WO2023201726A1 - 电池单体、电池以及用电装置 - Google Patents

电池单体、电池以及用电装置 Download PDF

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Publication number
WO2023201726A1
WO2023201726A1 PCT/CN2022/088579 CN2022088579W WO2023201726A1 WO 2023201726 A1 WO2023201726 A1 WO 2023201726A1 CN 2022088579 W CN2022088579 W CN 2022088579W WO 2023201726 A1 WO2023201726 A1 WO 2023201726A1
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WO
WIPO (PCT)
Prior art keywords
electrode assembly
restraint
battery cell
restraining member
main body
Prior art date
Application number
PCT/CN2022/088579
Other languages
English (en)
French (fr)
Inventor
金海族
刘威
许虎
Original Assignee
宁德时代新能源科技股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
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 CN202280035219.8A priority Critical patent/CN117321831A/zh
Priority to PCT/CN2022/088579 priority patent/WO2023201726A1/zh
Priority to EP22937962.3A priority patent/EP4376153A1/en
Publication of WO2023201726A1 publication Critical patent/WO2023201726A1/zh
Priority to US18/442,169 priority patent/US20240186622A1/en

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Classifications

    • 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
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/14—Primary casings; Jackets or wrappings for protecting against damage caused by external factors
    • 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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H01M10/0468—Compression means for stacks of electrodes and separators
    • 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
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/116—Primary casings; Jackets or wrappings characterised by the material
    • H01M50/121—Organic material
    • 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
    • H01M50/471—Spacing elements inside cells other than separators, membranes or diaphragms; Manufacturing processes thereof
    • H01M50/474—Spacing elements inside cells other than separators, membranes or diaphragms; Manufacturing processes thereof characterised by their position inside the cells
    • 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
    • H01M50/471—Spacing elements inside cells other than separators, membranes or diaphragms; Manufacturing processes thereof
    • H01M50/477—Spacing elements inside cells other than separators, membranes or diaphragms; Manufacturing processes thereof characterised by their shape
    • 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

