WO2024130525A1 - 电极组件、电池单体、电池以及用电装置 - Google Patents

电极组件、电池单体、电池以及用电装置 Download PDF

Info

Publication number
WO2024130525A1
WO2024130525A1 PCT/CN2022/140213 CN2022140213W WO2024130525A1 WO 2024130525 A1 WO2024130525 A1 WO 2024130525A1 CN 2022140213 W CN2022140213 W CN 2022140213W WO 2024130525 A1 WO2024130525 A1 WO 2024130525A1
Authority
WO
WIPO (PCT)
Prior art keywords
winding
pole piece
electrode assembly
section
assembly according
Prior art date
Application number
PCT/CN2022/140213
Other languages
English (en)
French (fr)
Inventor
廖国航
吴志阳
王艺若
林纲
黄靖华
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 EP22964629.4A priority Critical patent/EP4418402A1/en
Priority to PCT/CN2022/140213 priority patent/WO2024130525A1/zh
Priority to US18/638,655 priority patent/US20240266586A1/en
Publication of WO2024130525A1 publication Critical patent/WO2024130525A1/zh

Links

Images

Classifications

    • 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
    • H01M10/0431—Cells with wound or folded electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • 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
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present application relates to the technical field of batteries, and more particularly, to an electrode assembly, a battery cell, a battery, and an electrical device.
  • Battery monomers are widely used in electronic devices, such as mobile phones, laptop computers, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and electric tools, etc.
  • a battery cell includes an electrode assembly and an electrolyte.
  • the electrode assembly includes a positive electrode sheet, a negative electrode sheet and a separator.
  • the separator is used to separate the positive electrode sheet from the negative electrode sheet.
  • the positive electrode sheet, the negative electrode sheet and the separator are usually wound together.
  • the length of the separator is usually set much longer than the length of the positive electrode sheet and the length of the negative electrode sheet, resulting in waste of the separator.
  • the present application provides an electrode assembly, a battery cell, a battery and an electrical device, which can reduce the waste of isolation components and improve energy density.
  • an embodiment of the present application provides an electrode assembly, comprising a first pole piece, a second pole piece, and at least one isolating member for isolating the first pole piece from the second pole piece.
  • the first pole piece and the second pole piece have opposite polarities, and the first pole piece, the second pole piece, and the at least one isolating member are wound.
  • the length of the at least one isolating member is L1, the length of the first pole piece is L2, and
  • the above technical solution can limit the length difference between the isolating element and the first pole piece to within 50 mm. Under the premise of basically ensuring the insulation performance of the isolating element, it can reduce the waste of the isolating element and reduce the cost. At the same time, it can reduce the space occupied by the isolating element and improve the energy density.
  • L1 and L2 satisfy:
  • Limiting the length difference between the isolating member and the first pole piece to within 30 mm can further reduce the waste of the isolating member and reduce the cost while basically ensuring the insulation performance of the isolating member. At the same time, it can reduce the space occupied by the isolating member and improve the energy density.
  • L1 and L2 satisfy:
  • Limiting the length difference between the isolating element and the first pole piece to within 10 mm can further reduce the waste of the isolating element, reduce costs, and reduce the space occupied by the isolating element, thereby improving energy density, while basically ensuring the insulation performance of the isolating element.
  • L1 L2.
  • the separator can substantially completely cover the first electrode sheet to effectively separate the first electrode sheet from the second electrode sheet.
  • the length of the ineffective area of the separator i.e., the area of the separator that is not used to separate the first electrode sheet from the second electrode sheet
  • the length of the ineffective area of the separator is relatively small, thereby further reducing the amount of the separator, reducing costs, and improving the energy density of the electrode assembly.
  • the separator can cover the first pole piece to effectively separate the first pole piece from the second pole piece; the separator adopts an over-design to improve the safety performance of the electrode assembly.
  • the separator includes a first winding start section that exceeds the winding start end of the second pole piece, and the first pole piece includes a second winding start section that exceeds the winding start end of the second pole piece.
  • the first winding start section includes the winding start end of the separator
  • the second winding start section includes the winding start end of the first pole piece
  • the minimum spacing between the winding start end of the separator and the winding start end of the first pole piece is D1, and D1 ⁇ 20mm.
  • the above technical solution limits D1 to less than or equal to 20 mm, which can balance the amount of the separator and the amount of the first pole piece, reduce costs, and improve the energy density of the electrode assembly.
  • the minimum spacing between the winding head end of the separator and the winding head end of the first pole piece is less than or equal to 20 mm, and the first pole piece and the separator can be wound almost at the same time, thereby saving winding time and improving winding efficiency.
  • D1 ⁇ 10 mm Limiting D1 to less than or equal to 10 mm can further balance the amount of the separator and the amount of the first pole piece, reduce costs, increase the energy density of the electrode assembly, save winding time, and improve winding efficiency.
  • the length of the first winding start section is greater than the length of the second winding start section, and the first winding start section covers the winding head end of the first pole piece.
  • the electrode assembly will expand, causing the first winding start section to be easily pulled, further causing the risk of the first pole piece being exposed.
  • the above technical solution makes the length of the first winding start section greater than the length of the second winding start section, thereby reserving a certain margin for the first winding start section.
  • the first winding start section can cover the first pole piece, thereby reducing the risk of the first pole piece being exposed and improving safety.
  • the length of the first winding start section is equal to the length of the second winding start section, and the winding head end of the first pole piece is aligned with the winding head end of the separator.
  • the first winding start section can reduce the risk of the first pole piece being exposed and improve safety, and can also reduce the length waste of the first winding start section or the second winding start section, reduce costs, and improve the energy density of the electrode assembly.
  • the separator includes a first winding end section extending beyond the winding end of the second pole piece, and the first pole piece includes a second winding end section extending beyond the winding end of the second pole piece.
  • the first winding end section includes the winding end of the separator
  • the second winding end section includes the winding end of the first pole piece
  • the spacing between the winding end of the separator and the winding end of the first pole piece is D2, and D2 ⁇ 20mm.
  • the above technical solution limits D2 to less than or equal to 20 mm, which can balance the amount of the separator and the amount of the first pole piece, reduce costs, and improve the energy density of the electrode assembly.
  • the minimum spacing between the winding end of the separator and the winding end of the first pole piece is less than or equal to 20 mm, which can make the separator and the first pole piece stop winding almost at the same time, reduce the total winding time, save winding time, and improve winding efficiency.
  • D2 ⁇ 10 mm Limiting D2 to less than or equal to 10 mm can further balance the amount of the separator and the amount of the first pole piece, reduce costs, increase the energy density of the electrode assembly, save winding time, and improve winding efficiency.
  • the length of the first winding end section is greater than the length of the second winding end section, and the first winding end section covers the winding end of the first pole piece.
  • the electrode assembly will expand, causing the first winding tail section to be easily pulled, further causing the risk of the winding end of the first pole piece being exposed.
  • the above technical solution makes the length of the first winding tail section greater than the length of the second winding tail section, thereby reserving a certain margin for the first winding tail section.
  • the first winding tail section can cover the winding end of the first pole piece, thereby reducing the risk of the winding end of the first pole piece being exposed and improving safety.
  • the length of the first winding end section is equal to the length of the second winding end section, and the winding end of the first pole piece is aligned with the winding end of the separator.
  • the first winding end section can reduce the risk of the winding end of the first pole piece being exposed and improve safety, and can also reduce the length waste of the first winding end section or the length waste of the second winding end section, reduce costs, and improve the energy density of the electrode assembly.
  • the number of separators is two, and the lengths of the two separators are equal.
  • the two separators can cover the second pole piece from both sides to separate the second pole piece from the first pole piece, thereby reducing the risk of short circuit between the second pole piece and the first pole piece.
  • the lengths of the two separators are equal, which can reduce the amount of each separator, reduce costs, and improve the energy density of the electrode assembly.
  • the first pole piece, the separator, and the second pole piece are wound to form a straight region and two bending regions, and the two bending regions are respectively located on both sides of the straight region along the first direction.
  • the first pole piece includes a second winding start section extending beyond the winding head end of the second pole piece.
  • the second winding start section is entirely located in the straight region.
  • the second winding start section is clamped in the straight area, which can improve the stability of the second winding start section, reduce the risk of the second winding start section shifting when the electrode assembly is subjected to external impact, and improve safety.
  • the first pole piece includes a second winding start section that exceeds the winding head end of the second pole piece. At least a portion of the second winding start section is located in the bending area. Bending the second winding start section in the bending area can reduce the space occupied by the second winding start section in the first direction, thereby helping to improve the energy density of the electrode assembly.
  • the second winding start section includes a first part, a second part, and a third part that are continuously arranged, the first part includes the winding head end of the first pole piece, the third part has a junction aligned with the winding head end of the second pole piece, and the third part extends from the junction; the first part and the third part are both located in the straight area, and the second part is located in the bending area and is used to connect the first part and the third part.
  • the second winding start section is bent into a double-layer structure to reduce the space occupied by the second winding start section in the first direction, thereby improving the energy density of the electrode assembly.
  • the second portion supports the first pole piece and the second pole piece in the bending region and located outside the second portion.
  • the second part can provide support force for the first pole piece and the second pole piece in the bending area and the parts located on the outside of the second part, so that the first pole piece and the second pole piece in the bending area are more compact, and the gap between the part of the first pole piece in the bending area and the part of the second pole piece in the bending area is not easily increased due to external force, thereby reducing the risk of lithium plating.
  • the first pole piece further includes a single-sided reaction section continuously arranged with the third part, the single-sided reaction section and the third part are separated at the junction; only the active material layer on the outer surface of the single-sided reaction section is opposite to the active material layer of the second pole piece. At least a portion of the single-sided reaction section is stacked on the outer side of the second winding start section, and there is no separator and second pole piece between the portion of the single-sided reaction section stacked on the outer side of the second winding start section and the second winding start section.
  • the single-sided reaction section is adjacent to the second winding start section, and the separator between the two can be omitted, thereby saving the amount of separators and improving the energy density of the electrode assembly.
  • the single-sided reaction section and the second winding start section have the same polarity, and the adjacent arrangement of the two can reduce the risk of short circuit and improve safety.
  • a portion of the single-sided reaction section stacked on the outside of the second winding starting section is in contact with the second winding starting section.
  • the second winding starting section can be supported on the single-sided reaction section, and the supporting force provided by the second part can be first transmitted to the single-sided reaction section, and then transmitted to the second pole piece through the single-sided reaction section, so that the second winding starting section can provide better support for the single-sided reaction section and the second pole piece.
  • the second pole piece includes a third winding start section extending from the winding head end of the second pole piece, and the third winding start section is entirely located in the straight area; in the thickness direction of the third winding start section, the third winding start section does not overlap with the first part.
  • the third winding start section does not overlap with the first part, and the two can share the same space in the thickness direction, thereby improving space utilization and increasing the energy density of the electrode assembly.
  • the end of the third winding start section is not easy to squeeze the first part, and the end of the first part is not easy to squeeze the third winding start section, which can reduce stress concentration and reduce the risk of pole piece fracture caused by stress concentration.
  • the third winding start section in the first direction, is spaced apart from the first portion.
  • the third winding start section is spaced apart from the first portion to reduce the risk of the third winding start section overlapping with the first portion.
  • a minimum spacing between the third winding start segment and the first portion is greater than or equal to a size of the first portion.
  • the size deviation of the first part along the first direction may be large.
  • the above technical solution limits the minimum spacing between the third winding start section and the first part based on the size of the first part, which can effectively reduce the risk of overlapping between the third winding start section and the first part.
  • a distance L3 between the third winding start segment and the first portion is 5 mm-20 mm.
  • the electrode assembly will expand and deform. If L3 is too small, the third winding start section and the first part may overlap. The larger L3 is, the smaller the size of the third winding start section and the first part along the first direction is. If L3 is too large, it will cause space waste and reduce the energy density of the electrode assembly. Setting L3 to 5mm-20mm can reduce the risk of overlapping between the third winding start section and the first part and reduce the loss of energy density of the electrode assembly.
  • the winding end of the first pole piece is located in the bending region.
  • the straight area of the electrode assembly expands greatly, and the straight area is easily squeezed with the shell. If the winding end of the first pole piece is set in the straight area, the winding end of the first pole piece is prone to stress concentration, causing the second pole piece to be broken by the winding end of the first pole piece, lithium deposition, etc.
  • the above technical solution sets the winding end of the first pole piece in the bending area, which can reduce stress concentration, reduce the risk of second pole piece breakage, lithium deposition, etc., and improve safety.
  • the first pole piece includes a second winding tail section that exceeds the winding end of the second pole piece, and the second winding tail section includes the winding end of the first pole piece.
  • the second winding tail section is located in the bending area as a whole.
  • the second winding tail section is located in the bending area as a whole, which can reduce the length of the second winding tail section and reduce material waste.
  • the winding end of the second pole piece is located in the bending region.
  • Setting the winding end of the second pole piece in the bending area can reduce stress concentration, reduce the risk of the first pole piece being broken by the winding end of the second pole piece, reduce lithium plating, and improve safety.
  • the separator includes a first winding end section extending beyond the winding end of the second electrode sheet, and the first winding end section includes the winding end of the separator.
  • the electrode assembly also includes a binding member connected to the separator and used to bind the first winding end section. The binding member can bind the first winding end section to reduce the risk of the separator spreading.
  • the first pole piece includes a second winding tail section that extends beyond the winding end of the second pole piece, and the second winding tail section includes the winding end of the first pole piece.
  • the first winding tail section and the second winding tail section are located in the same bending area.
  • One end of the binding member is located outside the first winding tail section and is connected to the first winding tail section, and the other end of the binding member extends beyond the winding end of the first pole piece and the winding end of the isolation member, and is connected to the isolation member.
  • the binding member can connect the first winding tail section to other parts of the isolation member to bind the first winding tail section and reduce the risk of the isolation member falling apart.
  • the other end of the tie member is located in the straight region.
  • the straight region is relatively flat, which facilitates the connection between the tie member and the isolation member and increases the connection strength between the tie member and the isolation member.
  • the other end of the tie is located in another bending area. Placing the two ends of the tie in the bending area can reduce the pressure on the ends of the tie when the electrode assembly expands, reduce stress concentration, reduce the risk of the electrode being crushed, reduce lithium deposition, and improve safety.
