cell 20 composed of the electrode assembly 23; due to the third The coating density of the three active material layers 2321a is small. If the number of turns of the third segment 2321 is too large, the energy density of the battery cell 20 composed of the electrode assembly 23 will be affected.
  • the number of turns of the first segment 2311 is less than the number of turns of the second segment 2312.
  • the number of turns of the first segment 2311 refers to the number of winding turns of the first segment 2311.
  • One circle refers to starting from a certain point on the first segment 2311 and winding the first segment 2311 along the winding direction. When the first segment 2311 covers the starting point for the first time, the winding part of the first segment 2311 is one circle.
  • the number of turns of the second segment 2312 refers to the number of winding turns of the second segment 2312.
  • One circle refers to starting from a certain point on the second segment 2312, and the second segment 2312 moves along the winding direction. Winding, when the second segment 2312 covers the starting point for the first time, the wound part of the second segment 2312 is one circle.
  • the number of turns of the first segment 2311 is less than the number of turns of the second segment 2312. In other words, the number of turns of the second segment 2312 is greater than the number of turns of the first segment 2311. Since the second active material layer The coating density of 2312a is greater than that of the first active material layer 2311a. When the thickness of the electrode assembly 23 is the same, the number of winding turns of the second segment 2312 is greater, which can ensure that the electrode assembly 23 has a higher Energy Density.
  • the number of turns of the first segment 2311 is 1-5 turns.
  • the number of turns of the first segment 2311 is between 1 and 5, which can not only reduce the probability of cracks or breaks in the area of the first pole piece 231 close to the winding center, but also ensure the durability of the battery cell 20 composed of the electrode assembly 23 Energy Density. If the number of turns of the first segment 2311 is too small, the bending area 235 of the first pole piece 231 close to the winding center is prone to cracks or fractures, affecting the safety of the battery cell 20 composed of the electrode assembly 23; due to the The coating density of an active material layer 2311a is small. If the number of turns of the first segment 2311 is too large, the energy density of the battery cell 20 composed of the electrode assembly 23 will be affected.
  • the present application also provides a battery cell 20 including the electrode assembly 23 described in any of the above solutions.
  • the present application also provides a battery 100, including the battery cell 20 described in any of the above solutions.
  • the present application also provides an electrical device, including the battery 100 described in any of the above solutions, and the battery 100 is used to provide electrical energy for the electrical device.
  • the powered device may be any of the aforementioned devices or systems using the battery 100 .
  • the present application provides a battery cell 20 , including an end cover 21 , a housing 22 , an electrode assembly 23 and an electrode terminal 24 .
  • the electrode assembly 23 is disposed in the casing 22
  • the electrode terminal 24 is disposed in the end cover 21
  • the end cover 21 covers the opening of the casing 22 .
  • the electrode assembly 23 includes a first pole piece 231 , a second pole piece 232 and a separator 233 .
  • the first pole piece 231 , the separator 233 and the second pole piece 232 are wound along the winding direction to form the electrode assembly 23 .
  • the first pole piece 231 includes a first segment 2311 and a second segment 2312.
  • the first segment 2311 is provided with a first active material layer 2311a
  • the second segment 2312 is provided with a second active material layer 2312a.
  • the first segment 2311 is located upstream of the second segment 2312, and the coating density of the first active material layer 2311a is smaller than the coating density of the second active material layer 2312a.
  • the second pole piece 232 includes a third segment 2321 and a fourth segment 2322.
  • the third segment 2321 is provided with a third active material layer 2321a
  • the fourth segment 2322 is provided with a fourth active material layer 2322a.
  • the third segment 2321 is located upstream of the fourth segment 2322, and the coating density of the third active material layer 2321a is smaller than the coating density of the fourth active material layer 2322a.
  • Two diaphragms 233 are provided.
  • the diaphragms 233 are used to separate the first pole piece 231 and the second pole piece 232.
  • the first section 2311 and the second section 2312 are connected to one diaphragm 233.
  • the third section 2321 and the fourth section are connected to one diaphragm 233.
  • Segment 2322 is connected to another membrane 233.
  • the coating density of the first active material layer 2311a and the third active material layer 2321a are small, which reduces the close winding of the first pole piece 231.
  • the probability of cracks or breaks in the central bending area 235 reduces the probability of cracks or breaks in the bending area 235 of the second pole piece 232 close to the winding center, thereby improving the safety of the battery cell 20 .
  • FIG. 15 is a schematic structural diagram of a winding device 400 provided by some embodiments of the present application.
  • the winding equipment 400 includes a first providing device 411, a second providing device 412, a separator providing mechanism 42 and a winding mechanism 44.
  • the first providing device 411 is used to provide the first pole piece 231.
  • the first pole piece 231 includes a first section 2311 and a second section 2312.
  • the first section 2311 is provided with a third section.
  • An active material layer 2311a, and a second active material layer 2312a is provided on the second segment 2312.
  • the second providing device 412 is used to provide a second pole piece 232 with a polarity opposite to that of the first pole piece 231 .
  • the diaphragm providing mechanism 42 is used to provide the diaphragm 233.
  • the winding mechanism 44 is disposed downstream of the first providing device 411, the second providing device 412 and the diaphragm providing mechanism 42.
  • the winding mechanism 44 is used to connect the first segment 2311, the second segment 2312, the diaphragm 233 and the second pole.
  • the sheet 232 is wound in the winding direction to form the electrode assembly 23 .
  • the first providing device 411 is configured to provide the first pole piece 231 in the following manner: the first segment 2311 enters the winding mechanism 44 first, and the second segment 2312 enters the winding mechanism after the first segment 2311 44.
  • the upstream and downstream mentioned in this application refer to the before and after relationship in the winding and forming process of the electrode assembly 23.
  • the winding mechanism 44 is provided downstream of the first providing device 411, the second providing device 412 and the separator providing mechanism 42. It means that in the winding forming process, the first pole piece 231 provided by the first providing device 411 is transported to the winding mechanism 44, and the second pole piece 232 provided by the second providing device 412 is transported to the winding mechanism 44.
  • the separator providing mechanism The separator 233 provided by 42 is transported to the winding mechanism 44, so that the winding mechanism 44 winds the first segment 2311, the second segment 2312, the separator 233 and the second pole piece 232 along the winding direction to form the electrode assembly 23.
  • the first pole piece 231 (the first segment 2311 and the second segment 2312), the separator 233 and the second pole piece 232 are stacked and rolled to form the electrode assembly 23.
  • the separator 233 is disposed on the first pole piece 231 and the second pole piece 232.
  • the diaphragm 233 is used to separate the first pole piece 231 and the second pole piece 232 to prevent the first pole piece 231 and the second pole piece 232 from contacting and short-circuiting.
  • the winding mechanism 44 may include a rotary disk and a winding needle, and the rotary disk is used to drive the winding needle to rotate so as to wind the first pole piece 231, the diaphragm 233 and the second pole piece 232 around the winding needle.
  • the winding mechanism 44 winds the first segment 2311, the second segment 2312, the separator 233 and the second pole piece 232 to form the electrode assembly 23.
  • the first segment 2311 can be
  • the first segment 2311 and the second segment 2312 are processed differently respectively, so that the first segment 2311 and the second segment 2312 have different physical properties or chemical properties, and the performance of the electrode assembly 23 can be better adjusted through differentiated internal and external configurations.
  • the coating density of the first active material layer 2311a is different from the coating density of the second active material layer 2312a; and/or the thickness of the first active material layer 2311a is different from that of the second active material layer 2312a.
  • the thicknesses are different; and/or the active material material of the first active material layer 2311a is the same as or different from the active material material of the second active material layer 2312a.
  • the physical properties or chemical properties of the first segment 2311 and the second segment 2312 can be changed by changing the coating density, thickness and active material material coordination of the first active material layer 2311a and the second active material layer 2312a, so that The electrode assembly 23 meets different performance requirements and is suitable for different usage scenarios.
  • the coating density of the first active material layer 2311a is smaller than the coating density of the second active material layer 2312a.
  • the fracture toughness of the first segment 2311 is greater than the fracture toughness of the second segment 2312.
  • the bending of the first segment 2311 The region 235 is less likely to crack or break, which reduces the probability of the first pole piece 231 cracking or breaking, so that the battery cell 20 composed of the electrode assembly 23 has higher safety.
  • the first providing device 411 may include a first sub-providing mechanism 411a and a second sub-providing mechanism 411b.
  • the first sub-providing mechanism 411a is used to provide the first segment 2311, and the second sub-providing mechanism 411b For providing the second segment 2312.
  • the first sub-providing mechanism 411a may be an unwinding roller, used to provide the first segment 2311 of the first pole piece 231; the second sub-providing mechanism 411b may be an unwinding roller, used to provide the second section 2311 of the first pole piece 231. Section 2312. It should be noted that in this case, the first segment 2311 and the second segment 2312 are independent of each other.
  • the number of the first sub-providing mechanism 411a can be set to two and the number of the second sub-providing mechanism 411b can be set to two to ensure the supply requirements of the first section 2311 and the second section 2312 , ensuring the feeding progress of the first pole piece 231 and saving material changing time.
  • the diaphragm 233 includes a first diaphragm 233a and a second diaphragm 233b, and the diaphragm providing mechanism 42 is used to provide the first diaphragm 233a and the second diaphragm 233b; the winding device 400 also includes a first composite mechanism 431, The first composite mechanism 431 is located downstream of the first providing device 411 and the diaphragm providing mechanism 42.
  • the first composite mechanism 431 is used to composite the first diaphragm 233a, the first pole piece 231 and the second diaphragm 233b into the first pole piece assembly;
  • the first providing device 411 is configured to provide the first pole piece 231 in the following manner: the first segment 2311 enters the first composite mechanism 431 first, and the second segment 2312 enters the first composite mechanism after the first segment 2311 431;
  • the winding mechanism 44 is provided downstream of the first composite mechanism 431 and is used to wind the first pole piece assembly and the second pole piece 232 along the winding direction to form the electrode assembly 23.
  • the first composite mechanism 431 includes a pair of first composite rollers.
  • the first diaphragm 233a, the first pole piece 231 and the second diaphragm 233b are rolled by the pair of first composite rollers, so that the first pole piece 231 is connected to the first diaphragm.
  • 233a and the second diaphragm 233b form the first pole piece assembly.
  • the first segment 2311 enters the first composite mechanism 431 first
  • the second segment 2312 enters the first composite mechanism 431 after the first segment 2311
  • the first segment 2311 is first connected to the first diaphragm 233a and the second diaphragm 233b
  • the second section 2312 is connected to the first membrane 233a and the second membrane 233b after the first section 2311, so that the first section 2311 is located upstream of the second section 2312 in the winding direction from the inside to the outside.
  • the first diaphragm 233a, the first pole piece 231 and the second diaphragm 233b are combined to form the first pole piece assembly.
  • the first pole piece 231 is connected to the first diaphragm 233a and the second diaphragm 233b.
  • the second diaphragm 233b plays a positioning role in positioning the first pole piece 231, and the first diaphragm 233a and the second diaphragm 233b sandwich the second segment 2312 and then drive the second segment 2312 to wind, providing a coil for the second segment 2312.
  • the winding power is used to realize the sequential winding of the first segment 2311 and the second segment 2312.
  • the first providing device 411 further includes a first connection mechanism (not shown in the figure), the first connection mechanism is used to connect the tail of the first segment 2311 and the head of the second segment 2312 connected through the first connecting part.
  • the first connection part can be an adhesive tape
  • the first connection mechanism can be an adhesive application mechanism.
  • the adhesive application mechanism includes an adhesive tape providing component, a mechanical claw and a moving component.
  • the mechanical claw is used to clamp the tape
  • the moving component is used to drive the mechanical claw to move. Apply the tape to the first segment 2311 and the second segment 2312 on the mechanical claw, so that the tape connects the tail of the first segment 2311 and the head of the second segment 2312.
  • the first segment 2311 and the second segment 2312 are connected through the first connecting part.
  • the first segment 2311 can drive the second segment 2312 through the first connecting part, forming a second
  • the segment 2312 provides the power for winding, thereby realizing the sequential winding of the first segment 2311 and the second segment 2312.
  • the first connection part can also be glue
  • the first connection mechanism can also be a glue application mechanism.
  • the first connection mechanism applies glue to the tail of the first segment 2311 and the head of the second segment 2312 , so that the tail of the first segment 2311 and the head of the second segment 2312 are connected through glue.
  • Figure 16 is a schematic diagram of the first conveying mechanism 451 in the first conveying position provided by some embodiments of the present application
  • Figure 17 is a second conveying provided by some embodiments of the present application. Schematic illustration of mechanism 452 in the first delivery position.
  • the winding equipment 400 further includes: a first conveying mechanism 451 , a second conveying mechanism 452 and a first adjusting mechanism 453 .
  • the first conveying mechanism 451 is located between the first sub-providing mechanism 411a and the first composite mechanism 431.
  • the first conveying mechanism 451 is used to convey the first segment 2311 to the first composite mechanism 431 at the first conveying position; the second conveying mechanism The mechanism 452 is located between the second sub-providing mechanism 411b and the first composite mechanism 431.
  • the second conveying mechanism 452 is used to convey the second segment 2312 to the first compound mechanism 431 at the first conveying position; the first adjusting mechanism 453 is connected For the first conveying mechanism 451 and the second conveying mechanism 452, the first adjusting mechanism 453 is used to adjust the first conveying mechanism 451 or the second conveying mechanism 452 to the first conveying position.
  • the first conveying mechanism 451 and the second conveying mechanism 452 may have the same composition structure.
  • the first conveying mechanism 451 and the second conveying mechanism 452 may both include conveying rollers and conveying plates.
  • the first section 2311 and the second section 2312 respectively Conveyed by corresponding conveyor rollers and conveyor plates.
  • the first transport position refers to the position corresponding to the first pole piece 231 and the first composite mechanism 431. At the first transport position, the first pole piece 231 can be transported to the first composite mechanism 431 to be combined with the diaphragm 233 in the first composite position. Establishment 431 connections.
  • the first adjustment mechanism 453 can be a linear driving mechanism, for example, it can be a driving mechanism such as a hydraulic cylinder, a cylinder, an electric push rod, etc., or it can be a driving mechanism that cooperates with a motor and a transmission component.
  • the transmission component can be a rack and pinion, a screw, etc. Nuts and other transmission components.
  • the first adjustment mechanism 453 can also be another driving mechanism.
  • the first adjustment mechanism 453 can be a turntable.
  • the first conveying mechanism 451 and the second conveying mechanism 452 are both connected to the turntable, and the first conveying mechanism 451 and the second conveying mechanism 452 are driven by the turntable.
  • the second conveying mechanism 452 rotates, thereby causing the first conveying mechanism 451 or the second conveying mechanism 452 to adjust to the first conveying position.
  • the first conveying mechanism 451 when the first conveying mechanism 451 is at the first conveying position, the first conveying mechanism 451 conveys the first segment 2311 to the first composite mechanism 431. At this time, the second conveying mechanism 452 is at the first conveying position. The avoidance position is to avoid interference between the second conveying mechanism 452 and the first conveying mechanism 451 . As shown in Figure 17, when the second conveying mechanism 452 is in the first conveying position, the second conveying mechanism 452 conveys the second segment 2312 to the first composite mechanism 431. At this time, the first conveying mechanism 451 is in the second conveying position. The avoidance position is to avoid interference between the first conveying mechanism 451 and the second conveying mechanism 452 .
  • the second avoidance position and the first avoidance position are on both sides of the first conveying position, that is, along the action trajectory of the first adjustment mechanism 453, the first avoidance position, the first conveying position and the second avoidance position are The positions are set in sequence.
  • the positions of the first conveying mechanism 451 and the second conveying mechanism 452 are adjusted by the first adjusting mechanism 453, so that the first conveying mechanism 451 conveys the first segment 2311 to the first composite mechanism 431, or the second conveying mechanism 452 conveys the first segment 2311 to the first composite mechanism 431, or the second conveying mechanism 452 conveys
  • the second segment 2312 is transported to the first composite mechanism 431 to ensure the transportation efficiency of the first pole piece 231 and thus the production efficiency of the electrode assembly 23 .
  • the number of the first adjustment mechanism 453 can be one, and the first adjustment mechanism 453 is used to synchronously adjust the positions of the first conveying mechanism 451 and the second conveying mechanism 452; or, the number of the first adjusting mechanism 453 can be Two, one of the first adjusting mechanisms 453 is used to adjust the position of the first conveying mechanism 451, and the other first adjusting mechanism 453 is used to adjust the position of the second conveying mechanism 452.
  • the winding device 400 further includes a first caching mechanism 461 and a second caching mechanism 462.
  • the first caching mechanism 461 is disposed between the first sub-providing mechanism 411a and the second caching mechanism 462.
  • the first buffer mechanism 461 is used to buffer the first segment 2311, so as to ensure the continuous feeding of the first segment 2311 when the first adjustment mechanism 453 adjusts the position of the first conveying mechanism 451;
  • the second buffer mechanism 462 is provided between the second sub-providing mechanism 411b and the first adjusting mechanism 453.