Definitions

  • the present application relates to the field of battery technology, and more specifically, to a battery cell, a battery and an electrical device.
  • Batteries are widely used in electronic devices, such as mobile phones, laptops, battery cars, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, electric tools, etc.
  • the battery cells may include cadmium-nickel battery cells, nickel-hydrogen battery cells, lithium-ion battery cells, secondary alkaline zinc-manganese battery cells, etc.
  • This application provides a battery cell, a battery and an electrical device, which can improve the service life of the battery cell.
  • a battery cell including a casing, an electrode assembly and at least one restraining member; the electrode assembly is disposed in the casing, the electrode assembly includes a main body, and the main body has a structure oppositely arranged along the axial direction of the electrode assembly. The first end and the second end; at least one restraint is disposed between the peripheral side of the main body and the shell, wherein the at least one restraint includes a first restraint, and the minimum distance between the first restraint and the first end is less than the first restraint. The minimum distance between a restraint and the second end.
  • the first restraint by setting the minimum distance between the first restraint and the first end to be smaller than the minimum distance between the first restraint and the second end, as the number of charge and discharge cycles of the electrode assembly increases, the first restraint
  • the binding force distribution of the electrode assembly on the electrode assembly deviates from the mid-section setting, so that the internal stress of the electrode assembly deviates from the mid-section area is enhanced.
  • This can balance the internal stress difference of the electrode assembly itself, make the internal stress distribution of the electrode assembly as consistent as possible, and improve the electrode assembly.
  • the stability and consistency of charge and discharge performance thereby improving the cycle life of the battery cells.
  • the electrode assembly has a first attachment area on its peripheral side, and the first binding member is attached to at least a part of the first attachment area; the first attachment area starts from the first end and extends along The first attachment region extends axially, and the axial dimension of the first attachment region is less than 1/3 of the axial dimension of the main body portion. In this way, the internal stress difference of the electrode assembly is further reduced and the consistency of the charge and discharge performance of the electrode assembly is improved.
  • the electrode assembly includes a first pole piece, the first pole piece includes a first active material layer located on the main body, the first active material layer includes a base region and a thinned region, and the thickness of the thinned region is smaller than the base region
  • the thickness of the thinned area is located on the side of the base area close to the first end in the axial direction; in the axial direction, the first binding member is offset from the thinned area.
  • Providing a thinned area can reduce the stress concentration at the edge of the thinned area away from the base area, thereby reducing the risk of fracture of the first pole piece.
  • the distance between the first restraining member and the thinned area is 1 mm to 2 mm in the axial direction. In this way, the risk of the first restraint member exerting a binding force on the thinned area can be further reduced, thereby reducing the risk of the electrode assembly corresponding to the thinned area being greatly deformed and damaged.
  • At least one of the restraints includes a second restraint with a minimum distance from the second end that is less than a minimum separation of the second restraint from the first end.
  • a peripheral side of the electrode assembly has a second attachment area, and the second binding member is attached to at least a part of the second attachment area; the second attachment area starts from the second end and extends along The second attachment area extends axially, and the axial dimension of the second attachment area is less than 1/3 of the axial dimension of the main body portion. Further reduce the stress difference within the electrode assembly and improve the consistency of the charge and discharge performance of the electrode assembly.
  • the main body portion has a mid-section between the first end and the second end, and the second restraint and the first restraint are axially symmetrically disposed about the mid-section. It is conducive to further improving the consistency of stress distribution within the electrode assembly, thereby improving the consistency of the charge and discharge performance of the electrode assembly.
  • the at least one restraint includes a third restraint, the body portion having a mid-section between the first end and the second end, the third restraint covering the mid-section.
  • the restraining member can balance the stress within the electrode assembly and at the same time improve the stability of the electrode assembly within the housing.
  • the at least one restraint includes a third restraint, the body portion having a mid-section between the first end and the second end, and the third restraint is attached in a region between the mid-section and the first end. on, and the third binding member is located on the side of the first binding member close to the second end.
  • the thickness of the first restraint is greater than the thickness of the third restraint. In this way, it is more conducive to improving the consistency of the internal stress of the electrode assembly, thereby improving the consistency of the charge and discharge performance of the electrode assembly.
  • the body portion has a mid-section at the first and second ends; the at least one tie includes a fourth tie attached to a region between the mid-section and the second end, and The fourth binding member is located on a side of the second binding member close to the first end. In this way, the consistency of stress within the electrode assembly is further improved.
  • At least one restraint includes a third restraint, and the fourth restraint and the third restraint are disposed symmetrically about the mid-section. In this way, the consistency of the charge and discharge performance of the electrode assembly can still be further improved.
  • the restraint is configured to expand upon absorbing electrolyte. In this way, the restraining effect of the restraining member on the electrode assembly can be ensured, and at the same time, the operation of inserting the restraining member and the electrode assembly into the shell can be smoothly carried out during the assembly process.
  • the material of the restraint includes at least one of thermoplastic polyurethane, dextran gel, and hydroxyl-terminated polybutadiene-polyurethane.
  • the binding member will have a suitable thickness after swelling when exposed to the electrolyte, and then the binding member formed after expansion will have a suitable binding force on the electrode assembly.
  • the restraint along the circumferential direction of the electrode assembly, has a first free end and a second free end; the restraint includes an overlapping portion disposed between the first free end and the second free end along a circumferential direction of the electrode assembly.
  • the central angle ⁇ of the overlapping portion satisfies: ⁇ 30°. In this way, it is helpful to ensure the binding force of the binding member to the electrode assembly and facilitate the installation of the binding member.
  • the restraint along the circumferential direction of the electrode assembly, has a first free end and a second free end, and the first free end and the second free end are spaced apart;
  • the main body has an exposed area, and the exposed area is located at the first free end. between the end and the second free end, and is exposed outside the binding member;
  • the central angle ⁇ of the exposed area satisfies, ⁇ ⁇ 180°. While ensuring that the restraint provides certain restraints for the electrode assembly, it is convenient for the electrolyte to enter the interior of the electrode assembly through the exposed area, thereby improving the wettability of the electrolyte to the electrode assembly.
  • the exposed area can reserve space for the expansion of the electrode assembly, reducing the risk of damage to the electrode assembly due to expansion and deformation.
  • the restraint includes a plurality of first portions spaced apart circumferentially of the electrode assembly. It is beneficial to ensure the binding force of the restraint on the electrode assembly to reduce the possibility of shaking of the electrode assembly.
  • the gaps along the circumferential direction of the electrode assembly can be used as channels for electrolyte circulation to improve the flow of electrolyte. sex.
  • the gap between the first parts can reserve space for the expansion of the electrode assembly, further reducing the risk of damage to the electrode assembly due to expansion and deformation.
  • the electrode assembly includes a first pole piece, and the first pole piece is wound into multiple turns; in the circumferential direction of the electrode assembly, the binding member is offset from the tail end of the outermost first pole piece. In this way, it is helpful to reduce the risk of stress concentration in the electrode assembly at the tail end of the first pole piece, thereby reducing the risk of deformation and damage of the electrode assembly.
  • embodiments of the present application provide a battery, including the battery cell as in any embodiment of the first aspect.
  • the battery provided according to the embodiments of the present application uses the battery cell provided in any of the above embodiments, and therefore has the same technical effect, which will not be described again here.
  • an embodiment of the present application provides an electrical device, including a battery as in the embodiment of the second aspect, and the battery is used to provide electric energy.
  • the electrical device provided according to the embodiment of the present application uses the battery provided by the embodiment of the present application, and therefore has the same technical effect, which will not be described again here.
  • Figure 1 is a schematic structural diagram of a vehicle provided by an embodiment of the present application.
  • FIG. 2 is an exploded schematic diagram of a battery provided by an embodiment of the present application.
  • FIG. 3 is a schematic structural diagram of a battery module in a battery provided by an embodiment of the present application.
  • Figure 4 is an exploded schematic diagram of a battery cell provided by some embodiments of the present application.
  • Figure 5 is a schematic diagram of the exploded structure of another battery cell provided by the embodiment of the present application.
  • Figure 6 is a partial cross-sectional structural schematic diagram of the electrode assembly in the battery cell provided by the embodiment of the present application.
  • Figure 7 is a schematic diagram of the exploded structure of another battery cell provided by the embodiment of the present application.
  • Figure 8 is a schematic diagram of an exploded structure of another battery cell provided by an embodiment of the present application.
  • Figure 9 is a schematic diagram of the exploded structure of yet another battery cell provided by the embodiment of the present application.
  • Figure 10 is a schematic diagram of the exploded structure of yet another battery cell provided by the embodiment of the present application.
  • Figure 11 is a schematic cross-sectional structural view of a battery cell perpendicular to the axial direction according to an embodiment of the present application
  • Figure 12 is another cross-sectional structural schematic diagram of a battery cell perpendicular to the axial direction provided by the embodiment of the present application;
  • Figure 13 is another schematic cross-sectional structural diagram of a battery cell perpendicular to the axial direction provided by the embodiment of the present application;
  • Figure 14 is a schematic cross-sectional structural diagram of another battery cell perpendicular to the axial direction provided by the embodiment of the present application.
  • Vehicle 1a, motor; 1b, controller;
  • Electrode assembly 32a, first attachment area; 32b, second attachment area; 321, main body; 321a, first end; 321b, second end; 321c, base area; 321d, thinned area; 321e, exposed area; 321f, middle section; 3211, first pole piece; 3211a, tail end; 32111, first activity Material layer; 322, first pole; 33, binding member; 33a, first free end; 33b, second free end; 33c, overlapping portion; 33d, first part; 331, first binding member; 332, second Binding piece; 333, third binding piece; 334, fourth binding piece;
  • 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.
  • 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.
  • “Plural” appearing in this application means two or more (including two).
  • battery cells may include lithium ion secondary battery cells, lithium ion primary battery cells, lithium sulfur battery cells, sodium lithium ion battery cells, sodium ion battery cells or magnesium ion battery cells, etc.
  • the embodiments of the present application are not limited to this.
  • the battery cell may be in the shape of a cylinder, a flat body, a rectangular parallelepiped or other shapes, and the embodiments of the present application are not limited to this.
  • Battery cells are generally divided into three types according to packaging methods: cylindrical battery cells, square battery cells and soft-pack battery cells, and the embodiments of the present application are not limited to this.
  • the battery mentioned in the embodiments of this application 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.
  • Batteries generally include a box for packaging one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.
  • the battery cell includes an electrode assembly and an electrolyte.
  • the electrode assembly includes a positive electrode piece, a negative electrode piece 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, and the positive electrode active material layer is coated on the surface of the positive electrode current collector;
  • the positive electrode current collector includes a positive electrode current collecting part and a positive electrode convex part protruding from the positive electrode current collecting part, and the positive electrode current collecting part
  • the positive electrode convex part is coated with the positive electrode active material layer, and at least part of the positive electrode convex part is not coated with the positive electrode active material layer, and the positive electrode convex part serves as the positive electrode tab.
  • the material of the cathode current collector can be aluminum, and the cathode active material layer includes cathode active materials.
  • the cathode 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, and the negative electrode active material layer is coated on the surface of the negative electrode current collector; the negative electrode current collector includes a negative electrode current collecting part and a negative electrode convex part protruding from the negative electrode current collecting part, and the negative electrode current collecting part
  • the negative electrode active material layer is coated on the negative electrode active material layer, and at least part of the negative electrode protruding part is not coated with the negative electrode active material layer, and the negative electrode protruding part serves as the negative electrode tab.
  • the negative electrode current collector may be made of copper, and the negative electrode active material layer may include a negative electrode active material.
  • the negative electrode active material may 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 isolator can be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene), etc.
  • the electrode assembly may have a rolled structure or a laminated structure, and the embodiments of the present application are not limited thereto.
  • the inventor has improved the structure of the battery cell.
  • the technical solutions described in the embodiments of the present application are applicable to battery cells, batteries containing battery cells, and electrical devices using batteries.
  • the battery cell provided according to the embodiment of the present application includes a casing, an electrode assembly and at least one restraining member.
  • the electrode assembly is disposed in the housing and includes a main body.
  • the main body has a first end and a second end oppositely arranged along the axial direction of the electrode assembly.
  • At least one restraining member is disposed between the peripheral side of the main body and the housing.
  • At least one restraint includes a first restraint, and a minimum distance between the first restraint and the first end is less than a minimum distance between the first restraint and the second end.
  • the minimum distance between the first restraint and the first end is smaller than the minimum distance between the first restraint and the second end, that is, the first restraint is asymmetrical with respect to both ends of the main body. set up. Then the distribution of the binding force of the first binding member on the electrode assembly deviates from the mid-section of the main body, and the internal stress in the area of the main body deviating from the mid-section is enhanced due to the binding force of the first binding member to balance the proximity of this area to the electrode assembly.
  • the internal stress difference in the mid-section area improves the consistency of the internal stress of the electrode assembly and the consistency of the charge and discharge performance of the electrode assembly, thereby improving the cycle life of the battery cell.
  • Electrical devices can be vehicles, cell phones, portable devices, laptops, ships, spacecraft, electric toys and power tools, etc.
  • Vehicles can be fuel vehicles, gas vehicles or new energy vehicles, and new energy vehicles can be pure electric vehicles, hybrid vehicles or extended-range vehicles, etc.
  • spacecraft include aircraft, rockets, space shuttles, spaceships, etc.
  • electric toys include fixed Type or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc.
  • electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, for example, Electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, planers and more.
  • Electric drills Electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, planers and more.
  • the following embodiments take the electrical device as a vehicle as an example.
  • a battery 10 is provided inside the vehicle 1 .
  • the battery 10 may be disposed at the bottom, head or tail of the vehicle 1 .
  • the battery 10 may be used to power the vehicle 1 , for example, the battery 10 may serve as an operating power source for the vehicle 1 .
  • the vehicle 1 may also include a controller 1b and a motor 1a.
  • the controller 1b is used to control the battery 10 to supply power to the motor 1a, for example, for the starting, navigation and operating power requirements of the vehicle 1 when driving.
  • the battery 10 can not only be used as an operating power source for the vehicle 1 , but also can be used as a driving power source for the vehicle 1 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1 .
  • the battery 10 includes battery cells (not shown in FIG. 2 ).
  • the battery 10 may also include a case for housing the battery cells.
  • the box is used to accommodate battery cells, and the box can be of various structural forms.
  • the case may include a first case part 11 and a second case part 12 .
  • the first box part 11 and the second box part 12 cover each other.
  • the first box part 11 and the second box part 12 jointly define an accommodation space for accommodating battery cells.
  • the second box part 12 may be a hollow structure with one end open, and the first box part 11 is a plate-like structure.