  • the electrode assembly further comprises an identification mark disposed on a surface of the restraining member that is away from the straight region.
  • the production equipment of the electrode assembly can obtain relevant information of the electrode assembly by interpreting the identification mark, which helps to realize the automated production of the electrode assembly. Compared with the solution of setting the identification mark on the separator, setting the identification mark on the restraint can reduce the risk of damage to the separator.
  • the other end of the tie member exceeds the center line of the straight area, and the center line is parallel to the winding axis of the electrode assembly.
  • both edges of the binding member extend beyond the first pole piece.
  • the binding member can cover the first pole piece, reduce the risk of the active material layer of the first pole piece being exposed, and improve safety.
  • an embodiment of the present application provides a battery cell, comprising a housing and an electrode assembly provided by any embodiment of the first aspect, wherein the electrode assembly is accommodated in the housing.
  • an embodiment of the present application provides a battery comprising a plurality of battery cells provided in the second aspect.
  • an embodiment of the present application provides an electrical device, comprising the battery provided in the third aspect, and the battery is used to provide electrical energy.
  • FIG1 is a schematic diagram of the structure of a vehicle provided in some embodiments of the present application.
  • FIG2 is an exploded schematic diagram of a battery provided in some embodiments of the present application.
  • FIG3 is an exploded schematic diagram of a battery cell provided in some embodiments of the present application.
  • FIG4 is a schematic diagram of the structure of an electrode assembly provided in some embodiments of the present application.
  • FIG5 is a schematic diagram of the structure of the electrode assembly shown in FIG4 after being flattened
  • FIG6 is a schematic diagram of a winding device provided in some embodiments of the present application.
  • FIG7 is another schematic diagram of a winding device provided in some embodiments of the present application.
  • FIG8 is a schematic diagram of the structure of an electrode assembly provided in some embodiments of the present application.
  • FIG9 is a schematic structural diagram of the electrode assembly shown in FIG8 after being flattened
  • FIG10 is a partial schematic diagram of the electrode assembly shown in FIG4 ;
  • FIG11 is a schematic diagram of the electrode assembly shown in FIG10 in a flattened state
  • FIG12 is another partial schematic diagram of the electrode assembly shown in FIG4 ;
  • FIG13 is a schematic diagram of the electrode assembly shown in FIG12 in a flattened state
  • FIG14 is a schematic diagram of a three-dimensional structure of an electrode assembly provided in some embodiments of the present application.
  • FIG15 is a schematic cross-sectional view of the electrode assembly shown in FIG12 taken along line A-A;
  • FIG16 is a partial schematic diagram of an electrode assembly provided in some other embodiments of the present application.
  • FIG. 17 is a schematic diagram of the structure of an electrode assembly provided in some other embodiments of the present application.
  • the terms “installed”, “connected”, “connected”, and “attached” should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements.
  • installed should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements.
  • multiple refers to more than two (including two).
  • multiple groups refers to more than two groups (including two groups)
  • multiple sheets refers to more than two sheets (including two sheets).
  • 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., and the embodiments of the present application do not limit this.
  • Battery cells may be cylindrical, flat, rectangular or other shapes, etc., and the embodiments of the present application do not limit this. Battery cells are generally divided into three types according to the packaging method: cylindrical battery cells, square battery cells and soft-pack battery cells, and the embodiments of the present application do not limit this.
  • the battery cell includes an electrode assembly and an electrolyte.
  • the electrode assembly includes a positive electrode sheet, a negative electrode sheet and a separator.
  • the battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer.
  • the positive electrode active material layer is coated on the surface of the positive electrode current collector.
  • the current collector not coated with the positive electrode active material layer protrudes from the current collector coated with the positive electrode active material layer.
  • the current collector not coated with the positive electrode active material layer serves as the positive electrode tab.
  • the material of the positive electrode current collector may be aluminum, and the positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc.
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer.
  • the negative electrode active material layer is coated on the surface of the negative electrode current collector.
  • the current collector not coated with the negative electrode active material layer protrudes from the current collector coated with the negative electrode active material layer.
  • the current collector not coated with the negative electrode active material layer serves as the negative electrode tab.
  • the material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon or silicon, etc.
  • the number of positive pole ears is multiple and stacked together, and the number of negative pole ears is multiple and stacked together.
  • the material of the separator can be PP (polypropylene) or PE (polyethylene), etc.
  • the electrode assembly can be a winding structure or a laminated structure, and the embodiments of the present application are not limited to this.
  • performance parameters such as energy density, cycle life, discharge capacity, and charge and discharge rate.
  • the safety of the battery must also be considered.
  • the battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.
  • the battery mentioned in the present application may include a battery module or a battery pack.
  • the battery generally includes a box for encapsulating 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 separator has electronic insulation and is disposed between the positive electrode sheet and the negative electrode sheet. Its main function is to prevent the positive electrode sheet and the negative electrode sheet from contacting each other, thereby causing an internal short circuit in the electrode assembly.
  • the separator has a large number of through-holes, which can ensure the free passage of electrolyte ions.
  • the separator has good permeability to lithium ions.
  • the separator may include an isolation base layer and a functional layer located on the surface of the isolation base layer.
  • the isolation base layer may be at least one of polypropylene, polyethylene, ethylene-propylene copolymer, polybutylene terephthalate, etc.
  • the functional layer may be a mixture layer of ceramic oxide and binder.
  • the separator plays a very important role in the electrode assembly.
  • the length of the separator is much longer than the length of the electrode piece, and the separator has the problem of excessive length, which causes the separator to be wasted and increases the cost of the battery cell.
  • the excessive separator will take up space and affect the energy density of the electrode assembly.
  • the present application proposes a technical solution, which reduces the length difference between the separator and the electrode piece, thereby reducing the amount of separator used, reducing costs, and improving the energy density of the electrode assembly.
  • FIG1 is a schematic diagram of the structure of a vehicle provided in some embodiments of the present application.
  • a battery 2 is disposed inside the vehicle 1, and the battery 2 can be disposed at the bottom, head, or tail of the vehicle 1.
  • the battery 2 can be used to power the vehicle 1, for example, the battery 2 can be used as an operating power source for the vehicle 1.
  • the vehicle 1 may further include a controller 3 and a motor 4 , wherein the controller 3 is used to control the battery 2 to supply power to the motor 4 , for example, to meet the power requirements of starting, navigating, and driving the vehicle 1 .
  • the battery 2 can not only serve as an operating power source for the vehicle 1, but also serve 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.
  • FIG2 is an exploded schematic diagram of a battery provided in some embodiments of the present application.
  • the battery 2 includes a box body 5 and a battery cell 6 , and the battery cell 6 is accommodated in the box body 5 .
  • the box 5 is used to accommodate the battery cell 6, and the box 5 can be of various structures.
  • the box 5 can include a first box portion 5a and a second box portion 5b, the first box portion 5a and the second box portion 5b cover each other, and the first box portion 5a and the second box portion 5b jointly define a storage space 5c for accommodating the battery cell 6.
  • the second box portion 5b can be a hollow structure with one end open, the first box portion 5a is a plate-like structure, and the first box portion 5a covers the open side of the second box portion 5b to form a box 5 with a storage space 5c; the first box portion 5a and the second box portion 5b can also be hollow structures with one side open, and the open side of the first box portion 5a covers the open side of the second box portion 5b to form a box 5 with a storage space 5c.
  • the first box portion 5a and the second box portion 5b can be of various shapes, such as a cylinder, a cuboid, etc.
  • a sealing member such as a sealant, a sealing ring, etc., may also be provided between the first box body 5a and the second box body 5b.
  • the first box body portion 5a covers the top of the second box body portion 5b
  • the first box body portion 5a can also be called an upper box cover
  • the second box body portion 5b can also be called a lower box.
  • multiple battery cells 6 there are multiple battery cells 6.
  • Multiple battery cells 6 can be connected in series, in parallel, or in mixed connection.
  • Mixed connection means that multiple battery cells 6 are both connected in series and in parallel.
  • Multiple battery cells 6 can be directly connected in series, in parallel, or in mixed connection, and then the whole formed by multiple battery cells 6 is accommodated in the box 5; of course, multiple battery cells 6 can also be connected in series, in parallel, or in mixed connection to form a battery module, and multiple battery modules are then connected in series, in parallel, or in mixed connection to form a whole, and accommodated in the box 5.
  • FIG. 3 is an exploded schematic diagram of a battery cell provided in some embodiments of the present application.
  • the battery cell 6 refers to the smallest unit constituting the battery 2. As shown in FIG. 3 , the battery cell 6 includes a housing 20, an electrode assembly 10, and other functional components, wherein the electrode assembly 10 is accommodated in the housing 20.
  • the housing 20 includes an end cap 22 and a shell 21 .
  • the end cap 22 refers to a component that covers the opening of the shell 21 to isolate the internal environment of the battery cell 6 from the external environment.
  • the shape of the end cap 22 can be adapted to the shape of the shell 21 to match the shell 21.
  • the end cap 22 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 22 is not easily deformed when squeezed and collided, so that the battery cell 6 can have a higher structural strength and the safety performance can also be improved.
  • Functional components such as electrode terminals 30 can be provided on the end cap 22.
  • the electrode terminal 30 can be used to be electrically connected to the electrode assembly 10 for outputting or inputting electrical energy of the battery cell 6.
  • a pressure relief mechanism for releasing the internal pressure when the internal pressure or temperature of the battery cell 6 reaches a threshold value may also be provided on the end cap 22.
  • the material of the end cap 22 may also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not particularly limited in the embodiments of the present application.
  • an insulating member may be provided inside the end cap 22, and the insulating member may be used to isolate the electrical connection components in the housing 21 from the end cap 22 to reduce the risk of short circuit.
  • the insulating member may be plastic, rubber, or the like.
  • the shell 21 is a component used to cooperate with the end cap 22 to form the internal environment of the battery cell 6, wherein the formed internal environment can be used to accommodate the electrode assembly 10, the electrolyte and other components.
  • the shell 21 and the end cap 22 can be independent components, and an opening can be set on the shell 21, and the internal environment of the battery cell 6 is formed by covering the opening with the end cap 22 at the opening.
  • the end cap 22 and the shell 21 can also be integrated.
  • the end cap 22 and the shell 21 can form a common connection surface before other components are put into the shell, and when the interior of the shell 21 needs to be encapsulated, the end cap 22 covers the shell 21.
  • the shell 21 can be of various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the shell 21 can be determined according to the specific shape and size of the electrode assembly 10.
  • the material of the shell 21 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present application does not impose any special restrictions on this.
  • the electrode assembly 10 is a component that can undergo electrochemical reactions.
  • One or more electrode assemblies 10 may be included in the housing 21.
  • the electrode assembly 10 is mainly formed by winding a positive electrode sheet and a negative electrode sheet, and an isolation member is usually provided between the positive electrode sheet and the negative electrode sheet.
  • the portion of the positive electrode sheet and the negative electrode sheet having active materials constitutes the main body of the electrode assembly 10, and the portion of the positive electrode sheet and the negative electrode sheet not having active materials each constitutes a tab.
  • the positive tab and the negative tab may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery cell 6, the positive active material and the negative active material react with the electrolyte, and the tabs connect the electrode terminals 30 to form a current loop.
  • FIG. 4 is a schematic diagram of the structure of an electrode assembly provided in some embodiments of the present application
  • FIG. 5 is a schematic diagram of the structure of the electrode assembly shown in FIG. 4 after being flattened.
  • an embodiment of the present application provides an electrode assembly 10, which includes a first pole piece 11, a second pole piece 12, and an isolating member 13 for isolating the first pole piece 11 and the second pole piece 12.
  • the first pole piece 11 and the second pole piece 12 have opposite polarities.
  • the first pole piece 11, the second pole piece 12, and at least one isolating member 13 are wound.
  • the length of at least one isolating member 13 is L1, the length of the first pole piece 11 is L2, and
  • the electrode assembly 10 is a wound structure, which can be in various shapes.
  • the electrode assembly 10 can be cylindrical, flat, prism (such as triangular prism, quadrangular prism or hexagonal prism) or other shapes.
  • One of the first pole piece 11 and the second pole piece 12 is a positive pole piece, and the other is a negative pole piece.
  • the separator 13 includes an insulating film.
  • the insulating film has a large number of through micropores, which can ensure the free passage of metal ions; illustratively, the insulating film has good permeability to lithium ions and basically cannot block the passage of lithium ions.
  • the length of the spacer 13 refers to the length of the spacer 13 in a flattened state
  • the length of the first pole piece 11 refers to the length of the first pole piece 11 in a flattened state.
  • the spacer 13 in a flattened state, is generally a rectangular sheet, and the length of the spacer 13 is the length of the rectangular sheet.
  • the separator 13 may be one or more.
  • two separators 13 may be provided.
  • one separator 13, the first pole piece 11, another separator 13 and the second pole piece 12 may be stacked in sequence, and then wound more than two times to form a winding structure.
  • At least one isolator 13 has a length of L1. In some examples, there is one isolator 13, and the length of the isolator 13 is L1. In other examples, there are two isolators 13, and the length of one isolator 13 is L1, while the length of the other isolator 13 is not limited, for example, the length of the other isolator 13 can be greater than, less than, or equal to L1.
  • L1 may be greater than, less than or equal to L2, as long as the isolation member 13 can separate the first pole piece 11 from the second pole piece 12 .
  • can be 50mm, 40mm, 30mm, 20mm, 10mm, 5mm, 2mm, 1mm or 0mm.
  • the waste of the separator 13 can be reduced, the cost can be reduced, and at the same time, the space occupied by the separator 13 can be reduced, thereby improving the energy density.
  • the separator 13 when L1-L2 ⁇ 0, the larger the value of L1-L2, the more the separator 13 is used; if the value of L1-L2 is too large, the separator 13 will be used in a larger amount, resulting in a higher cost and lower energy density of the electrode assembly 10.
  • L1-L2 ⁇ 0 the smaller the value of L1-L2, the smaller the area of the first pole piece 11 covered by the separator 13; if the value of L1-L2 is too small, the risk of insulation failure will be caused, causing the first pole piece 11 and the second pole piece 12 to short-circuit, causing safety hazards.
  • the amount of the separator 13 can be reduced, the cost can be reduced, and the energy density of the electrode assembly 10 can be improved while achieving the insulation function of the separator 13.