  • the second buffering mechanism 462 is used to buffer the second segment 2312, so as to ensure that the first adjusting mechanism 453 adjusts the position of the second conveying mechanism 452.
  • the second section 2312 continuously feeds materials.
  • the first buffering mechanism 461 and the second buffering mechanism 462 can both be swing-bar buffering mechanisms, which include multiple swing-bars, and the distance between the corresponding first pole pieces is changed by adjusting the distance between two adjacent swing-bars.
  • the length of the corresponding cache mechanism is used to realize the cache of the first pole piece.
  • the winding equipment 400 further includes a first correction mechanism 471 and a second correction mechanism 472.
  • the first correction mechanism 471 is disposed between the first sub-providing mechanism 411a and the second correction mechanism 472.
  • the first correction mechanism 471 is used to correct the first segment 2311 to ensure the conveying accuracy of the first segment 2311;
  • the second correction mechanism 472 is provided between the second sub-providing mechanism 411b and the first conveying mechanism.
  • the second correction mechanism 472 is used to correct the second segment 2312 to ensure the conveying accuracy of the second segment 2312.
  • the first correction mechanism 471 and the second correction mechanism 472 may refer to the correction devices in the prior art, which will not be described in detail in this application.
  • a first cutting mechanism 481 is provided upstream of the first composite mechanism 431, and the first cutting mechanism 481 is used to cut the first segment 2311 or the first segment 2311.
  • the two sections 2312 are used to facilitate the first adjusting mechanism 453 to adjust the positions of the first conveying mechanism 451 and the second conveying mechanism 452 .
  • the first cutting mechanism 481 may refer to the cutting device in the prior art, which will not be described in detail in this application.
  • the winding equipment 400 also includes a first image detection system 491 and a first pre-rolling correction mechanism 492.
  • the first image detection system 491 and the first winding The front correction mechanism 492 is provided between the first composite mechanism 431 and the winding mechanism 44.
  • the first image detection system 491 is used to obtain the image information of the first pole piece 231 and the diaphragm 233 after the first composite mechanism 431 composites.
  • the first The deflection correction mechanism 492 before rolling is used to correct the first pole piece 231 and the diaphragm 233 .
  • the first image detection system 491 can be a CCD (charge coupled device) camera; the first pre-rolling correction mechanism 492 can refer to the correction device of the prior art, which will not be introduced in detail in this application.
  • the winding equipment 400 further includes a first pre-roll tension system 511 , which is disposed upstream of the winding mechanism 44 for adjustment.
  • the first pre-winding tension system 511 includes a first tension roller and a first adjustment member. The first adjustment member is used to adjust the position of the first tension roller to change the tension of the first pole piece 231 .
  • FIG. 18 is a schematic structural diagram of a winding device 400 provided by other embodiments of the present application.
  • the second pole piece 232 includes a third segment 2321 and a fourth segment 2322; the third segment 2321 is provided with a third active material layer 2321a; The fourth segment 2322 is provided with a fourth active material layer 2322a; wherein the second providing device 412 is configured to provide the second pole piece 232 in the following manner: the third segment 2321 enters the winding mechanism 44 first, so that the The fourth segment 2322 enters the winding mechanism 44 after the third segment 2321 .
  • the third segment 2321 and the fourth segment 2322 can be processed differently respectively, so that the third segment 2321 and the fourth segment 2322 have different physical properties or chemical properties, which can be better adjusted through differentiated internal and external configurations. Performance of electrode assembly 23.
  • the coating density of the third active material layer 2321a is different from the coating density of the fourth active material layer 2322a; and/or, the thickness of the third active material layer 2321a is different from that of the fourth active material layer 2322a. have different thicknesses; and/or, the active material material of the third active material layer 2321a is the same as or different from the active material material of the fourth active material layer 2322a.
  • the physical properties or chemical properties of the third segment 2321 and the fourth segment 2322 can be changed by changing the coating density, thickness and active material material formula of the third active material layer 2321a and the fourth active material layer 2322a, so that The electrode assembly 23 meets different performance requirements and is suitable for different usage scenarios.
  • the coating density of the third active material layer 2321a is smaller than the coating density of the fourth active material layer 2322a.
  • the second pole piece 232 includes a third segment 2321 and a fourth segment 2322.
  • the coating density of the third active material layer 2321a is smaller than the coating density of the fourth active material layer 2322a, so that the fracture toughness of the third segment 2321 is greater than
  • the fracture toughness of the fourth segment 2322 and the bending area 235 of the third segment 2321 are not prone to cracks or fractures, which reduces the probability of cracks or fractures in the second pole piece 232, making the battery cell 20 composed of the electrode assembly 23 Has higher security.
  • the second providing device 412 may include a third sub-providing mechanism 412a and a fourth sub-providing mechanism 412b.
  • the third sub-providing mechanism 412a is used to provide the third segment 2321
  • the fourth sub-providing mechanism 412b is used to provide the fourth segment 2322.
  • the third sub-providing mechanism 412a may be an unwinding roller, used to provide the third segment 2321 of the second pole piece 232; the fourth sub-providing mechanism 412b may be an unwinding roller, used to provide the fourth section 2321 of the second pole piece 232. Section 2322. It should be noted that in this case, the third segment 2321 and the fourth segment 2322 are independent of each other.
  • the number of the third sub-providing mechanism 412a can be set to two, and the number of the fourth sub-providing mechanism 412b can be set to two to ensure the supply requirements of the third section 2321 and the fourth section 2322. , ensuring the feeding progress of the second pole piece 232 and saving material changing time.
  • the membrane 233 includes a first membrane 233a and a second membrane 233b
  • the winding device 400 includes two membrane providing mechanisms 42, one membrane providing mechanism 42 is used to provide the first membrane 233a, and the other membrane provides Mechanism 42 is used to provide a second diaphragm 233b.
  • the winding device 400 also includes a first compounding mechanism 431 and a second compounding mechanism 432 .
  • the first compounding mechanism 431 is located downstream of the first providing device 411 and a diaphragm providing mechanism 42.
  • the first compounding mechanism 431 is used to compound the first pole piece 231 and the first diaphragm 233a into the first pole piece assembly.
  • the second compounding mechanism 432 is located downstream of the second providing device 412 and another diaphragm providing mechanism 42.
  • the second compounding mechanism 432 is used to compound the second pole piece 232 and the second diaphragm 233b into a second pole piece assembly.
  • the first providing device 411 is configured to provide the first pole piece 231 in the following manner: the first segment 2311 enters the first composite mechanism 431 first, and the second segment 2312 enters the first composite mechanism after the first segment 2311 431;
  • the winding mechanism 44 is provided downstream of the first composite mechanism 431 and the second composite mechanism 432, and is used to roll the first pole piece assembly and the second pole piece assembly along the winding direction to form the electrode assembly 23.
  • the first pole piece 231 and the first diaphragm 233a are combined into the first pole piece assembly through the first compounding mechanism 431, so that the first pole piece 231 is positioned through the first diaphragm 233a, and the second pole piece 231 is positioned through the second compounding mechanism 432.
  • the diode piece 232 and the second diaphragm 233b are combined into a second pole piece assembly, so as to facilitate the positioning of the second pole piece 232 through the second diaphragm 233b, thereby ensuring that the first pole piece 231 and the first pole piece 231 in the rolled electrode assembly 23 are
  • the second pole piece 232 is separated by the first separator 233a and the second separator 233b to prevent the first pole piece 231 and the second pole piece 232 from contacting and causing a short circuit, ensuring the safety of the battery cell 20 composed of the electrode assembly 23.
  • the composite of the first pole piece 231 and the first diaphragm 233a is called the first pole piece assembly.
  • the first segment 2311 is composited with the first diaphragm 233a first
  • the second segment 2312 is composited with the first diaphragm 233a after the first segment 2311.
  • the first diaphragm 233a provides winding power for the first segment 2311 and the second segment 2312. Driven by the first diaphragm 233a, the first segment 2311 and the second segment 2312 are wound in sequence.
  • the second providing device 412 is configured to provide the second pole piece 232 in the following manner: the third section 2321 enters the first section.
  • the second composite mechanism 432 allows the fourth segment 2322 to enter the second composite mechanism 432 after the third segment 2321.
  • the third segment 2321 enters the second composite mechanism 432 first, and the fourth segment 2322 enters the second composite mechanism 432 after the third segment 2321.
  • the third segment 2321 is first connected to the second diaphragm 233b, and the fourth segment 2322
  • the third section 2321 is connected to the second membrane 233b behind it, so that in the winding direction from the inside to the outside, the third section 2321 is located upstream of the fourth section 2322.
  • the composite of the second pole piece 232 and the second diaphragm 233b is called the second pole piece assembly.
  • the third segment 2321 is composited with the second diaphragm 233b first
  • the fourth segment 2322 is composited with the second diaphragm 233b after the third segment 2321.
  • the second diaphragm 233b provides winding power for the third segment 2321 and the fourth segment 2322.
  • the third segment 2321 and the fourth segment 2322 are wound in sequence.
  • Figure 19 is a schematic diagram of the third conveying mechanism 454 in the second conveying position provided by some embodiments of the present application.
  • Figure 20 is a fourth conveying mechanism provided by some embodiments of the present application. Schematic illustration of mechanism 455 in the second transport position.
  • the winding device 400 further includes: a third conveying mechanism 454 , a fourth conveying mechanism 455 and a second adjusting mechanism 456 .
  • the third conveying mechanism 454 is located between the third sub-providing mechanism 412a and the second compounding mechanism 432.
  • the third conveying mechanism 454 is used to convey the third segment 2321 to the second compounding mechanism 432 at the second conveying position; the fourth conveying The mechanism 455 is located between the fourth sub-providing mechanism 412b and the second compound mechanism 432.
  • the fourth conveying mechanism 455 is used to convey the fourth segment 2322 to the second compound mechanism 432 at the second conveying position; the second adjusting mechanism 456 is connected For the third conveying mechanism 454 and the fourth conveying mechanism 455, the second adjusting mechanism 456 is used to adjust the third conveying mechanism 454 or the fourth conveying mechanism 455 to the second conveying position.
  • the third conveying mechanism 454 and the fourth conveying mechanism 455 may have the same composition structure.
  • the third conveying mechanism 454 and the fourth conveying mechanism 455 may both include conveying rollers and conveying plates.
  • the third section 2321 and the fourth section 2322 respectively Conveyed by corresponding conveyor rollers and conveyor plates.
  • the second transport position refers to the position corresponding to the second pole piece 232 and the second composite mechanism 432.
  • the second pole piece 232 can be transported to the second composite mechanism 432 to be combined with the diaphragm 233 in the second composite position. Establishment 432 connections.
  • the second adjustment mechanism 456 can be a linear driving mechanism, for example, it can be a driving mechanism such as a hydraulic cylinder, a pneumatic cylinder, an electric push rod, etc., or it can be a driving mechanism that cooperates with a motor and a transmission component, and the transmission component can be a rack and pinion, a screw, etc. Nuts and other transmission components.
  • the second adjustment mechanism 456 can also be another driving mechanism.
  • the second adjustment mechanism 456 can be a turntable.
  • the third conveyor mechanism 454 and the fourth conveyor mechanism 455 are both connected to the turntable, and the third conveyor mechanism 454 and the fourth conveyor mechanism 455 are driven by the turntable.
  • the fourth conveying mechanism 455 rotates, thereby causing the third conveying mechanism 454 or the fourth conveying mechanism 455 to adjust to the second conveying position.
  • the third conveying mechanism 454 conveys the third segment 2321 to the second composite mechanism 432.
  • the fourth conveying mechanism 455 is in the third conveying position.
  • the avoidance position is to avoid interference between the fourth conveying mechanism 455 and the third conveying mechanism 454 .
  • the fourth conveying mechanism 455 conveys the fourth segment 2322 to the second composite mechanism 432.
  • the third conveying mechanism 454 is in the fourth conveying position.
  • the avoidance position is to avoid interference between the third conveying mechanism 454 and the fourth conveying mechanism 455 .
  • the fourth avoidance position and the third avoidance position are on both sides of the second conveying position, that is, along the action trajectory of the second adjustment mechanism 456, the third avoidance position, the second conveying position and the fourth avoidance position are The positions are set in sequence.
  • the positions of the third conveying mechanism 454 and the fourth conveying mechanism 455 are adjusted through the second adjusting mechanism 456, so that the third conveying mechanism 454 conveys the third segment 2321 to the second composite mechanism 432, or the fourth conveying mechanism 455 conveys The fourth segment 2322 is transported to the second composite mechanism 432 to ensure the transport efficiency of the first pole piece 231 and thus the production efficiency of the electrode assembly 23 .
  • the number of the second adjusting mechanism 456 may be one, and the second adjusting mechanism 456 is used to synchronously adjust the positions of the third conveying mechanism 454 and the fourth conveying mechanism 455; or, the number of the second adjusting mechanism 456 may be Two, one of the second adjustment mechanisms 456 is used to adjust the position of the third conveying mechanism 454, and the other second adjustment mechanism 456 is used to adjust the position of the fourth conveying mechanism 455.
  • the winding device 400 further includes a third caching mechanism 463 and a fourth caching mechanism 464.
  • the third caching mechanism 463 is disposed between the third sub-providing mechanism 412a and the second adjusting mechanism 456.
  • the caching mechanism 463 is used to cache the third segment 2321 to ensure continuous feeding of the third segment 2321 when the second adjustment mechanism 456 adjusts the position of the third conveying mechanism 454; the fourth caching mechanism 464 is provided at the fourth sub-providing mechanism 412b Between the fourth adjusting mechanism 456 and the second adjusting mechanism 456, the fourth buffering mechanism 464 is used to buffer the fourth segment 2322, so as to ensure continuous feeding of the fourth segment 2322 when the second adjusting mechanism 456 adjusts the position of the fourth conveying mechanism 455.
  • the third buffering mechanism 463 and the fourth buffering mechanism 464 can both be swing-bar buffering mechanisms, which include multiple swing-bars, and the distance between the corresponding second pole pieces is changed by adjusting the distance between two adjacent swing-bars. Part of the length of the corresponding cache mechanism is used to realize the cache of the second pole piece.
  • the winding equipment 400 further includes a third correction mechanism 473 and a fourth correction mechanism 474.
  • the third correction mechanism 473 is provided between the third sub-providing mechanism 412a and the third correction mechanism 474.
  • the third correcting mechanism 473 is used to correct the third section 2321 to ensure the conveying accuracy of the third section 2321;
  • the fourth correcting mechanism 474 is provided between the fourth sub-providing mechanism 412b and the third conveying mechanism.
  • the fourth correction mechanism 474 is used to correct the deviation of the fourth segment 2322 to ensure the conveying accuracy of the fourth segment 2322.
  • the third correction mechanism 473 and the fourth correction mechanism 474 may refer to the correction devices in the prior art, and will not be described in detail in this application.
  • a second cutting mechanism 482 is provided upstream of the second composite mechanism 432, and the second cutting mechanism 482 is used to cut the third segment 2321 or the third section.
  • Four sections 2322 are used to facilitate the second adjustment mechanism 456 to adjust the positions of the third conveying mechanism 454 and the fourth conveying mechanism 455 .
  • the second cutting mechanism 482 may refer to the cutting device in the prior art, which will not be described in detail in this application.
  • the winding equipment 400 also includes a second image detection system 493 and a second pre-rolling correction mechanism 494.
  • the second image detection system 493 and the second winding The front correction mechanism 494 is disposed between the second composite mechanism 432 and the winding mechanism 44.
  • the second image detection system 493 is used to obtain the image information of the second pole piece 232 and the diaphragm 233 composited by the second composite mechanism 432.
  • the second The deflection correction mechanism 494 before rolling is used to correct the second pole piece 232 and the diaphragm 233 .
  • the second image detection system 493 can be a CCD camera; the second pre-rolling correction mechanism 494 can refer to the correction device in the prior art, which will not be described in detail in this application.
  • the winding device 400 further includes a second pre-roll tension system 512 , and the second pre-roll tension system 512 is provided upstream of the winding mechanism 44 for adjusting The tension of the second pole piece 232.
  • the second pre-winding tension system 512 includes a second tension roller and a second adjustment member. The second adjustment member is used to adjust the position of the second tension roller to change the tension of the second pole piece 232 .
  • the winding equipment 400 also includes a diaphragm cutter 52, a finishing press wheel 53 and a gluing press wheel 54.
  • the diaphragm cutter 52, the finishing press wheel 53 and the gluing press wheel 54 are The glue rollers 54 are arranged at the winding mechanism 44.
  • the diaphragm cutter 52 is used to cut the diaphragm 233 after the electrode assembly 23 is rolled and formed; the finishing roller 53 is used to roll the wound electrode assembly 23 to prevent winding.