  • the first box part 11 is covered with the opening side of the second box part 12 to form a container with accommodating space.
  • Box The first box part 11 and the second box part 12 may also be hollow structures with one side open.
  • the open side of the first box part 11 is covered with the open side of the second box part 12 to form a box with an accommodation space.
  • the first box part 11 and the second box part 12 can be in various shapes, such as cylinder, rectangular parallelepiped, etc.
  • a sealing member such as sealant, sealing ring, etc., may be provided between the first box part 11 and the second box part 12 .
  • the first box part 11 can also be called an upper box cover, and the second box part 12 can also be called a lower box.
  • the battery 10 there may be one battery cell or a plurality of battery cells. If there are multiple battery cells, the multiple battery cells can be connected in series, parallel, or mixed. Hybrid connection means that multiple battery cells are connected in series and in parallel. Multiple battery cells can be directly connected in series, parallel, or mixed together, and then the whole composed of multiple battery cells can be accommodated in the box. Multiple battery cells can also be connected in series, parallel, or mixed to form a battery. Module 20. A plurality of battery modules 20 are connected in series, parallel, or mixed to form a whole, and are accommodated in the box.
  • FIG. 3 is a schematic structural diagram of the battery module 20 shown in FIG. 2 .
  • the battery module 20 has a plurality of battery cells 30 .
  • a plurality of battery cells 30 are first connected in series, parallel, or mixed to form the battery module 20 .
  • a plurality of battery modules 20 are connected in series, parallel, or mixed to form a whole, and are accommodated in the box.
  • the plurality of battery cells 30 in the battery module 20 can be electrically connected through bus components to realize parallel, series or mixed connection of the plurality of battery cells 30 in the battery module 20 .
  • FIG. 4 is an exploded schematic diagram of the battery cell 30 shown in FIG. 3 .
  • the battery cell 30 provided in the embodiment of the present application includes an electrode assembly 32 and a casing 31.
  • the casing 31 has an accommodating cavity, and the electrode assembly 32 is accommodated in the accommodating cavity.
  • the housing 31 may include a housing 311 and an end cover 312.
  • the housing 311 is a hollow structure with one side open.
  • the end cover 312 covers the opening 311a of the housing 311 and forms a sealing connection to form a user-friendly structure. in a sealed space containing the electrode assembly 32 and the electrolyte.
  • the electrode assembly 32 When assembling the battery cell 30, the electrode assembly 32 can be first placed into the case 311, and then the end cap 312 is closed to the opening of the case 311, and then the electrolyte is injected into the case through the electrolyte injection port on the end cap 312. Within 311.
  • housing 31 may also be used to contain an electrolyte, such as an electrolyte solution.
  • the housing 31 can have various structural forms.
  • Figure 4 shows a schematic structural diagram of a battery cell provided by an embodiment of the present application.
  • the housing 311 can be in various shapes, such as cylinder, cuboid, etc.
  • the shape of the housing 311 can be determined according to the specific shape of the electrode assembly 32 . For example, if the electrode assembly 32 has a cylindrical structure, the housing 311 can be selected to have a cylindrical structure. If the electrode assembly 32 has a rectangular parallelepiped structure, the housing 311 may have a rectangular parallelepiped structure. In FIG. 4 , as an example, both the housing 311 and the electrode assembly 32 have a rectangular parallelepiped structure.
  • the housing 311 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., which are not particularly limited in the embodiment of the present application.
  • Electrodes assemblies 32 There may be one or more electrode assemblies 32 accommodated in the housing 311 .
  • FIG. 4 there are two electrode assemblies 32 accommodated in the housing 311 .
  • electrode assembly 32 also includes a positive electrode tab, a negative electrode tab, and a separator.
  • the electrode assembly 32 may be a rolled structure formed by winding a positive electrode piece, a separator, and a negative electrode piece.
  • the electrode assembly 32 may also be a stacked structure formed by a stacked arrangement of a positive electrode piece, a separator, and a negative electrode piece.
  • the positive electrode sheet may include a positive electrode current collector and a positive electrode active material layer.
  • the positive active material layer is coated on the surface of the positive current collector.
  • the negative electrode sheet may include a negative electrode current collector and a negative electrode active material layer.
  • the negative active material layer is coated on the surface of the negative current collector.
  • the separator is between the positive electrode piece and the negative electrode piece and is used to isolate the positive electrode piece and the negative electrode piece to reduce the risk of short circuit between the positive electrode piece and the negative electrode piece.
  • the pole tabs in the electrode assembly 32 are divided into positive pole tabs and negative pole tabs.
  • the positive electrode tab may be a portion of the positive electrode current collector that is not coated with the positive electrode active material layer.
  • the negative electrode tab may be a portion of the negative electrode current collector that is not coated with the negative electrode active material layer.
  • FIG. 5 shows a schematic diagram of an exploded structure of the battery cell 30 provided by the embodiment of the present application.
  • a battery cell 30 provided according to an embodiment of the present application includes a housing 31 , an electrode assembly 32 and at least one binding member 33 .
  • the electrode assembly 32 is disposed in the housing 31 .
  • the electrode assembly 32 includes a main body 321 .
  • the main body 321 has a first end 321 a and a second end 321 b oppositely arranged along the axial direction X of the electrode assembly 32 .
  • At least one restraining member 33 is provided between the peripheral side of the main body 321 and the housing 31 , wherein the at least one restraining member 33 includes a first restraining member 331 , and the minimum distance between the first restraining member 331 and the first end 321 a is smaller than the first restraining member 331 . The minimum distance between the restraining member 331 and the second end 321b.
  • the electrode assembly 32 can be cylindrical or square, and the pole pieces of the electrode assembly 32 can be rolled or laminated.
  • the surface of the main body portion 321 has an arcuate area and a planar area, and the axis X of the electrode assembly 32 may be a direction parallel to the extending direction of the arcuate area.
  • the electrode assembly 32 may include one tab or two tabs.
  • the tab can be led out from the first end 321a of the main body part 321 or the second end 321b of the main body part 321.
  • the two tabs can be led out from the first end 321a and the second end 321b respectively, or both tabs can be led out from the first end 321a, or both tabs can be lead out from the first end 321a.
  • the pole ears are all led out from the second end 321b, and there is no restriction here.
  • the at least one restraining member 33 may only include the first restraining member 331 , and may also include other restraining members 33 .
  • the shapes, structures, or positional relationships of the different restraining members 33 relative to the electrode assembly 32 may be different from those of the first restraining member 331 . 331 may or may not be the same.
  • the number of the first binding member 331 may be one or multiple, and may be selected according to actual needs.
  • the plurality of first restraining members 331 may be disposed along the axial direction X of the electrode assembly 32 , and two adjacent first restraining members 331 may be disposed at intervals or adjacent to each other. .
  • the peripheral surface of the main body part 321 is the surface of the main body part located between the first end 321a and the second end 321b.
  • At least one binding member 33 is disposed between the peripheral side of the main body 321 and the housing 31 . Then, before the battery cell 30 is charged and discharged, the binding member 33 may be in contact with both the housing 31 and the peripheral side of the main body 321 , or the binding member 33 is in contact with either one of the shell 31 and the main body part 321 , or the restraining member 33 is spaced apart from both the shell 31 and the main body part 321 .
  • the electrode assembly 32 gradually expands, and finally the restraining member 33 contacts between the peripheral side of the main body 321 and the housing 31 to exert a certain restraining force on the main body 321 .
  • the direction of the binding force of the binding member 33 on the electrode assembly 32 may be a direction that competes with the direction of the expansion force of the electrode assembly 32 itself, and may be disposed along the radial direction of the electrode assembly 32 .
  • the minimum distance between the restraining member 33 and the first end 321a may be the distance between the end of the restraining member 33 close to the first end 321a and the first end 321a.
  • the minimum distance between the restraining member 33 and the second end 321b may be the distance between the restraining member 33 and the second end 321b. The distance between the end close to the second end 321b and the second end 321b.
  • the main body part 321 has a middle section 321f located at the first end 321a and the second end 321b.
  • the distance from the first end 321a to the middle section 321f is equal to the distance from the second end 321b to the middle section 321f.
  • the minimum distance between the first restraining part 331 and the first end 321a is less than the minimum distance between the first restraining part 331 and the second end 321b, then the first restraining part 331 is disposed closer to the first end 321a.
  • the first binding member 331 may be provided to cover the middle section 321f, or may be provided at a distance from the middle section 321f, or one end of the first binding member 331 may be provided close to the middle section 321f.
  • the expansion amount of the anode electrode piece of the electrode assembly 32 gradually increases, and the expansion amount of the electrode assembly 32 is greater as it approaches the middle section 321f. If the restraint 33 is not provided, then The closer to the middle section 321f, the greater the internal stress of the electrode assembly 32 itself. In addition, as the electrode assembly 32 gradually expands, the binding force of the first binding member 331 on the electrode assembly 32 gradually increases.
  • the binding force distribution of the first restraining member 331 on the electrode assembly 32 deviates from the middle section 321f, that is, the electrode assembly 32 deviates from the middle section 321f and the internal stress in the area close to the first end 321a is enhanced, which can balance the
  • the difference in internal stress between at least part of the region of the first restraint 331 corresponding to the electrode assembly 32 and the region of the first restraint 331 close to the mid-section 321f can make the internal stress of the electrode assembly 32 corresponding to the two regions as consistent as possible, thereby providing an electrode assembly. 32 consistency of charge and discharge performance.
  • the binding force exerted by the first binding member 331 on the electrode assembly 32 may be equal or distributed in a curve.
  • the binding force of the first binding member 331 on the electrode assembly 32 can be gradually increased to balance the internal stress difference of the electrode assembly 32 itself.
  • At least one restraining member 33 is provided between the peripheral side of the main body 321 and the housing 31 .
  • the at least one restraining member 33 includes a first restraining member 331 .
  • the first restraining member 331 may be disposed in any area between the first end 321a and the middle section 321f, or the first restraining member 331 may be partially disposed on a side of the middle section 321f close to the second end 321b, specifically. You can choose according to your needs, there are no restrictions here.
  • the electrode assembly 32 has a first attachment region 32a on its peripheral side, and the first binding member 331 is attached to at least a portion of the first attachment region 32a.
  • the first attachment area 32a starts from the first end 321a and extends along the axial direction X, and the size of the first attachment area 32a along the axial direction X is less than 1/3 of the size of the main body portion 321 along the axial direction X.
  • the first binding member 331 may be attached to the entire area of the first attachment area 32a, or may be attached to a partial area of the first attachment area 32a.
  • the first binding member 331 is attached to the first attachment area 32a, then the first binding member 331 can be connected to the main body portion 321 of the first attachment area 32a as a whole through bonding or other methods, or a third binding member 331 can be provided.
  • a restraining member 331 only resists the main body part 321 of the first accessory area, as long as the first restraining member 331 can generate a restraining force on the main body part 321.
  • the difference in internal stress of the electrode assembly 32 in the area close to the mid-section 321f is more conducive to improving the consistency and stability of the charge and discharge performance of the electrode assembly 32.
  • FIG. 6 shows a schematic cross-sectional structural diagram of a battery cell along the axial direction according to an embodiment of the present application.
  • the electrode assembly 32 includes a first pole piece 3211.
  • the first pole piece 3211 includes a first active active material layer located in the main body portion 321.
  • the first active material layer 32111 includes a base region 321c. and a thinned area 321d.
  • the thickness of the thinned area 321d is smaller than the thickness of the base area 321c.
  • the thinned area 321d is located on the side of the base area 321c close to the first end 321a in the axial direction X.
  • the first pole piece 3211 can be a positive pole piece or a negative pole piece. Therefore, one of the positive pole piece and the negative pole piece can be provided to include the base region 321c and the thinned region 321d, or it can be provided Both the positive electrode piece and the negative electrode piece include a base region 321c and a thinned region 321d.
  • the stress at the edge of the thinned area 321d away from the base area 321c, that is, the first end 321a of the main body part 321, can be reduced. Concentrate to reduce the risk of breakage of the first pole piece 3211.
  • the surface of the thinned area 321d may be a flat surface or a curved surface.
  • the thickness of the first pole piece 3211 in the thinned area 321d may be equal or unequal.
  • the specific thickness may be selected according to the requirements, and is not limited here.
  • the first restraint 331 is offset from the thinned area 321d.
  • the first restraining member 331 is disposed offset from the thinned area 321d, that is, the thinned area 321d is not provided with the first restraining member 331, and does not overlap with the first restraining member 331. Since the thickness of the thinned region 321d of the first pole piece 3211 is smaller than the thickness of the base region 321c, the gap of the first pole piece 3211 of the thinned region 321d is larger than the gap of the first pole piece 3211 of the base region 321c, and the gap of the thinned region 321d The strength of the first pole piece 3211 is lower than the strength of the first pole piece 3211 in the base region 321c.
  • the thinned area 321d is more likely to deform. Therefore, arranging the first restraining member 331 and the thinned area 321d in an offset position can reduce the risk of the first restraining member 331 causing large deformation and damage to the thinned area 321d.
  • first binding member 331 and the thinned area 321d may be arranged adjacent to each other, or may be arranged at intervals. In the embodiment in which the first binding member 331 and the thinned area 321d are arranged at intervals, the first binding member 331 and the thinned area 321d may be arranged at intervals.
  • the spacing of area 321d is not limited and can be selected according to actual needs.
  • the distance between the first restraining member 331 and the thinned area 321d is 1 mm ⁇ 2 mm. Specifically, the distance between the first restraining member 331 and the thinned area 321d may be 1 mm, 1.5 mm or 2 mm, etc.
  • the distance between the first restraining member 331 and the thinned area 321d may be the distance from an end of the first restraining member 331 close to the thinned area 321d to an end of the thinned area 321d close to the first restraining member 331.
  • Setting the distance between the first binding member 331 and the thinned area 321d to be 1 mm to 2 mm can further reduce the risk of the first binding member 331 exerting a binding force on the thinned area 321d, thereby reducing the risk of the electrode assembly 32 corresponding to the thinned area 321d producing larger Risk of damage due to large deformation.
  • FIG. 7 shows a schematic diagram of an exploded structure of another battery cell 30 provided by an embodiment of the present application.
  • At least one restraint 33 includes a second restraint 332 , and a minimum distance between the second restraint 332 and the second end 321 b is less than a minimum distance between the second restraint 332 and the first end 321 a. spacing.
  • the thickness, shape, structure, etc. of the second binding member 332 and the first binding member 331 may be the same or different.
  • the second restraining member 332 and the first restraining member 331 may be arranged symmetrically with respect to the middle section 321f, or may be arranged asymmetrically with respect to the middle section 321f.
  • the first restraining member 331 is disposed closer to one end, and the second restraining member 332 is disposed closer to the second end 321b,
  • the minimum distance between the second binding part 332 and the second end 321b is less than the minimum distance between the second binding part 332 and the first end 321a. Then along the axial direction X, the second binding part 332 is disposed closer to the second end 321b. Then, as As the number of charge and discharge cycles of the electrode assembly 32 increases, the expansion amount of the electrode assembly 32 gradually increases, and the binding force of the second binding member 332 on the electrode assembly 32 gradually increases.
  • the binding force distribution of the second restraining member 332 on the electrode assembly 32 deviates from the middle section 321f and is closer to the second end 321b, that is, the internal stress in the area of the electrode assembly 32 that deviates from the middle section 321f and is close to the second end 321b is enhanced.
  • the difference in internal stress between at least part of the area of the electrode assembly 32 corresponding to the first restraint 331 and the area close to the middle section 321f can be balanced, so that the internal stress of the electrode assembly 32 is as consistent as possible, further improving the consistency of the charge and discharge performance of the electrode assembly 32 .
  • the binding force of the binding member 33 on the electrode assembly 32 can be adjusted by changing the thickness of the binding member 33 or the like. Therefore, the thickness of the first restraint 331 and the second restraint 332 can be adjusted, so that after the first restraint 331 and the second restraint 332 enhance the internal stress of the electrode assembly 32, the electrode assembly 32 is separated from the first restraint 332 respectively.