  • L1 and L2 satisfy:
  • L1 and L2 satisfy:
  • L1 and L2 satisfy:
  • the separator 13 may substantially completely cover the first electrode sheet 11 to effectively separate the first electrode sheet 11 from the second electrode sheet 12.
  • the length of the ineffective area of the separator 13 i.e., the area of the separator 13 that is not used to separate the first electrode sheet 11 from the second electrode sheet 12
  • the length of the ineffective area of the separator 13 is relatively small, thereby further reducing the amount of the separator 13, reducing costs, and improving the energy density of the electrode assembly 10.
  • the isolation member 13 includes a first winding start section 131 extending beyond the winding head end 12 a of the second pole piece, and the first pole piece 11 includes a second winding start section 111 extending beyond the winding head end 12 a of the second pole piece.
  • the two ends of the first pole piece 11 along its length direction are the winding head end 11a of the first pole piece and the winding tail end 11b of the first pole piece.
  • the winding head end 11a of the first pole piece is close to the inside of the electrode assembly 10, and the first pole piece starts to be wound at the winding head end 11a; the winding tail end 11b of the first pole piece is close to the outside of the electrode assembly 10, and the first pole piece stops winding at the winding tail end 11b.
  • the two ends of the second pole piece 12 along its length direction are the winding head end 12a of the second pole piece and the winding tail end 12b of the second pole piece.
  • the winding head end 12a of the second pole piece is close to the inside of the electrode assembly 10, and the second pole piece starts to be wound at the winding head end 12a; the winding tail end 12b of the second pole piece is close to the outside of the electrode assembly 10, and the second pole piece stops winding at the winding tail end 12b.
  • the separator 13 When the separator 13 is in a flattened state, the two ends of the separator 13 along its length direction are the separator's winding head end 13a and the separator's winding tail end 13b.
  • the separator's winding head end 13a When in the winding state, the separator's winding head end 13a is close to the inside of the electrode assembly 10, the separator starts to wind at the winding head end 13a, the separator's winding tail end 13b is close to the outside of the electrode assembly 10, and the separator stops winding at the winding tail end 13b.
  • the first winding start section 131 is the portion of the separator 13 that exceeds the winding head end 12a of the second pole piece.
  • the length K1 of the first winding start section 131 is the length of the separator 13 in the length direction when the separator 13 is in a flat state.
  • the second winding start section 111 is a portion of the first pole piece 11 that exceeds the winding head end 12a of the second pole piece 11.
  • the length K2 of the second winding start section 111 is the length of the second winding start section 111 in the length direction of the first pole piece 11 when the first pole piece 11 is in a flat state.
  • the embodiment of the present application does not limit the length K1 of the first winding start section 131 and the length K2 of the second winding start section 111 .
  • the length K1 of the first winding start section 131 may be greater than, less than or equal to the length K2 of the second winding start section 111 .
  • the first pole piece 11 and the isolating member 13 both exceed the winding head end 12a of the second pole piece.
  • the isolating member 13 can insulate the winding head end 12a of the second pole piece from the first pole piece 11 to reduce the risk of short circuit.
  • the first electrode 11 is a negative electrode
  • the second electrode 12 is a positive electrode.
  • the first electrode 11 exceeds the winding head 12a of the second electrode, and the first electrode 11 can receive metal ions released from the second electrode 12, thereby reducing the risk of metal ion precipitation.
  • the first winding start section 131 includes the winding head end 13a of the insulating member
  • the second winding start section 111 includes the winding head end 11a of the first pole piece.
  • the minimum distance between the winding head end 13a of the insulating member and the winding head end 11a of the first pole piece is D1, and D1 ⁇ 20mm.
  • the first pole piece 11, the isolation member 13 and the second pole piece 12 are flattened, and the relative positions of the three remain unchanged; at this time, in the length direction of the isolation member 13, the minimum distance between the winding head end 13a of the isolation member and the winding head end 11a of the first pole piece is D1.
  • the first winding starting section 131 extends from the winding head end 13a of the insulating member to the position where the insulating member 13 intersects with the winding head end 12a of the second pole piece
  • the second winding starting section 111 extends from the winding head end 11a of the first pole piece to the position where the first pole piece 11 intersects with the winding head end 12a of the second pole piece; in other words, the absolute value of the difference between the length K1 of the first winding starting section 131 and the length K2 of the second winding starting section 111 is D1.
  • the amount of the separator 13 and the amount of the first pole piece 11 can be balanced, the cost can be reduced, and the energy density of the electrode assembly 10 can be improved.
  • the minimum spacing between the winding head end 13a of the separator and the winding head end 11a of the first pole piece is less than or equal to 20 mm, and the first pole piece 11 and the separator 13 can be wound almost at the same time, thereby saving winding time and improving winding efficiency.
  • the separator 13 exceeds the winding head end 11a of the first pole piece, the larger D1 is, the larger the length K1 of the first winding starting section 131 is, and the more the separator 13 is used; if D1 is too large, the separator 13 will be seriously wasted, the cost will be increased, and the energy density will be reduced.
  • the first pole piece 11 exceeds the winding head end 13a of the separator, the larger D1 is, the larger the length K2 of the second winding starting section 111 is, and the more the first pole piece 11 is used; if D1 is too large, the first pole piece 11 will be seriously wasted, the cost will be increased, and the energy density will be reduced.
  • D1 By limiting D1 to be less than or equal to 20 mm, the usage of the separator 13 and the usage of the first pole piece 11 can be balanced, thereby reducing costs and improving the energy density of the electrode assembly 10 .
  • the winding needle 7 may be used to wind the first pole piece 11, the separator 13 and the second pole piece 12.
  • the winding needle 7 may include two oppositely disposed winding semi-axes 71, and the winding semi-axes 71 may be semi-cylindrical, semi-elliptical or other shapes.
  • the first winding starting section 131 and the second winding starting section 111 can be first clamped between the two winding half-axes 71; then, the two winding half-axes 71 are rotated to wind the first pole piece 11 and the isolation member 13. At the same time, the second pole piece 12 is carried and wound on the outside of the two winding half-axes 71 under the action of the friction force between the second pole piece 12 and the isolation member 13.
  • D1 is limited to less than or equal to 20 mm, which can reduce the length difference between the first winding starting section 131 and the second winding starting section 111, so that the first winding starting section 131 and the second winding starting section 111 are clamped between the two winding half-axes 71 at the same time, and the winding needle 7 can almost simultaneously wind the first pole piece 11 and the isolation member 13, thereby improving the winding efficiency of the electrode assembly 10.
  • D1 ⁇ 10 mm D1 ⁇ 10 mm.
  • the amount of the separator 13 and the amount of the first pole piece 11 can be further balanced, the cost can be reduced, the energy density of the electrode assembly 10 can be increased, the winding time can be saved, and the winding efficiency can be improved.
  • D1 is 20 mm, 15 mm, 10 mm, 5 mm, 3 mm, 1 mm, or 0 mm.
  • the length K1 of the first winding start section 131 is equal to the length K2 of the second winding start section 111, and the winding head end 11a of the first pole piece is aligned with the winding head end 13a of the separator.
  • D1 is 0 mm.
  • the first winding start section 131 can reduce the risk of the first winding head end 11a of the first pole piece being exposed, thereby improving safety, and can also reduce the length waste of the first winding start section 131 or the length waste of the second winding start section 111, thereby reducing costs and improving the energy density of the electrode assembly.
  • the first winding head end 11a of the first pole piece being exposed means that both sides of the first winding head end 11a of the first pole piece are not covered by the isolation member.
  • the first pole piece 11 and the separator 13 usually need to be cut.
  • the winding head end 11a of the first pole piece is the cutting point of the first pole piece 11 in the continuous production
  • the winding head end 13a of the separator is the cutting point of the separator 13 in the continuous production.
  • the winding head end 11a of the first pole piece and the winding head end 13a of the separator are aligned, and the cutter mechanism 8 can be used to synchronously cut the first pole piece 11 and the separator 13, thereby improving production efficiency and simplifying production equipment.
  • the spacer 13 includes a first winding end section 132 extending beyond the winding end 12 b of the second pole piece, and the first pole piece 11 includes a second winding end section 112 extending beyond the winding end 12 b of the second pole piece.
  • the first winding end section 132 is the portion of the separator 13 that exceeds the winding end 12b of the second pole piece.
  • the length K3 of the first winding end section 132 is the dimension of the first winding end section 132 in the length direction of the separator 13 when the separator 13 is in a flattened state.
  • the second winding end section 112 is a portion of the first pole piece 11 that exceeds the winding end 12b of the second pole piece 11.
  • the length K4 of the second winding end section 112 is the dimension of the second winding end section 112 in the length direction of the first pole piece 11 when the first pole piece 11 is in a flat state.
  • the embodiment of the present application does not limit the length K3 of the first winding end section 132 and the length K4 of the second winding end section 112 .
  • the length K3 of the first winding end section 132 may be greater than, less than or equal to the length K4 of the second winding end section 112 .
  • the first pole piece 11 and the separator 13 both exceed the winding end 12b of the second pole piece, and the separator 13 can insulate the winding end 12b of the second pole piece from the first pole piece 11 to reduce the risk of short circuit.
  • the first pole piece 11 is a negative pole piece
  • the second pole piece 12 is a positive pole piece.
  • the first pole piece 11 exceeds the winding end 12b of the second pole piece, and the first pole piece 11 can receive the metal ions released from the second pole piece 12, thereby reducing the risk of metal ion precipitation.
  • the first winding end section 132 is located outside the second winding end section 112 .
  • the first winding end section 132 includes the winding end 13b of the insulating member
  • the second winding end section 112 includes the winding end 11b of the first pole piece.
  • the distance between the winding end 13b of the insulating member and the winding end 11b of the first pole piece is D2, and D2 ⁇ 20mm.
  • the first pole piece 11, the separator 13 and the second pole piece 12 are flattened, and the relative positions of the three remain unchanged; at this time, in the length direction of the separator 13, the minimum distance between the winding end 13b of the separator and the winding end 11b of the first pole piece is D2.
  • the first winding end section 132 extends from the winding end 13b of the insulating member to the junction of the winding end 12b of the insulating member 13 and the second pole piece, and the second winding end section 112 extends from the winding end 11b of the first pole piece to the junction of the winding end 12b of the first pole piece 11 and the second pole piece; in other words, the absolute value of the difference between the length K3 of the first winding end section 132 and the length K4 of the second winding end section 112 is D2.
  • the amount of the separator 13 and the amount of the first pole piece 11 can be balanced, the cost can be reduced, and the energy density of the electrode assembly 10 can be improved.
  • the minimum spacing between the winding end 13b of the separator and the winding end 11b of the first pole piece is less than or equal to 20 mm, which can make the separator 13 and the first pole piece 11 stop winding almost at the same time, reducing the total winding time, saving winding time, and improving winding efficiency.
  • the larger D2 is, the larger the length K3 of the first winding end section 132 is, and the more the spacer 13 is used; if D2 is too large, the spacer 13 will be seriously wasted, the cost will be increased, and the energy density will be reduced.
  • the larger D2 is, the larger the length K4 of the second winding end section 112 is, and the more the first pole piece 11 is used; if D2 is too large, the first pole piece 11 will be seriously wasted, the cost will be increased, and the energy density will be reduced.
  • Limiting D2 to be less than or equal to 20 mm can balance the usage of the separator 13 and the usage of the first pole piece 11 , reduce costs, and improve the energy density of the electrode assembly 10 .
  • D2 ⁇ 10 mm D2 ⁇ 10 mm.
  • the amount of the separator 13 and the amount of the first pole piece 11 can be further balanced, the cost can be reduced, the energy density of the electrode assembly 10 can be increased, the winding time can be saved, and the winding efficiency can be improved.
  • D2 is 20 mm, 15 mm, 10 mm, 5 mm, 3 mm, 1 mm, or 0 mm.
  • the length K3 of the first winding end section 132 is equal to the length K4 of the second winding end section 112, and the winding end 11b of the first pole piece is aligned with the winding end 13b of the separator.
  • D2 is 0 mm.
  • the first winding tail section 132 can not only reduce the risk of exposure of the winding end 11b of the first pole piece and improve safety, but also reduce the length waste of the first winding tail section 132 or the length waste of the second winding tail section 112, thereby reducing costs and improving the energy density of the electrode assembly.
  • the first pole piece 11 and the separator 13 usually need to be cut.
  • the winding end 11b of the first pole piece is the cutting point of the first pole piece 11 in the continuous production
  • the winding end 13b of the separator is the cutting point of the separator 13 in the continuous production.
  • the winding end 11b of the first pole piece and the winding end 13b of the separator are aligned, and the cutter mechanism 8 can be used to synchronously cut the first pole piece 11 and the separator 13, thereby improving production efficiency and simplifying production equipment.
  • the number of the spacers 13 is two, and the lengths of the two spacers 13 are equal.
  • the lengths of the two spacers 13 are both L1.
  • “equal length” allows a certain error. For example, when the length difference between the two spacers 13 is less than or equal to 2 mm, the lengths of the two spacers 13 can be considered to be equal.
  • the two separators 13 can cover the second pole piece 12 from both sides to separate the second pole piece 12 from the first pole piece 11, thereby reducing the risk of short circuit between the second pole piece 12 and the first pole piece 11.
  • the two separators 13 are equal in length, which can reduce the amount of each separator 13, reduce costs, and improve the energy density of the electrode assembly 10.
  • the minimum distance between the winding head end 13a of an isolating member and the winding head end 11a of the first pole piece is D1, and D1 ⁇ 50mm.
  • the minimum distance between the winding head end 13a of another isolating member and the winding head end 11a of the first pole piece is D3, and D3 ⁇ 50mm.
  • D1 D3.
  • the winding head ends 13 a of the two separators are aligned, and the winding tail ends 13 b of the two separators are aligned.
  • the first pole piece 11 , the isolation member 13 , and the second pole piece 12 are wound to form a straight region B1 and two bending regions B2 , and the two bending regions B2 are respectively located on both sides of the straight region B1 along the first direction X.
  • the bending region B2 is a region having a bending structure in the electrode assembly 10, in which the first pole piece 11, the second pole piece 12 and the separator 13 are all bent.