  • the final electrode assembly 23 is loose; the glue applying pressure wheel 54 is used to apply finishing glue to the wound electrode assembly 23 .
  • a compaction station 55 is usually provided downstream of the winding mechanism 44 to compact the wound electrode assembly 23 to ensure that the battery cell 20 composed of the electrode assembly 23 has a high energy density.
  • FIG 21 shows a schematic flow chart of a winding method 600 provided by some embodiments of the present application.
  • the winding method 600 may include:
  • the first pole piece 231 includes a first segment 2311 and a second segment 2312.
  • the first segment 2311 is provided with a first active material layer 2311a
  • the second segment 2312 is provided with a first active material layer 2311a.
  • step “604 wind the first segment 2311, the second segment 2312, the diaphragm 233 and the second pole piece 232 along the winding direction"
  • the winding direction is from inside to outside. direction
  • the first segment 2311 is located upstream of the second segment 2312.
  • the coating density of the first active material layer 2311a is different from the coating density of the second active material layer 2312a; and/or the thickness of the first active material layer 2311a is different from that of the second active material layer 2312a.
  • the thicknesses are different; and/or the active material material of the first active material layer 2311a is the same as or different from the active material material of the second active material layer 2312a.
  • the coating density of the first active material layer 2311a is smaller than the coating density of the second active material layer 2312a.

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Abstract

本申请涉及一种电极组件、电池单体、电池、用电设备、卷绕设备及方法，属于电池技术领域。电极组件包括极性相反的第一极片和第二极片，所述第一极片和所述第二极片层叠并沿卷绕方向卷绕形成所述电极组件；所述第一极片包括第一分段和第二分段，所述第一分段上设有第一活性物质层，所述第二分段上设有第二活性物质层，沿由内至外的卷绕方向，所述第一分段位于所述第二分段的上游。该电极组件，能够根据性能需求分段差异化处理，满足不同的性能需求。

Description

电极组件、电池单体、电池、用电设备、卷绕设备及方法
相关申请的交叉引用
本申请要求享有于2022年03月31日提交的名称为“电极组件、电池单体、电池、用电设备、卷绕设备及方法”的中国专利申请202210335343.8的优先权，该申请的全部内容通过引用并入本文中。
技术领域
本申请涉及电池技术领域，特别是涉及一种电极组件、电池单体、电池、用电设备、卷绕设备及方法。
背景技术
节能减排是汽车产业可持续发展的关键，电动车辆由于其节能环保的优势成为汽车产业可持续发展的重要组成部分。对于电动车辆而言，电池技术又是关乎其发展的一项重要因素。
电池包括至少一个电池单体，电池单体包括电极组件，电极组件通常由正极极片和负极极片卷绕而成，极片的性能决定电极组件的性能。相关技术中，电极组件的性能较差，无法差异化处理。
发明内容
本申请的目的在于提供一种电极组件、电池单体、电池、用电设备、卷绕设备及方法。该电极组件，能够根据性能需求分段处理，满足不同的性能需求。
本申请是通过如下技术方案实现的：
第一方面，本申请提供了一种电极组件，包括极性相反的第一极片和第二极片，所述第一极片和所述第二极片层叠并沿卷绕方向卷绕形成所述电极组件；所述第一极片包括第一分段和第二分段，所述第一分段上设有第一活性物质层，所述第二分段上设有第二活性物质层，沿由内至外的卷绕方向，所述第一分段位于所述第二分段的上游。
根据本申请实施例的电极组件，第一极片包括第一分段和第二分段，沿由内至外的卷绕方向，第一分段位于第二分段的上游通过将第一极片分为第一分段和第二分段，可以对处于内圈的第一分段和处于外圈的第二分段分别做不同的处理，使第一分段和第二分段具备不同的物理性能或者化学性能，通过内外差异化配置以更好地调节电极组件的性能，满足不同的性能需求。
根据本申请的一些实施例，所述第一活性物质层的涂敷密度与所述第二活性物质层的涂敷密度不同。
在上述方案中，第一活性物质层的涂敷密度与第二活性物质层的涂敷密度不同，可以调节电极组件的能量密度，满足电极组件的不同的能量密度需求。
根据本申请的一些实施例，所述第一活性物质层的涂敷密度小于所述第二活性物质层的涂敷密度。
在上述方案中，第一活性物质层的涂敷密度小于第二活性物质层的涂敷密度，第一分段的断裂韧性大于第二分段的断裂韧性，使得第一分段的弯折区不易产生裂纹或断裂，降低了第一极片产生裂纹或断裂的概率，进而提高了该电极组件构成的电池单体的安全性。
根据本申请的一些实施例，所述第一活性物质层的厚度与所述第二活性物质层的厚度比为1/2-3/2。
在上述方案中，在满足第一活性物质层的涂敷密度小于第二活性物质层的涂敷密度的情况下，第一活性物质层的厚度与第二活性物质层的厚度比满足上述范围，保证第一分段和第二分段的过渡处不会出现台阶，避免活性物质脱落或者导致压痕，保证电极组件的质量。
根据本申请的一些实施例，所述第一活性物质层的活性物质材料与所述第二活性物质层的活性物质材料相同或者不同。
在上述方案中，第一活性物质层的活性物质材料与第二活性物质层的活性物质材料不同，能够调整第一分段和第二分段的性能，以满足电极组件具有不同物理性能或者化学性能。
根据本申请的一些实施例，沿由内至外的卷绕方向，所述第一分段的尾部和所述第二分段的头部相连接或者所述第一分段的尾部和所述第二分段的头部之间设有间隙。
在上述方案中，在第一分段的尾部和第二分段的头部相连接的实施例中，便于保证第一极片的连续性，第一极片具有较多的活性物质，保证电极组件具有较高的能量密度；在第一分段的尾部和第二分段的头部之间设有间隙的实施例中，可以便于第一分段和第二分段的加工，降低第一极片的制造难度。
根据本申请的一些实施例，所述第一极片还包括第一集流体，所述第一活性物质层和所述第二活性物质层分别设于所述第一集流体上。
根据本申请的一些实施例，所述第一极片还包括第一集流体分段和第二集流体分段，所述第一活性物质层设于所述第一集流体分段上以形成所述第一分段，所述第二活性物质层设于所述第二集流体分段上以形成所述第二分段。
在上述方案中，第一活性物质层设于第一集流体分段上形成第一分段，第二活性物质层设于第二集流体分段上形成第二分段，便于实现第一分段和第二分段的加工制造。
根据本申请的一些实施例，所述第一分段的尾部和所述第二分段的头部通过第一连接部相连接。
在上述方案中，通过第一连接部连接第一分段和第二分段，实现对第一分段和第二分段的定位，限制第一分段和第二分段发生位置移动，在第一分段被卷绕时，可由第一分段通过第一连接部带动第二分段，为第二分段提供卷绕的动力，进而实现第一分段和第二分段的依次卷绕。
根据本申请的一些实施例，所述电极组件还包括隔膜，用于分隔所述第一极片和所述第二极片。
在上述方案中，通过隔膜分隔第一极片和第二极片，避免第一极片和第二极片接触短路，提高安全性。
根据本申请的一些实施例，所述第二分段的头部连接于所述隔膜。
在上述方案中，第二分段的头部连接于隔膜，通过隔膜实现对第二分段的头部的定位，限制第一分段和第二分段发生位置移动，在卷绕时，可由隔膜带动第二分段的头部卷入，为第二分段提供卷绕的动力，以实现第一分段和第二分段的依次卷绕。
根据本申请的一些实施例，所述第二极片包括第三分段和第四分段；所述第三分段上设有第三活性物质层；所述第四分段上设有第四活性物质层；沿由内至外的卷绕方向，所述第三分段位于所述第四分段的上游。
在上述方案中，通过将第二极片分为第三分段和第四分段，可以对处于内圈的第三分段和处于外圈的第四分段分别做不同的处理，使第三分段和第四分段具备不同的物理性能或者化学性能，通过内外差异化配置以更好地调节电极组件的性能。
根据本申请的一些实施例，所述第三活性物质层的涂敷密度与所述第四活性物质层的涂敷密度不同；和/或，所述第三活性物质层的厚度与所述第四活性物质层的厚度不同；和/或，所述第三活性物质层的活性物质材料与所述第四活性物质层的活性物质材料相同或者不同。
在上述方案中，可以通过改变第三活性物质层和第四活性物质层的涂敷密度、厚度以及活性物质材料配方，来改变第三分段和第四分段的物理性能或化学性能，以使得电极组件满足不同的性能需求，适用于不同的使用场景。
根据本申请的一些实施例，所述第三活性物质层的厚度与所述第四活性物质层的厚度比为1/2-3/2。
在上述方案中，在保证第三活性物质层的涂敷密度小于第四活性物质层的涂敷密度的情况下，第三活性物质层的厚度与第四活性物质层的厚度比满足上述范围，保证第三分段和第四分段过渡处不会出现台阶，避免活性物质脱落或者导致压痕，保证电极组件的质量。
根据本申请的一些实施例，沿由内至外的卷绕方向，所述第三分段的尾部和所述第四分段的头部相连接或者所述第三分段的尾部和所述第四分段的头部之间设有间隙。
在上述方案中，在第三分段的尾部和第四分段的头部相连接的实施例中，便于保证第二极片的连续性，第二极片具有较多的活性物质，保证电极组件具有较高的能量密度；在第三分段的尾部和第四分段的头部之间设有间隙的实施例中，可以便于第三分段和第四分段的加工，降低第二极片的制造难度。
根据本申请的一些实施例，所述第二极片还包括第二集流体，所述第三活性物质层和所述第四活性物质层分别设于所述第二集流体上。
根据本申请的一些实施例，所述第二极片还包括第三集流体分段和第四集流体分段，所述第三活性物质层设于所述第三集流体分段上以形成所述第三分段，所述第四活性物质层设于所述第四集流体分段上以形成所述第四分段。
在上述方案中，第三活性物质层设于第三集流体分段上形成第三分段，第四活性物质层设于第四集流体分段上形成第四分段，便于实现第三分段和第四分段的加工制造。
根据本申请的一些实施例，所述第三分段的尾部和所述第四分段的头部通过第二连接部相连接。
在上述方案中，通过第二连接部连接第三分段和第四分段，实现对第三分段和第四分段的定位，限制第三分段和第四分段发生位置移动，在第三分段被卷绕时，可由第三分段通过第二连接部带动第四分段，为第四分段提供卷绕的动力，进而实现第三分段和第四分段的依次卷绕。
根据本申请的一些实施例，所述电极组件还包括隔膜，用于分隔所述第一极片和所述第二极片，所述第四分段的头部连接于所述隔膜。
在上述方案中，第四分段的头部连接于隔膜，通过隔膜实现对第四分段的头部的定位，限制第三分段和第四分段发生位置移动，在卷绕时，可由隔膜带动第四分段的头部卷入，为第四分段提供卷绕的动力，以实现第三分段和第四分段的依次卷绕。
根据本申请的一些实施例，所述电极组件包括两个所述隔膜，两个所述隔膜分别位于所述第二极片的两侧，所述第二分段的头部与一个所述隔膜连接，所述第四分段的头部与另一个所述隔膜连接。
在上述方案中，一个隔膜连接第二分段的头部，另一个隔膜连接第四分段的头部，一个隔膜限制第二分段的位置，另一个隔膜限制第四分段的位置。在卷绕成型电极组件时，可由一个隔膜带动第二分段的头部卷入，为第二分段提供卷绕的动力，以实现第一分段和第二分段的依次卷绕；可由另一个隔膜带动第四分段的头部卷入，为第四分段提供卷绕的动力，以实现第三分段和第四分段的依次卷绕。
根据本申请的一些实施例，所述第三分段的圈数小于所述第四分段的圈数。
在上述方案中，第三分段的圈数小于第四分段的圈数，换句话说，第四活性物质层的卷绕圈数大于第三活性物质层的卷绕圈数，由于第四活性物质层的涂敷密度小于第三活性物质层的涂敷密度，在同等电极组件厚度的情况下，第四活性物质层的卷绕圈数占比较多，能够保证电极组件具有较高的能量密度。
根据本申请的一些实施例，所述第一分段的圈数小于所述第二分段的圈数。
在上述方案中，第一分段的圈数小于第二分段的圈数，以保证电极组件具有较高的能量密度。
根据本申请的一些实施例，所述第二活性物质层的涂敷密度比所述第一活性物质层的涂敷密度大10％-200％。
在上述方案中，第二活性物质层的涂敷密度比第一活性物质层的涂敷密度大，保证第一极片具有较多的活性物质，进而保证该电极组件构成的电池具有较大的能量密度。
第二方面，本申请提供了一种电池单体，其包括上述实施例中的电极组件。
第三方面，本申请提供了一种电池，其包括上述实施例中的电池单体。
第四方面，本申请提供了一种用电设备，其包括上述实施例中的电池。
第五方面，本申请提供了一种卷绕设备，所述卷绕设备包括：第一提供装置，用于提供第一极片，所述第一极片包括第一分段和第二分段；所述第一分段上设有第一活性物质层；所述第二分段上设有第二活性物质层；第二提供装置，用于提供与所述第一极片的极性相反的第二极片；隔膜提供机构，用于提供隔膜；卷绕机构，设置于所述第一提供装置、所述第二提供装置和所述隔膜提供机构的下游，用于将所述第一分段、所述第二分段、所述隔膜和所述第二极片沿卷绕方向卷绕，以形成电极组件；其中，所述第一提供装置被配置为以如下方式提供所述第一极片：使所述第一分段先进入所述卷绕机构，使所述第二分段在所述第一分段之后进入所述卷绕机构。
根据本申请实施例的卷绕设备，卷绕机构将第一分段、第二分段、隔膜及第二极片卷绕形成电极组件，可以对第一分段和第二分段分别做不同的处理，使得第一分段和第二分段具备不同的物理性能或者化学性能，通过内外差异化配置以更好地调节电极组件的性能。
根据本申请的一些实施例，所述第一活性物质层的涂敷密度与所述第二活性物质层的涂敷密度不同；和/或所述第一活性物质层的厚度与所述第二活性物质层的厚度不同；和/或所述第一活性物质层的活性物质材料与所述第二活性物质层的活性物质材料相同或者不同。
在上述方案中，可以通过改变第一活性物质层和第二活性物质层的涂敷密度、厚度以及活性物质材料配合，来改变第一分段和第二分段的物理性能或化学性能，以使得电极组件满足不同的性能需求，适用于不同的使用场景。
根据本申请的一些实施例，所述第二极片包括第三分段和第四分段；所述第三分段上设有第三活性物质层；所述第四分段上设有第四活性物质层；其中，所述第二提供装置被配置为以如下方式提供所述第二极片：使所述第三分段先进入所述卷绕机构，使所述第四分段在所述第三分段之后进入所述卷绕机构。
在上述方案中，可以对第三分段和第四分段分别做不同的处理，使得第三分段和第四分段具备不同的物理性能或者化学性能，通过内外差异化配置以更好地调节电极组件的性能。
根据本申请的一些实施例，所述第三活性物质层的涂敷密度与所述第四活性物质层的涂敷密度不同；和/ 或，所述第三活性物质层的厚度与所述第四活性物质层的厚度不同；和/或，所述第三活性物质层的活性物质材料与所述第四活性物质层的活性物质材料相同或者不同。
在上述方案中，可以通过改变第三活性物质层和第四活性物质层的涂敷密度、厚度以及活性物质材料配方，来改变第三分段和第四分段的物理性能或化学性能，以使得电极组件满足不同的性能需求，适用于不同的使用场景。