  • the internal stresses in the corresponding areas of the binding member 331 and the second binding member 332 are as consistent as possible. In this way, the consistency of the charge and discharge performance of the electrode assembly 32 can be further improved.
  • the second binding member 332 may be disposed in any area between the second end 321b and the middle section 321f, or the second binding member 332 may be partially disposed on a side of the middle section 321f close to the first end 321a. Specifically, Select according to actual needs, there are no restrictions here.
  • the electrode assembly 32 has a second attachment region 32b on its peripheral side, and the second restraint 332 is attached to at least a portion of the second attachment region 32b.
  • the second end 321b of the second attachment area 32b is the starting end and extends along the axial direction X, and the size along the axial direction X of the second attachment area 32b is less than 1/3 of the size along the axial direction X of the main body part 321.
  • the second restraint 332 may be attached to the entire area of the second attachment area 32b, or may be attached to a part of the second attachment area 32b.
  • the second binding member 332 can be integrally connected with the second attachment area 32b through bonding or other methods, or the second binding member 332 can be provided to only resist the second attachment area 32b, as long as the second binding member 332 can be The piece 332 only needs to produce a binding force on the main body part 321.
  • the difference in internal stress of the electrode assembly 32 between the region and the region close to the mid-section 321f is more conducive to improving the consistency and stability of the charge and discharge performance of the electrode assembly 32.
  • the second restraint 332 and the first restraint 331 are arranged symmetrically in the axial direction X with respect to the mid-section 321f.
  • the binding force of the first restraining member 331 on the electrode assembly 32 is arranged symmetrically with respect to the middle section 321f, which is conducive to further improving the consistency of the stress distribution within the electrode assembly 32, thereby improving the consistency of the charge and discharge performance of the electrode assembly 32.
  • FIG. 8 shows a schematic diagram of an exploded structure of a battery cell 30 provided by yet another embodiment of the present application.
  • At least one restraint 33 includes a third restraint 333 covering the mid-section 321f.
  • the binding force of the first binding member 331 and the third binding member 333 on the electrode assembly 32 can be adjusted so that the binding force of the first binding member 331 on the electrode assembly 32 is smaller than the binding force of the third binding member 333 on the electrode assembly 32 .
  • the binding force enables the third binding member 333 to have a certain fixing effect on the electrode assembly 32 while balancing the internal stress of the electrode assembly 32, thereby improving the stability of the electrode assembly 32 in the housing 31.
  • the three restraints 331 , 332 and the third restraint 333 may be arranged at intervals, and according to the relative position of the three restraints along the axial direction X of the electrode assembly 32 Position, set the three to have appropriate thickness or materials, so that after the three exert binding force on the electrode assembly 32, the internal stress of the electrode assembly 32 will be as consistent as possible, thereby improving the consistency of the charge and discharge performance of the electrode assembly 32.
  • FIG. 9 shows a schematic diagram of an exploded structure of yet another battery cell 30 provided by an embodiment of the present application.
  • the third restraint 333 is attached to the area between the mid-section 321f and the first end 321a, and the third restraint 333 is located near the first restraint 331 and the second restraint 333.
  • the first binding member 331 and the third binding member 333 may be provided with different thicknesses or materials, so that the binding force of the third binding member 333 on the electrode assembly 32 is smaller than the binding force of the first binding member 331 on the electrode assembly 32
  • the binding force is such that the internal stresses of the two corresponding electrode assemblies 32 are as consistent as possible. Such an arrangement can still improve the consistency of the charge and discharge performance of the electrode assembly 32 and improve the structural stability of the electrode assembly 32 .
  • first binding member 331 and the third binding member 333 may be provided with different thicknesses, or different materials, or both thicknesses and materials may be different, so that they are opposite to the electrode assembly 32 The binding force is different.
  • the thickness of the first restraint 331 is greater than the thickness of the third restraint 333 .
  • the greater the thickness of the restraining member 33 the greater the space occupied between the housing 31 and the electrode assembly 32 .
  • the restraining force of the restraining member 33 on the electrode assembly 32 becomes greater. Since the first restraint 331 is closer to the first end 321a than the third restraint 333 and the third restraint 333 is disposed closer to the middle section 321f than the first restraint 331, the electrode assembly 32 corresponding to the first restraint 331 Its own expansion amount and internal stress are smaller than those of the electrode assembly 32 corresponding to the third expansion member.
  • setting the thickness of the first restraining member 331 to be greater than the thickness of the third restraining member 333 is more conducive to improving the consistency of the internal stress of the electrode assembly 32, thereby improving the consistency of the charge and discharge performance of the electrode assembly 32.
  • the first binding member 331 and the third binding member 333 may be set to have appropriate thicknesses according to their corresponding positions of the electrode assembly 32 so that the internal stresses of the electrode components 32 corresponding to the two are as consistent as possible.
  • FIG. 10 shows a schematic diagram of an exploded structure of yet another battery cell 30 provided by an embodiment of the present application.
  • At least one restraint 33 includes a fourth restraint 334 attached to the area between the mid-section 321f and the second end 321b, and the fourth restraint 334 is attached to the area between the mid-section 321f and the second end 321b.
  • the member 334 is located on a side of the second binding member 332 close to the first end 321a.
  • first binding member 331 , the second binding member 332 and the fourth binding member 334 can be set to have different thicknesses, materials and other information, so that the first binding member 331 , the second binding member 332 and the fourth binding member 334 334 respectively have appropriate binding force on the electrode assembly 32, thereby making the internal stresses of the three corresponding electrode assemblies 32 as consistent as possible.
  • the third restraint 333 may be related to the fourth restraint 334 .
  • the middle section 321f is set symmetrically, and may also be asymmetrical.
  • At least one restraint 33 includes a third restraint 333 , and the fourth restraint 334 and the third restraint 333 are symmetrically disposed about the mid-section 321f.
  • the third restraint 333 and the fourth restraint 334 can be set to have equal restraints on the electrode assembly 32 respectively, and since the electrode assembly 32 corresponding to the two is symmetrically arranged with respect to the middle section 321f, the electrode assembly 32 corresponding to the two is Their internal stresses are basically the same. In this way, the internal stresses of the electrode assembly 32 corresponding to the third binding member 333 and the fourth binding member 334 are basically the same, which is beneficial to further improving the consistency of the charge and discharge performance of the electrode assembly 32.
  • the first restraint 331 and the second restraint 332 may be symmetrically arranged with respect to the middle section 321f, or may be asymmetrically arranged with respect to the middle section 321f. set up. It can be understood that by simultaneously arranging the first restraining member 331 and the second restraining member 332 to be symmetrically arranged about the middle section 321f, and the third restraining member 333 and the fourth restraining member 334 to be symmetrically arranged about the middle section 321f, the electrode assembly can be better improved. 32 consistency of charge and discharge performance.
  • the binding member 33 may be an elastic member or a non-elastic member.
  • the binding member 33 may be a member whose shape and structure are determined before assembly, or may be a structure with stable structure and performance formed after the battery cells 30 are assembled or during the assembly process.
  • restraint 33 is configured to expand upon absorption of electrolyte.
  • the restraints 33 include a first restraint 331 , a second restraint 332 , a third restraint 333 and a fourth restraint 334
  • the first restraint 331 , the second restraint 334 may be provided. 332.
  • Any one or more of the third binding member 333 and the fourth binding member 334 are configured to expand after absorbing the electrolyte, while the other binding members 33 adopt other structural types.
  • the binding member 33 has a smaller volume before it expands when encountering the electrolyte, which facilitates the binding member 33 to enter the housing 31 together with the electrode assembly 32 .
  • the restraining member 33 expands to a preset thickness and volume, so as to form a certain restraining force on the electrode assembly 32 during subsequent use.
  • the restraining member 33 by arranging the restraining member 33 to expand after absorbing the electrolyte, it is possible to ensure the restraining effect of the restraining member 33 on the electrode assembly 32 and at the same time facilitate the smooth insertion operation of the restraining member 33 and the electrode assembly 32 into the shell during the assembly process. conduct.
  • the material of the restraint 33 includes at least one of thermoplastic polyurethane, dextran gel, and hydroxyl-terminated polybutadiene-polyurethane.
  • the material of the restraint 33 may include one of thermoplastic polyurethane, dextran gel, and hydroxyl-terminated polybutadiene-polyurethane, or the restraint 33 may be made of a material including thermoplastic polyurethane, dextran gel. glue and hydroxyl-terminated polybutadiene-polyurethane.
  • the materials of the different restraints 33 may be the same or different. , you can select according to your needs.
  • the expansion coefficient of thermoplastic polyurethane is 30 to 40
  • the expansion coefficient of dextran gel is 1 to 4
  • the expansion coefficient of hydroxyl-terminated polybutadiene-polyurethane is 0.3 ⁇ 8. Therefore, the material of the binding member 33 includes at least one of thermoplastic polyurethane, dextran gel, and hydroxyl-terminated polybutadiene-polyurethane, and the ratio of each component in the material of the binding member 33 can be reasonably distributed to achieve the desired result.
  • the binding member 33 is made to have a suitable thickness after being expanded by the electrolyte, so that the binding member 33 formed after expansion has a suitable binding force on the electrode assembly 32 .
  • the binding member 33 can be disposed around one circle, less than one circle, or more than one circle of the electrode assembly 32, which can be selected as needed, and is not limited here.
  • Figures 11 to 14 respectively show schematic cross-sectional structural views of battery cells perpendicular to the axial direction provided by different embodiments.
  • the restraint 33 has a first free end 33 a and a second free end 33 b.
  • the binding member 33 extends from the first free end 33a to the second free end 33b.
  • the structural forms of different binding members 33 of the same battery cell 30 may be the same or different, and may be selected according to specific requirements.
  • first free end 33a and the second free end 33b may be arranged overlappingly or at intervals.
  • the binding member 33 just covers the entire circumference of the electrode assembly 32 .
  • the binding member 33 covers the electrode assembly 32 for less than one week or more than one week along the circumferential direction of the electrode assembly 32.
  • the restraint 33 includes an overlapping portion 33c disposed between the first free end 33a and the second free end 33b.
  • the central angle of the overlapping portion 33c ⁇ satisfies: ⁇ 30°.
  • the restraining member 33 covers the electrode assembly 32 for more than one turn along the circumferential direction of the electrode assembly 32 .
  • the central angle ⁇ of the overlapping portion 33c may be 5°, 10°, 15°, 20°, 25°, 30°, etc.
  • the binding member 33 has an overlapping portion 33 c and that the central angle ⁇ of the overlapping portion 33 c satisfies ⁇ ⁇ 30° will help ensure the binding force of the binding member 33 to the electrode assembly 32 and facilitate the installation of the binding member 33 .
  • the first free end 33a and the second free end 33b are spaced apart, and the main body 321 has an exposed area 321e, and the exposed area 321e is located at the first free end 33a and the second free end 33b. between them, and expose the outside of the binding member 33 .
  • the central angle ⁇ of the exposed area 321e satisfies, ⁇ 180°.
  • the central angle ⁇ of the exposed area 321e may be 30°, 45°, 60°, 90°, 120°, 150°, or 180°, etc.
  • the electrode assembly 32 is provided with an exposed area 321e between the first free end 33a and the second free end 33b, which ensures that the restraint 33 provides a certain restraining force for the electrode assembly 32 and also facilitates the electrolyte to enter through the exposed area 321e. Inside the electrode assembly 32, the wettability of the electrolyte to the electrode assembly 32 is improved. In addition, the exposed area 321e between the first free end 33a and the second free end 33b can reserve space for the expansion of the electrode assembly 32, thereby reducing the risk of damage to the electrode assembly 32 due to expansion and deformation.
  • the first free end 33a and the second free end 33b coincide.
  • the binding member 33 is disposed exactly around the circumference of the electrode assembly 32, and the first free end 33a and the second free end 33b do not overlap. In this way, it is beneficial to improve the flatness of the surface of the binding member 33 and improve the structural stability of the battery cell 30 .
  • the restraining member 33 includes a plurality of first portions 33d that are spaced apart along the circumference of the electrode assembly 32 .
  • the number of first portions 33d of one restraining member 33 may be two, three or more.
  • the corresponding central angles of different first parts 33d may be the same or different.
  • the spacing distances between the plurality of first parts 33d may be the same or different, and may be set according to actual needs.
  • Providing the restraint 33 with a plurality of first parts 33d and arranging the plurality of first parts 33d at intervals is beneficial to ensuring the restraining force of the restraint 33 on the electrode assembly 32 to reduce the possibility of the electrode assembly 32 shaking, and at the same time,
  • the gaps between the plurality of first portions 33d along the circumferential direction of the electrode assembly 32 are used as channels for the electrolyte to flow, thereby improving the fluidity of the electrolyte.
  • the gap between the first parts 33d can reserve space for the expansion of the electrode assembly 32, further reducing the risk of damage to the electrode assembly 32 due to expansion and deformation.
  • the electrode assembly 32 includes a first pole piece 3211, and the first pole piece 3211 is wound into multiple turns. In the circumferential direction of the electrode assembly 32 , the binding member 33 is offset from the tail end 3211 a of the outermost first pole piece 3211 .
  • the first pole piece 3211 may be a positive pole piece or a negative pole piece.
  • the first pole piece 3211 can be wound in multiple turns along the winding direction, and the winding direction is perpendicular to the axial direction X.
  • the tail end 3211a of the first pole piece 3211 is the outer ring of the mouth of the first pole piece 3211 along the winding direction. edge.
  • the binding member 33 is offset from the tail end 3211a of the outermost first pole piece 3211, so that along the circumferential direction of the electrode assembly 32, the tail end 3211a of the first pole piece 3211 is in contact with the binding member 33.
  • the tail end 3211a of the first pole piece 3211 can be disposed in the exposed area 321e of the electrode assembly 32, or the tail end 3211a of the first pole piece 3211 can be disposed in the area between two adjacent first portions 33d, To realize the misalignment of the first part 33e and the tail end 3211a.
  • the restraint 33 will not exert a large force on the tail end 3211a of the first pole piece 3211, which is conducive to reducing the risk of stress concentration in the electrode assembly 32 at the tail end 3211a of the first pole piece 3211, thereby reducing the risk of stress concentration. There is a risk that the electrode assembly 32 may be deformed and damaged.
  • the battery cell 30 includes a casing 31 , an electrode assembly 32 and a restraining member 33 .
  • the restraining member 33 includes a first restraining member 331 , a second restraining member 332 , a third restraining member 333 and a fourth restraining member that are spaced apart. Item 334.
  • the electrode assembly 32 includes a main body 321 having a first end 321a and a second end 321b oppositely arranged along the axial direction X of the electrode assembly 32, and a middle section 321f located between the first end 321a and the second end 321b. .
  • the restraining member 33 is provided between the peripheral side surface of the main body 321 and the housing 31 , and is configured to expand when exposed to electrolyte.
  • the first restraining member 331 and the second restraining member 332 are symmetrically arranged with respect to the middle section 321f, the third middle section 321f and the fourth middle section 321f are arranged oppositely, and the first restraining member 331 and the third restraining member 333 are located close to the middle section 321f.
  • the main body 321 includes a first pole piece 3211, which is wound into multiple turns. In the circumferential direction of the electrode assembly 32, the binding member 33 and the tail end 3211a of the outermost first pole piece 3211 are disposed in an offset position.
  • the first substrate includes a first active material layer 32111.
  • the first active material layer 32111 includes a base region 321c and a thinned region 321d.
  • the thickness of the thinned region 321d is smaller than the thickness of the base region 321c.
  • the thinned region 321d is located in the axial direction X.
  • the base region 321c is located on a side close to the first end 321a and on a side of the base region 321c close to the second end 321b.
  • the restraining member 33 is offset from the thinned area 321d, and the minimum distance from the restraining member 33 is 1 mm to 2 mm.
  • the battery 10 provided according to the embodiment of the present application includes the battery cell 30 provided in any of the above embodiments.
  • the battery 10 provided in the embodiment of the present application uses the battery cell 30 provided in any of the above embodiments, and therefore has the same technical effect, which will not be described again here.
  • the electrical device provided according to the embodiment of the present application includes the battery 10 provided in the above embodiment, and the battery 10 is used to provide electric energy.
  • the electrical device provided in the embodiment of the present application uses the battery 10 provided in the above embodiment, and therefore has the same technical effect, which will not be described again here.