  • the portion of the first pole piece 11 located in the bending region B2 is generally bent into an arc shape
  • the portion of the second pole piece 12 located in the bending region B2 is generally bent into an arc shape.
  • the straight region B1 is a region of the electrode assembly 10 having a straight structure, and the first pole piece 11 and the second pole piece 12 are substantially straightly arranged in the straight region B1.
  • the surface of each layer of the first pole piece and the surface of each layer of the second pole piece in the straight region B1 are substantially flat.
  • the electrode assembly 10 of the embodiment of the present application has a flat structure, which can be applied to square battery cells.
  • Figure 6 is a schematic diagram of a winding device provided in some embodiments of the present application
  • Figure 7 is another schematic diagram of a winding device provided in some embodiments of the present application.
  • the winding device includes at least one winding needle 7 located at the winding station P1 and at least one winding needle 7 located at the non-winding station P2 .
  • the winding needle 7 i.e. the winding needle 7 on the upper side located at the winding station P1 is used to wind the first pole sheet 11, the second pole sheet 12 and the separator 13.
  • the first pole sheet 11, the second pole sheet 12 and the separator 13 are wound to a set number of turns, the second pole sheet 12 is cut off.
  • the winding needle 7 wound with the first pole piece 11, the separator 13 and the second pole piece 12 moves to the non-winding station P2 (as shown in FIG. 7 , moves to the lower right side).
  • Another winding needle 7 moves from the non-winding station P2 to the winding station P1, and clamps the first pole piece 11 and the separator 13.
  • the portion of the first pole piece 11 clamped by the other winding needle 7 is a portion of the second winding starting section 111
  • the portion of the separator 13 clamped by the other winding needle 7 is a portion of the first winding starting section 131.
  • the cutter mechanism 8 separates the first pole piece 11 and the separator 13.
  • the cutter mechanism 8 cuts the first pole piece 11 and the separator 13 simultaneously, so that the winding head end 11a of the first pole piece and the winding head end 13a of the separator are aligned.
  • the assembly consisting of the first pole piece 11, the second pole piece 12 and the isolation member 13 on the winding needle 7 on the lower right side may be subjected to other processes, such as pasting the binding member described later.
  • the second pole sheet 12 is cut off to enter the next cycle.
  • the winding device includes three winding needles 7, one of which is located at the winding station P1, and the other two are located at the non-winding station P2.
  • the winding needle 7 on the upper side is the winding needle 7 located at the winding station P1
  • the winding needle 7 on the lower left side and the winding needle 7 on the lower right side are the winding needles 7 located at the non-winding station P2.
  • the winding needle 7 on the lower left side is used for the unloading process.
  • FIG8 is a schematic diagram of the structure of an electrode assembly provided in some embodiments of the present application
  • FIG9 is a schematic diagram of the structure of the electrode assembly shown in FIG8 after being flattened.
  • the separator 13 can cover the first pole piece 11 to effectively separate the first pole piece 11 from the second pole piece 12 ; the separator 11 adopts an over-design, which can improve the safety performance of the electrode assembly.
  • L1-L2 is 0.1 mm-5 mm.
  • the length K1 of the first winding start segment 131 is greater than the length K2 of the second winding start segment 111 , and the first winding start segment 131 covers the winding head end 11 a of the first pole piece.
  • the first winding starting section 131 covers the winding head end 11a of the first pole piece, which means that after the first pole piece 11 and the isolation member 13 are flattened, in the thickness direction of the first pole piece, the projection of the winding head end 11a of the first pole piece is located within the projection of the first winding starting section 131 .
  • the electrode assembly 10 will expand, causing the first winding start section 131 to be easily pulled, further causing the risk of the winding head end 11a of the first pole piece being exposed.
  • the length of the first winding start section 131 is greater than the length of the second winding start section 111, thereby reserving a certain margin for the first winding start section 131.
  • the first winding start section 131 can cover the winding head end 11a of the first pole piece, thereby reducing the risk of the winding head end 11a of the first pole piece being exposed and improving safety.
  • the difference between the length K1 of the first winding start section 131 and the length K2 of the second winding start section 111 is 0.05 mm-2.5 mm.
  • the length K3 of the first winding end section 132 is greater than the length K4 of the second winding end section 112 , and the first winding end section 132 covers the winding end 11 b of the first pole piece.
  • the first winding tail section 132 covering the winding end 11b of the first pole piece means that after the first pole piece 11 and the isolation member 13 are flattened, in the thickness direction of the first pole piece, the projection of the winding end 11b of the first pole piece is located within the projection of the first winding tail section 132 .
  • the electrode assembly 10 will expand, causing the first winding tail section 132 to be easily pulled, further causing the risk of the winding end 11b of the first pole piece being exposed.
  • the length of the first winding tail section 132 is greater than the length of the second winding tail section 112, thereby reserving a certain margin for the first winding tail section 132.
  • the first winding tail section 132 can cover the winding end 11b of the first pole piece, thereby reducing the risk of the winding end 11b of the first pole piece being exposed and improving safety.
  • the difference between the length K3 of the first winding end section 132 and the length K4 of the second winding end section 112 is 0.05 mm-2.5 mm.
  • FIG. 10 is a partial schematic diagram of the electrode assembly shown in FIG. 4 ; and FIG. 11 is a schematic diagram of the electrode assembly shown in FIG. 10 in a flattened state.
  • the first pole piece 11 includes a second winding start section 111 extending beyond the winding head end 12a of the second pole piece. At least a portion of the second winding start section 111 is located in the bending area B2.
  • Bending the second winding start segment 111 at the bending area B2 can reduce the space occupied by the second winding start segment 111 in the first direction X, thereby helping to improve the energy density of the electrode assembly 10 .
  • the second winding start section 111 includes a first portion 1111, a second portion 1112, and a third portion 1113 that are continuously arranged.
  • the first portion 1111 includes the winding head end 11a of the first pole piece.
  • the third portion 1113 has a junction aligned with the winding head end 12a of the second pole piece, and the third portion 1113 extends from the junction.
  • the first portion 1111 and the third portion 1113 are both located in the straight area B1, and the second portion 1112 is located in the bending area B2 and is used to connect the first portion 1111 and the third portion 1113.
  • the second winding start section 111 is bent into a double-layer structure to reduce the space occupied by the second winding start section 111 in the first direction X, thereby improving the energy density of the electrode assembly 10 .
  • At least a portion of the first portion 1111 is located outside the winding needle 7, and at least a portion of the third portion 1113 may be clamped in the winding needle 7. At least a portion of the first portion 1111 extends outside the winding needle 7, which can facilitate the cutter mechanism 8 to cut off the first electrode sheet 11 and the separator 13.
  • the embodiment of the present application can increase the distance between the winding needle 7 and the winding head end 12a of the second pole piece, reduce the impact on the winding head end 12a of the second pole piece when the winding needle 7 is pulled out, and reduce the risk of the winding head end 12a of the second pole piece deviating from the predetermined position.
  • the second portion 1112 supports the first pole piece 11 and the second pole piece 12 in the bending area B2 and is located outside the second portion 1112 .
  • the second part 1112 can provide support force for the first pole piece 11 and the second pole piece 12 in the bending area B2 and located on the outside of the second part 1112, so that the first pole piece 11 and the second pole piece 12 in the bending area B2 are more compact, and the gap between the first pole piece 11 in the bending area B2 and the second pole piece 12 in the bending area B2 is not easily increased due to external force, thereby reducing the risk of lithium plating.
  • the second portion 1112 can also prop up the portion of the first pole piece 11 located outside the second portion 1112, increase the radius of curvature of the portion of the first pole piece 11 located outside the second portion 1112, reduce the shedding of active material from the portion of the first pole piece 11 located outside the second portion 1112, and reduce the risk of lithium deposition.
  • the second portion 1112 can also prop up the portion of the second pole piece 12 located outside the second portion 1112, increase the radius of curvature of the portion of the second pole piece 12 located outside the second portion 1112, reduce the shedding of active material from the portion of the second pole piece 12 located outside the second portion 1112, and reduce the risk of lithium deposition.
  • the second portion 1112 extends beyond the second electrode sheet 12, and does not participate in the reaction with the second electrode sheet 12.
  • the second portion 1112 may not be coated with active material.
  • the second portion 1112 may be disposed in the bending region B2.
  • the first pole piece 11 further includes a single-sided reaction section 113 continuously arranged with the third portion 1113, and the single-sided reaction section 113 is demarcated from the third portion 1113 at the junction. Only the active material layer 113a on the outer surface of the single-sided reaction section 113 is opposite to the active material layer 120a of the second pole piece 12. At least a portion of the single-sided reaction section 113 is stacked on the outer side of the second winding starting section 111, and there is no isolation member 13 and the second pole piece 12 between the portion of the single-sided reaction section 113 stacked on the outer side of the second winding starting section 111 and the second winding starting section 111.
  • the active material layer 113a on the inner surface of the single-sided reaction section 113 basically does not participate in the electrochemical reaction with the second electrode plate 12.
  • the second winding start section 111 is closer to the winding center of the electrode assembly than the portion of the single-sided reaction section 113 stacked outside the second winding start section 111 .
  • the single-sided reaction section 113 is adjacent to the second winding start section 111, and the separator 13 between the two can be omitted, thereby saving the amount of the separator 13 and improving the energy density of the electrode assembly 10.
  • the single-sided reaction section 113 and the second winding start section 111 have the same polarity, and the adjacent arrangement of the two can reduce the risk of short circuit and improve safety.
  • the second electrode sheet 12 is a negative electrode sheet.
  • the single-side reaction section 113 and the second winding start section 111 are adjacent to each other, which is not likely to cause lithium deposition risk.
  • the single-sided reaction section 113 is wound in one circle.
  • a portion of the single-sided reaction section 113 stacked on the outside of the second winding starting section 111 is in contact with the second winding starting section 111 .
  • the second winding starting section 111 can be supported on the single-sided reaction section 113, and the supporting force provided by the second part 1112 can be first transmitted to the single-sided reaction section 113, and then transmitted to the second pole piece 12 through the single-sided reaction section 113, so that the second winding starting section 111 can provide better support for the single-sided reaction section 113 and the second pole piece 12.
  • the second pole piece 12 includes a third winding start section 121 extending from the winding head end 12a of the second pole piece, and the third winding start section 121 is entirely located in the straight area B1. In the thickness direction Y of the third winding start section 121, the third winding start section 121 does not overlap with the first portion 1111.
  • the third winding start section 121 does not overlap with the first portion 1111, and the two can share the same space in the thickness direction Y, thereby improving space utilization and improving the energy density of the electrode assembly 10.
  • the end of the third winding start section 121 is not easy to squeeze the first portion 1111, and the end of the first portion 1111 is not easy to squeeze the third winding start section 121, which can reduce stress concentration and reduce the risk of pole piece fracture caused by stress concentration.
  • the end of the third winding start section 121 is the winding head end 12a of the second pole piece, and the end of the first portion 1111 is the winding head end 11a of the first pole piece.
  • the third winding start section 121 extends from the winding head end 12a of the second pole piece along the negative direction of the first direction X, and the first portion 1111 extends from the winding head end 11a of the first pole piece along the positive direction of the first direction X.
  • the third winding start segment 121 is spaced apart from the first portion 1111 .
  • the third winding starting section 121 is spaced apart from the first portion 1111 to reduce the risk of the third winding starting section 121 overlapping with the first portion 1111 .
  • the distance between the third winding start section 121 and the first portion 1111 is L3, and L3 is 5 mm-20 mm.
  • L3 is 5 mm, 8 mm, 10 mm, 15 mm or 20 mm.
  • the electrode assembly 10 will expand and deform. If L3 is too small, the third winding start section 121 and the first portion 1111 may overlap. The larger L3 is, the smaller the size of the third winding start section 121 and the first portion 1111 along the first direction X is. If L3 is too large, it will cause space waste and reduce the energy density of the electrode assembly 10.
  • the size of the first portion 1111 is 5 mm-20 mm in the first direction X.
  • the size of the first portion 1111 in the first direction X is 5 mm, 7 mm, 10 mm, 12 mm, 15 mm, 18 mm or 20 mm.
  • a minimum distance between the third winding start segment 121 and the first portion 1111 is greater than or equal to a size of the first portion 1111 .
  • the minimum distance between the third winding start section 121 and the first portion 1111 is L3.
  • the first portion 1111 may have a large size deviation along the first direction X. Defining the minimum spacing between the third winding start section 121 and the first portion 1111 based on the size of the first portion 1111 can effectively reduce the risk of overlapping between the third winding start section 121 and the first portion 1111 .
  • FIG. 12 is another partial schematic diagram of the electrode assembly shown in FIG. 4 ; and FIG. 13 is a schematic diagram of the electrode assembly shown in FIG. 12 in a flattened state.
  • the winding end 11 b of the first pole piece is located in the bending region B2 .
  • the embodiment of the present application does not limit the winding end 12b of the second pole piece.
  • the winding end 12b of the second pole piece can be located in the bending area B2 or in the straight area B1.
  • the straight area B1 of the electrode assembly 10 expands greatly, and the straight area B1 is easily squeezed with the shell. If the winding end 11b of the first pole piece is set in the straight area B1, the winding end 11b of the first pole piece is prone to stress concentration, causing the second pole piece 12 to be broken by the winding end 11b of the first pole piece, lithium deposition, and other risks.
  • the embodiment of the present application sets the winding end 11b of the first pole piece in the bending area B2, which can reduce stress concentration, reduce the risk of breaking the second pole piece 12, lithium deposition, etc., and improve safety.
  • the first pole piece 11 includes a second winding end section 112 extending beyond the winding end 12b of the second pole piece, and the second winding end section 112 includes the winding end 11b of the first pole piece.
  • the second winding end section 112 is entirely located in the bending area B2.
  • the second winding end section 112 is entirely located in the bending area B2, which can reduce the length K4 of the second winding end section 112 and reduce material waste.
  • the inner surface of the second winding end section 112 is approximately a part of a cylindrical surface.
  • the projection of the inner surface of the second winding end section 112 along the winding axis Z is an arc line, and the center angle of the arc line is ⁇ , 0° ⁇ 90°.
  • ⁇ is 10°, 30°, 45°, 60°, 75° or 85°.
  • the second winding end section 112 is substantially bent into an arc shape in the bending area B2.