根据本申请的一些实施例，所述隔膜包括第一隔膜和第二隔膜，所述隔膜提供机构用于提供所述第一隔膜和所述第二隔膜；所述卷绕设备还包括第一复合机构，所述第一复合机构位于所述第一提供装置和所述隔膜提供机构的下游，所述第一复合机构用于将所述第一隔膜、所述第一极片和所述第二隔膜复合成为第一极片组件；所述第一提供装置被配置为以如下方式提供所述第一极片：使所述第一分段先进入所述第一复合机构，使所述第二分段在所述第一分段之后进入所述第一复合机构；所述卷绕机构，设置于所述第一复合机构的下游，用于将所述第一极片组件和所述第二极片沿卷绕方向卷绕，以形成电极组件。
在上述方案中，第一隔膜、第一极片和第二隔膜复合成为第一极片组，第一隔膜和第二隔膜对第一极片起到定位作用，并由第一隔膜和第二隔膜夹住第二分段进而带动第二分段卷入，为第二分段提供卷绕的动力，进而实现第一分段和第二分段的依次卷入。
根据本申请的一些实施例，所述第一提供装置包括第一连接机构，所述第一连接机构用于将所述第一分段的尾部和所述第二分段的头部通过第一连接部相连接。
在上述方案中，通过第一连接部连接第一分段和第二分段，在第一分段被卷绕时，可由第一分段通过第一连接部带动第二分段，为第二分段提供卷绕的动力，进而实现第一分段和第二分段的依次卷绕。
根据本申请的一些实施例，所述隔膜包括第一隔膜和第二隔膜，所述卷绕设备包括两个所述隔膜提供机构，一个所述隔膜提供机构用于提供所述第一隔膜，另一个所述隔膜提供机构用于提供所述第二隔膜；所述卷绕设备还包括：第一复合机构，位于所述第一提供装置和一个所述隔膜提供机构的下游，所述第一复合机构用于将所述第一极片和所述第一隔膜复合成为第一极片组件；第二复合机构，位于所述第二提供装置和另一个所述隔膜提供机构的下游，所述第二复合机构用于将所述第二极片和所述第二隔膜复合成为第二极片组件；所述第一提供装置被配置为以如下方式提供所述第一极片：使所述第一分段先进入所述第一复合机构，使所述第二分段在所述第一分段之后进入所述第一复合机构；所述卷绕机构设置于所述第一复合机构和所述第二复合机构的下游，用于将所述第一极片组件和所述第二极片组件沿卷绕方向卷绕，以形成电极组件。
在上述方案中，通过第一复合机构将第一极片和第一隔膜复合成为第一极片组件，以便于通过第一隔膜实现对第一极片的定位，通过第二复合机构将第二极片和第二隔膜复合成为第二极片组件，以便于通过第二隔膜实现对第二极片的定位，进而保证卷绕成型的电极组件中第一极片和第二极片被第一隔膜和第二隔膜分隔，避免第一极片和第二极片接触而引发短路，保证电极组件构成的电池单体的安全性。
第六方面，本申请提供了一种卷绕方法，所述卷绕方法包括：提供第一极片，所述第一极片包括第一分段和第二分段，所述第一分段上设有第一活性物质层，所述第二分段上设有第二活性物质层；提供第二极片，所述第二极片的极性与所述第一极片的极性相反；提供隔膜；将所述第一分段、所述第二分段、所述隔膜和所述第二极片沿卷绕方向卷绕，以形成电极组件，其中，所述第一分段先与所述隔膜和所述第二极片卷绕，所述第二分段在所述第一分段之后与所述隔膜和所述第二极片卷绕。
根据本申请的一些实施例，所述第一活性物质层的涂敷密度与所述第二活性物质层的涂敷密度不同；和/或所述第一活性物质层的厚度与所述第二活性物质层的厚度不同；和/或所述第一活性物质层的活性物质材料与所述第二活性物质层的活性物质材料相同或者不同。
上述说明仅是本申请技术方案的概述，为了能够更清楚了解本申请的技术手段，而可依照说明书的内容予以实施，并且为了让本申请的上述和其它目的、特征和优点能够更明显易懂，以下特举本申请的具体实施方式。
附图说明
为了更清楚地说明本申请实施例的技术方案，下面将对本申请实施例中所需要使用的附图作简单地介绍，显而易见地，下面所描述的附图仅仅是本申请的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据附图获得其他的附图。
图1为本申请一些实施例提供的车辆的结构示意图；
图2为本申请一些实施例提供的电池的分解结构示意图；
图3为本申请一些实施例提供的电池单体的分解结构示意图；
图4为本申请一些实施例提供的电极组件的结构示意图；
图5为本申请一些实施例提供的第一极片的结构示意图；
图6为本申请另一些实施例提供的第一极片的结构示意图；
图7为本申请一些实施例提供的第一分段和第二分段通过第一连接部连接的示意图；
图8为本申请一些实施例提供的第一分段和第二分段与隔膜的连接示意图；
图9为本申请另一些实施例提供的第一分段和第二分段与隔膜的连接示意图；
图10为本申请另一些实施例提供的电极组件的结构示意图；
图11为本申请一些实施例提供的第二极片的结构示意图；
图12为本申请另一些实施例提供的第二极片的结构示意图；
图13为本申请一些实施例提供的第三分段和第四分段通过第二连接部连接的示意图；
图14为本申请一些实施例提供的第一极片、第二极片与隔膜的连接示意图；
图15为本申请一些实施例提供的卷绕设备的结构示意图；
图16为本申请一些实施例提供的第一输送机构处于第一输送位置的示意图；
图17为本申请一些实施例提供的第二输送机构处于第一输送位置的示意图；
图18为本申请另一些实施例提供的卷绕设备的结构示意图；
图19为本申请一些实施例提供的第三输送机构处于第二输送位置的示意图；
图20为本申请一些实施例提供的第四输送机构处于第二输送位置的示意图；
图21为本申请一些实施例提供的卷绕方法的示意性流程图；
在附图中，附图并未按照实际的比例绘制。
标记说明：100-电池；10-箱体；11-第一子箱体；12-第二子箱体；20-电池单体；21-端盖；22-壳体；23-电极组件；231-第一极片；2311-第一分段；2311a-第一活性物质层；2311b-第一集流体分段；2312-第二分段；2312a-第二活性物质层；2312b-第二集流体分段；2313-第一集流体；2314-第一连接部；232-第二极片；2321-第三分段；2321a-第三活性物质层；2321b-第三集流体分段；2322-第四分段；2322a-第四活性物质层；2322b-第四集流体分段；2323-第二集流体；233-隔膜；233a-第一隔膜；233b-第二隔膜；2324-第二连接部；234-平直区；235-弯折区；24-电极端子；200-控制器；300-马达；400-卷绕设备；411-第一提供装置；411a-第一子提供机构；411b-第二子提供机构；412-第二提供装置；412a-第三子提供机构；412b-第四子提供机构；42-隔膜提供机构；431-第一复合机构；432-第二复合机构；44-卷绕机构；451-第一输送机构；452-第二输送机构；453-第一调节机构；454-第三输送机构；455-第四输送机构；456-第二调节机构；461-第一缓存机构；462-第二缓存机构；463-第三缓存机构；464-第四缓存机构；471-第一纠偏机构；472-第二纠偏机构；473-第三纠偏机构；474-第四纠偏机构；481-第一裁切机构；482-第二裁切机构；491-第一图像检测系统；492-第一入卷前纠偏机构；493-第二图像检测系统；494-第二入卷前纠偏机构；511-第一卷前张力系统；512-第二卷前张力系统；52-隔膜切刀；53-收尾压轮；54-贴胶压轮；55-压实工位；1000-车辆。
具体实施方式
为使本申请实施例的目的、技术方案和优点更加清楚，下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例是本申请一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。
除非另有定义，本申请所使用的所有的技术和科学术语与属于本申请的技术领域的技术人员通常理解的含义相同；本申请中在申请的说明书中所使用的术语只是为了描述具体的实施例的目的，不是旨在于限定本申请；本申请的说明书和权利要求书及上述附图说明中的术语“包括”和“具有”以及它们的任何变形，意图在于覆盖不排他的包含。本申请的说明书和权利要求书或上述附图中的术语“第一”、“第二”等是用于区别不同对象，而不是用于描述特定顺序或主次关系。
在本申请中提及“实施例”意味着，结合实施例描述的特定特征、结构或特性可以包含在本申请的至少一个实施例中。在说明书中的各个位置出现该短语并不一定均是指相同的实施例，也不是与其它实施例互斥的独立的或备选的实施例。本领域技术人员显式地和隐式地理解的是，本申请所描述的实施例可以与其它实施例相结合。
在本申请的描述中，需要说明的是，除非另有明确的规定和限定，术语“安装”、“相连”、“连接”、“附接”应做广义理解，例如，可以是固定连接，也可以是可拆卸连接，或一体地连接；可以是直接相连， 也可以通过中间媒介间接相连，可以是两个元件内部的连通。对于本领域的普通技术人员而言，可以根据具体情况理解上述术语在本申请中的具体含义。
本申请中术语“和/或”，仅仅是一种描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：存在A，同时存在A和B，存在B这三种情况。另外，本申请中字符“/”，一般表示前后关联对象是一种“或”的关系。
本申请中出现的“多个”指的是两个以上(包括两个)，同理，“多组”指的是两组以上(包括两组)，“多片”指的是两片以上(包括两片)。
在本申请中，所提及的电池是指包括一个或多个电池单体以提供更高的电压和容量的单一的物理模块。例如，本申请中所提及的电池可以包括电池模块或电池包等。
电池单体包括电极组件和电解液，电极组件由正极极片、负极极片和隔膜组成。电池单体主要依靠金属离子在正极极片和负极极片之间移动来工作。正极极片包括正极集流体和正极活性物质层，正极活性物质层涂覆于正极集流体的表面，未涂敷正极活性物质层的集流体凸出于已涂覆正极活性物质层的集流体，未涂敷正极活性物质层的集流体作为正极极耳。以锂离子电池为例，正极集流体的材料可以为铝，正极活性物质可以为钴酸锂、磷酸铁锂、三元锂或锰酸锂等。负极极片包括负极集流体和负极活性物质层，负极活性物质层涂覆于负极集流体的表面，未涂敷负极活性物质层的集流体凸出于已涂覆负极活性物质层的集流体，未涂敷负极活性物质层的集流体作为负极极耳。负极集流体的材料可以为铜，负极活性物质可以为碳或硅等。为了保证通过大电流而不发生熔断，正极极耳的数量为多个且层叠在一起，负极极耳的数量为多个且层叠在一起。隔膜的材质可以为PP(polypropylene，聚丙烯)或PE(polyethylene，聚乙烯)等。
隔膜具有电子绝缘性，用于隔离相邻的正极极片和负极极片，防止相邻的正极极片和负极极片短路。隔膜具有大量贯通的微孔，能够保证电解质离子自由通过，对锂离子有很好的透过性，所以，隔膜基本上不能阻挡锂离子通过。
为使得锂离子电池单体体积更小，能量密度更高，锂离子电池单体的电极组件中的负极极片、正极极片和隔膜可以进行卷绕，然后压实。该电极组件包括平直区和位于该平直区两端的弯折区，平直区是指该电极组件中具有平行结构的区域，即在该平直区内的负极极片、正极极片和隔膜的表面均为平面。弯折区是指该电极组件中具有弯折结构的区域，即在该弯折区内的负极极片、正极极片和隔膜均弯折，即电极组件在弯折区的每层负极极片、正极极片和隔膜的表面均为曲面。本申请实施例中以电极组件为卷绕式结构为例进行介绍。本申请实施例中，隔膜的数量为两个，电极组件可以为负极极片、第一隔膜、正极极片及第二隔膜层叠卷绕而成，也可以为第一隔膜、负极极片、第二隔膜及正极极片层叠卷绕而成。
活性物质涂敷于集流体的表面后形成活性物质层，活性物质层的涂敷密度是指单位表面积上活性物质的涂敷重量。在活性物质层涂敷于集流体后，还需要进行烘干、辊压等操作，以成型极片。烘干操作，使活性物质层中的水分降低至工艺所需要求；辊压操作，使得活性物质层压实，极片的厚度降低至工艺需求。当极片在烘干、辊压等操作后，极片上的活性物质的涂敷密度越大，极片的断裂韧性越低，极片在折弯等情况下容易产生裂纹或断裂。
电池技术的发展要同时考虑多方面的设计因素，例如，能量密度、放电容量、充放电倍率等性能参数，另外，还需要考虑电池的安全性。
对于电池单体来说，电池单体的性能取决于电极组件的性能。电极组件通常由正极极片和负极极片卷绕而成，极片的性能决定电极组件的性能。极片通常为连续的带状结构，极片的各位置性能相差不大，极片卷绕后的电极组件的性能确定；依据电极组件的性能，电极组件的性能较差，无法差异化处理。
例如，现有技术中，由于追求能量密度，极片的活性物质层的涂敷密度较高，在极片经过辊压之后，极片的断裂韧性较小，极片较脆，在受力弯折时容易产生裂纹甚至断裂。卷绕后的电极组件在压实或后期制备过程中，极片的弯折区容易产生裂纹甚至断裂，使得弯折区处嵌锂空间不足，容易出现析锂，锂结晶容易刺穿隔膜，同时，断裂的极片也容易刺穿隔膜，进而导致内短路，影响电池单体的安全性，使得电极组件构成的电池单体无法在安全性要求较高的环境中使用。
鉴于此，为了解决电极组件的性能较差、无法差异化处理的问题，发明人经过深入研究，设计了一种电极组件，该电极组件包括极性相反的第一极片和第二极片，第一极片和第二极片层叠并沿卷绕方向卷绕形成电极组件，第一极片包括第一分段和第二分段，第一分段上设有第一活性物质层，第二分段上设有第二活性物质层，沿由内至外的卷绕方向，第一分段位于第二分段的上游。可以对处于内圈的第一分段和处于外圈的第二分段分别做不同的处理，使第一分段和第二分段具备不同的物理性能或者化学性能，通过内外差异化配置以更好地调节电极组件的性能，满足不同的使用需求。
在这样的电极组件中，将第一极片分为第一分段和第二分段，可以根据不同的需求对第一分段和第二分段分别做不同的处理，满足不同的性能需求。
本申请实施例公开的电池单体可以但不限用于车辆、船舶或飞行器等用电设备中。可以使用具备本申请公开的电池单体、电池等组成该用电设备的电源系统。
本申请实施例提供一种使用电池作为电源的用电设备，用电设备可以为但不限于手机、平板电脑、笔记本电脑、电动玩具、电动工具、电动自行车、电动摩托车、电动汽车、轮船、航天器等等。其中，电动玩具可以包括固定式或移动式的电动玩具，例如，游戏机、电动汽车玩具、电动轮船玩具和电动飞机玩具等等，航天器可以包括飞机、火箭、航天飞机和宇宙飞船等等。
以下实施例为了方便说明，以本申请一实施例的一种用电设备为车辆1000为例进行说明。
请参照图1，图1为本申请一些实施例提供的车辆1000的结构示意图。车辆1000可以为燃油汽车、燃气汽车或新能源汽车，新能源汽车可以是纯电动汽车、混合动力汽车或增程式汽车等。车辆1000的内部设置有电池100，电池100可以设置在车辆1000的底部或头部或尾部。电池100可以用于车辆1000的供电，例如，电池100可以作为车辆1000的操作电源，用于车辆的电路系统，例如用于车辆的启动、导航和运行时的工作用电需求。
车辆1000还可以包括控制器200和马达300，控制器200用来控制电池100为马达300供电，例如，用于车辆1000的启动、导航和行驶时的工作用电需求。
在本申请一些实施例中，电池100不仅可以作为车辆1000的操作电源，还可以作为车辆1000的驱动电源，代替或部分地代替燃油或天然气为车辆1000提供驱动动力。
请参照图2，图2为本申请一些实施例提供的电池100的分解结构示意图。电池100包括箱体10和电池单体20，电池单体20容纳于箱体10内。其中，箱体10用于为电池单体20提供容纳空间，箱体10可以采用多种结构。在一些实施例中，箱体10可以包括第一子箱体11和第二子箱体12，第一子箱体11与第二子箱体12相互盖合，第一子箱体11和第二子箱体12共同限定出用于容纳电池单体20的容纳空间。第二子箱体12可以为一端开口的空心结构，第一子箱体11可以为板状结构，第一子箱体11盖合于第二子箱体12的开口侧，以使第一子箱体11与第二子箱体12共同限定出容纳空间；第一子箱体11和第二子箱体12也可以是均为一侧开口的空心结构，第一子箱体11的开口侧盖合于第二子箱体12的开口侧。当然，第一子箱体11和第二子箱体12形成的箱体10可以是多种形状，比如，圆柱体、长方体等。
在电池100中，电池单体20可以是多个，多个电池单体20之间可串联或并联或混联，混联是指多个电池单体20中既有串联又有并联。多个电池单体20之间可直接串联或并联或混联在一起，再将多个电池单体20构成的整体容纳于箱体10内；当然，电池100也可以是多个电池单体20先串联或并联或混联组成电池模块形式，多个电池模块再串联或并联或混联形成一个整体，并容纳于箱体10内。电池100还可以包括其他结构，例如，该电池100还可以包括汇流部件，用于实现多个电池单体20之间的电连接。
其中，每个电池单体20可以为二次电池或一次电池；还可以是锂硫电池、钠离子电池或镁离子电池，但不局限于此。电池单体20可呈圆柱体、扁平体、长方体或其它形状等。
请参照图3，图3为本申请一些实施例提供的电池单体20的分解结构示意图。电池单体20是指组成电池的最小单元。如图3，电池单体20包括有端盖21、壳体22、电极组件23以及其他的功能性部件。