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Abstract

提供了一种电池单体（30）、电池以及用电装置。电池单体（30）包括外壳（31）、电极组件（32）和至少一束缚件（33）。电极组件（32）设置于外壳（31）内，电极组件（32）包括主体部（321），主体部（321）具有沿电极组件（32）的轴向相对设置的第一端（321a）和第二端（321b）。至少一个束缚件（33）设置于主体部（321）的周侧面和外壳（31）之间，其中，至少一个束缚件（33）包括第一束缚件（331），第一束缚件（331）与第一端（321a）的最小间距小于第一束缚件（331）与第二端（321b）的最小间距。提供的电池单体（30），能够提高电池单体（30）的电极组件（32）内应力的一致性，以提高电极组件（32）充放电性能的稳定性和一致性，进而提高电池单体（30）的循环寿命。

Description

电池单体、电池以及用电装置 技术领域
本申请涉及电池技术领域，并且更具体地，涉及一种电池单体、电池以及用电装置。
背景技术
电池广泛用于电子设备，例如手机、笔记本电脑、电瓶车、电动汽车、电动飞机、电动轮船、电动玩具汽车、电动玩具轮船、电动玩具飞机和电动工具等等。电池单体可以包括镉镍电池单体、氢镍电池单体、锂离子电池单体和二次碱性锌锰电池单体等。
在电池单体技术的发展中，除了提高电池单体的性能外，如何电提高电池单体的使用寿命也是一个不可忽视的问题。提高电池单体的使用寿命对于节约能源有着重大的影响。因此，如何提高电池单体的使用寿命，是电池单体技术中一个持续改进的技术问题。
发明内容
本申请提供了一种电池单体、电池以及用电装置，能够提高电池单体的使用寿命。
第一方面，本申请实施例提供了一种电池单体包括外壳、电极组件和至少一束缚件；电极组件设置于外壳内，电极组件包括主体部，主体部具有沿电极组件的轴向相对设置的第一端和第二端；至少一个束缚件设置于主体部的周侧面和外壳之间，其中，至少一个束缚件包括第一束缚件，第一束缚件与第一端的最小间距小于第一束缚件与第二端的最小间距。
本申请实施例提供的电池单体，通过设置第一束缚件与第一端的最小间距小于第一束缚件到第二端的最小间距，则随着电极组件循环充放电次数的增加，第一束缚件对电极组件的束缚力分布偏离中截面设置，使得电极组件偏离中截面区域的内应力得到增强，如此可以平衡电极组件自身内应力差异，使得电极组件的内应力分布尽可能一致，提高电极组件充放电性能的稳定性和一致性，进而提高电池单体的循环寿命。
在一些实施例中，电极组件的周侧面具有第一附接区域，第一束缚件附接于第一附接区域的至少一部分区域上；第一附接区域以第一端为起始端并沿轴向延伸，且第一附接区域的沿轴向的尺寸小于主体部沿轴向尺寸的1/3。如此，进一步降低电极组件的内应力差异，提高电极组件充放电性能的一致性。
在一些实施例中，电极组件包括第一极片，第一极片包括位于主体部的第一活性物质层，第一活性物质层包括基体区和削薄区，削薄区的厚度小于基体区的厚度，削薄区在轴向上位于基体区的靠近第一端的一侧；在轴向上，第一束缚件与削薄区错位设置。设置削薄区可以降低削薄区远离基体区的边缘处的应力集中，以降低第一极片断裂的风险。设置第一束缚件与削薄区错位设置，可以降低第一束缚件使得削薄区产生较大变形而损坏的风险。
在一些实施例中，在轴向上，第一束缚件与削薄区的间距为1mm～2mm。如此，可以进一步降低第一束缚件对削薄区产生约束力的风险，以降低削薄区对应的电极组件产生较大变形而损坏的风险。
在一些实施例中，至少一个束缚件包括第二束缚件，第二束缚件与第二端的最小间距小于第二束缚件与第一端的最小间距。如此设置，可以进一步提高电极组件内应力的一致性，以提高电极组件充放电性能的一致性。
在一些实施例中，电极组件的周侧面具有第二附接区域，第二束缚件附接于第二附接区域的至少一部分区域上；第二附接区域以第二端为起始端并沿轴向延伸，且第二附接区域沿轴向的尺寸小于主体部沿轴向尺寸的1/3。进一步降低电极组件内应力差异，提高电极组件充放电性能的一致性。
在一些实施例中，主体部具有位于第一端和第二端之间的中截面，第二束缚件与第一束缚件在轴向上关于中截面对称设置。有利于进一步提高电极组件内应力分布的一致性，进而提高电极组件充放电性能的一致性。
在一些实施例中，至少一个束缚件包括第三束缚件，主体部具有位于第一端和第二端之间的中截面，第三束缚件覆盖中截面。如此，在实现束缚件平衡电极组件内应力作用的同时，提高电极组件在外壳内的稳定性。
在一些实施例中，至少一个束缚件包括第三束缚件，主体部具有位于第一端和第二端之间的中截面，第三束缚件附接于中截面与第一端之间的区域上，且第三束缚件位于第一束缚件靠近第二端的一侧。如此设置依然能够在提高电极组件充放电性能一致性的同时，提高电极组件的结构稳定性。
在一些实施例中，第一束缚件的厚度大于第三束缚件的厚度。如此，更有利于提高电极组件内应力的一致性，进而提高电极组件充放电性能的一致性。
在一些实施例中，主体部具有位于第一端和第二端的中截面；至少一个束缚件包括第四束缚件，第四束缚件附接于中截面与第二端之间的区域上，且第四束缚件位于第二束缚件靠近第一端的一侧。如此，进一步提高电极组件内应力的一致性。
在一些实施例中，至少一个束缚件包括第三束缚件，第四束缚件与第三束缚件关于中截面对称设置。如此，依然可以进一步提高电极组件充放电性能的一致性。
在一些实施例中，束缚件配置为在吸收电解液后膨胀。如此，可以在保证束缚件对电极组件的束缚作用的同时，便于束缚件和电极组件在组装的过程中入壳操作的顺利进行。
在一些实施例中，束缚件的材料包括热塑性聚氨酯、葡聚糖凝胶以及端羟基聚丁二烯-聚氨酯中的至少一者。如此一来，通过合理分配束缚件的材料中各组分的配比， 以使束缚件遇电解液发生膨胀后具有合适的厚度，进而使得膨胀后形成的束缚件对电极组件具有合适的约束力。
在一些实施例中，沿电极组件的周向，束缚件具有第一自由端和第二自由端；束缚件包括设置于第一自由端和第二自由端之间的重叠部，沿电极组件的周向，重叠部的中心角α满足：α≤30°。如此，则有利于保证束缚件对电极组件的束缚力，并便于束缚件的安装。
在一些实施例中，沿电极组件的周向，束缚件具有第一自由端和第二自由端，第一自由端和第二自由端间隔设置；主体部具有裸露区，裸露区位于第一自由端和第二自由端之间，并裸露于束缚件的外部；沿电极组件的周向，裸露区的中心角β满足，β≤180°。在保证束缚件为电极组件提供一定的约束例的同时，便于电解液通过裸露区进入电极组件内部，提高电解液对电极组件的浸润性。另外，裸露区可以为电极组件的膨胀预留空间，降低电极组件因膨胀变形而损坏的风险。
在一些实施例中，束缚件包括多个第一部分，多个第一部分沿电极组件的周向间隔设置。有利于在保证束缚件对电极组件的约束力，以降低电极组件产生晃动的可能性的同时，可以利用多个第一部分沿电极组件周向的间隙作为电解液流通的通道，提高电解液的流动性。另外，第一部分之间的间隙可以为电极组件的膨胀预留空间，进一步降低电极组件因膨胀变形而损坏的风险。
在一些实施例中，电极组件包括第一极片，第一极片卷绕为多圈；在电极组件的周向上，束缚件与最外圈的第一极片的尾端错位设置。如此，有利于降低电极组件在第一极片的尾端处产生应力集中的风险，进而降低电极组件产生变形而损坏的风险。
第二方面，本申请实施例提供了一种电池，包括如第一方面任一实施例的电池单体。
根据本申请实施例提供的电池，由于采用上述任一实施例提供的电池单体，因而具有同样的技术效果，在此不再赘述。
第三方面，本申请实施例提供了一种用电装置，包括如第二方面实施例的电池，电池用于提供电能。
根据本申请实施例提供的用电装置，由于采用了本申请实施例提供的电池，因而具有同样的技术效果，在此不再赘述。
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为本申请一实施例提供的车辆的结构示意图；
图2为本申请一实施例提供的电池的爆炸示意图；
图3为本申请实施例提供的电池中电池模块的结构示意图；
图4为本申请一些实施例提供的一种电池单体的爆炸示意图；
图5为本申请实施例提供的另一种电池单体的爆炸结构示意图；
图6为本申请实施例提供的电池单体中电极组件的局部剖视结构示意图；
图7为本申请实施例提供的又一种电池单体的爆炸结构示意图；
图8为本申请实施例提供的还一种电池单体的爆炸结构示意图；
图9为本申请实施例提供的再一种电池单体的爆炸结构示意图；
图10为本申请实施例提供的再一种电池单体的爆炸结构示意图；
图11为本申请实施例提供的电池单体沿垂直于轴向的一种剖视结构示意图；
图12为本申请实施例提供的电池单体沿垂直于轴向的另一种剖视结构示意图；
图13为本申请实施例提供的电池单体沿垂直于轴向的又一种剖视结构示意图；
图14为本申请实施例提供的电池单体沿垂直于轴向的再一种剖视结构示意图；
在附图中，附图并未按照实际的比例绘制。
附图标记说明：
1、车辆；1a、马达；1b、控制器；
10、电池；11、第一箱体部；12、第二箱体部；
20、电池模块；
30、电池单体；31、外壳；311、壳体；311a、开口；312、端盖；32、电极组件；32a、第一附接区域；32b、第二附接区域；321、主体部；321a、第一端；321b、第二端；321c、基体区；321d、削薄区；321e、裸露区；321f、中截面；3211、第一极片；3211a、尾端；32111、第一活性物质层；322、第一极耳；33、束缚件；33a、第一自由端；33b、第二自由端；33c、重叠部；33d、第一部分；331、第一束缚件；332、第二束缚件；333、第三束缚件；334、第四束缚件；
X、轴向。
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作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，不是旨在于限制本申请；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。
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，C和/或D，可以表示：单独存在C，同时存在C和D，单独存在D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。
在本申请的实施例中，相同的附图标记表示相同的部件，并且为了简洁，在不同实施例中，省略对相同部件的详细说明。应理解，附图示出的本申请实施例中的各种部件的厚度、长宽等尺寸，以及集成装置的整体厚度、长宽等尺寸仅为示例性说明，而不应对本申请构成任何限定。
本申请中出现的“多个”指的是两个以上(包括两个)。
本申请中，电池单体可以包括锂离子二次电池单体、锂离子一次电池单体、锂硫电池单体、钠锂离子电池单体、钠离子电池单体或镁离子电池单体等，本申请实施例对此并不限定。电池单体可呈圆柱体、扁平体、长方体或其它形状等，本申请实施例对此也不限定。电池单体一般按封装的方式分成三种：柱形电池单体、方形电池单体和软包电池单体，本申请实施例对此也不限定。
本申请的实施例所提到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，本申请中所提到的电池可以包括电池模块或电池包等。电池一般包括用于封装一个或多个电池单体的箱体。箱体可以避免液体或其他异物影响电池单体的充电或放电。
电池单体包括电极组件和电解液，电极组件包括正极极片、负极极片和隔离件。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；正极集流体包括正极集流部和凸出于正极集流部的正极凸部，正极集流部涂覆有正极活性物质层，正极凸部的至少部分未涂覆正极活性物质层，正极凸部作为正极极耳。以锂离子电池为例，正极集流体的材料可以为铝，正极活性物质层包括正极活性物质，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；负极集流体包括负极集流部和凸出于负极集流部的负极凸部，负极集流部涂覆有负极活性物质层，负极凸部的至少部分未涂覆负极活性物质层，负极凸部作为负极极耳。负极集流体的材料可以为铜，负极活性物质层包括负极活性物质，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。隔离件的材质可以为PP(polypropylene，聚丙烯)或PE(polyethylene，聚乙烯)等。此外，电极组件可以是卷绕式结构，也可以是叠片式结构，本申请实施 例并不限于此。
发明人发现电池单体的工作寿命较低的问题后，便对电池单体的结构和工作过程进行了系统的分析和研究，结果发现，随着电池单体的电极组件循环充放电次数的增加，电极组件的阳极极片逐渐发生膨胀，且沿电极组件的轴向，靠近中间区域的膨胀量大于两端区域的膨胀量，因此，越靠近电极组件沿轴向的中间区域，电极组件的内应力越大，越靠近电极组件沿轴向的两端，内应力越小。随着电极组件的循环充放电次数的增加，电极组件中间区域和两端的内应力差异逐渐增大，电极组件充放电性能一致性逐渐降低，对应的电池单体的储能量逐渐降低，如此，严重影响电池单体的使用寿命。
基于发明人发现的上述问题，发明人对电池单体的结构进行了改进，本申请实施例描述的技术方案适用于电池单体、包含电池单体的电池以及使用电池的用电装置。
根据本申请实施例提供的电池单体包括外壳、电极组件和至少一个束缚件。电极组件设置于外壳内，包括主体部，主体部具有沿电极组件的轴向相对设置的第一端和第二端。至少一个束缚件设置于主体部的周侧面和外壳之间。至少一个束缚件包括第一束缚件，第一束缚件与第一端的最小间距小于第一束缚件与第二端的最小间距。
本申请实施例提供的电池单体，通过设置第一束缚件与第一端的最小间距小于第一束缚件与第二端的最小间距，即第一束缚件相对于主体部的两端为非对称设置。则第一束缚件对电极组件的束缚力分布偏离主体部的中截面，则主体部偏离中截面的区域的内应力由于第一束缚件的束缚力而得到增强，以平衡该区域与电极组件靠近中截面区域的内应力差异，提高电极组件内应力的一致性，以及电极组件的充放电性能的一致性，进而提高电池单体的循环寿命。
用电装置可以是车辆、手机、便携式设备、笔记本电脑、轮船、航天器、电动玩具和电动工具等等。车辆可以是燃油汽车、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；航天器包括飞机、火箭、航天飞机和宇宙飞船等等；电动玩具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；电动工具包括金属切削电动工具、研磨电动工具、装配电动工具和铁道用电动工具，例如，电钻、电动砂轮机、电动扳手、电动螺丝刀、电锤、冲击电钻、混凝土振动器和电刨等等。本申请实施例对上述用电装置不做特殊限制。
以下实施例为了方便说明，以用电装置为车辆为例进行说明。
如图1所示，车辆1的内部设置有电池10。电池10可以设置在车辆1的底部或头部或尾部。电池10可以用于车辆1的供电，例如，电池10可以作为车辆1的操作电源。