  • the length of the second winding end section 112 can be set as needed.
  • ⁇ is 40°-50°; further optionally, ⁇ is 45°.
  • the larger ⁇ is, the larger the length K4 of the second winding end section 112 is, the larger the space and weight occupied by the second winding end section 112 is, and the lower the energy density of the electrode assembly 10 is.
  • the electrode assembly 10 expands during the charge and discharge process, which may cause the risk of the second winding end section 112 shifting; if ⁇ is too small, the first pole piece 11 may not be able to cover the second pole piece 12 due to the shift of the second winding end section 112, thereby causing safety problems such as lithium deposition.
  • the safety and energy density of the electrode assembly 10 can be balanced.
  • the length K4 of the second winding end section 112 is 5 mm-20 mm; illustratively, the length K4 of the second winding end section 112 is 5 mm, 7 mm, 10 mm, 12 mm, 15 mm, 18 mm or 20 mm.
  • the winding end 12b of the second pole piece is located in the bending region B2.
  • the winding end 12b of the second pole piece and the winding end 11b of the first pole piece may be located in the same bending region B2, or may be located in two bending regions B2 respectively.
  • the winding end 12b of the second pole piece is arranged at the bending area B2, which can reduce stress concentration, reduce the risk of the first pole piece 11 being broken by the winding end 12b of the second pole piece, reduce lithium plating, and improve safety.
  • the winding end 12 b of the second pole piece and the winding end 11 b of the first pole piece may be located in the same bending region B2 .
  • the second pole piece 12 includes a third winding end section 122 , which extends from the winding end 12 b of the second pole piece and is entirely located in the bending region B2 .
  • the inner surface of the third winding end section 122 is approximately a part of a cylindrical surface.
  • the projection of the inner surface of the third winding end section 122 along the winding axis Z is an arc line, and the central angle of the arc line is ⁇ , 0° ⁇ 45°.
  • 0° ⁇ 45° is a projection of the inner surface of the third winding end section 122 along the winding axis Z.
  • Figure 14 is a schematic diagram of the three-dimensional structure of the electrode assembly provided in some embodiments of the present application;
  • Figure 15 is a schematic diagram of a cross-sectional view of the electrode assembly shown in Figure 12 taken along line A-A.
  • the separator 13 includes a first winding end section 132 that exceeds the winding end 12b of the second electrode sheet, and the first winding end section 132 includes the winding end 13b of the separator.
  • the electrode assembly 10 also includes a binding member 14, which is connected to the separator 13 and is used to bind the first winding end section 132.
  • the tie 14 can tie the first winding end section 132 to reduce the risk of the separator 13 being untied.
  • the first winding end section 132 is located outside the second winding end section 112 , and the binding member 14 binds the second winding end section 112 through the first winding end section 132 to reduce the risk of the first pole piece 11 being unravelled.
  • the first pole piece 11 includes a second winding end section 112 that extends beyond the winding end 12b of the second pole piece, and the second winding end section 112 includes the winding end 11b of the first pole piece.
  • the first winding end section 132 and the second winding end section 112 are located in the same bending area B2.
  • One end of the tie 14 is located outside the first winding end section 132 and connected to the first winding end section 132, and the other end of the tie 14 extends beyond the winding end 11b of the first pole piece and the winding end 13b of the isolating member, and is connected to the isolating member 13.
  • the embodiment of the present application does not limit the positions of the winding end 11b of the first pole piece and the winding end 13b of the separator.
  • the winding end 11b of the first pole piece exceeds the winding end 13b of the separator; in other examples, the winding end 13b of the separator exceeds the winding end 11b of the first pole piece; in still other examples, the winding end 11b of the first pole piece is flush with the winding end 13b of the separator.
  • the other end of the binding member 14 may be located in the bending area B2 or in the straight area B1.
  • the tie 14 can connect the first winding end section 132 to other parts of the separator 13 to tie the first winding end section 132 and reduce the risk of the separator 13 falling apart.
  • the tie member 14 extends along the winding direction W of the second pole piece 12
  • one end of the tie member 14 is the head end of the tie member 14 along the winding direction W
  • the other end of the tie member 14 is the end end of the tie member 14 along the winding direction W.
  • the winding direction W of the second pole piece 12 is counterclockwise.
  • the other end of the tie member 14 is located in the flat region B1.
  • the flat region B1 is relatively flat, which facilitates the connection between the tie member 14 and the isolation member 13 and increases the connection strength between the tie member 14 and the isolation member 13.
  • the tie 14 comprises tape.
  • the tie 14 comprises insulating tape.
  • the electrode assembly 10 further includes an identification mark 15 , which is disposed on a surface of the restraining member 14 that is away from the straight region B1 .
  • the identification mark 15 can record the production data of the electrode assembly 10 to facilitate subsequent data tracing.
  • the production equipment of the electrode assembly 10 can obtain relevant information of the electrode assembly 10 by interpreting the identification mark 15, which helps to realize the automated production of the electrode assembly 10. Compared with the solution of setting the identification mark 15 on the separator 13, setting the identification mark 15 on the restraining member 14 can reduce the risk of damage to the separator 13.
  • the thickness of the binding member 14 is greater than that of the isolation member 13.
  • the binding member 14 has a greater thickness and strength, and can not only effectively bind the isolation member 13, but also support the identification mark 15.
  • the other end of the tie 14 exceeds the center line C of the straight area B1, and the center line C is parallel to the winding axis Z of the electrode assembly 10.
  • the identification mark 15 covers at least a portion of the center line C.
  • the winding axis Z is perpendicular to the first direction X and the winding direction W of the second pole piece 12 .
  • the center line C is a virtual straight line.
  • the projection of the straight area B1 is substantially a rectangle; the center line C can be the center line of the rectangular projection parallel to the winding axis Z.
  • the identification mark 15 is disposed near the center of the flat area B1 along the first direction X to facilitate detection by external equipment.
  • the projection of the flat area B1 is substantially rectangular in a plane parallel to the first direction X and the winding axis Z, and the identification mark 15 is located at the center of the rectangular projection. This embodiment can facilitate the code reader to identify the identification mark 15 .
  • both edges of the restraining member 14 extend beyond the first pole piece 11 .
  • both edges of the restraining member 14 extend beyond the first pole piece 11 , which means that both edges of the restraining member 14 extend beyond the active material layer of the first pole piece 11 .