端盖21是指盖合于壳体22的开口处以将电池单体20的内部环境隔绝于外部环境的部件。不限地，端盖21的形状可以与壳体22的形状相适应以配合壳体22。可选地，端盖21可以由具有一定硬度和强度的材质(如铝合金)制成，这样，端盖21在受挤压碰撞时就不易发生形变，使电池单体20能够具备更高的结构强度，安全性能也可以有所提高。端盖21上可以设置有如电极端子24等的功能性部件。电极端子24可以用于与电极组件23电连接，以用于输出或输入电池单体20的电能。在一些实施例中，端盖21上还可以设置有用于在电池单体20的内部压力或温度达到阈值时泄放内部压力的泄压机构。端盖21的材质也可以是多种的，比如，铜、铁、铝、不锈钢、铝合金、塑胶等，本申请实施例对此不作特殊限制。在一些实施例中，在端盖21的内侧还可以设置有绝缘件，绝缘件可以用于隔离壳体22内的电连接部件与端盖21，以降低短路的风险。示例性的，绝缘件可以是塑料、橡胶等。
壳体22是用于配合端盖21以形成电池单体20的内部环境的组件，其中，形成的内部环境可以用于容纳电极组件23、电解液以及其他部件。壳体22和端盖21可以是独立的部件，可以于壳体22上设置开口，通过在开口处使端盖21盖合开口以形成电池单体20的内部环境。不限地，也可以使端盖21和壳体22一体化，具体地，端盖21和壳体22可以在其他部件入壳前先形成一个共同的连接面，当需要封装壳体22的内部时，再使端盖21盖合壳体22。壳体22可以是多种形状和多种尺寸的，例如长方体形、圆柱体形、六棱柱形等。具体地，壳体22的形状可以根据电极组件23的具体形状和尺寸大小来确定。壳体22的材质可以是多种，比如，铜、铁、铝、不锈 钢、铝合金、塑胶等，本申请实施例对此不作特殊限制。
电极组件23是电池单体20中发生电化学反应的部件。壳体22内可以包含一个或更多个电极组件23。电极组件23主要由正极极片和负极极片卷绕形成，并且通常在正极极片与负极极片之间设有隔膜，隔膜用于绝缘隔离正极极片和负极极片，以避免内接短路。正极极片和负极极片具有活性物质的部分构成电芯组件的主体部，正极极片和负极极片不具有活性物质的部分各自构成极耳。正极极耳和负极极耳可以共同位于主体部的一端或是分别位于主体部的两端。在电池的充放电过程中，正极活性物质和负极活性物质与电解液发生反应，极耳连接电极端子以形成电流回路。
根据本申请的一些实施例，参照图4至图6，图4为本申请一些实施例提供的电极组件23的结构示意图，图5为本申请一些实施例提供的第一极片231的结构示意图，图6为本申请另一些实施例提供的第一极片231的结构示意图。本申请提供了一种电极组件23，该电极组件23包括极性相反的第一极片231和第二极片232。第一极片231和第二极片232层叠并沿卷绕方向形成电极组件23。第一极片231包括第一分段2311和第二分段2312，第一分段2311上设有第一活性物质层2311a，第二分段2312上设有第二活性物质层2312a，沿由内至外的卷绕方向，第一分段2311位于第二分段2312的上游。
第一极片231和第二极片232的极性相反，第一极片231可以为负极极片，第二极片232可以为正极极片，或者，第一极片231可以为正极极片，第二极片232可以为负极极片。本申请实施例以第一极片231为负极极片、第二极片232为正极极片为例进行介绍。
第一分段2311和第二分段2312为构成第一极片231的两个部分，第一分段2311和第二分段2312沿由内至外的卷绕方向排布，第一分段2311和第二分段2312可以一体成型，或者，第一分段2311和第二分段2312也可以分体设置。沿卷绕方向，第一分段2311和第二分段2312可以部分重叠，或者，如图5所示，第一分段2311的尾部与第二分段2312的头部相贴合，又或者，如图4和图6所示，第一分段2311和第二分段2312之间具有间隙。可选地，第一分段2311的尾部和第二分段2312的头部相贴合，或者，第一分段2311和第二分段2312之间具有间隙，但是间隙较小；这种情况下，第一分2311和第二分段2312不重叠，以避免第一分段2311和第二分段2312的重叠区域增加电极组件23的厚度，减少空间占用。
第一分段2311位于第二分段2312的上游是指，在卷绕成型电极组件23时，第一分段2311先于第二分段2312卷绕，使得第一分段2311相对于第二分段2312靠近卷绕中心。
第一分段2311为第一极片231的位于电极组件23的内侧的部分，也即，第一极片231的靠近卷绕中心的部分；第二分段2312为第一极片231的位于电极组件23的外侧的部分，也即，第一极片231的远离卷绕中心的部分。第一分段2311为卷绕结构，第一分段2311的圈数大于或等于一圈，也即，第一分段2311至少具有两个弯折区235。第二分段2312为卷绕结构，第二分段2312的圈数大于一圈，也即，第二分段2312具有多个弯折区235。
根据本申请实施例的电极组件23，第一极片231包括第一分段2311和第二分段2312，沿由内至外的卷绕方向，第一分段2311为第二分段内2312的上游，通过将第一极片231分为第一分段2311和第二分段2312，可以对处于内圈的第一分段2311和处于外圈的第二分段2312分别做不同的处理，使第一分段2311和第二分段2312具备不同的物理性能或者化学性能，通过内外差异化配置以更好地调节电极组件23的性能，满足不同的性能需求。
根据本申请的一些实施例，第一活性物质层2311a的涂敷密度与第二活性物质层2312a的涂敷密度不同。
第一活性物质层2311a的涂敷密度，是指在单位表面积上第一活性物质层2311a的活性物质材料的涂敷重量。第二活性物质层2312a的涂敷密度，是指在单位表面积上第二活性物质层2312a的活性物质材料的涂敷重量。
第一活性物质层2311a的涂敷密度与第二活性物质层2312a的涂敷密度不同，可以调节电极组件23的能量密度，满足电极组件的不同的能量密度需求。
根据本申请的一些实施例，第一活性物质层2311a的涂敷密度小于第二活性物质层2312a的涂敷密度。
该电极组件23包括平直区234和位于该平直区234两端的弯折区235，平直区234是指该电极组件23中具有平行结构的区域，即在该平直区234内的第一极片231、第二极片232和隔膜的表面均为平面。弯折区235是指该电极组件23中具有弯折结构的区域，即在该弯折区235内的第一极片231、第二极片232和隔膜均弯折，即电极组件23在弯折区235的每层第一极片231、第二极片232和隔膜的表面均为曲面。
第一活性物质层2311a的涂敷密度小于第二活性物质层2312a的涂敷密度，第一分段2311的断裂韧 性大于第二分段2312的断裂韧性，使得第一分段2311的弯折区235不易产生裂纹或断裂，降低了第一极片231产生裂纹或断裂的概率，进而提高了该电极组件23构成的电池单体20的安全性。
根据本申请的一些实施例，第二活性物质层2312a的涂敷密度比第一活性物质层2311a的涂敷密度大10％-200％。
第二活性物质层2312a的涂敷密度为H2，第一活性物质层2311a的涂敷密度为H1，满足0.1≤(H2-H1)/H1≤2。
第二活性物质层2312a的涂敷密度比第一活性物质层2311a的涂敷密度大，保证第一极片231具有较多的活性物质，进而保证该电极组件23构成的电池单体20具有较大的能量密度。
可选地，第二活性物质层2312a的涂敷密度比第一活性物质层2311a的涂敷密度大20％-150％。
可选地，第二活性物质层2312a的涂敷密度比第一活性物质层2311a的涂敷密度大40％-120％。
可选地，第二活性物质层2312a的涂敷密度比第一活性物质层2311a的涂敷密度大30％、50％、60％、70％、100％、130％、150％或180％等。
根据本申请的一些实施例，第一活性物质层2311a的厚度与第二活性物质层2312a的厚度比为1/2-3/2。
第一活性物质层2311a的厚度为D1，第二活性物质层2312a的厚度为D2，满足1/2≤D1/D2≤3/2，换句话说，第一活性物质层2311a和第二活性物质层2312a的厚度接近。
例如，D1/D2可以为5/8、3/4、7/8、1、9/8、5/4、11/8等。
在满足第一活性物质层2311a的涂敷密度小于第二活性物质层2312a的情况下，第一活性物质层2311a的厚度与第二活性物质层2312a的厚度比满足上述范围，保证第一分段2311和第二分段2312的过渡处不会出现台阶，避免活性物质脱落或者导致压痕，保证电极组件23的质量。
根据本申请的一些实施例，第一活性物质层2311a的活性物质材料与第二活性物质层2312a的活性物质材料相同或者不同。
第一活性物质层2311a的活性物质材料与第二活性物质层2312a的活性物质材料不同，能够调整第一分段2311和第二分段2312的性能，以满足电极组件23具有不同物理性能或者化学性能。
例如，第一活性物质层2311a和第二活性物质层2312a可以采用相同配方，例如，采用相同种类的活性物质材料、活性物质材料的配比相同；或者，第一活性物质层2311a和第二活性物质层2312a可以采用不同的配方，例如，采用相同种类的活性物质材料、活性物质材料的配比不同；又或者，第一活性物质层2311a和第二活性物质层2312a可以采用不同种类的活性物质材料，例如，不同化学体系。
以第一活性物质层2311a的活性物质材料和第二活性物质层2312a的活性物质材料为负极活性物质材料为例，负极活性物质材料可以为石墨(人造石墨、天然石墨)、无定形碳(软碳、硬碳、其他无定形碳)、钛酸锂中至少一种。以第一活性物质层2311a的活性物质材料和第二活性物质层2312a的活性物质材料为正极活性物质材料为例，正极活性物质材料可以钴酸锂、锰酸锂、磷酸铁锂、镍钴锰酸锂、富锂锰酸锂、镍钴铝酸锂中至少一种。
根据本申请的一些实施例，沿由内至外的卷绕方向，第一分段2311的尾部和第二分段2312的头部相连接；或者，如图4和图6所示，第一分段2311的尾部和第二分段2312的头部之间设有间隙。
第一分段2311的尾部是指沿卷绕方向第一分段2311的末端的部位，换句话说，第一分段2311的尾部是指第一分段2311的收尾部位；第二分段2312的头部是指沿卷绕方向第二分段2312的首端的部位，换句话说，第二分段2312的头部是指第二分段2312的起始部位。
在第一分段2311的尾部和第二分段2312的头部相连接的实施例中，便于保证第一极片231的连续性，第一极片231具有较多的活性物质，保证电极组件23具有较高的能量密度；在第一分段2311的尾部和第二分段2312的头部之间设有间隙的实施例中，可以便于第一分段2311和第二分段2312的加工，降低第一极片231的制造难度。
根据本申请的一些实施例，如图5所示，第一极片231还包括第一集流体2313，第一活性物质层2311a和第二活性物质层2312a分别设于第一集流体2313上。
第一集流体2313为连续的带状结构，第一活性物质层2311a和第二活性物质层2312a分别设置于第一集流体2313上。此种情况下，第一分段2311为第一极片231的活性物质层的涂敷密度较小的区域，第二分段2312为第一极片231的活性物质层的涂敷密度较大的区域。在第一极片231的制备过程中，对活性物质层进行辊压时，通过调节一对压辊之间的距离，改变一对压辊对第一极片231的辊压力，活性物质层的涂敷密度较小的区域形成第一分段2311，活性物质层的涂敷密度较大的区域形成第二分段2312。
根据本申请的一些实施例，如图6所示，第一极片231还包括第一集流体分段2311b和第二集流体分段2312b，第一活性物质层2311a设于第一集流体分段2311b上以形成第一分段2311，第二活性物质层2312a设于第二集流体分段2312b上以形成第二分段2312。
第一集流体分段2311b和第二集流体分段2312b为两个不同的集流体段，此种情况下，第一分段2311和第二分段2312为断开的两个部分。
第一活性物质层2311a设于第一集流体分段2311b上形成第一分段2311，第二活性物质层2312a设于第二集流体分段2312b上形成第二分段2312，便于实现第一分段2311和第二分段2312的加工制造，降低第一极片231的制造难度。
请参见图7，图7为本申请一些实施例提供的第一分段2311和第二分段2312通过第一连接部2314连接的示意图。根据本申请的一些实施例，如图7所示，第一分段2311的尾部和第二分段2312的头部通过第一连接部2314相连接。
第一连接部2314为用于连接第一分段2311和第二分段2312的连接部件，第一连接部2314可以为胶带，也可以为带有胶层的隔膜。第一连接部2314可采用离子可通过的材料，使第一连接部2314覆盖的活性材料可以发挥作用，有利于提升能量密度。第一连接部2314可以位于第一分段2311和第二分段2312的一侧，或者，如图7所示，第一连接部2314可以位于第一分段2311和第二分段2312的两侧。
通过第一连接部连接第一分段2311和第二分段2312，实现对第一分段2311和第二分段2312的定位，限制第一分段2311和第二分段2312发生位置移动，在第一分段2311被卷绕时，可由第一分段2311通过第一连接部2314带动第二分段2312，为第二分段2312提供卷绕的动力，进而实现第一分段2311和第二分段2312的依次卷绕。
请参见图8，图8为本申请一些实施例提供的第一分段2311和第二分段2312与隔膜233的连接示意图。根据本申请的一些实施例，如图4和图8所示，电极组件23还包括隔膜233，隔膜233用于分隔第一极片231和第二极片232。
隔膜233设置于第一极片231和第二极片232之间，隔膜233为电绝缘的膜状结构，能够绝缘隔离第一极片231和第二极片232，从而分隔第一极片231和第二极片232。
通过隔膜233分隔第一极片231和第二极片232，避免第一极片231和第二极片232接触短路，提高安全性。
根据本申请的一些实施例，第二分段2312的头部连接于隔膜233。
第二分段2312的头部连接于隔膜233，通过隔膜233实现对第二分段2312的头部的定位，限制第一分段2311和第二分段2312发生位置移动，在卷绕成型电极组件23时，可由隔膜233带动第二分段2312的头部卷入，为第二分段2312提供卷绕的动力，以实现第一分段2311和第二分段2312的依次卷绕。
根据本申请的一些实施例，如图8所示，第一分段2311和第二分段2312均连接于隔膜233。
第一分段2311和第二分段2312连接于隔膜233，通过隔膜233实现对第一分段2311和第二分段2312的定位，限制第一分段2311和第二分段2312发生位置移动，降低第一极片231和第二极片232接触短路的风险，保证电极组件23构成的电池单体20的安全性。
请参见图9，图9为本申请另一些实施例提供的第一分段2311和第二分段2312与隔膜233的连接示意图。根据本申请的一些实施例，如图4和图9所示，电极组件23可以包括两个隔膜233，两个隔膜233分别位于第一极片231的两侧，第一极片231与两个隔膜233连接。换句话说，通过两个隔膜233连接第一分段2311和第二分段2312，实现对第一分段2311和第二分段2312的定位。
请参见图10至图12，图10为本申请另一些实施例提供的电极组件23的结构示意图，图11为本申请一些实施例提供的第二极片232的结构示意图，图12为本申请另一些实施例提供的第二极片232的结构示意图。根据本申请的一些实施例，第二极片232包括第三分段2321和第四分段2322；第三分段2321上设有第三活性物质层2321a；第四分段2322上设有第四活性物质层2322a；沿由内至外的卷绕方向，第三分段2321位于第四分段2322的上游。
第三分段2321和第四分段2322为构成第二极片232的两个部分，第三分段2321和第四分段2322沿由内至外的卷绕方向排布，第三分段2321和第四分段2322可以一体成型，或者，第三分段2321和第四分段2322也可以分体设置。沿卷绕方向，第三分段2321和第四分段2322可以重叠，或者，如图11所示，第三分段2321的尾部和第四分段2322的头部相贴合，又或者，如图12所示，第三分段2321和第四分段2322之间具有间隙。可选地，第三分段2321的尾部和第四分段2322的头部相贴合，或者，第三分段2321和第四分段2322之间具有间隙，但是间隙较小；这种情况下，第三分段2321和第四分段2322不重叠，以避免第三分段2321和第四分段2322的重 叠区域增加电极组件23的厚度，减少空间占用。
第三分段2321位于第四分段2322的上游是指，在卷绕成型电极组件23时，第三分段2321先于第四分段2322卷绕，使得第三分段2321相对于第四分段2322靠近卷绕中心。
第三分段2321为第二极片232的位于电极组件23的内侧的部分，也即，第二极片232的靠近卷绕中心的部分；第四分段2322为第二极片232的位于电极组件23的外侧的部分，也即，第二极片232的远离卷绕中心的部分。第三分段2321为卷绕结构，第三分段2321的圈数大于或等于一圈，也即，第三分段2321至少具有两个弯折区235。第四分段2322为卷绕机构，第四分段2322的圈数大于一圈，也即，第四分段2322具有多个弯折区235。
通过将第二极片232分为第三分段2321和第四分段2322，可以对处于内圈的第三分段2321和处于外圈的第四分段2322分别做不同的处理，使第三分段2321和第四分段2322具备不同的物理性能或者化学性能，通过内外差异化配置以更好地调节电极组件23的性能，适应不同的使用环境。