车辆1还可以包括控制器1b和马达1a。控制器1b用来控制电池10为马达1a供电，例如，用于车辆1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10不仅仅可以作为车辆1的操作电源，还可以作为车辆1的驱动电源，代替或部分地代替燃油或天然气为车辆1提供驱动动力。
参见图2所示，电池10包括电池单体(图2未示出)。电池10还可以包括用 于容纳电池单体的箱体。
箱体用于容纳电池单体，箱体可以是多种结构形式。在一些实施例中，箱体可以包括第一箱体部部11和第二箱体部12。第一箱体部11与第二箱体部12相互盖合。第一箱体部11和第二箱体部12共同限定出用于容纳电池单体的容纳空间。第二箱体部12可以是一端开口的空心结构，第一箱体部11为板状结构，第一箱体部11盖合于第二箱体部12的开口侧，以形成具有容纳空间的箱体；第一箱体部11和第二箱体部12也可以均为一侧开口的空心结构。第一箱体部11的开口侧盖合于第二箱体部12的开口侧，以形成具有容纳空间的箱体。当然，第一箱体部11和第二箱体部12可以是多种形状，比如，圆柱体、长方体等。
为提高第一箱体部11和第二箱体部12连接后的密封性，第一箱体部11和第二箱体部12之间还可以设置密封件，比如，密封胶、密封圈等。
假设第一箱体部11盖合于第二箱体部12，第一箱体部11亦可称之为上箱盖，第二箱体部12亦可称之为下箱体。
在电池10中，电池单体可以是一个，也可以是多个。若电池单体为多个，多个电池单体之间可串联或并联或混联。混联是指多个电池单体中既有串联又有并联。多个电池单体之间可直接串联或并联或混联在一起，再将多个电池单体构成的整体容纳于箱体内，也可以是多个电池单体先串联或并联或混联组成电池模块20。多个电池模块20再串联或并联或混联形成一个整体，并容纳于箱体内。
在一些实施例中，如图3所示，图3为图2所示的电池模块20的结构示意图。在电池模块20中，电池单体30为多个。多个电池单体30先串联或并联或混联组成电池模块20。多个电池模块20再串联或并联或混联形成一个整体，并容纳于箱体内。
在一些实施例，电池模块20中的多个电池单体30之间可通过汇流部件实现电连接，以实现电池模块20中的多个电池单体30的并联或串联或混联。
请参照图4，图4为图3所示的电池单体30的爆炸示意图。本申请实施例提供的电池单体30包括电极组件32和外壳31，外壳31具有容置腔，电极组件32容纳于容置腔内。
在一些实施例中，外壳31可以包括壳体311和端盖312，壳体311为一侧开口的空心结构，端盖312盖合于壳体311的开口311a处并形成密封连接，以形成用于容纳电极组件32和电解质的密封空间。
在组装电池单体30时，可先将电极组件32放入壳体311内，再将端盖312盖合于壳体311的开口，然后经由端盖312上的电解质注入口将电解质注入壳体311内。
在一些实施例中，外壳31还可用于容纳电解质，例如电解液。外壳31可以是多种结构形式。
如图4示出了本申请实施例提供的电池单体的结构示意图。
壳体311可以是多种形状，比如，圆柱体、长方体等。壳体311的形状可以根据电极组件32的具体形状来确定。例如，若电极组件32为圆柱体结构，壳体311则可选用为圆柱体结构。若电极组件32为长方体结构，壳体311则可选用长方体结构。在图4中，示例性地，壳体311和电极组件32均为长方体结构。
壳体311的材质可以是多种，比如，铜、铁、铝、不锈钢、铝合金等，本申请实施例对此不作特殊限制。
容纳于壳体311内的电极组件32可以是一个或多个。在图4中，容纳于壳体311内的电极组件32为两个。
在一些实施例中，电极组件32还包括正极极片、负极极片和隔离件。电极组件32可以是由正极极片、隔离件和负极极片通过卷绕形成的卷绕式结构。电极组件32也可以是由正极极片、隔离件和负极极片通过层叠布置形成的层叠式结构。
正极极片可以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。负极极片可以包括负极集流体和负极极活性物质层。负极活性物质层涂覆于负极集流体的表面。隔离件在正极极片与负极极片之间，用于将正极极片与负极极片隔离，以降低正极极片与负极极片之间出现短路的风险。
电极组件32中的极耳分为正极耳和负极耳。正极耳可以是正极集流体中未涂覆正极活性物质层的部分。负极耳可以是负极集流体中未涂覆负极活性物质层的部分。
如图5示出了本申请实施例提供的电池单体30一种爆炸结构示意图。
如图5所示，根据本申请实施例提供的电池单体30包括外壳31、电极组件32和至少一个束缚件33。电极组件32设置于外壳31内，电极组件32包括主体部321，主体部321具有沿电极组件32的轴向X相对设置的第一端321a和第二端321b。至少一个束缚件33，设置于主体部321的周侧面和外壳31之间，其中，至少一个束缚件33包括第一束缚件331，第一束缚件331与第一端321a的最小间距小于第一束缚件331与第二端321b的最小间距。
可选地，电极组件32可以呈圆柱形，也可以呈方形，电极组件32的极片可以为卷绕式，也可以为叠片式。在电极组件32呈方形的实施例中，主体部321的表面具有弧形区和平面区，电极组件32的轴向X可以为平行于弧形区的延伸方向的方向。
可选地，电极组件32可以包括一个极耳，也可以包括两个极耳。在电极组件32包括一个极耳的实施例中，该极耳可以从主体部321的第一端321a引出，也可以从主体部321的第二端321b引出。而在电极组件32包括两个极耳的实施例中，两个极耳可以分别从第一端321a和第二端321b引出，也可以两个极耳均从第一端321a引出，或者两个极耳均从第二端321b引出，这里不做限制。
可选地，至少一个束缚件33可以仅包括第一束缚件331，还可以包括其它束缚件33，不同束缚件33的形状、结构或者相对于电极组件32的位置关系等可以与第一束缚件331相同，也可以不相同。
可选地，第一束缚件331的数量可以是一个，也可以是多个，可以根据实际需要进行选取。在第一束缚件331的数量为多个的实施例中，多个第一束缚件331可以沿电极组件32的轴向X设置，相邻两第一束缚件331可以间隔设置，也可以相互邻接。
主体部321的周侧面为本体部位于第一端321a和第二端321b之间的表面。至少一个束缚件33设置于主体部321的周侧面和外壳31之间，则在电池单体30进行充放电之前，束缚件33可以与外壳31和主体部321的周侧面均接触，或者束缚件33与外壳31和主体部321中的任一者接触，亦或者束缚件33与壳外壳31和主体部321均 间隔设置。后续随着电池单体30循环充放电次数的增加，电极组件32逐渐发生膨胀，最终束缚件33抵接于主体部321的周侧面与外壳31之间，以对主体部321施加一定的束缚力。
束缚件33对电极组件32的束缚力的方向可以为与电极组件32自身的膨胀力方向相抗衡的方向，且可以沿电极组件32的径向设置。
束缚件33与第一端321a的最小间距可以为束缚件33靠近第一端321a的一端与第一端321a的距离，同理，束缚件33与第二端321b的最小间距可以为束缚件33靠近第二端321b的一端与第二端321b的距离。
主体部321具有位于第一端321a和第二端321b的中截面321f，第一端321a到中截面321f的距离与第二端321b到中截面321f的距离相等。
第一束缚件331与第一端321a的最小间距小于第一束缚件331与第二端321b的最小间距，则第一束缚件331更靠近第一端321a设置。可选地，第一束缚件331可以覆盖中截面321f设置，也可以与中截面321f间隔设置，或者第一束缚件331的一端紧贴中截面321f设置。
随着电极组件32循环充放电次数的增加，电极组件32的阳极极片的膨胀量逐渐增大，且电极组件32越靠近中截面321f区域的膨胀量越大，如果没有设置束缚件33，则越靠近中截面321f电极组件32自身的内应力越大。另外，随着电极组件32的逐渐膨胀，第一束缚件331对电极组件32的束缚力逐渐增大。由于设置第一束缚件331与第一端321a的最小间距小于第一束缚件331与第二端321b的最小间距，即第一束缚件331在主体部321的轴向X相对于中截面321f为非对称设置，则第一束缚件331对电极组件32的束缚力分布偏离中截面321f设置，即电极组件32偏离中截面321f而靠近第一端321a的区域的内应力得到增强，如此可以平衡与第一束缚件331对应电极组件32的至少部分区域与第一束缚件331靠近中截面321f区域的内应力差异，以使得两个区域对应的电极组件32的内应力尽可能一致，进而提供电极组件32充放电性能的一致性。
可选地，沿主体部321的轴向X，第一束缚件331对电极组件32各处的束缚力可以相等，也可以呈曲线分布。示例性地，由中截面321f到第一端321a的轴向X，可以设置第一束缚件331对电极组件32的束缚力逐渐增大，以平衡电极组件32自身的内应力差异。
本申请实施例提供的电池单体30，在主体部321的周侧面与外壳31之间设置至少一个束缚件33，至少一个束缚件33包括第一束缚件331。通过设置第一束缚件331到第一端321a的最小间距小于第一束缚件331到第二端321b的最小间距，则随着电极组件32循环充放电次数的增加，第一束缚件331对电极组件32的束缚力分布偏离中截面321f设置，使得电极组件32偏离中截面321f区域的内应力得到增强，如此可以平衡电极组件32自身内应力差异，使得电极组件32的内应力分布尽可能一致，提高电极组件32充放电性能的稳定性和一致性，进而提高电池单体30的循环寿命。
可选地，第一束缚件331可以设置于第一端321a与中截面321f之间的任意区域，或者第一束缚件331可以部分设置于中截面321f的靠近第二端321b的一侧，具体 可以根据需要进行选取，这里不做限制。
在一些实施例中，电极组件32的周侧面具有第一附接区域32a，第一束缚件331附接于第一附接区域32a的至少一部分区域上。第一附接区域32a以第一端321a为起始端并沿轴向X延伸，且第一附接区域32a沿轴向X的尺寸小于主体部321沿轴向X尺寸的1/3。
可选地，沿电极组件32的轴向X，第一束缚件331可以附接于第一附接区域32a的全部区域，也可以附接于第一附接区域32a的部分区域。
可选地，第一束缚件331附接于第一附接区域32a，则第一束缚件331可以与第一附接区域32a的主体部321通过粘接等方式连接为一体，也可以设置第一束缚件331仅仅与第一附件区域的主体部321相抵，只要能够使得第一束缚件331对主体部321产生束缚力即可。
可以理解的是，由主体部321的中截面321f，越靠近第一端321a，电极组件32的膨胀变形越小，则主体部321越靠近第一端321a的区域，其与主体部321靠近中截面321f的区域的膨胀变形差异越大，因此，设置第一束缚件331设置于第一附接区域32a，则更有利于平衡第一附接区域32a上与第一束缚件331相配合的区域与靠近中截面321f的区域的电极组件32的内应力差异，进而更有利于提高电极组件32充放电性能的一致性和稳定性。
如图6示出了本申请实施例提供的电池单体沿轴向的剖视结构示意图。
如图6所示，在一些实施例中，电极组件32包括第一极片3211，第一极片3211包括位于主体部321的第一活性活性物质层，第一活性物质层32111包括基体区321c和削薄区321d，削薄区321d的厚度小于基体区321c的厚度，削薄区321d在轴向X上位于基体区321c靠近第一端321a的一侧。
可选地，第一极片3211可以为正极极片，也可以为负极极片，因此，可以设置正极极片和负极极片中的一者包括基体区321c和削薄区321d，也可以设置在正极极片和负极极片均包括基体区321c和削薄区321d。
通过减小削薄区321d的厚度，在对第一极片3211进行冷压成型的过程中，可以降低削薄区321d的远离基体区321c的边缘处即主体部321的第一端321a的应力集中，降低第一极片3211断裂的风险。
可选地，削薄区321d的表面可以呈平面，也可以呈弧形面。削薄区321d内各处第一极片3211的厚度可以相等，也可以不相等，具体可以根据需求进行选取，这里不做限制。
在一些实施例中，在轴向X上，第一束缚件331与削薄区321d错位设置。
设置第一束缚件331与削薄区321d错位设置，即削薄区321d没有设置第一束缚件331，也没有与第一束缚件331存在交叠。由于第一极片3211的削薄区321d的厚度小于基体区321c的厚度，削薄区321d的第一极片3211的间隙大于基体区321c第一极片3211的间隙，且削薄区321d的第一极片3211的强度相对于基体区321c的第一极片3211的强度要低一些。在外力作用下，削薄区321d更容易产生变形。因此，设置第一束缚件331与削薄区321d错位设置，可以降低第一束缚件331使得削薄区321d产生 较大变形而损坏的风险。
可选地，第一束缚件331与削薄区321d可以相邻设置，也可以间隔设置，在第一束缚件331与削薄区321d间隔设置的实施例中，第一束缚件331与削薄区321d的间距不做限制，可以根据实际需求进行选取。
在一些实施例中，在轴向X上，第一束缚件331与削薄区321d的间距为1mm～2mm。具体地，第一束缚件331与削薄区321d的间距可以为1mm、1.5mm或者2mm等。
可以理解的是，第一束缚件331与削薄区321d的间距可以为第一束缚件331靠近削薄区321d的一端到削薄区321d靠近第一束缚件331一端的距离。
设置第一束缚件331与削薄区321d的间距为1mm～2mm，可以进一步降低第一束缚件331对削薄区321d产生约束力的风险，以降低削薄区321d对应的电极组件32产生较大变形而损坏的风险。
如图7示出了本申请实施例提供的另一种电池单体30的爆炸结构示意图。
如图7所示，在一些实施例中，至少一个束缚件33包括第二束缚件332，第二束缚件332与第二端321b的最小间距小于第二束缚件332与第一端321a的最小间距。
可选地，第二束缚件332与第一束缚件331的厚度、形状或者结构等可以相同，也可以不相同。
可选地，沿轴向X，第二束缚件332与第一束缚件331可以相对于中截面321f对称设置，也可以相对于中截面321f不对称设置。第一束缚件331更靠近一端设置，第二束缚件332更靠近第二端321b设置，
第二束缚件332到第二端321b的最小间距小于第二束缚件332到第一端321a的最小间距，则沿轴向X，第二束缚件332更靠近第二端321b设置，则随着电极组件32循环充放电次数的增加，电极组件32的膨胀量逐渐增大，第二束缚件332对电极组件32的束缚力逐渐增大，由于第二束缚件332更靠近第二端321b设置，则第二束缚件332对电极组件32的束缚力分布偏离中截面321f，而更靠近第二端321b，即使得电极组件32偏离中截面321f的靠近第二端321b的区域的内应力得到增强，如此可以平衡第一束缚件331对应的电极组件32的至少部分区域与靠近中截面321f区域的内应力差异，使得电极组件32的内应力尽可能一致，进一步提高电极组件32充放电性能的一致性。
可以理解的是，可以通过改变束缚件33的厚度等，以调整束缚件33对电极组件32的束缚力大小。因此，可以通过调整第一束缚件331和第二束缚件332的厚度等，以使第一束缚件331和第二束缚件332对电极组件32进行内应力增强后，电极组件32分别与第一束缚件331和第二束缚件332对应的区域的内应力尽可能一致，如此，可以进一步提高电极组件32充放电性能的一致性。