  • the restraining member 14 can cover the first pole piece 11 , thereby reducing the risk of the active material layer of the first pole piece 11 being exposed and improving safety.
  • the cut-off spacer 13 may undergo elastic contraction, causing the length K3 of the first winding end section 132 to be smaller than the length K4 of the second winding end section 112, resulting in a portion of the second winding end section 112 being exposed.
  • the restraining member 14 may cover the portion of the second winding end section 112 that is not covered by the first winding end section 132, thereby reducing the risk of the first pole piece 11 being exposed and improving safety.
  • FIG16 is a partial schematic diagram of an electrode assembly provided in some other embodiments of the present application.
  • the other end of the restraining member 14 is located at another bending area B2 .
  • the two ends of the tie member 14 along the winding direction W of the second pole piece 12 are respectively located at two bending regions B2.
  • the tie member 14 along the winding direction W of the second pole piece 12 extends from one bending region B2 across the straight region B1 to another bending region B2.
  • the two ends of the restraint 14 are arranged in the bending area B2, which can reduce the pressure on the ends of the restraint 14 when the electrode assembly 10 expands, reduce stress concentration, reduce the risk of the electrode being crushed, reduce lithium deposition, and improve safety.
  • FIG. 17 is a schematic diagram of the structure of an electrode assembly provided in some other embodiments of the present application.
  • the first pole piece 11 includes a second winding start section 111 extending beyond the winding head end 12a of the second pole piece.
  • the second winding start section 111 is entirely located in the straight region B1.
  • the second winding start section 111 is clamped in the straight area B1, which can improve the stability of the second winding start section 111, reduce the risk of the second winding start section 111 being offset when the electrode assembly 10 is subjected to external impact, and improve safety.
  • the embodiment of the present application can also reduce the length K2 of the second winding starting section 111 , save materials, and improve the energy density of the electrode assembly 10 .
  • the first winding start section 131 is entirely located in the straight area B1.
  • the length K1 of the first winding starting section 131 is equal to the length K2 of the second winding starting section 111.
  • the third winding start section 121 is entirely located in the straight area B1.
  • the present application further provides a battery cell, which includes a housing and an electrode assembly according to any of the above embodiments, wherein the electrode assembly is accommodated in the housing.
  • the present application also provides a battery, comprising a plurality of battery cells according to any of the above embodiments.
  • the present application further provides an electric device, comprising a battery in any of the above embodiments, the battery is used to provide electric energy to the electric device.
  • the electric device can be any of the above-mentioned devices or systems using the battery.
  • the embodiments of the present application provide a wound electrode assembly 10, which includes a first electrode sheet 11, a second electrode sheet 12, and two separators 13.
  • the first electrode sheet 11 is a negative electrode sheet
  • the second electrode sheet 12 is a positive electrode sheet
  • the two separators 13 are used to separate the first electrode sheet 11 from the second electrode sheet 12.
  • the first pole piece 11, the second pole piece 12 and two separators 13 are wound together.
  • the length of each separator 13 is L1
  • the spacer 13 includes a first winding start section 131 extending beyond the winding head end 12a of the second pole piece, and the first pole piece 11 includes a second winding start section 111 extending beyond the winding head end 12a of the second pole piece.
  • the length K1 of the first winding start section 131 is equal to the length K2 of the second winding start section 111.
  • the spacer 13 includes a first winding end section 132 extending beyond the winding end 12b of the second pole piece, and the first pole piece 11 includes a second winding end section 112 extending beyond the winding end 12b of the second pole piece.
  • the length K3 of the first winding end section 132 is equal to the length K4 of the second winding end section 112.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Secondary Cells (AREA)

Abstract

本申请实施例提供一种电极组件、电池单体、电池以及用电装置。电极组件包括第一极片、第二极片和用于隔离第一极片和第二极片的至少一个隔离件。第一极片和第二极片极性相反，第一极片、第二极片和至少一个隔离件卷绕设置。至少一个隔离件的长度为L1，第一极片的长度为L2，|L1-L2|≤50mm。

Description

电极组件、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，涉及一种电极组件、电池单体、电池以及用电装置。
背景技术
电池单体广泛用于电子设备，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。
电池单体包括电极组件和电解质，电极组件包括正极极片、负极极片和隔离件，隔离件用于将正极极片和负极极片隔开。正极极片、负极极片和隔离件通常卷绕设置，而为了保证正极极片和负极极片之间的绝缘性，通常会设置隔离件的长度远大于正极极片的长度以及负极极片的长度，造成隔离件的浪费。
发明内容
本申请提供了一种电极组件、电池单体、电池以及用电装置，其能减少隔离件的浪费，提高能量密度。
第一方面，本申请实施例提供了一种电极组件，包括第一极片、第二极片和用于隔离第一极片和第二极片的至少一个隔离件。第一极片和第二极片极性相反，第一极片、第二极片和至少一个隔离件卷绕设置。至少一个隔离件的长度为L1，第一极片的长度为L2，|L1-L2|≤50mm。
上述技术方案可将隔离件和第一极片的长度差限定在50mm内，在基本保证隔离件的绝缘性能的前提下，可以降低隔离件的浪费，降低成本，同时，可以减少隔离件占用的空间，提高能量密度。
在一些实施例中，L1和L2满足：|L1-L2|≤30mm。将隔离件和第一极片的长度差限定在30mm内，在基本保证隔离件的绝缘性能的前提下，可进一步降低隔离件的浪费，降低成本，同时，可以减少隔离件占用的空间，提高能量密度。
在一些实施例中，L1和L2满足：|L1-L2|≤10mm。将隔离件和第一极片的长度差限定在10mm内，在基本保证隔离件的绝缘性能的前提下，可进一步降低隔离件的浪费，降低成本，并减少隔离件占用的空间，提高能量密度。
在一些实施例中，L1＝L2。隔离件可以基本完全覆盖第一极片，以有效地隔开第一极片和第二极片。隔离件的无效区域(即隔离件的没有用于隔离第一极片和第二极片的区域)的长度较小，从而进一步减少隔离件的用量，降低成本，提高电极组件的能量密度。
在一些实施例中，L1＞L2。
隔离件可以覆盖第一极片，以有效地隔开第一极片和第二极片；隔离件采用过量设计，可提高电极组件的安全性能。
在一些实施例中，隔离件包括超出第二极片的卷绕首端的第一卷绕起始段，第一极片包括超出第二极片的卷绕首端的第二卷绕起始段。第一卷绕起始段包括隔离件的卷绕首端，第二卷绕起始段包括第一极片的卷绕首端，隔离件的卷绕首端和第一极片的卷绕首端的最小间距为D1，D1≤20mm。
上述技术方案将D1限定为小于或等于20mm，可平衡隔离件的用量和第一极片的用量，降低成本，提高电极组件的能量密度。隔离件的卷绕首端和第一极片的卷绕首端的最小间距小于或等于20mm，第一极片和隔离件几乎可以同时开始卷绕，从而节约卷绕时间，提高卷绕效率。
在一些实施例中，D1≤10mm。将D1限定为小于或等于10mm，可进一步平衡隔离件的用量和第一极片的用量，降低成本，提高电极组件的能量密度，节约卷绕时间，提高卷绕效率。
在一些实施例中，第一卷绕起始段的长度大于第二卷绕起始段的长度，且第一卷绕起始段覆盖第一极片的卷绕首端。
电极组件在充放电过程中，会发生膨胀，导致第一卷绕起始段容易被拉扯，进一步造成第一极片的卷绕首端裸露的风险。上述技术方案使第一卷绕起始段的长度大于第二卷绕起始段的长度，从而为第一卷绕起始段预留一定余量，在第一卷绕起始段受到拉扯时，第一卷绕起始段能够覆盖第一极片的卷绕首端，以降低第一极片的卷绕首端裸露的风险，提高安全性。
在一些实施例中，第一卷绕起始段的长度等于第二卷绕起始段的长度，第一极片的卷绕首端和隔离件的卷绕首端对齐。第一卷绕起始段既可以降低第一极片的卷绕首端裸露的风险，提高安全性，还能够减少第一卷绕起始段的长度浪费或第二卷绕起始段的长度浪费，降低成本，提高电极组件的能量密度。
在一些实施例中，隔离件包括超出第二极片的卷绕末端的第一卷绕收尾段，第一极片包括超出第二极片的卷绕末端的第二卷绕收尾段。第一卷绕收尾段包括隔离件的卷绕末端，第二卷绕收尾段包括第一极片的卷绕末端，隔离件的卷绕末端和第一极片的卷绕末端的间距为D2，D2≤20mm。
上述技术方案将D2限定为小于或等于20mm，可平衡隔离件的用量和第一极片的用量，降低成本，提高电极组件的能量密度。隔离件的卷绕末端和第一极片的卷绕末端的最小间距小于或等于20mm，可使隔离件和第一极片几乎同时停止卷绕，减少卷绕的总时长，节约卷绕时间，提高卷绕效率。
在一些实施例中，D2≤10mm。将D2限定为小于或等于10mm，可进一步平衡隔离件的用量和第一极片的用量，降低成本，提高电极组件的能量密度，并节约卷绕时间，提高卷绕效率。
在一些实施例中，第一卷绕收尾段的长度大于第二卷绕收尾段的长度，第一卷绕收尾段覆盖第一极片的卷绕末端。
电极组件在充放电过程中，会发生膨胀，导致第一卷绕收尾段容易被拉扯，进一步造成第一极片的卷绕末端裸露的风险。上述技术方案使第一卷绕收尾段的长度大于第二卷绕收尾段的长度，从而为第一卷绕收尾段预留一定余量，在第一卷绕收尾段受到拉扯时，第一卷绕收尾段能够覆盖第一极片的卷绕末端，以降低第一极片的卷绕末端裸露的风险，提高安全性。
在一些实施例中，第一卷绕收尾段的长度等于第二卷绕收尾段的长度，第一极片的卷绕末端和隔离件的卷绕末端对齐。第一卷绕收尾段既可以降低第一极片的卷绕末端裸露的风险，提高安全性，还能够减少第一卷绕收尾段的长度浪费或第二卷绕收尾段的长度浪费，降低成本，提高电极组件的能量密度。
在一些实施例中，隔离件的数量为两个，两个隔离件的长度相等。两个隔离件可以从两侧覆盖第二极片，以将第二极片与第一极片隔开，从而降低第二极片和第一极片短路的风险。两个隔离件的长度相等，可减少每个隔离件的用量，降低成本，提高电极组件的能量密度。
在一些实施例中，第一极片、隔离件和第二极片经过卷绕形成平直区域和两个弯折区域，两个弯折区域分别位于平直区域沿第一方向的两侧。
在一些实施例中，第一极片包括超出第二极片的卷绕首端的第二卷绕起始段。第二卷绕起始段整体位于平直区域。
在上述技术方案中，第二卷绕起始段在平直区域被夹持，可提高第二卷绕起始段的稳定性，降低第二卷绕起始段在电极组件受到外部冲击时偏移的风险，提高安全性。
在一些实施例中，第一极片包括超出第二极片的卷绕首端的第二卷绕起始段。第二卷绕起始段的至少一部分位于弯折区域。将第二卷绕起始段在弯折区域折弯，可减小第二卷绕起始段在第一方向上占用的空间，从而有助于提高电极组件的能量密度。
在一些实施例中，第二卷绕起始段包括连续设置的第一部分、第二部分和第三部分，第一部分包括第一极片的卷绕首端，第三部分具有与第二极片的卷绕首端对齐的交界处，第三部分从交界处延伸；第一部分和第三部分均位于平直区域，第二部分位于弯折区域，并用于连接第一部分和第三部分。将第二卷绕起始段弯折成双层结构，以减小第二卷绕起始段在第一方向上占用的空间，从而提高电极组件的能量密度。
在一些实施例中，第二部分支撑第一极片和第二极片在弯折区域并位于第二部分的外侧的部分。