根据本申请的一些实施例，第三活性物质层2321a的涂敷密度与第四活性物质层2322a的涂敷密度不同；和/或，第三活性物质层2321a的厚度与第四活性物质层2322a的厚度不同；和/或，第三活性物质层2321a的活性物质材料与第四活性物质层2322a的活性物质材料相同或者不同。
第三活性物质层2321a的涂敷密度，是指在单位表面积上第三活性物质层2321a的活性物质材料的涂敷重量。第四活性物质层2322a的涂敷密度，是指在单位表面积上第四活性物质层2322a的活性物质材料的涂敷重量。
可以通过改变第三活性物质层2321a和第四活性物质层2322a的涂敷密度、厚度以及活性物质材料配方，来改变第三分段2321和第四分段2322的物理性能或化学性能，以使得电极组件23满足不同的性能需求，适用于不同的使用场景。
根据本申请的一些实施例，第三活性物质层2321a的涂敷密度小于第四活性物质层2322a的涂敷密度。
第三活性物质层2321a的涂敷密度小于第四活性物质层2322a的涂敷密度，第三分段2321的断裂韧性大于第四分段2322的断裂韧性，使得第三分段2321的弯折区235不易产生裂纹或断裂，降低了第二极片232产生裂纹或断裂的概率，进而提高了电极组件23构成的电池单体20的安全性。
根据本申请的一些实施例，第四活性物质层2322a的涂敷密度比第三活性物质层2321a的涂敷密度大10％-200％。
第四活性物质层2322a的涂敷密度为H4，第三活性物质层2321a的涂敷密度为H3，满足0.1≤(H4-H3)/H3≤2。
第四活性物质层2322a的涂敷密度比第三活性物质层2321a的涂敷密度大，保证第二极片232具有较多的活性物质，进而保证该电极组件23构成的电池单体20具有较大的能量密度。
可选地，第四活性物质层2322a的涂敷密度比第三活性物质层2321a的涂敷密度大20％-150％。
可选地，第四活性物质层2322a的涂敷密度比第三活性物质层2321a的涂敷密度大40％-120％。
可选地，第四活性物质层2322a的涂敷密度比第三活性物质层2321a的涂敷密度大30％、50％、60％、70％、100％、130％、150％或180％等。
根据本申请的一些实施例，第三活性物质层2321a和第四活性物质层2322a可以采用相同配方，例如，采用相同种类的活性物质材料、活性物质材料的配比相同；或者，第三活性物质层2321a和第四活性物质层2322a可以采用不同的配方，例如，采用相同种类的活性物质材料、活性物质材料的配比不同；又或者，第三活性物质层2321a和第四活性物质层2322a可以采用不同种类的活性物质材料，例如，不同化学体系。
以第三活性物质层2321a的活性物质材料和第四活性物质层2322a的活性物质材料为负极活性物质材料为例，负极活性物质材料可以为石墨(人造石墨、天然石墨)、无定形碳(软碳、硬碳、其他无定形碳)、钛酸锂中至少一种。以第三活性物质层2321a的活性物质材料和第四活性物质层2322a的活性物质材料为正极活性物质材料为例，正极活性物质材料可以钴酸锂、锰酸锂、磷酸铁锂、镍钴锰酸锂、富锂锰酸锂、镍钴铝酸锂中至少一种。
根据本申请的一些实施例，第三活性物质层2321a的厚度与第四活性物质层2322a的厚度比为1/2-3/2。
第三活性物质层2321a的厚度为D3，第四活性物质层2322a的厚度为D4，满足1/2≤D3/D4≤3/2，换句话说，第三活性物质层2321a和第四活性物质层2322a的厚度接近。
例如，D1/D2可以为5/8、3/4、7/8、1、9/8、5/4、11/8等。
在满足第三活性物质层2321a的涂敷密度小于第四活性物质层2322a的涂敷密度的情况下，第三活性物质层2321a的厚度与第四活性物质层2322a的厚度比满足上述范围，保证第三分段2321和第四分段2322的过渡处不会出现台阶，避免活性物质脱落或者导致压痕，保证电极组件23的质量。
根据本申请的一些实施例，沿由内至外的卷绕方向，第三分段2321的尾部和第四分段2322的头部相连接，或者，如图12所示，第三分段2321的尾部和第四分段2322的头部之间设有间隙。
第三分段2321的尾部是指沿卷绕方向第三分段2321的末端的部位，换句话说，第三分段2321的尾部是指第三分段2321的收尾部位；第四分段2322的头部是指沿卷绕方向第四分段2322的首端的部位，换句话说，第四分段2322的头部是指第四分段2322的起始部位。
在第三分段2321的尾部和第四分段2322的头部相连接的实施例中，便于保证第二极片232的连续性，第二极片232具有较多的活性物质，保证电极组件23具有较高的能量密度；在第三分段2321的尾部和第四分段2322的头部之间设有间隙的实施例中，可以便于第三分段2321和第四分段2322的加工，降低第二极片232的制造难度。
根据本申请的一些实施例，如图11所示，第二极片232还包括第二集流体2323，第三活性物质层2321a和第四活性物质层2322a分别设于第二集流体2323上。
第二集流体2323为连续的带状结构，第三活性物质层2321a和第四活性物质层2322a分别设置于第二集流体2323上。此种情况下，第三分段2321为第二极片232的活性物质层的涂敷密度较小的区域，第四分段2322为第二极片232的活性物质层的涂敷密度较大的区域。在第二极片232的制备过程中，对活性物质层进行辊压时，通过调节一对压辊之间的距离，改变一对压辊对第二极片232的辊压力，活性物质层的涂敷密度较小的区域形成第三分段2321，活性物质层的涂敷密度较大的区域形成第四分段2322。
根据本申请的一些实施例，如图12所示，第二极片232还包括第三集流体分段2321b和第四集流体分段2322b，第三活性物质层2321a设于第三集流体分段2321b上以形成第三分段2321，第四活性物质层2322a设于第四集流体分段2322b上以形成第四分段2322。
第三集流体分段2321b和第四集流体分段2322b为两个不同的集流体段，此种情况下，第三集流体分段2321b和第四集流体分段2322b为断开的两个部分。
第三活性物质层2321a设于第三集流体分段2321b上形成第三分段2321，第四活性物质层2322a设于第四集流体分段2322b上形成第四分段2322，便于实现第三分段2321和第四分段2322的加工制造，降低第二极片232的制造难度。
请参见图13，图13为本申请一些实施例提供的第三分段2321和第四分段2322通过第二连接部2324连接的示意图。根据本申请的一些实施例，第三分段2321的尾部和第四分段2322的头部通过第二连接部2324相连接。
第二连接部2324为用于连接第三分段2321和第四分段2322的连接部件，第二连接部2324可以为胶带，也可以为带有胶层的隔膜。第二连接部2324可采用离子可通过的材料，使第二连接部2324覆盖的活性材料可以发挥作用，有利于提升能量密度。第二连接部2324可以位于第三分段2321和第四分段2322的一侧，或者，如图13所示，第二连接部2324可以位于第三分段2321和第四分段2322的两侧。
通过第二连接部2324连接第三分段2321和第四分段2322，实现对第三分段2321和第四分段2322的定位，限制第三分段2321和第四分段2322发生位置移动，在第三分段2321被卷绕时，可由第三分段2321通过第二连接部2324带动第四分段2322，为第四分段2322提供卷绕的动力，进而实现第三分段2321和第四分段2322的依次卷绕。
根据本申请的一些实施例，如图10所示，电极组件还包括隔膜233，隔膜233用于分隔第一极片231和第二极片232，第四分段2322的头部连接于隔膜233。
第四分段2322的头部连接于隔膜233，通过隔膜233实现对第四分段2322的定位，限制第三分段2321和第四分段2322发生位置移动，在卷绕时，可由隔膜233带动第四分段2322的头部卷入，为第四分段2322提供卷绕的动力，以实现第三分段2321和第四分段2322的依次卷绕。
根据本申请的一些实施例，电极组件23包括两个隔膜233，两个隔膜233分别位于第二极片232的两侧，第二分段2312的头部与一个隔膜233连接，第四分段2322的头部与另一个隔膜233连接。
一个隔膜233连接第二分段2312的头部，另一个隔膜233连接第四分段2322的头部，一个隔膜233限制第二分段2312的位置，另一个隔膜233限制第四分段2322的位置。在卷绕成型电极组件23时，可由一个隔膜233带动第二分段2312的头部卷入，为第二分段2312提供卷绕的动力，以实现第一分段2311和第二分段2312的依次卷绕；可由另一个隔膜233带动第四分段2322的头部卷入，为第四分段2322提供卷绕的动力，以实现第三分 段2321和第四分段2322的依次卷绕。
请参见图14，图14为本申请一些实施例提供的第一极片231、第二极片232与隔膜233的连接示意图。根据本申请的一些实施例，如图10和图14所示，电极组件23还包括隔膜233，隔膜233用于分隔第一极片231和第二极片232，第三分段2321和第四分段2322均连接于隔膜233。
隔膜233设置于第一极片231和第二极片232之间，隔膜233为电绝缘的膜状结构，以分隔第一极片231和第二极片232。
第三分段2321和第四分段2322连接于隔膜233，通过隔膜233实现对第三分段2321和第四分段2322的定位，限制第三分段2321和第四分段2322发生位置移动，降低第一极片231和第二极片232接触短路的风险，保证电极组件23构成的电池单体20的安全性。
根据本申请的一些实施例，如图10和图14所示，电极组件23包括两个隔膜233，两个隔膜233分别位于第二极片232的两侧，第一分段2311和第二分段2312均与一个隔膜233连接，第三分段2321和第四分段2322均与另一个隔膜233连接。
在电极组件23卷绕成型时，两个隔膜233与第一极片231和第二极片232的层叠方式可以为：隔膜233、第一极片231、隔膜233和第二极片232，也可以为，第一极片231、隔膜233、第二极片232和隔膜233。
一个隔膜233连接第一分段2311和第二分段2312，另一个隔膜233连接第三分段2321和第四分段2322，保证第一分段2311和第二分段2312被一个隔膜233定位、第三分段2321和第四分段2322被另一个隔膜233定位，一个隔膜233限制第一分段2311和第二分段2312的位置，另一个隔膜233限制第三分段2321和第四分段2322的位置，降低第一极片231和第二极片232接触短路的风险，保证电极组件23构成的电池单体20的安全性。
根据本申请的一些实施例，第三分段2321的圈数小于第四分段2322的圈数。
第三分段2321的圈数是指第三分段2321的卷绕圈数，一圈是指以第三分段2321上的某一点为起点，第三分段2321沿卷绕方向卷绕，第三分段2321第一次覆盖该起点时，第三分段2321所卷绕的部分为一圈。
同理，第四分段2322的圈数是指第四分段2322的卷绕圈数，一圈是指以第四分段2322上的某一点为起点，第四分段2322沿卷绕方向卷绕，第四分段2322第一次覆盖该起点时，第四分段2322所卷绕的部分为一圈。
第三分段2321的圈数小于第四分段2322的圈数，换句话说，第四分段2322的卷绕圈数大于第三分段2321的卷绕圈数，由于第四活性物质层2322a的涂敷密度大于第三活性物质层2321a的涂敷密度，在同等电极组件23厚度的情况下，第四分段2322的卷绕圈数占比较多，能够保证电极组件23具有较高的能量密度。
根据本申请的一些实施例，第三分段2321的圈数为1-5圈。
第三分段2321的圈数在1-5圈，既能降低第二极片232的靠近卷绕中心的区域产生裂纹或断裂的概率，还能够保证该电极组件23构成的电池单体20的能量密度。如果第三分段2321的圈数过小，则第二极片232的靠近卷绕中心的弯折区235容易产生裂纹或断裂，影响电极组件23构成的电池单体20的安全性；由于第三活性物质层2321a的涂敷密度较小，如果第三分段2321的圈数过大，影响电极组件23构成的电池单体20的能量密度。
根据本申请的一些实施例，第一分段2311的圈数小于第二分段2312的圈数。
第一分段2311的圈数是指第一分段2311的卷绕圈数，一圈是指以第一分段2311上的某一点为起点，第一分段2311沿卷绕方向卷绕，第一分段2311第一次覆盖该起点时，第一分段2311所卷绕的部分为一圈。
同理，第二分段2312的圈数是指第二分段2312的卷绕圈数，一圈是指以第二分段2312上的某一点为起点，第二分段2312沿卷绕方向卷绕，第二分段2312第一次覆盖该起点时，第二分段2312所卷绕的部分为一圈。
第一分段2311的圈数小于第二分段2312的圈数，换句话说，第二分段2312的卷绕圈数大于第一分段2311的卷绕圈数，由于第二活性物质层2312a的涂敷密度大于第一活性物质层2311a的涂敷密度，在同等电极组件23厚度的情况下，第二分段2312的卷绕圈数占比较多，能够保证电极组件23具有较高的能量密度。
根据本申请的一些实施例，第一分段2311的圈数为1-5圈。
第一分段2311的圈数在1-5圈，既能降低第一极片231的靠近卷绕中心的区域产生裂纹或断裂的概率，还能够保证该电极组件23构成的电池单体20的能量密度。如果第一分段2311的圈数过小，则第一极片231的靠近卷绕中心的弯折区235容易产生裂纹或断裂，影响电极组件23构成的电池单体20的安全性；由于第一活性物质层2311a的涂敷密度较小，如果第一分段2311的圈数过大，影响电极组件23构成的电池单体20的能量密度。
根据本申请的一些实施例，本申请还提供了一种电池单体20，包括以上任一方案所述的电极组件23。
根据本申请的一些实施例，本申请还提供了一种电池100，包括以上任一方案所述的电池单体20。
根据本申请的一些实施例，本申请还提供了一种用电设备，包括以上任一方案所述的电池100，并且电池100用于为用电设备提供电能。
用电设备可以是前述任一应用电池100的设备或系统。
根据本申请的一些实施例，请参见图3至图14，本申请提供了一种电池单体20，包括端盖21、壳体22、电极组件23及电极端子24。电极组件23设置于壳体22内，电极端子24设置于端盖21，端盖21覆盖于壳体22的开口。电极组件23包括第一极片231、第二极片232和隔膜233，第一极片231、隔膜233和第二极片232沿卷绕方向卷绕形成电极组件23。第一极片231包括第一分段2311和第二分段2312，第一分段2311上设有第一活性物质层2311a，第二分段2312上设有第二活性物质层2312a，沿由内至外的卷绕方向，第一分段2311位于第二分段2312的上游，第一活性物质层2311a的涂敷密度小于第二活性物质层2312a的涂敷密度。第二极片232包括第三分段2321和第四分段2322，第三分段2321上设有第三活性物质层2321a，第四分段2322上设有第四活性物质层2322a，沿由内至外的卷绕方向，第三分段2321位于第四分段2322的上游，第三活性物质层2321a的涂敷密度小于第四活性物质层2322a的涂敷密度。隔膜233设置有两个，隔膜233用于分隔第一极片231和第二极片232，第一分段2311和第二分段2312连接于一个隔膜233，第三分段2321和第四分段2322连接于另一个隔膜233。
在构成该电池单体20的电极组件23中，第一活性物质层2311a的涂敷密度较小、第三活性物质层2321a的涂敷密度较小，降低了第一极片231的靠近卷绕中心的弯折区235产生裂纹或断裂的概率、降低了第二极片232的靠近卷绕中心的弯折区235产生裂纹或断裂的概率，进而提高了电池单体20的安全性。
根据本申请的一些实施例，参见图15，图15为本申请一些实施例提供的卷绕设备400的结构示意图。本申请提供了一种卷绕设备400。卷绕设备400包括第一提供装置411、第二提供装置412、隔膜提供机构42及卷绕机构44。第一提供装置411用于提供第一极片231，如图4至图6所示，第一极片231包括第一分段2311和第二分段2312，第一分段2311上设有第一活性物质层2311a，第二分段2312上设有第二活性物质层2312a。第二提供装置412用于提供与第一极片231的极性相反的第二极片232。隔膜提供机构42用于提供隔膜233。卷绕机构44设置于第一提供装置411、第二提供装置412和隔膜提供机构42的下游，卷绕机构44用于将第一分段2311、第二分段2312、隔膜233和第二极片232沿卷绕方向卷绕，以形成电极组件23。其中，第一提供装置411被配置为以如下方式提供第一极片231：使第一分段2311先进入卷绕机构44，使第二分段2312在第一分段2311之后进入卷绕机构44。
本申请提及的上游和下游是指，电极组件23的卷绕成型工艺中的前后关系，例如，卷绕机构44设置于第一提供装置411、第二提供装置412和隔膜提供机构42的下游是指，卷绕成型工艺中，第一提供装置411提供的第一极片231输送至卷绕机构44，第二提供装置412提供的第二极片232输送至卷绕机构44，隔膜提供机构42提供的隔膜233输送至卷绕机构44，以使卷绕机构44将第一分段2311、第二分段2312、隔膜233和第二极片232沿卷绕方向卷绕形成电极组件23。