可选地，第二束缚件332可以设置于第二端321b与中截面321f之间的任意区域，或者第二束缚件332可以部分设置于中截面321f靠近第一端321a的一侧，具体可以根据实际需要进行选取，这里不做限制。
在一些实施例中，电极组件32的周侧面具有第二附接区域32b，第二束缚件 332附接于第二附接区域32b的至少一部分区域上。第二附接区域32b第二端321b为起始端并沿轴向X延伸，且第二附接区域32b的沿轴向X的尺寸小于主体部321沿轴向X尺寸的1/3。
可选地，沿轴向X，第二束缚件332可以附接于第二附接区域32b的全部区域，也可以附接于第二附接区域32b的部分区域。
可选地，第二束缚件332可以与第二附接区域32b通过粘接等方式连接为一体，也可以设置第二束缚件332仅仅与第二附接区域32b相抵，只要能够使得第二束缚件332对主体部321产生束缚力即可。
可理解的是，由主体部321的中截面321f开始，越靠近第二端321b，电极组件32的膨胀变形越小，则主体部321越靠近第二端321b的区域，其与主体部321靠近中截面321f的区域的膨胀变形差异越大，因此，设置第二束缚件332设置于第二附接区域32b，则更有利于平衡第二附接区域32b上与第二束缚件332相配合的区域与靠近中截面321f的区域的电极组件32的内应力差异，进而更有利于提高电极组件32充放电性能的一致性和稳定性。
在一些实施例中，第二束缚件332与第一束缚件331在轴向X上关于中截面321f对称设置。
如此，第一束缚件331对电极组件32束缚力关于中截面321f对称设置，有利于进一步提高电极组件32内应力分布的一致性，进而提高电极组件32充放电性能的一致性。
如图8示出了本申请又一实施例提供的电池单体30的爆炸结构示意图。
如图8所示，在一些实施例中，至少一个束缚件33包括第三束缚件333，第三束缚件333覆盖中截面321f。
具体地，可以通过调整第一束缚件331与第三束缚件333对电极组件32的束缚力，以使第一束缚件331对电极组件32的束缚力小于第三束缚件333对电极组件32的束缚力，以在平衡电极组件32内应力的同时，使得第三束缚件333对电极组件32具有一定的固定作用，提高电极组件32在外壳31内的稳定性。
而在束缚件33同时包括第一束缚件331、第二束缚件332以及第三束缚件333的实施例中，可以设置三者间隔设置，且根据三者在电极组件32沿轴向X的相对位置，设置三者具有合适的厚度或者材料等，以使三者对电极组件32施加约束力后，电极组件32内应力尽可能的一致，进而提高电极组件32充放电性能的一致性。
如图9示出了本申请实施例提供的再一种电池单体30的爆炸结构示意图。
如图9所示，在另一些实施例中，第三束缚件333附接于中截面321f与第一端321a之间的区域上，且第三束缚件333位于第一束缚件331靠近第二端321b的一侧。
具体地，可以通过设置第一束缚件331和第三束缚件333具有不同的厚度或者材料等，以使第三束缚件333对电极组件32的束缚力小于第一束缚件331对电极组件32的束缚力，以使二者对应的电极组件32的内应力尽量一致，如此设置，依然能够提高电极组件32充放电性能的一致性，并提高电极组件32的结构稳定性。
可选地，可以通过设置第一束缚件331和第三束缚件333的厚度不同，或者设 置二者的材料不同，或者设置二者的厚度和材料均不相同，以使二者对电极组件32的束缚力不同。
在一些实施例中，第一束缚件331的厚度大于第三束缚件333的厚度。
可以理解的是，束缚件33的厚度越大，占用外壳31与电极组件32之间的空间越大，随着电极组件32的膨胀，束缚件33对电极组件32的束缚力也越大。由于第一束缚件331相对于第三束缚件333更靠近第一端321a、第三束缚件333相对于第一束缚件331更靠近中截面321f设置，则第一束缚件331对应的电极组件32自身的膨胀量和内应力小于第三膨胀件对应的电极组件32自身的膨胀量和内应力。因此，设置第一束缚件331的厚度大于第三束缚件333的厚度，更有利于提高电极组件32内应力的一致性，进而提高电极组件32充放电性能的一致性。
可以根据第一束缚件331和第三束缚件333对应的电极组件32的位置，设置二者具有合适的厚度，以使二者对应的电极组件32的内应力尽可能一致。
如图10示出了本申请实施例提供的再一种电池单体30的爆炸结构示意图。
如图10所示，在一些实施例中，至少一个束缚件33包括第四束缚件334，第四束缚件334附接于中截面321f与第二端321b之间的区域上，且第四束缚件334位于第二束缚件332靠近第一端321a的一侧。
具体地，可以通过设置第一束缚件331、第二束缚件332以及第四束缚件334具有不同的厚度和材料等信息，以使第一束缚件331、第二束缚件332以及第四束缚件334分别对电极组件32具有合适的约束力，进而使得三者对应的电极组件32的内应力尽可能的一致。
在至少一个束缚件33同时包括第一束缚件331、第二束缚件332、第三束缚件333以及第四束缚件334的实施例中，第三束缚件333可以与第四束缚件334可以关于中截面321f对称设置，也可以不对称。
在一些实施例中，至少一个束缚件33包括第三束缚件333，第四束缚件334与第三束缚件333关于中截面321f对称设置。
具体地，可以设置第三束缚件333和第四束缚件334分别对电极组件32具有同等的约束力，且由于二者对应的电极组件32关于中截面321f对称设置，则二者对应电极组件32自身的内应力基本相同，如此，第三束缚件333和第四束缚件334对应的电极组件32的内应力基本一致，有利于进一步提高电极组件32充放电性能的一致性。
在第三束缚件333和第四束缚件334关于中截面321f对称设置的实施例中，第一束缚件331与第二束缚件332可以关于中截面321f对称设置，也可以关于中截面321f非对称设置。可以理解的是，同时设置第一束缚件331与第二束缚件332关于中截面321f对称设置、第三束缚件333与第四束缚件334关于中截面321f对称设置，可以更好地提高电极组件32充放电性能的一致性。
可选地，束缚件33可以为弹性件，也可以为非弹性件。束缚件33可以为在组装之前即已确定形状和结构的构件，也可以是在电池单体30组装后或者组装活成中形成的具有稳定结构和性能的结构体。
在一些实施例中，束缚件33配置为在吸收电解液后膨胀。
可选地，在束缚件33包括第一束缚件331、第二束缚件332、第三束缚件333以及第四束缚件334的实施例中，可以设置第一束缚件331件、第二束缚件332、第三束缚件333以及第四束缚件334中的任一者或者多者配置为吸收电解液后膨胀，而其它的束缚件33采用别的结构型式。
在电池单体30组装的过程中，束缚件33在遇电解液产生膨胀之前，体积较小，如此便于束缚件33随电极组件32一起进入外壳31内。而在对电池单体30加注电解液后，束缚件33便发生膨胀，达到预设的厚度和体积，便于后续在使用的过程中对电极组件32形成一定的束缚力。
因此，通过设置束缚件33配置为在吸收电解液后膨胀，可以在保证束缚件33对电极组件32的束缚作用的同时，便于束缚件33和电极组件32在组装的过程中入壳操作的顺利进行。
为了使束缚件33吸收电解液后膨胀，可以设置多种束缚件33的材料。在一些实施例中，束缚件33的材料包括热塑性聚氨酯、葡聚糖凝胶以及端羟基聚丁二烯-聚氨酯中的至少一者。
可选地，可以设置束缚件33的材料包括热塑性聚氨酯、葡聚糖凝胶以及端羟基聚丁二烯-聚氨酯中的一者，也可以设置束缚件33的材料包括热塑性聚氨酯、葡聚糖凝胶以及端羟基聚丁二烯-聚氨酯中的两者或者全部。
在束缚件33包括第一束缚件331、第二束缚件332、第三束缚件333以及第四束缚件334的实施例中，可选地，可以设置不同束缚件33的材料相同，或者不相同，可以根据需要进行选取。
可以理解的是，不同材料的膨胀系数不同，比如，热塑性聚氨酯的膨胀系数为30～40、葡聚糖凝胶的膨胀系数为1～4、端羟基聚丁二烯-聚氨酯的膨胀系数为0.3～8。因此，设置束缚件33的材料包括热塑性聚氨酯、葡聚糖凝胶以及端羟基聚丁二烯-聚氨酯中的至少一者，可以通过合理分配束缚件33的材料中各组分的配比，以使束缚件33遇电解液发生膨胀后具有合适的厚度，进而使得膨胀后形成的束缚件33对电极组件32具有合适的约束力。
可选地，沿电极组件32的周向，束缚件33可以围绕电极组件32的一周、少于一周或者大于一周设置，可以根据需要进行选取，这里不做限制。
如图11至图14分别示出了不同实施例提供的电池单体沿垂直于轴向的剖视结构示意图。
如图11至图13所示，在一些实施例中，沿电极组件32的周向，束缚件33具有第一自由端33a和第二自由端33b。具体地，沿电极组件32的周向，束缚件33由第一自由端33a延伸到第二自由端33b。
可选地，同一电池单体30的不同束缚件33的结构形式可以相同，也可以不相同，可以根据具体需求进行选取。
可选地，第一自由端33a和第二自由端33b可以重叠设置，也可以间隔设置。在第一自由端33a和第二自由端33b重叠设置时，束缚件33正好覆盖电极组件32的一周。而在第一自由端33a和第二自由端33b间隔设置时，则沿电极组件32的周向，束 缚件33覆盖电极组件32不到一周或者多于一周。
如图11所示，在一些实施例中，束缚件33包括设置于第一自由端33a和第二自由端33b之间的重叠部33c，沿电极组件32的周向，重叠部33c的中心角α满足：α≤30°。
上述实施例中，束缚件33沿电极组件32的周向覆盖电极组件32大于一周。
可选地，重叠部33c中心角α可以为5°、10°、15°、20°、25°或者30°等。
设置束缚件33具有重叠部33c，并设置重叠部33c的中心角α满足：α≤30°，则有利于保证束缚件33对电极组件32的束缚力，并便于束缚件33的安装。
如图12所示，在另一些实施例中，第一自由端33a和第二自由端33b间隔设置，主体部321具有裸露区321e，裸露区321e位于第一自由端33a和第二自由端33b之间，并裸露与束缚件33的外部。沿电极组件32的周向，裸露区321e的中心角β满足，β≤180°。
可选地，裸露区321e的中心角β可以为30°、45°、60°、90°、120°、150°或者180°等。
设置电极组件32具有位于第一自由端33a和第二自由端33b之间的裸露区321e，能够保证束缚件33为电极组件32提供一定的约束力的同时，还便于电解液通过裸露区321e进入电极组件32内部，提高电解液对电极组件32的浸润性。另外，第一自由端33a和第二自由端33b之间的裸露区321e可以为电极组件32的膨胀预留空间，降低电极组件32因膨胀变形而损坏的风险。
如图13所示，在又一些实施例中，第一自由端33a和第二自由端33b重合。则束缚件33正好围绕电极组件32的一周设置，且第一自由端33a和第二自由端33b没有交叠。如此，有利于提高束缚件33表面的平整性，以提高电池单体30结构的稳定性。
如图14所示，在一些实施例中，束缚件33包括多个第一部分33d，多个第一部分33d沿电极组件32的周向间隔设置。
可选地，一个束缚件33的第一部分33d的数量可以是两个、三个或者更多个。不同第一部分33d对应的中心角可以相同，也可以不相同。多个第一部分33d的间隔距离可以相同，也可以不相同，可以根据实际需要进行设置。
设置束缚件33具有多个第一部分33d，并设置多个第一部分33d间隔设置，有利于在保证束缚件33对电极组件32的约束力，以降低电极组件32产生晃动的可能性的同时，可以利用多个第一部分33d沿电极组件32周向的间隙作为电解液流通的通道，提高电解液的流动性。另外，第一部分33d之间的间隙可以为电极组件32的膨胀预留空间，进一步降低电极组件32因膨胀变形而损坏的风险。
在一些实施例中，电极组件32包括第一极片3211，第一极片3211卷绕为多圈。在电极组件32的周向上，束缚件33与最外圈的第一极片3211的尾端3211a错位设置。
可选地，第一极片3211可以为正极极片，也可以为负极极片。第一极片3211可以沿卷绕方向卷绕呈多圈，卷绕方向垂直于轴向X，第一极片3211的尾端3211a即为第一极片3211沿卷绕方向的嘴外圈的边缘。
束缚件33与最外圈的第一极片3211的尾端3211a错位设置，则沿电极组件32 的周向上，第一极片3211的尾端3211a内有与束缚件33抵接。
可选地，可以将第一极片3211的尾端3211a设置于电极组件32的裸露区321e，也可以将第一极片3211的尾端3211a设置于相邻两第一部分33d之间的区域，以实现第一部分33e与尾端3211a错位设置。
如此，束缚件33便不会对第一极片3211的尾端3211a产生较大的作用力，有利于降低电极组件32在第一极片3211的尾端3211a处产生应力集中的风险，进而降低电极组件32产生变形而损坏的风险。
在一些实施例中，电池单体30包括外壳31、电极组件32和束缚件33，束缚件33包括间隔设置的第一束缚件331、第二束缚件332、第三束缚件333和第四束缚件334。电极组件32包括主体部321，主体部321具有沿电极组件32的轴向X相对设置的第一端321a和第二端321b，以及位于第一端321a和第二端321b之间的中截面321f。束缚件33设置于主体部321的周侧面和外壳31之间，束缚件33配置为遇电解液后膨胀。第一束缚件331和第二束缚件332相对于中截面321f对称设置，第三中截面321f和第四中截面321f相对设置，且第一束缚件331和第三束缚件333位于中截面321f靠近第一端321a的一侧，第二束缚件332和第四束缚件334位于中截面321f靠近第二端321b的一侧，且第一束缚件331位于第三束缚件333靠近第一端321a的一侧，第一束缚件331的厚度大于第二束缚件332的厚度。主体部321包括第一极片3211，第一极片3211卷绕为多圈，在电极组件32的周向上，束缚件33和最外圈的第一极片3211的尾端3211a错位设置。第一基板包括第一活性物质层32111，第一活性物质层32111包括基体区321c和削薄区321d，削薄区321d的厚度小于基体区321c的厚度，削薄区321d在轴向X上位于基体区321c靠近第一端321a的一侧，以及位于基体区321c靠近第二端321b的一侧。束缚件33与削薄区321d错位设置，且距离束缚件33的最小间距为1mm～2mm。
根据本申请实施例提供的电池10包括上述任一实施例提供的电池单体30。
本申请实施例提供的电池10，由于采用了上述任一实施例提供的电池单体30，因而具有同样的技术效果，在此不再赘述。
根据本申请实施例提供的用电装置包括上述实施例提供的电池10，电池10用于提供电能。
本申请实施例提供的用电装置，由于采用了上述实施例提供的电池10，因而具有同样的技术效果，在此不再赘述。
需要说明的是，在不冲突的情况下，本申请中的实施例及实施例中的特征可以相互组合。
最后应说明的是：以上实施例仅用以说明本申请的技术方案，而非对其限制；尽管参照前述实施例对本申请进行了详细的说明，本领域的普通技术人员应当理解：其依然可以对前述各实施例所记载的技术方案进行修改，或者对其中部分技术特征进行等同替换，但这些修改或者替换，并不使相应技术方案的本质脱离本申请各实施例技术方案的精神和范围。