第二部分可以为第一极片和第二极片在弯折区域并位于第二部分的外侧的部分提供支撑力，使得第一极片和第二极片在弯折区域的部分更为紧凑，第一极片在弯折区域的部分与第二极片在弯折区域的部分之间的间隙不易因受到外力作用而增大，从而降低析锂风险。
在一些实施例中，第一极片还包括与第三部分连续设置的单侧反应段，单侧反应段与第三部分在交界处分界；单侧反应段仅外侧表面上的活性物质层与第二极片的活性物质层相对。单侧反应段的至少一部分层叠于第二卷绕起始段外侧，单侧反应段的层叠于第二卷绕起始段外侧的部分和第二卷绕起始段之间无隔离件和第二极片。
单侧反应段与第二卷绕起始段相邻，两者之间的隔离件可以省略，从而节约隔离件的用量，提高电极组件的能量密度。同时，单侧反应段与第二卷绕起始段极性相同，两者相邻设置可降低短路风险，提高安全性。
在一些实施例中，单侧反应段层叠于第二卷绕起始段外侧的部分和第二卷绕起始段接触。
第二卷绕起始段可支撑于单侧反应段，第二部分提供的支撑力可先传递给单侧反应段，再通过单侧反应段传递给第二极片，使得第二卷绕起始段对单侧反应段和第二极片产生更好的支撑作用。
在一些实施例中，第二极片包括从第二极片的卷绕首端延伸的第三卷绕起始段，第三卷绕起始段整体位于平直区域；在第三卷绕起始段的厚度方向上，第三卷绕起始段与第一部分不重叠。
第三卷绕起始段与第一部分不重叠，两者可以在厚度方向上共用相同的空间，从而提高空间利用率，提高电极组件的能量密度。另外，第三卷绕起始段的端部不易挤压第一部分，第一部分的端部也不易挤压第三卷绕起始段，这样可以减小应力集中，降低因应力集中引发的极片断裂的风险。
在一些实施例中，在第一方向上，第三卷绕起始段与第一部分间隔设置。将第三卷绕起始段与第一部分间隔设置，以降低第三卷绕起始段与第一部分重叠的风险。
在一些实施例中，在第一方向上，第三卷绕起始段与第一部分之间的最小间距大于或等于第一部分的尺寸。
在电极组件的卷绕过程中，因为工艺误差，可能会造成第一部分沿第一方向的尺寸偏差较大。上述技术方案基于第一部分的尺寸来限定第三卷绕起始段与第一部分之间的最小间距，可有效地降低第三卷绕起始段和第一部分重叠的风险。
在一些实施例中，在第一方向上，第三卷绕起始段与第一部分之间的间距为L3，L3为5mm-20mm。
在充放电过程中，电极组件会出现膨胀变形。如果L3过小，第三卷绕起始段和第一部分可能会出现重叠。L3越大，第三卷绕起始段和第一部分沿第一方向的尺寸也越小。如果L3过大，会造成空间浪费，降低电极组件的能量密度。将L3为5mm-20mm，可降低第三卷绕起始段和第一部分重叠的风险，减少电极组件的能量密度的损失。
在一些实施例中，第一极片的卷绕末端位于弯折区域。
在电池单体的充放电过程中，电极组件的平直区域膨胀较大，且平直区域易与外壳互相挤压。如果第一极片的卷绕末端设置在平直区域，第一极片的卷绕末端容易产生应力集中，引发第二极片被第一极片的卷绕末端压断、析锂等风险。上述技术方案将第一极片的卷绕末端设置于弯折区域，可以减小应力集中，降低第二极片断裂、析锂等风险，提高安全性。
在一些实施例中，第一极片包括超出第二极片的卷绕末端的第二卷绕收尾段，第二卷绕收尾段包括第一极片的卷绕末端。第二卷绕收尾段整体位于弯折区域。第二卷绕收尾段整体位于弯折区域，可减小第二卷绕收尾段的长度，减少物料浪费。
在一些实施例中，第二极片的卷绕末端位于弯折区域。
将第二极片的卷绕末端设置于弯折区域，可以减小应力集中，降低第一极片被第二极片的卷绕末端压断的风险，减少析锂，提高安全性。
在一些实施例中，隔离件包括超出第二极片的卷绕末端的第一卷绕收尾段，第一卷绕收尾段包括隔离件的卷绕末端。电极组件还包括束缚件，束缚件连接于隔离件并用于束缚第一卷绕收尾段。束缚件可以束缚第一卷绕收尾段，以降低隔离件散开的风险。
在一些实施例中，第一极片包括超出第二极片的卷绕末端的第二卷绕收尾段，第二卷绕收尾段包括第一极片的卷绕末端。第一卷绕收尾段和第二卷绕收尾段位于同一个弯折区域。束缚件的一端位于第一卷绕收尾段的外侧并连接于第一卷绕收尾段，束缚件的另一端超出第一极片的卷绕末端和隔离件的卷绕末端，并连接于隔离件。束缚件可以将第一卷绕收尾段连接到隔离件的其它部分，以束缚第一卷绕收尾段，降低隔离件散开的风险。
在一些实施例中，束缚件的另一端位于平直区域。平直区域较为平整，便于实现束缚件与隔离件的连接，并增大束缚件与隔离件的连接强度。
在一些实施例中，束缚件的另一端位于另一个弯折区域。将束缚件的两端设置于弯折区域，可在电极组件膨胀时减小束缚件的端部受到的压力，减小应力集中，降低极片被压断的风险，减少析锂，提高安全性。
在一些实施例中，电极组件还包括识别标记，识别标记设置于束缚件的背离平直区域的表面。
电极组件的生产设备可通过解读识别标记来得到电极组件的相关信息，有助于实现电极组件的自动化生产。与在隔离件上设置识别标记的方案相比，在束缚件上设置识别标记可降低隔离件损伤的风险。
在一些实施例中，束缚件的另一端超过平直区域的中线，中线平行于电极组件的卷绕轴向。
在一些实施例中，在电极组件的卷绕轴向上，束缚件的两个边缘均超出第一极片。束缚件可以覆盖第一极片，减少第一极片的活性物质层外露的风险，提高安全性。
第二方面，本申请实施例提供了一种电池单体，包括外壳和第一方面任一实施例提供的电极组件，电极组件容纳于外壳内。
第三方面，本申请实施例提供了一种电池，包括多个第二方面提供的电池单体。
第四方面，本申请实施例提供了一种用电装置，包括第三方面提供的电池，电池用于提供电能。
附图说明
为了更清楚地说明本申请实施例的技术方案，下面将对本申请实施例中所需要使用的附图作简单地介绍，显而易见地，下面所描述的附图仅仅是本申请的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据附图获得其他的附图。
图1为本申请一些实施例提供的车辆的结构示意图；
图2为本申请一些实施例提供的电池的爆炸示意图；
图3为本申请一些实施例提供的电池单体的爆炸示意图；
图4为本申请一些实施例提供的电极组件的结构示意图；
图5为图4所示的电极组件在展平后的结构示意图；
图6为本申请一些实施例提供的卷绕设备的一示意图；
图7为本申请一些实施例提供的卷绕设备的另一示意图；
图8为本申请一些实施例提供的电极组件的结构示意图；
图9为图8所示的电极组件在展平后的结构示意图；
图10为图4所示的电极组件的一局部示意图；
图11为图10所示的电极组件在展平状态下的示意图；
图12为图4所示的电极组件的另一局部示意图；
图13为图12所示的电极组件在展平状态下的示意图；
图14为本申请一些实施例提供的电极组件的立体结构示意图；
图15为图12所示的电极组件沿线A-A作出的剖视示意图；
图16为本申请另一些实施例提供的电极组件的局部示意图；
图17为本申请另一些实施例提供的电极组件的结构示意图。
在附图中，附图并未按照实际的比例绘制。
具体实施方式
为使本申请实施例的目的、技术方案和优点更加清楚，下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例是本申请一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员在没有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，本文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；本文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。
在本申请的描述中，需要理解的是，术语“中心”、“横向”、“长度”、“宽度”、“上”、“下”、“前”、“后”、“左”、“右”、“竖直”、“水平”、“顶”、“底”、“内”、“外”、“轴向”、“径向”、“周向”等指示的方位或位置关系为基于附图所示的方位或位置关系，仅是为了便于描述本申请和简化描述，而不是指示或暗示所指的装置或元件必须具有特定的方位、以特定的方位构造和操作，因此不能理解为对本申请的限制。
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。
在本文中提及“实施例”意味着，结合实施例描述的特定特征、结构或特性可以包含在本申请的至少一个实施例中。在说明书中的各个位置出现该短语并不一定均是指相同的实施例，也不是与其它实施例互斥的独立的或备选的实施例。本领域技术人员显式地和隐式地理解的是，本文所描述的实施例可以与其它实施例相结合。
本文中术语“和/或”，仅仅是一种描述关联对象的关联关系，表示可以存在三种关系，例如，A和/或B，可以表示：单独存在A，同时存在A和B，单独存在B这三种情况。另外，本文中字符“/”，一般表示前后关联对象是一种“或”的关系。
本申请中出现的“多个”指的是两个以上(包括两个)，同理，“多组”指的是两组以上(包括两组)，“多片”指的是两片以上(包括两片)。
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。
电池单体包括电极组件和电解质，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，未涂覆正极活性物质层的集流体凸出于已涂覆正极活性物质层的集流体，未涂覆正极活性物质层的集流体作为正极极耳。以锂离子电池为例，正极集流体的材料可以为铝，正极活性物质可以为钴酸锂、磷酸铁锂、三元锂或锰酸锂等。负极极片包括负极集流体和负极活性物质层，负极活性物质层涂覆于负极集流体的表面，未涂覆负极活性物质层的集流体凸出于已涂覆负极活性物质层的集流体，未涂覆负极活性物质层的集流体作为负极极耳。负极集流体的材料可以为铜，负极活性物质可以为碳或硅等。为了保证通过大电流而不发生熔断，正极极耳的数量为多个且层叠在一起，负极极耳的数量为多个且层叠在一起。隔离件的材质可以为PP(聚丙烯)或PE(聚乙烯)等。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。电池技术的发展要同时考虑多方面的设计因素，例如，能量密度、循环寿命、放电容量、充放电倍率等性能参数，另外，还需要考虑电池的安全性。
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。
隔离件具有电子绝缘性，其设置于正极极片和负极极片之间，其主要作用是防 止正极极片和负极极片相接触，进而造成电极组件发生内部短路。隔离件具有大量的贯通的微孔，能够保证电解质离子自由通过，特别地，隔离件对锂离子有很好的透过性。示例性地，隔离件可包括隔离基层和位于隔离基层表面的功能层，隔离基层可以是聚丙烯、聚乙烯、乙烯—丙烯共聚物、聚对苯二甲酸丁二醇酯等的至少一种，功能层可以是陶瓷氧化物和粘结剂的混合物层。
隔离件在电极组件中占有十分重要的地位。在相关技术中，隔离件的长度远大于极片的长度，隔离件都存在长度过量的问题，这造成隔离件浪费，增高了电池单体的成本，且过量的隔离件会占用空间，影响电极组件的能量密度。
鉴于此，本申请提出了一种技术方案，其通过减小了隔离件与极片的长度差，从而降低隔离件的用量，降低成本，提高电极组件的能量密度。
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。
图1为本申请一些实施例提供的车辆的结构示意图。如图1所示，车辆1的内部设置有电池2，电池2可以设置在车辆1的底部或头部或尾部。电池2可以用于车辆1的供电，例如，电池2可以作为车辆1的操作电源。
车辆1还可以包括控制器3和马达4，控制器3用来控制电池2为马达4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2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。
图2为本申请一些实施例提供的电池的爆炸示意图。如图2所示，电池2包括箱体5和电池单体6，电池单体6容纳于箱体5内。
箱体5用于容纳电池单体6，箱体5可以是多种结构。在一些实施例中，箱体5可以包括第一箱体部5a和第二箱体部5b，第一箱体部5a与第二箱体部5b相互盖合，第一箱体部5a和第二箱体部5b共同限定出用于容纳电池单体6的容纳空间5c。第二箱体部5b可以是一端开口的空心结构，第一箱体部5a为板状结构，第一箱体部5a盖合于第二箱体部5b的开口侧，以形成具有容纳空间5c的箱体5；第一箱体部5a和第二箱体部5b也均可以是一侧开口的空心结构，第一箱体部5a的开口侧盖合于第二箱体部5b的开口侧，以形成具有容纳空间5c的箱体5。当然，第一箱体部5a和第二箱体部5b可以是多种形状，比如，圆柱体、长方体等。
为提高第一箱体部5a与第二箱体部5b连接后的密封性，第一箱体部5a与第二箱体部5b之间也可以设置密封件，比如，密封胶、密封圈等。
假设第一箱体部5a盖合于第二箱体部5b的顶部，第一箱体部5a亦可称之为上箱盖，第二箱体部5b亦可称之为下箱体。
在电池2中，电池单体6为多个。多个电池单体6之间可串联或并联或混联，混联是指多个电池单体6中既有串联又有并联。多个电池单体6之间可直接串联或并联或混联在一起，再将多个电池单体6构成的整体容纳于箱体5内；当然，也可以是多个电池单体6先串联或并联或混联组成电池模块，多个电池模块再串联或并联或混联形成一个整体，并容纳于箱体5内。
图3为本申请一些实施例提供的电池单体的爆炸示意图。
电池单体6是指组成电池2的最小单元。如图3所示，电池单体6包括外壳20、电极组件10以及其他的功能性部件，电极组件10容纳于外壳20内。
在一些实施例中，外壳20包括端盖22和壳体21。
端盖22是指盖合于壳体21的开口处以将电池单体6的内部环境隔绝于外部环境的部件。不限地，端盖22的形状可以与壳体21的形状相适应以配合壳体21。可选地，端盖22可以由具有一定硬度和强度的材质(如铝合金)制成，这样，端盖22在受挤压碰撞时就不易发生形变，使电池单体6能够具备更高的结构强度，安全性能也可以有所提高。端盖22上可以设置有如电极端子30等的功能性部件。电极端子30可以用于与电极组件10电连接，以用于输出或输入电池单体6的电能。
在一些实施例中，端盖22上还可以设置有用于在电池单体6的内部压力或温度达到阈值时泄放内部压力的泄压机构。端盖22的材质也可以是多种的，比如，铜、铁、铝、不锈钢、铝合金、塑胶等，本申请实施例对此不作特殊限制。
在一些实施例中，在端盖22的内侧还可以设置有绝缘件，绝缘件可以用于隔离壳体21内的电连接部件与端盖22，以降低短路的风险。示例性的，绝缘件可以是塑料、橡胶等。
壳体21是用于配合端盖22以形成电池单体6的内部环境的组件，其中，形成的内部环境可以用于容纳电极组件10、电解液以及其他部件。壳体21和端盖22可以是独立的部件，可以于壳体21上设置开口，通过在开口处使端盖22盖合开口以形成电池单体6的内部环境。不限地，也可以使端盖22和壳体21一体化，具体地，端盖22和壳体21可以在其他部件入壳前先形成一个共同的连接面，当需要封装壳体21的内部时，再使端盖22盖合壳体21。壳体21可以是多种形状和多种尺寸的，例如长方体形、圆柱体形、六棱柱形等。具体地，壳体21的形状可以根据电极组件10的具体形状和尺寸大小来确定。壳体21的材质可以是多种，比如，铜、铁、铝、不锈钢、铝合金、塑胶等，本申请实施例对此不作特殊限制。
电极组件10是能够发生电化学反应的部件。壳体21内可以包含一个或多个电极组件10。电极组件10主要由正极极片和负极极片卷绕形成，并且通常在正极极片与负极极片之间设隔离件。正极极片和负极极片具有活性物质的部分构成电极组件10的主体部，正极极片和负极极片不具有活性物质的部分各自构成极耳。正极极耳和负极极耳可以共同位于主体部的一端或是分别位于主体部的两端。在电池单体6的充放电过程中，正极活性物质和负极活性物质与电解液发生反应，极耳连接电极端子30以形成电流回路。
图4为本申请一些实施例提供的电极组件的结构示意图；图5为图4所示的电极组件在展平后的结构示意图。
如图4和图5所示，本申请实施例提供可一种电极组件10，其包括第一极片11、第二极片12和用于隔离第一极片11和第二极片12的隔离件13。第一极片11和第二极片12极性相反。第一极片11、第二极片12和至少一个隔离件13卷绕设置。至少一个隔离件13的长度为L1，第一极片11的长度为L2，|L1-L2|≤50mm。
电极组件10为卷绕结构，其可以是多种形状，例如，电极组件10可呈圆柱体、 扁平体、棱柱体(例如三棱柱、四棱柱或六棱柱)或其它形状。
第一极片11和第二极片12中的一者为正极极片，另一者为负极极片。
隔离件13包括绝缘膜。绝缘膜具有大量贯通的微孔，能够保证金属离子自由通过；示例性地，绝缘膜对锂离子有很好的透过性，基本上不能阻挡锂离子通过。
在本实施例中，隔离件13的长度是指隔离件13在展平状态下的长度，第一极片11的长度是指第一极片11在展平状态下的长度。示例性地，在展平状态下，隔离件13大体为矩形薄片，隔离件13的长度即为矩形薄片的长度。
隔离件13可以为一个，也可以是多个。示例性地，隔离件13可设置为两个，本申请可以先将一个隔离件13、第一极片11、另一个隔离件13和第二极片12依次层叠，然后再卷绕两圈以上以形成卷绕结构。
至少一个隔离件13的长度为L1。在一些示例中，隔离件13为一个，该一个隔离件13的长度为L1。在另一些示例中，隔离件13为两个，一个隔离件13的长度为L1，而另一个隔离件13的长度不作限制，例如，另一个隔离件13的长度可以大于、小于或等于L1。
在本申请实施例中，L1可大于、小于或等于L2，只要隔离件13能够将第一极片11和第二极片12隔开即可。
|L1-L2|的值可为50mm、40mm、30mm、20mm、10mm、5mm、2mm、1mm或0mm。
通过将隔离件13和第一极片11的长度差限定在50mm内，在基本保证隔离件13的绝缘性能的前提下，可以降低隔离件13的浪费，降低成本，同时，可以减少隔离件13占用的空间，提高能量密度。
在一些实施例中，在L1-L2≥0时，L1-L2的值越大，隔离件13的用量也越多；如果L1-L2的值过大，将会造成隔离件13的用量偏大，造成电极组件10成本偏高、能量密度偏低。在L1-L2＜0时，L1-L2的值越小，第一极片11的被隔离件13覆盖的区域越小；如果L1-L2的值过小，将会引发绝缘失效的风险，造成第一极片11和第二极片12短路，引发安全隐患。
通过将|L1-L2|限定为小于或等于50mm，可在实现隔离件13的绝缘功能的前提下，减少隔离件13的用量，降低成本，提高电极组件10的能量密度。