第一极片231(第一分段2311和第二分段2312)、隔膜233和第二极片232层叠卷绕形成电极组件23，隔膜233设置于第一极片231和第二极片232之间，隔膜233用于分隔第一极片231和第二极片232，以避免第一极片231和第二极片232接触短路。
卷绕机构44可以包括转盘和卷针，转盘用于驱动卷针转动，以将第一极片231、隔膜233和第二极片232卷绕于卷针。
根据本申请实施例的卷绕设备400，卷绕机构44将第一分段2311、第二分段2312、隔膜233及第二极片232卷绕形成电极组件23，可以对第一分段2311和第二分段2312分别做不同的处理，使得第一分段2311和第二分段2312具备不同的物理性能或者化学性能，通过内外差异化配置以更好地调节电极组件23的性能。
根据本申请的一些实施例，第一活性物质层2311a的涂敷密度与第二活性物质层2312a的涂敷密度不同；和/或第一活性物质层2311a的厚度与第二活性物质层2312a的厚度不同；和/或第一活性物质层2311a的活性物质材料与第二活性物质层2312a的活性物质材料相同或者不同。
可以通过改变第一活性物质层2311a和第二活性物质层2312a的涂敷密度、厚度以及活性物质材料配合，来改变第一分段2311和第二分段2312的物理性能或化学性能，以使得电极组件23满足不同的性能需求，适用于不同的使用场景。
根据本申请的一些实施例，第一活性物质层2311a的涂敷密度小于第二活性物质层2312a的涂敷密度。
由于第一活性物质层2311a的涂敷密度小于第二活性物质层2312a的涂敷密度，使得第一分段2311的断裂韧性大于第二分段2312的断裂韧性，第一分段2311的弯折区235不易产生裂纹或断裂，降低了第一极片 231产生裂纹或断裂的概率，使得该电极组件23构成的电池单体20具有较高的安全性。
根据本申请的一些实施例，第一提供装置411可以包括第一子提供机构411a和第二子提供机构411b，第一子提供机构411a用于提供第一分段2311，第二子提供机构411b用于提供第二分段2312。
第一子提供机构411a可以为放卷辊，用于提供第一极片231的第一分段2311；第二子提供机构411b可以为放卷辊，用于提供第一极片231的第二分段2312。需要指出的是，此种情况下，第一分段2311和第二分段2312彼此独立。
可选地，为了提高生产效率，第一子提供机构411a可以设置为两个、第二子提供机构411b可以设置为两个，以保证第一分段2311和第二分段2312的供料需求，保证第一极片231的送料进度，节省换料时间。
根据本申请的一些实施例，隔膜233包括第一隔膜233a和第二隔膜233b，隔膜提供机构42用于提供第一隔膜233a和第二隔膜233b；卷绕设备400还包括第一复合机构431，第一复合机构431位于第一提供装置411和隔膜提供机构42的下游，第一复合机构431用于将第一隔膜233a、第一极片231和第二隔膜233b复合成为第一极片组件；第一提供装置411被配置为以如下方式提供第一极片231：使第一分段2311先进入第一复合机构431，使第二分段2312在第一分段2311之后进入第一复合机构431；卷绕机构44，设置于第一复合机构431的下游，用于将第一极片组件和第二极片232沿卷绕方向卷绕，以形成电极组件23。
第一复合机构431包括一对第一复合辊，第一隔膜233a、第一极片231和第二隔膜233b被一对第一复合辊辊压，以使第一极片231连接于第一隔膜233a和第二隔膜233b形成第一极片组件。
第一分段2311先进入第一复合机构431，第二分段2312在第一分段2311之后进入第一复合机构431，第一分段2311先与第一隔膜233a和第二隔膜233b连接，第二分段2312在第一分段2311之后与第一隔膜233a和第二隔膜233b连接，使得沿由内至外的卷绕方向，第一分段2311位于第二分段2312的上游。
第一隔膜233a、第一极片231和第二隔膜233b复合成为第一极片组件，换句话说，第一极片231连接于第一隔膜233a和第二隔膜233b，第一隔膜233a和第二隔膜233b对第一极片231起到定位作用，并由第一隔膜233a和第二隔膜233b夹住第二分段2312进而带动第二分段2312卷绕，为第二分段2312提供卷绕的动力，进而实现第一分段2311和第二分段2312的依次卷绕。通过第一隔膜233a和第二隔膜233b的输送，能够实现第一极片231的输送，保证第一分段2311和第二分段2312的输送稳定。
根据本申请的一些实施例，第一提供装置411还包括第一连接机构(图中未示出)，第一连接机构用于将第一分段2311的尾部和第二分段2312的头部通过第一连接部相连接。
第一连接部可以为胶带，第一连接机构可以为贴胶机构，贴胶机构包括胶带提供组件、机械爪以及移动组件，机械爪用于夹取胶带，移动组件用于驱动机械爪移动，以便于机械爪将胶带贴于第一分段2311和第二分段2312，以使胶带连接第一分段2311的尾部和第二分段2312的头部。
通过第一连接部连接第一分段2311和第二分段2312，在第一分段2311被卷绕时，可由第一分段2311通过第一连接部带动第二分段2312，为第二分段2312提供卷绕的动力，进而实现第一分段2311和第二分段2312的依次卷绕。
在其他实施例中，第一连接部还可以为胶水，第一连接机构还可以为涂胶机构，第一连接机构将胶水涂抹于第一分段2311的尾部和第二分段2312的头部，以使第一分段2311的尾部和第二分段2312的头部通过胶水连接。
请参见图15，并进一步参见图16和图17，图16为本申请一些实施例提供的第一输送机构451处于第一输送位置的示意图，图17为本申请一些实施例提供的第二输送机构452处于第一输送位置的示意图。根据本申请的一些实施例，如图15至图17所示，卷绕设备400还包括：第一输送机构451、第二输送机构452及第一调节机构453。第一输送机构451位于第一子提供机构411a和第一复合机构431之间，第一输送机构451用于在第一输送位置将第一分段2311输送至第一复合机构431；第二输送机构452位于第二子提供机构411b和第一复合机构431之间，第二输送机构452用于在第一输送位置将第二分段2312输送至第一复合机构431；第一调节机构453连接于第一输送机构451和第二输送机构452，第一调节机构453用于将第一输送机构451或第二输送机构452调节至第一输送位置。
第一输送机构451和第二输送机构452可以具有相同的组成结构，第一输送机构451和第二输送机构452可以均包括输送辊和输送板，第一分段2311和第二分段2312分别被对应的输送辊和输送板输送。
第一输送位置是指第一极片231与第一复合机构431对应的位置，在第一输送位置处，第一极片231能够被输送至第一复合机构431以与隔膜233在第一复合机构431处连接。
第一调节机构453可以为直线驱动机构，例如，可以为液压缸、气缸、电推杆等驱动机构，也可以为电机和传动组件配合的驱动机构，该传动组件可以为齿轮齿条、丝杠螺母等传动组件。或者，第一调节机构453 也可以为其他驱动机构，例如，第一调节机构453可以为转盘，第一输送机构451和第二输送机构452均连接于转盘，通过转盘驱动第一输送机构451和第二输送机构452转动，进而使得第一输送机构451或第二输送机构452调节至第一输送位置。
如图16所示，当第一输送机构451处于第一输送位置处时，第一输送机构451将第一分段2311输送至第一复合机构431，此时，第二输送机构452处于第一避让位置，以避免第二输送机构452与第一输送机构451干涉。如图17所示，当第二输送机构452处于第一输送位置处时，第二输送机构452将第二分段2312输送至第一复合机构431，此时，第一输送机构451处于第二避让位置，以避免第一输送机构451与第二输送机构452干涉。需要指出的是，第二避让位置与第一避让位置处于第一输送位置的两侧，也即，沿第一调节机构453的动作轨迹上，第一避让位置、第一输送位置和第二避让位置依次设置。
通过第一调节机构453调节第一输送机构451和第二输送机构452的位置，以使得第一输送机构451将第一分段2311输送至第一复合机构431，或使得第二输送机构452将第二分段2312输送至第一复合机构431，保证第一极片231的输送效率，进而保证电极组件23的生产效率。
需要指出的是，第一调节机构453的数量可以为一个，第一调节机构453用于同步调节第一输送机构451和第二输送机构452的位置；或者，第一调节机构453的数量可以为两个，其中一个第一调节机构453用于调节第一输送机构451的位置，另一个第一调节机构453用于调节第二输送机构452的位置。
根据本申请的一些实施例，如图15至图17所示，卷绕设备400还包括第一缓存机构461和第二缓存机构462，第一缓存机构461设置于第一子提供机构411a和第一调节机构453之间，第一缓存机构461用于缓存第一分段2311，以便于第一调节机构453调节第一输送机构451的位置时保证第一分段2311持续送料；第二缓存机构462设置于第二子提供机构411b和第一调节机构453之间，第二缓存机构462用于缓存第二分段2312，以便于第一调节机构453调节第二输送机构452的位置时保证第二分段2312持续送料。
可选地，第一缓存机构461和第二缓存机构462可以均为摆杆缓存机构，其包括多个摆杆，通过调节相邻两个摆杆之间的距离改变对应的第一极片经过对应的缓存机构的长度，进而实现第一极片的缓存。
根据本申请的一些实施例，如图15至图17所示，卷绕设备400还包括第一纠偏机构471和第二纠偏机构472，第一纠偏机构471设置于第一子提供机构411a和第一输送机构451之间，第一纠偏机构471用于对第一分段2311纠偏，以保证第一分段2311的输送精度；第二纠偏机构472设置于第二子提供机构411b和第一输送机构451之间，第二纠偏机构472用于对第二分段2312纠偏，以保证第二分段2312的输送精度。第一纠偏机构471和第二纠偏机构472可以参照现有技术的纠偏装置，本申请不作详细介绍。
根据本申请的一些实施例，如图15至图17所示，第一复合机构431的上游设置有第一裁切机构481，第一裁切机构481用于裁切第一分段2311或第二分段2312，以便于第一调节机构453调节第一输送机构451和第二输送机构452的位置。第一裁切机构481可以参照现有技术的裁切装置，本申请不作详细介绍。
根据本申请的一些实施例，如图15至图17所示，卷绕设备400还包括第一图像检测系统491和第一入卷前纠偏机构492，第一图像检测系统491和第一入卷前纠偏机构492设置于第一复合机构431和卷绕机构44之间，第一图像检测系统491用于获取第一复合机构431复合后的第一极片231和隔膜233的图像信息，第一入卷前纠偏机构492用于纠正该第一极片231和隔膜233。第一图像检测系统491可以为CCD(charge coupled device，电荷耦合器件)相机；第一入卷前纠偏机构492可以参照现有技术的纠偏装置，本申请不作详细介绍。
根据本申请的一些实施例，如图15至图17所示，卷绕设备400还包括第一卷前张力系统511，第一卷前张力系统511设置于卷绕机构44的上游，用于调节第一极片231的张力。第一卷前张力系统511包括第一张力辊和第一调节件，第一调节件用于调节第一张力辊的位置，以改变第一极片231的张力。
请参见图18，图18为本申请另一些实施例提供的卷绕设备400的结构示意图。根据本申请的一些实施例，结合图10至图12所示，第二极片232包括第三分段2321和第四分段2322；第三分段2321上设有第三活性物质层2321a；第四分段2322上设有第四活性物质层2322a；其中，第二提供装置412被配置为以如下方式提供第二极片232：使第三分段2321先进入卷绕机构44，使第四分段2322在第三分段2321之后进入卷绕机构44。
可以对第三分段2321和第四分段2322分别做不同的处理，使得第三分段2321和第四分段2322具备不同的物理性能或者化学性能，通过内外差异化配置以更好地调节电极组件23的性能。
根据本申请的一些实施例，第三活性物质层2321a的涂敷密度与第四活性物质层2322a的涂敷密度不同；和/或，第三活性物质层2321a的厚度与第四活性物质层2322a的厚度不同；和/或，第三活性物质层2321a的活性物质材料与第四活性物质层2322a的活性物质材料相同或者不同。
可以通过改变第三活性物质层2321a和第四活性物质层2322a的涂敷密度、厚度以及活性物质材料配方，来改变第三分段2321和第四分段2322的物理性能或化学性能，以使得电极组件23满足不同的性能需求，适 用于不同的使用场景。
根据本申请的一些实施例，第三活性物质层2321a的涂敷密度小于第四活性物质层2322a的涂敷密度。
第二极片232包括第三分段2321和第四分段2322，第三活性物质层2321a的涂敷密度小于第四活性物质层2322a的涂敷密度，使得第三分段2321的断裂韧性大于第四分段2322的断裂韧性，第三分段2321的弯折区235不易产生裂纹或断裂，降低了第二极片232产生裂纹或断裂的概率，使得该电极组件23构成的电池单体20具有较高的安全性。
根据本申请的一些实施例，如图18所示，第二提供装置412可以包括第三子提供机构412a和第四子提供机构412b，第三子提供机构412a用于提供第三分段2321，第四子提供机构412b用于提供第四分段2322。
第三子提供机构412a可以为放卷辊，用于提供第二极片232的第三分段2321；第四子提供机构412b可以为放卷辊，用于提供第二极片232的第四分段2322。需要指出的是，此种情况下，第三分段2321和第四分段2322彼此独立。
可选地，为了提高生产效率，第三子提供机构412a可以设置为两个、第四子提供机构412b可以设置为两个，以保证第三分段2321和第四分段2322的供料需求，保证第二极片232的送料进度，节省换料时间。
根据本申请的一些实施例，隔膜233包括第一隔膜233a和第二隔膜233b，卷绕设备400包括两个隔膜提供机构42，一个隔膜提供机构42用于提供第一隔膜233a，另一个隔膜提供机构42用于提供第二隔膜233b。卷绕设备400还包括第一复合机构431和第二复合机构432。第一复合机构431位于第一提供装置411和一个隔膜提供机构42的下游，第一复合机构431用于将第一极片231和第一隔膜233a复合成为第一极片组件。第二复合机构432位于第二提供装置412和另一个隔膜提供机构42的下游，第二复合机构432用于将第二极片232和第二隔膜233b复合成为第二极片组件。第一提供装置411被配置为以如下方式提供第一极片231：使第一分段2311先进入第一复合机构431，使第二分段2312在第一分段2311之后进入第一复合机构431；卷绕机构44设置于第一复合机构431和第二复合机构432的下游，用于将第一极片组件和第二极片组件沿卷绕方向卷绕，以形成电极组件23。
通过第一复合机构431将第一极片231和第一隔膜233a复合成为第一极片组件，以便于通过第一隔膜233a实现对第一极片231的定位，通过第二复合机构432将第二极片232和第二隔膜233b复合成为第二极片组件，以便于通过第二隔膜233b实现对第二极片232的定位，进而保证卷绕成型的电极组件23中第一极片231和第二极片232被第一隔膜233a和第二隔膜233b分隔，避免第一极片231和第二极片232接触而引发短路，保证电极组件23构成的电池单体20的安全性。
第一极片231和第一隔膜233a复合称为第一极片组件，第一分段2311先与第一隔膜233a复合，第二分段2312在第一分段2311之后与第一隔膜233a复合，第一隔膜233a为第一分段2311和第二分段2312提供卷绕的动力，在第一隔膜233a的带动下，第一分段2311和第二分段2312依次卷绕。
在第二极片232包括第三分段2321和第四分段2322的实施例中，第二提供装置412被配置为以如下方式提供第二极片232：使第三分段2321先进入第二复合机构432，使第四分段2322在第三分段2321之后进入第二复合机构432。第三分段2321先进入第二复合机构432，第四分段2322在第三分段2321之后进入第二复合机构432，第三分段2321先与第二隔膜233b连接，第四分段2322在第三分段2321之后与第二隔膜233b连接，使得沿由内至外的卷绕方向，第三分段2321位于第四分段2322的上游。
第二极片232和第二隔膜233b复合称为第二极片组件，第三分段2321先与第二隔膜233b复合，第四分段2322在第三分段2321之后与第二隔膜233b复合，第二隔膜233b为第三分段2321和第四分段2322提供卷绕的动力，在第二隔膜233b的带动下，第三分段2321和第四分段2322依次卷绕。
请参见图18，并进一步参见图19和图20，图19为本申请一些实施例提供的第三输送机构454处于第二输送位置的示意图，图20为本申请一些实施例提供的第四输送机构455处于第二输送位置的示意图。根据本申请的一些实施例，如图18至图20所示，卷绕设备400还包括：第三输送机构454、第四输送机构455及第二调节机构456。第三输送机构454位于第三子提供机构412a和第二复合机构432之间，第三输送机构454用于在第二输送位置将第三分段2321输送至第二复合机构432；第四输送机构455位于第四子提供机构412b和第二复合机构432之间，第四输送机构455用于在第二输送位置将第四分段2322输送至第二复合机构432；第二调节机构456连接于第三输送机构454和第四输送机构455，第二调节机构456用于将第三输送机构454或第四输送机构455调节至所述第二输送位置。