Claims (20)

  1. 一种电池，包括：
    外壳；
    电极组件，设置于所述外壳内，所述电极组件包括主体部，所述主体部具有沿所述电极组件的轴向相对设置的第一端和第二端；
    至少一个束缚件，设置于所述主体部的周侧面和所述外壳之间，
    其中，所述至少一个束缚件包括第一束缚件，所述第一束缚件与所述第一端的最小间距小于所述第一束缚件与所述第二端的最小间距。
  2. 根据权利要求1所述的电池单体，其中，所述电极组件的周侧面具有第一附接区域，所述第一束缚件附接于所述第一附接区域的至少一部分区域上；所述第一附接区域以所述第一端为起始端并沿所述轴向延伸，且所述第一附接区域的沿所述轴向的尺寸小于所述主体部沿所述轴向尺寸的1/3。
  3. 根据权利要求1或2所述的电池单体，其中，所述电极组件包括第一极片，所述第一极片包括位于所述主体部的第一活性物质层，所述第一活性物质层包括基体区和削薄区，所述削薄区的厚度小于所述基体区的厚度，所述削薄区在所述轴向上位于所述基体区的靠近所述第一端的一侧；
    在所述轴向上，所述第一束缚件与所述削薄区错位设置。
  4. 根据权利要求3所述的电池单体，其中，在所述轴向上，所述第一束缚件与所述削薄区的间距为1mm～2mm。
  5. 根据权利要求1至4任一项所述的电池单体，其中，所述至少一个束缚件包括第二束缚件，所述第二束缚件与所述第二端的最小间距小于所述第二束缚件与所述第一端的最小间距。
  6. 根据权利要求5所述的电池单体，其中，所述电极组件的周侧面具有第二附接区域，所述第二束缚件附接于所述第二附接区域的至少一部分区域上；所述第二附接区域以所述第二端为起始端并沿所述轴向延伸，且所述第二附接区域沿所述轴向的尺寸小于所述主体部沿所述轴向尺寸的1/3。
  7. 据权利要求5或6所述的电池单体，其中，所述主体部具有位于所述第一端和所述第二端之间的中截面，所述第二束缚件与所述第一束缚件在所述轴向上关于所述中截面对称设置。
  8. 根据权利要求1至7任一项所述的电池单体，其中，所述至少一个束缚件包括第三束缚件，所述主体部具有位于所述第一端和所述第二端之间的中截面，所述第三束缚件覆盖所述中截面。
  9. 根据权利要求1至7任一项所述的电池单体，其中，所述至少一个束缚件包括第三束缚件，所述主体部具有位于所述第一端和所述第二端之间的中截面，所述第三束缚件附接于所述中截面与所述第一端之间的区域上，且所述第三束缚件位于所述第一束缚件靠近所述第二端的一侧。
  10. 根据权利要求8或9所述的电池单体，其中，所述第一束缚件的厚度大于所述第三束缚件的厚度。
  11. 根据权利要求5至7任一项所述的电池单体，其中，所述主体部具有位于所述第一端和所述第二端的中截面；
    所述至少一个束缚件包括第四束缚件，所述第四束缚件附接于所述中截面与所述第二端之间的区域上，且所述第四束缚件位于所述第二束缚件靠近所述第一端的一侧。
  12. 根据权利要求11所述的电池单体，其中，所述至少一个束缚件包括第三束缚件，所述第四束缚件与所述第三束缚件关于所述中截面对称设置。
  13. 根据权利要求1至12任一项所述的电池单体，其中，所述束缚件配置为在吸收电解液后膨胀。
  14. 根据权利要求13所述的电池单体，其中，所述束缚件的材料包括热塑性聚氨酯、葡聚糖凝胶以及端羟基聚丁二烯-聚氨酯中的至少一者。
  15. 根据权利要求1至14任一项所述的电池单体，其中，沿所述电极组件的周向，所述束缚件具有第一自由端和第二自由端；
    所述束缚件包括设置于所述第一自由端和所述第二自由端之间的重叠部，沿所述电极组件的周向，所述重叠部的中心角α满足：α≤30°。
  16. 根据权利要求1至14任一项所述的电池单体，其中，沿所述电极组件的周向，所述束缚件具有第一自由端和第二自由端，所述第一自由端和所述第二自由端间隔设置；
    所述主体部具有裸露区，所述裸露区位于所述第一自由端和所述第二自由端之间，并裸露于所述束缚件的外部；沿所述电极组件的周向，所述裸露区的中心角β满足，β≤180°。
  17. 根据权利要求1至14任一项所述的电池单体，其中，所述束缚件包括多个第一部分，多个所述第一部分沿所述电极组件的周向间隔设置。
  18. 根据权利要求16或17所述电池单体，其中，所述电极组件包括第一极片，所述第一极片卷绕为多圈；
    在所述电极组件的周向上，所述束缚件与最外圈的所述第一极片的尾端错位设置。
  19. 一种电池，包括如权利要求1至18任一项所述的电池单体。
  20. 一种用电装置，包括如权利要求19所述的电池，所述电池用于提供电能。
PCT/CN2022/088579 2022-04-22 2022-04-22 电池单体、电池以及用电装置 WO2023201726A1 (zh)

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CN102427136A (zh) * 2011-12-09 2012-04-25 江苏双登集团有限公司 高温环境下通信用铅酸蓄电池
CN102456909A (zh) * 2010-11-03 2012-05-16 Sb锂摩托有限公司 可再充电电池
CN205564885U (zh) * 2016-04-21 2016-09-07 苏州协鑫集成科技工业应用研究院有限公司 电池卷芯组件及电池
KR20170009591A (ko) * 2015-07-17 2017-01-25 주식회사 엘지화학 2차전지

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Publication number Priority date Publication date Assignee Title
CN102456909A (zh) * 2010-11-03 2012-05-16 Sb锂摩托有限公司 可再充电电池
CN102427136A (zh) * 2011-12-09 2012-04-25 江苏双登集团有限公司 高温环境下通信用铅酸蓄电池
KR20170009591A (ko) * 2015-07-17 2017-01-25 주식회사 엘지화학 2차전지
CN205564885U (zh) * 2016-04-21 2016-09-07 苏州协鑫集成科技工业应用研究院有限公司 电池卷芯组件及电池

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