第三输送机构454和第四输送机构455可以具有相同的组成结构，第三输送机构454和第四输送机构455可以均包括输送辊和输送板，第三分段2321和第四分段2322分别被对应的输送辊和输送板输送。
第二输送位置是指第二极片232与第二复合机构432对应的位置，在第二输送位置处，第二极片232 能够被输送至第二复合机构432以与隔膜233在第二复合机构432处连接。
第二调节机构456可以为直线驱动机构，例如，可以为液压缸、气缸、电推杆等驱动机构，也可以为电机和传动组件配合的驱动机构，该传动组件可以为齿轮齿条、丝杠螺母等传动组件。或者，第二调节机构456也可以为其他驱动机构，例如，第二调节机构456可以为转盘，第三输送机构454和第四输送机构455均连接于转盘，通过转盘驱动第三输送机构454和第四输送机构455转动，进而使得第三输送机构454或第四输送机构455调节至第二输送位置。
如图19所示，当第三输送机构454处于第二输送位置处时，第三输送机构454将第三分段2321输送至第二复合机构432，此时，第四输送机构455处于第三避让位置，以避免第四输送机构455与第三输送机构454干涉。如图20所示，当第四输送机构455处于第二输送位置处时，第四输送机构455将第四分段2322输送至第二复合机构432，此时，第三输送机构454处于第四避让位置，以避免第三输送机构454与第四输送机构455干涉。需要指出的是，第四避让位置与第三避让位置处于第二输送位置的两侧，也即，沿第二调节机构456的动作轨迹上，第三避让位置、第二输送位置和第四避让位置依次设置。
通过第二调节机构456调节第三输送机构454和第四输送机构455的位置，以使得第三输送机构454将第三分段2321输送至第二复合机构432，或使得第四输送机构455将第四分段2322输送至第二复合机构432，保证第一极片231的输送效率，进而保证电极组件23的生产效率。
需要指出的是，第二调节机构456的数量可以为一个，第二调节机构456用于同步调节第三输送机构454和第四输送机构455的位置；或者，第二调节机构456的数量可以为两个，其中一个第二调节机构456用于调节第三输送机构454的位置，另一个第二调节机构456用于调节第四输送机构455的位置。
根据本申请的一些实施例，卷绕设备400还包括第三缓存机构463和第四缓存机构464，第三缓存机构463设置于第三子提供机构412a和第二调节机构456之间，第三缓存机构463用于缓存第三分段2321，以便于第二调节机构456调节第三输送机构454的位置时保证第三分段2321持续送料；第四缓存机构464设置于第四子提供机构412b和第二调节机构456之间，第四缓存机构464用于缓存第四分段2322，以便于第二调节机构456调节第四输送机构455的位置时保证第四分段2322持续送料。
可选地，第三缓存机构463和第四缓存机构464可以均为摆杆缓存机构，其包括多个摆杆，通过调节相邻两个摆杆之间的距离改变对应的第二极片的部分经过对应的缓存机构的长度，进而实现第二极片的缓存。
根据本申请的一些实施例，如图18至图20所示，卷绕设备400还包括第三纠偏机构473和第四纠偏机构474，第三纠偏机构473设置于第三子提供机构412a和第三输送机构454之间，第三纠偏机构473用于对第三分段2321纠偏，以保证第三分段2321的输送精度；第四纠偏机构474设置于第四子提供机构412b和第三输送机构454之间，第四纠偏机构474用于对第四分段2322纠偏，以保证第四分段2322的输送精度。第三纠偏机构473和第四纠偏机构474可以参照现有技术的纠偏装置，本申请不作详细介绍。
根据本申请的一些实施例，如图18至图20所示，第二复合机构432的上游设置有第二裁切机构482，第二裁切机构482用于裁切第三分段2321或第四分段2322，以便于第二调节机构456调节第三输送机构454和第四输送机构455的位置。第二裁切机构482可以参照现有技术的裁切装置，本申请不作详细介绍。
根据本申请的一些实施例，如图18至图20所示，卷绕设备400还包括第二图像检测系统493和第二入卷前纠偏机构494，第二图像检测系统493和第二入卷前纠偏机构494设置于第二复合机构432和卷绕机构44之间，第二图像检测系统493用于获取第二复合机构432复合后的第二极片232和隔膜233的图像信息，第二入卷前纠偏机构494用于纠正该第二极片232和隔膜233。第二图像检测系统493可以为CCD相机；第二入卷前纠偏机构494可以参照现有技术的纠偏装置，本申请不作详细介绍。
根据本申请的一些实施例，如图18至图20所示，卷绕设备400还包括第二卷前张力系统512，第二卷前张力系统512设置于卷绕机构44的上游，用于调节第二极片232的张力。第二卷前张力系统512包括第二张力辊和第二调节件，第二调节件用于调节第二张力辊的位置，以改变第二极片232的张力。
根据本申请的一些实施例，如图15至图20所示，卷绕设备400还包括隔膜切刀52、收尾压轮53和贴胶压轮54，隔膜切刀52、收尾压轮53和贴胶压轮54均设置于卷绕机构44处，隔膜切刀52用于在电极组件23卷绕成型后切断隔膜233；收尾压轮53用于辊压卷绕后的电极组件23，防止卷绕后的电极组件23松散；贴胶压轮54用于在卷绕后的电极组件23贴收尾胶。
根据本申请的一些实施例，在卷绕机构44的下游，通常设置有压实工位55，以将卷绕后的电极组件23压实，保证电极组件23构成的电池单体20具有较高的能量密度。
上文描述了本申请实施例的电极组件23和卷绕设备，下面将描述本申请实施例的卷绕方法，其中未详细描述的部分可参见前述各实施例。
图21示出了本申请一些实施例提供的卷绕方法600的示意性流程图。如图21所示，该卷绕方法600可以包括：
601，提供第一极片231，第一极片231包括第一分段2311和第二分段2312，第一分段2311上设有第一活性物质层2311a，第二分段2312上设有第二活性物质层2312a；
602，提供第二极片232，第二极片232的极性与第一极片231的极性相反；
603，提供隔膜233；
604，将第一分段2311、第二分段2312、隔膜233和第二极片232沿卷绕方向卷绕，以形成电极组件23，其中，第一分段2311先与隔膜233和第二极片232卷绕，第二分段2312在第一分段2311之后与隔膜233和第二极片232卷绕。
需要指出的是，在步骤“604，将第一分段2311、第二分段2312、隔膜233和第二极片232沿卷绕方向卷绕”的步骤中，沿由内至外的卷绕方向，第一分段2311位于第二分段2312的上游。
根据本申请的一些实施例，第一活性物质层2311a的涂敷密度与第二活性物质层2312a的涂敷密度不同；和/或第一活性物质层2311a的厚度与第二活性物质层2312a的厚度不同；和/或第一活性物质层2311a的活性物质材料与第二活性物质层2312a的活性物质材料相同或者不同。
根据本申请的一些实施例，第一活性物质层2311a的涂敷密度小于第二活性物质层2312a的涂敷密度。
虽然已经参考优选实施例对本申请进行了描述，但在不脱离本申请的范围的情况下，可以对其进行各种改进并且可以用等效物替换其中的部件。尤其是，只要不存在结构冲突，各个实施例中所提到的各项技术特征均可以任意方式组合起来。本申请并不局限于文中公开的特定实施例，而是包括落入权利要求的范围内的所有技术方案。

Claims (36)

  1. 一种电极组件，包括极性相反的第一极片和第二极片，所述第一极片和所述第二极片层叠并沿卷绕方向卷绕形成所述电极组件；
    所述第一极片包括第一分段和第二分段；所述第一分段上设有第一活性物质层；所述第二分段上设有第二活性物质层；沿由内至外的卷绕方向，所述第一分段位于所述第二分段的上游。
  2. 根据权利要求1所述的电极组件，其中，所述第一活性物质层的涂敷密度与所述第二活性物质层的涂敷密度不同。
  3. 根据权利要求2所述的电极组件，其中，所述第一活性物质层的涂敷密度小于所述第二活性物质层的涂敷密度。
  4. 根据权利要求1-3中任一项所述的电极组件，其中，所述第一活性物质层的厚度与所述第二活性物质层的厚度不同。
  5. 根据权利要求4所述的电极组件，其中，所述第一活性物质层的厚度与所述第二活性物质层的厚度比为1/2-3/2。
  6. 根据权利要求1所述的电极组件，其中，所述第一活性物质层的活性物质材料与所述第二活性物质层的活性物质材料相同或者不同。
  7. 根据权利要求1-6中任一项所述的电极组件，其中，沿由内至外的卷绕方向，所述第一分段的尾部和所述第二分段的头部相连接或者所述第一分段的尾部和所述第二分段的头部之间设有间隙。
  8. 根据权利要求7所述的电极组件，其中，所述第一极片还包括第一集流体，所述第一活性物质层和所述第二活性物质层分别设于所述第一集流体上。
  9. 根据权利要求7所述的电极组件，其中，所述第一极片还包括第一集流体分段和第二集流体分段，所述第一活性物质层设于所述第一集流体分段上以形成所述第一分段，所述第二活性物质层设于所述第二集流体分段上以形成所述第二分段。
  10. 根据权利要求9所述的电极组件，其中，所述第一分段的尾部和所述第二分段的头部通过第一连接部相连接。
  11. 根据权利要求1所述的电极组件，其中，所述电极组件还包括隔膜，用于分隔所述第一极片和所述第二极片。
  12. 根据权利要求11所述的电极组件，其中，所述第二分段的头部连接于所述隔膜。
  13. 根据权利要求1-6中任一项所述的电极组件，其中，所述第二极片包括第三分段和第四分段；所述第三分段上设有第三活性物质层；所述第四分段上设有第四活性物质层；沿由内至外的卷绕方向，所述第三分段位于所述第四分段的上游。
  14. 根据权利要求13所述的电极组件，其中，
    所述第三活性物质层的涂敷密度与所述第四活性物质层的涂敷密度不同；和/或
    所述第三活性物质层的厚度与所述第四活性物质层的厚度不同；和/或
    所述第三活性物质层的活性物质材料与所述第四活性物质层的活性物质材料相同或者不同。
  15. 根据权利要求14所述的电极组件，其中，所述第三活性物质层的厚度与所述第四活性物质层的厚度比为1/2-3/2。
  16. 根据权利要求13-15中任一项所述的电极组件，其中，沿由内至外的卷绕方向，所述第三分段的尾部和所述第四分段的头部相连接或者所述第三分段的尾部和所述第四分段的头部之间设有间隙。
  17. 根据权利要求16所述的电极组件，其中，所述第二极片还包括第二集流体，所述第三活性物质层和所述第四活性物质层分别设于所述第二集流体上。
  18. 根据权利要求16所述的电极组件，其中，所述第二极片还包括第三集流体分段和第四集流体分段，所述第三活性物质层设于所述第三集流体分段上以形成所述第三分段，所述第四活性物质层设于所述第四集流体分段上以形成所述第四分段。
  19. 根据权利要求18所述的电极组件，其中，所述第三分段的尾部和所述第四分段的头部通过第二连接部相连接。
  20. 根据权利要求13所述的电极组件，其中，所述电极组件还包括隔膜，用于分隔所述第一极片和所述第二极片，所述第四分段的头部连接于所述隔膜。
  21. 根据权利要求20所述的电极组件，其中，所述电极组件包括两个所述隔膜，两个所述隔膜分别位于所述第二极片的两侧，所述第二分段的头部与一个所述隔膜连接，所述第四分段的头部与另一个所述隔膜连接。
  22. 根据权利要求13-21中任一项所述的电极组件，其中，所述第三分段的圈数小于所述第四分段的圈数。
  23. 根据权利要求1-22中任一项所述的电极组件，其中，所述第一分段的圈数小于所述第二分段的圈数。
  24. 根据权利要求1-23中任一项所述的电极组件，其中，所述第二活性物质层的涂敷密度比所述第一活性物质层的涂敷密度大10％-200％。
  25. 一种电池单体，包括如权利要求1-24中任一项所述的电极组件。
  26. 一种电池，包括如权利要求25所述的电池单体。
  27. 一种用电设备，包括如权利要求26所述的电池。
  28. 一种卷绕设备，所述卷绕设备包括：
    第一提供装置，用于提供第一极片，所述第一极片包括第一分段和第二分段；所述第一分段上设有第一活性物质层；所述第二分段上设有第二活性物质层；
    第二提供装置，用于提供与所述第一极片的极性相反的第二极片；
    隔膜提供机构，用于提供隔膜；
    卷绕机构，设置于所述第一提供装置、所述第二提供装置和所述隔膜提供机构的下游，用于将所述第一分段、所述第二分段、所述隔膜和所述第二极片沿卷绕方向卷绕，以形成电极组件；
    其中，所述第一提供装置被配置为以如下方式提供所述第一极片：使所述第一分段先进入所述卷绕机构，使所述第二分段在所述第一分段之后进入所述卷绕机构。
  29. 根据权利要求28所述的卷绕设备，其中，所述第一活性物质层的涂敷密度与所述第二活性物质层的涂敷密度不同；和/或
    所述第一活性物质层的厚度与所述第二活性物质层的厚度不同；和/或
    所述第一活性物质层的活性物质材料与所述第二活性物质层的活性物质材料相同或者不同。
  30. 根据权利要求28或29所述的卷绕设备，其中，所述第二极片包括第三分段和第四分段；所述第三分段上设有第三活性物质层；所述第四分段上设有第四活性物质层；
    其中，所述第二提供装置被配置为以如下方式提供所述第二极片：使所述第三分段先进入所述卷绕机构，使所述第四分段在所述第三分段之后进入所述卷绕机构。
  31. 根据权利要求30所述的卷绕设备，其中，所述第三活性物质层的涂敷密度与所述第四活性物质层的涂敷密度不同；和/或
    所述第三活性物质层的厚度与所述第四活性物质层的厚度不同；和/或
    所述第三活性物质层的活性物质材料与所述第四活性物质层的活性物质材料相同或者不同。
  32. 根据权利要求28所述的卷绕设备，其中，所述隔膜包括第一隔膜和第二隔膜，所述隔膜提供机构用于提供所述第一隔膜和所述第二隔膜；
    所述卷绕设备还包括第一复合机构，所述第一复合机构位于所述第一提供装置和所述隔膜提供机构的下游，所述第一复合机构用于将所述第一隔膜、所述第一极片和所述第二隔膜复合成为第一极片组件；
    所述第一提供装置被配置为以如下方式提供所述第一极片：使所述第一分段先进入所述第一复合机构，使所述第二分段在所述第一分段之后进入所述第一复合机构；
    所述卷绕机构，设置于所述第一复合机构的下游，用于将所述第一极片组件和所述第二极片沿卷绕方向卷绕，以形成电极组件。
  33. 根据权利要求28所述的卷绕设备，其中，所述第一提供装置包括第一连接机构，所述第一连接机构用于将所述第一分段的尾部和所述第二分段的头部通过第一连接部相连接。
  34. 根据权利要求28所述的卷绕设备，其中，所述隔膜包括第一隔膜和第二隔膜，所述卷绕设备包括两个所述隔膜提供机构，一个所述隔膜提供机构用于提供所述第一隔膜，另一个所述隔膜提供机构用于提供所述第二隔膜；
    所述卷绕设备还包括：
    第一复合机构，位于所述第一提供装置和一个所述隔膜提供机构的下游，所述第一复合机构用于将所述第一极片和所述第一隔膜复合成为第一极片组件；
    第二复合机构，位于所述第二提供装置和另一个所述隔膜提供机构的下游，所述第二复合机构用于将所述第二极片和所述第二隔膜复合成为第二极片组件；
    所述第一提供装置被配置为以如下方式提供所述第一极片：使所述第一分段先进入所述第一复合机构，使所述第二分段在所述第一分段之后进入所述第一复合机构；
    所述卷绕机构设置于所述第一复合机构和所述第二复合机构的下游，用于将所述第一极片组件和所述第二极片组件沿卷绕方向卷绕，以形成电极组件。
  35. 一种卷绕方法，所述卷绕方法包括：
    提供第一极片，所述第一极片包括第一分段和第二分段，所述第一分段上设有第一活性物质层，所述第二分段上设有第二活性物质层；
    提供第二极片，所述第二极片的极性与所述第一极片的极性相反；
    提供隔膜；
    将所述第一分段、所述第二分段、所述隔膜和所述第二极片沿卷绕方向卷绕，以形成电极组件，其中，所述第一分段先与所述隔膜和所述第二极片卷绕，所述第二分段在所述第一分段之后与所述隔膜和所述第二极片卷绕。
  36. 根据权利要求35所述的卷绕方法，其中，所述第一活性物质层的涂敷密度与所述第二活性物质层的涂敷密度不同；和/或
    所述第一活性物质层的厚度与所述第二活性物质层的厚度不同；和/或
    所述第一活性物质层的活性物质材料与所述第二活性物质层的活性物质材料相同或者不同。
PCT/CN2022/121435 2022-03-31 2022-09-26 电极组件、电池单体、电池、用电设备、卷绕设备及方法 WO2023184903A1 (zh)

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