在一些实施例中，L1和L2满足：|L1-L2|≤30mm。通过将隔离件13和第一极片11的长度差限定在30mm内，在基本保证隔离件13的绝缘性能的前提下，可进一步降低隔离件13的浪费，降低成本，同时，可以减少隔离件13占用的空间，提高能量密度。
在一些实施例中，L1和L2满足：|L1-L2|≤10mm。通过将隔离件13和第一极片11的长度差限定在10mm内，在基本保证隔离件13的绝缘性能的前提下，可进一步降低隔离件13的浪费，降低成本，并减少隔离件13占用的空间，提高能量密度。
在一些实施例中，L1和L2满足：|L1-L2|≤3mm。
在一些实施例中，L1＝L2。隔离件13可以基本完全覆盖第一极片11，以有效地隔开第一极片11和第二极片12。隔离件13的无效区域(即隔离件13的没有用于隔离第一极片11和第二极片12的区域)的长度较小，从而进一步减少隔离件13的用量， 降低成本，提高电极组件10的能量密度。
在一些实施例中，隔离件13包括超出第二极片的卷绕首端12a的第一卷绕起始段131，第一极片11包括超出第二极片的卷绕首端12a的第二卷绕起始段111。
在第一极片11处于展平状态时，第一极片11沿自身长度方向的两端为第一极片的卷绕首端11a和第一极片的卷绕末端11b。在处于卷绕状态时，第一极片的卷绕首端11a靠近电极组件10的内部，第一极片在卷绕首端11a开始卷绕；第一极片的卷绕末端11b靠近电极组件10的外部，第一极片在卷绕末端11b停止卷绕。
在第二极片12处于展平状态时，第二极片12沿自身长度方向的两端为第二极片的卷绕首端12a和第二极片的卷绕末端12b。在处于卷绕状态时，第二极片的卷绕首端12a靠近电极组件10的内部，第二极片在卷绕首端12a开始卷绕；第二极片的卷绕末端12b靠近电极组件10的外部，第二极片在卷绕末端12b停止卷绕。
在隔离件13处于展平状态时，隔离件13沿自身长度方向的两端为隔离件的卷绕首端13a和隔离件的卷绕末端13b。在处于卷绕状态时，隔离件的卷绕首端13a靠近电极组件10的内部，隔离件在卷绕首端13a开始卷绕，隔离件的卷绕末端13b靠近电极组件10的外部，隔离件在卷绕末端13b停止卷绕。
第一卷绕起始段131为隔离件13的超出第二极片的卷绕首端12a的部分。第一卷绕起始段131的长度K1为：在隔离件13处于展平状态时，第一卷绕起始段131在隔离件13的长度方向上的尺寸。
第二卷绕起始段111为第一极片11的超出第二极片的卷绕首端12a的部分。第二卷绕起始段111的长度K2为：在第一极片11处于展平状态时，第二卷绕起始段111在第一极片11的长度方向上的尺寸。
本申请实施例不限制第一卷绕起始段131的长度K1和第二卷绕起始段111的长度K2，换言之，第一卷绕起始段131的长度K1可大于、小于或等于第二卷绕起始段111的长度K2。
本申请实施例中，第一极片11和隔离件13均超过第二极片的卷绕首端12a，隔离件13可将第二极片的卷绕首端12a与第一极片11绝缘隔离，降低短路风险。
在一些实施例中，第一极片11为负极极片，第二极片12为正极极片。第一极片11超出第二极片的卷绕首端12a，第一极片11能够接收从第二极片12脱出的金属离子，从而降低金属离子析出的风险。
在一些实施例中，第一卷绕起始段131包括隔离件的卷绕首端13a，第二卷绕起始段111包括第一极片的卷绕首端11a，隔离件的卷绕首端13a和第一极片的卷绕首端11a的最小间距为D1，D1≤20mm。
在拆解电极组件10后，将第一极片11、隔离件13以及第二极片12展平，三者之间的相对位置不变；此时，在隔离件13的长度方向上，隔离件的卷绕首端13a和第一极片的卷绕首端11a的最小间距即为D1。
第一卷绕起始段131从隔离件的卷绕首端13a延伸至隔离件13的与第二极片的卷绕首端12a交界的位置，第二卷绕起始段111从第一极片的卷绕首端11a延伸至第一极片11的与第二极片的卷绕首端12a交界的位置；换言之，第一卷绕起始段131的长 度K1与第二卷绕起始段111的长度K2之差的绝对值即为D1。
通过将D1限定为小于或等于20mm，可平衡隔离件13的用量和第一极片11的用量，降低成本，提高电极组件10的能量密度。隔离件的卷绕首端13a和第一极片的卷绕首端11a的最小间距小于或等于20mm，第一极片11和隔离件13几乎可以同时开始卷绕，从而节约卷绕时间，提高卷绕效率。
在一些实施例中，在隔离件13超出第一极片的卷绕首端11a时，D1越大，第一卷绕起始段131的长度K1越大，隔离件13的用量越大；如果D1过大，将会造成隔离件13浪费严重，增高成本，降低能量密度。在第一极片11超出隔离件的卷绕首端13a时，D1越大，第二卷绕起始段111的长度K2也越大，第一极片11的用量越大；如果D1过大，将会造成第一极片11浪费严重，增高成本，降低能量密度。
将D1限定为小于或等于20mm，可平衡隔离件13的用量和第一极片11的用量，降低成本，提高电极组件10的能量密度。
在一些实施例中，可使用卷针7卷绕第一极片11、隔离件13和第二极片12。卷针7可包括相对设置的两个卷绕半轴71，卷绕半轴71可呈半圆柱形、半椭圆柱形或其它形状。
在制备电极组件10时，可先将第一卷绕起始段131和第二卷绕起始段111夹持在两个卷绕半轴71之间；然后，两个卷绕半轴71转动，以卷绕第一极片11和隔离件13，同时，第二极片12在第二极片12与隔离件13之间摩擦力的作用下走带并卷绕在两个卷绕半轴71的外侧。
在本申请实施例中，将D1限定为小于或等于20mm，可以减小第一卷绕起始段131和第二卷绕起始段111的长度差，以使第一卷绕起始段131和第二卷绕起始段111同时夹持在两个卷绕半轴71之间，卷针7几乎可以同时卷绕第一极片11和隔离件13，从而提高电极组件10的卷绕效率。
在一些实施例中，D1≤10mm。通过将D1限定为小于或等于10mm，可进一步平衡隔离件13的用量和第一极片11的用量，降低成本，提高电极组件10的能量密度，节约卷绕时间，提高卷绕效率。
在一些实施例中，D1为20mm、15mm、10mm、5mm、3mm、1mm或0mm。
在一些实施例中，第一卷绕起始段131的长度K1等于第二卷绕起始段111的长度K2，第一极片的卷绕首端11a和隔离件的卷绕首端13a对齐。示例性地，D1为0mm。
在本申请实施例中，第一卷绕起始段131既可以降低第一极片的卷绕首端11a裸露的风险，提高安全性，还能够减少第一卷绕起始段131的长度浪费或第二卷绕起始段111的长度浪费，降低成本，提高电极组件的能量密度。第一极片的卷绕首端11a裸露是指：第一极片的卷绕首端11a的两侧均未被隔离件覆盖。
电极组件10的连续生产过程中，第一极片11和隔离件13通常需要切断。第一极片的卷绕首端11a为第一极片11在连续生产中的切断处，隔离件的卷绕首端13a为隔离件13在连续生产中的切断处。本申请实施例使第一极片的卷绕首端11a和隔离件的卷绕首端13a对齐，可使用切刀机构8同步切断第一极片11和隔离件13，从而提高生产效率，简化生产设备。
在一些实施例中，隔离件13包括超出第二极片的卷绕末端12b的第一卷绕收尾段132，第一极片11包括超出第二极片的卷绕末端12b的第二卷绕收尾段112。
第一卷绕收尾段132为隔离件13超出第二极片的卷绕末端12b的部分。第一卷绕收尾段132的长度K3为：在隔离件13处于展平状态时，第一卷绕收尾段132在隔离件13的长度方向上的尺寸。
第二卷绕收尾段112为第一极片11的超出第二极片的卷绕末端12b的部分。第二卷绕收尾段112的长度K4为：在第一极片11处于展平状态时，第二卷绕收尾段112在第一极片11的长度方向上的尺寸。
本申请实施例不限制第一卷绕收尾段132的长度K3和第二卷绕收尾段112的长度K4，换言之，第一卷绕收尾段132的长度K3可大于、小于或等于第二卷绕收尾段112的长度K4。
第一极片11和隔离件13均超过第二极片的卷绕末端12b，隔离件13可将第二极片的卷绕末端12b与第一极片11绝缘隔离，降低短路风险。示例性地，第一极片11为负极极片，第二极片12为正极极片。第一极片11超出第二极片的卷绕末端12b，第一极片11能够接收从第二极片12脱出的金属离子，从而降低金属离子析出的风险。
在一些实施例中，第一卷绕收尾段132位于第二卷绕收尾段112的外侧。
在一些实施例中，第一卷绕收尾段132包括隔离件的卷绕末端13b，第二卷绕收尾段112包括第一极片的卷绕末端11b，隔离件的卷绕末端13b和第一极片的卷绕末端11b的间距为D2，D2≤20mm。
在拆解电极组件10后，将第一极片11、隔离件13以及第二极片12展平，三者之间的相对位置不变；此时，在隔离件13的长度方向上，隔离件的卷绕末端13b和第一极片的卷绕末端11b的最小间距即为D2。
第一卷绕收尾段132从隔离件的卷绕末端13b延伸至隔离件13的与第二极片的卷绕末端12b交界的位置，第二卷绕收尾段112从第一极片的卷绕末端11b延伸至第一极片11的与第二极片的卷绕末端12b交界的位置；换言之，第一卷绕收尾段132的长度K3与第二卷绕收尾段112的长度K4之差的绝对值即为D2。
通过将D2限定为小于或等于20mm，可平衡隔离件13的用量和第一极片11的用量，降低成本，提高电极组件10的能量密度。隔离件的卷绕末端13b和第一极片的卷绕末端11b的最小间距小于或等于20mm，可使隔离件13和第一极片11几乎同时停止卷绕，减少卷绕的总时长，节约卷绕时间，提高卷绕效率。
在隔离件13超出第一极片的卷绕末端11b时，D2越大，第一卷绕收尾段132的长度K3越大，隔离件13的用量越大；如果D2过大，将会造成隔离件13浪费严重，增高成本，降低能量密度。在第一极片11超出隔离件的卷绕末端13b时，D2越大，第二卷绕收尾段112的长度K4也越大，第一极片11的用量越大；如果D2过大，将会造成第一极片11浪费严重，增高成本，降低能量密度。
将D2限定为小于或等于20mm，可平衡隔离件13的用量和第一极片11的用量，降低成本，提高电极组件10的能量密度。
在一些实施例中，D2≤10mm。通过将D2限定为小于或等于10mm，可进一步平 衡隔离件13的用量和第一极片11的用量，降低成本，提高电极组件10的能量密度，并节约卷绕时间，提高卷绕效率。
在一些实施例中，D2为20mm、15mm、10mm、5mm、3mm、1mm或0mm。
在一些实施例中，第一卷绕收尾段132的长度K3等于第二卷绕收尾段112的长度K4，第一极片的卷绕末端11b和隔离件的卷绕末端13b对齐。示例性地，D2为0mm。
在本申请实施例中，第一卷绕收尾段132既可以降低第一极片的卷绕末端11b裸露的风险，提高安全性，还能够减少第一卷绕收尾段132的长度浪费或第二卷绕收尾段112的长度浪费，降低成本，提高电极组件的能量密度。
电极组件10的连续生产过程中，第一极片11和隔离件13通常需要切断。第一极片的卷绕末端11b为第一极片11在连续生产中的切断处，隔离件的卷绕末端13b为隔离件13在连续生产中的切断处。本申请实施例使第一极片的卷绕末端11b和隔离件的卷绕末端13b对齐，可使用切刀机构8同步切断第一极片11和隔离件13，从而提高生产效率，简化生产设备。
在一些实施例中，隔离件13的数量为两个，两个隔离件13的长度相等。
示例性地，两个隔离件13的长度均为L1。
示例性地，“长度相等”允许存在一定的误差，例如，在两个隔离件13的长度差小于或等于2mm时，可认为两个隔离件13的长度相等。
两个隔离件13可以从两侧覆盖第二极片12，以将第二极片12与第一极片11隔开，从而降低第二极片12和第一极片11短路的风险。两个隔离件13的长度相等，可减少每个隔离件13的用量，降低成本，提高电极组件10的能量密度。
在一些实施例中，一个隔离件的卷绕首端13a和第一极片的卷绕首端11a的最小间距为D1，D1≤50mm。可选地，D1≤20mm；进一步可选地，D1≤10mm。
在一些实施例中，另一个隔离件的卷绕首端13a和第一极片的卷绕首端11a的最小间距为D3，D3≤50mm。可选地，D3≤20mm；进一步可选地，D3≤10mm。
在一些实施例中，D1＝D3。
在一些实施例，两个隔离件的卷绕首端13a对齐，两个隔离件的卷绕末端13b对齐。
在一些实施例中，第一极片11、隔离件13和第二极片12经过卷绕形成平直区域B1和两个弯折区域B2，两个弯折区域B2分别位于平直区域B1沿第一方向X的两侧。
弯折区域B2为电极组件10中具有弯折结构的区域，在该弯折区域B2，第一极片11、第二极片12和隔离件13均弯折。示例性地，第一极片11的位于弯折区域B2的部分大体弯折为圆弧形，第二极片12的位于弯折区域B2的部分大体弯折为圆弧形。
平直区域B1为电极组件10具有平直结构的区域，第一极片11和第二极片12的位于平直区域B1的部分基本平直设置。示例性地，位于平直区域B1的每层第一极片的表面和每层第二极片的表面均基本为平面。
本申请实施例的电极组件10呈扁平结构。扁平结构可应用于方形电池单体。
图6为本申请一些实施例提供的卷绕设备的一示意图；图7为本申请一些实施 例提供的卷绕设备的另一示意图。
如图6和图7所示，在一些实施例中，卷绕设备包括至少一个位于卷绕工位P1的卷针7和至少一个位于非卷绕工位P2的卷针7。
如图6所示，位于卷绕工位P1的卷针7(即上侧的卷针7)用于卷绕第一极片11、第二极片12和隔离件13。当第一极片11、第二极片12和隔离件13卷绕到设定圈数后将第二极片12切断。
然后，卷绕有第一极片11、隔离件13和第二极片12的卷针7中移动至非卷绕工位P2(如图7所示，移动至右下侧)。另一个卷针7从非卷绕工位P2移动至卷绕工位P1，并夹持第一极片11和隔离件13。示例性地，该另一个卷针7夹持的第一极片11的部分为第二卷绕起始段111的一部分，该另一个卷针7夹持的隔离件13的部分为第一卷绕起始段131的一部分。
再然后，切刀机构8将第一极片11和隔离件13隔断。切刀机构8将第一极片11和隔离件13同时切断，以使第一极片的卷绕首端11a和隔离件的卷绕首端13a对齐。
最后，移动至卷绕工位P1的该另一个卷针7开始卷绕第一极片11、隔离件13和第二极片12。
可对右下侧的卷针7上的由第一极片11、第二极片12和隔离件13组成的组件进行其它工艺，例如粘贴后述的束缚件。
在卷绕工位P1将第一极片11、隔离件13以及第二极片12卷绕至预定圈数后，将第二极片12切断，以进入下一个循环。
在一些实施例中，卷绕设备包括三个卷针7，一个位于卷绕工位P1，另外两个位于非卷绕工位P2。示例性地，上侧的卷针7为位于卷绕工位P1的卷针7，左下侧的卷针7和右下侧的卷针7为位于非卷绕工位P2的卷针7。示例性地，左下侧的卷针7用于进行下料工序。
图8为本申请一些实施例提供的电极组件的结构示意图；图9为图8所示的电极组件在展平后的结构示意图。
如图8和图9所示，在一些实施例中，L1＞L2。
隔离件13可以覆盖第一极片11，以有效地隔开第一极片11和第二极片12；隔离件11采用过量设计，可提高电极组件的安全性能。
在一些实施例中，L1-L2为0.1mm-5mm。
在一些实施例中，第一卷绕起始段131的长度K1大于第二卷绕起始段111的长度K2，且第一卷绕起始段131覆盖第一极片的卷绕首端11a。
第一卷绕起始段131覆盖第一极片的卷绕首端11a是指：在第一极片11和隔离件13展平后，在第一极片的厚度方向上，第一极片的卷绕首端11a的投影位于第一卷绕起始段131的投影内。
电极组件10在充放电过程中，会发生膨胀，导致第一卷绕起始段131容易被拉扯，进一步造成第一极片的卷绕首端11a裸露的风险。本申请实施例使第一卷绕起始段131的长度大于第二卷绕起始段111的长度，从而为第一卷绕起始段131预留一定余 量，在第一卷绕起始段131受到拉扯时，第一卷绕起始段131能够覆盖第一极片的卷绕首端11a，以降低第一极片的卷绕首端11a裸露的风险，提高安全性。
可选地，第一卷绕起始段131的长度K1与第二卷绕起始段111的长度K2之差为0.05mm-2.5mm。
在一些实施例中，第一卷绕收尾段132的长度K3大于第二卷绕收尾段112的长度K4，第一卷绕收尾段132覆盖第一极片的卷绕末端11b。
第一卷绕收尾段132覆盖第一极片的卷绕末端11b是指：在第一极片11和隔离件13展平后，在第一极片的厚度方向上，第一极片的卷绕末端11b的投影位于第一卷绕收尾段132的投影内。
电极组件10在充放电过程中，会发生膨胀，导致第一卷绕收尾段132容易被拉扯，进一步造成第一极片的卷绕末端11b裸露的风险。本申请实施例使第一卷绕收尾段132的长度大于第二卷绕收尾段112的长度，从而为第一卷绕收尾段132预留一定余量，在第一卷绕收尾段132受到拉扯时，第一卷绕收尾段132能够覆盖第一极片的卷绕末端11b，以降低第一极片的卷绕末端11b裸露的风险，提高安全性。
可选地，第一卷绕收尾段132的长度K3与第二卷绕收尾段112的长度K4之差为0.05mm-2.5mm。
图10为图4所示的电极组件的一局部示意图；图11为图10所示的电极组件在展平状态下的示意图。
如图10和图11所示，在一些实施例中，第一极片11包括超出第二极片的卷绕首端12a的第二卷绕起始段111。第二卷绕起始段111的至少一部分位于弯折区域B2。
将第二卷绕起始段111在弯折区域B2折弯，可减小第二卷绕起始段111在第一方向X上占用的空间，从而有助于提高电极组件10的能量密度。
在一些实施例中，第二卷绕起始段111包括连续设置的第一部分1111、第二部分1112和第三部分1113。第一部分1111包括第一极片的卷绕首端11a。第三部分1113具有与第二极片的卷绕首端12a对齐的交界处，第三部分1113从交界处延伸。第一部分1111和第三部分1113均位于平直区域B1，第二部分1112位于弯折区域B2，并用于连接第一部分1111和第三部分1113。
本申请实施例将第二卷绕起始段111弯折成双层结构，以减小第二卷绕起始段111在第一方向X上占用的空间，从而提高电极组件10的能量密度。
在一些实施例中，如图7所示，在电极组件10的卷绕过程中，第一部分1111的至少部分位于卷针7的外侧，第三部分1113的至少部分可夹持于卷针7中。第一部分1111的至少部分延伸到卷针7外，可便于切刀机构8切断第一极片11和隔离件13。
本申请实施例可增大卷针7与第二极片的卷绕首端12a的间距，减小在抽出卷针7时对第二极片的卷绕首端12a的影响，降低第二极片的卷绕首端12a偏离预定位置的风险。
在一些实施例中，第二部分1112支撑第一极片11和第二极片12在弯折区域B2并位于第二部分1112的外侧的部分。
第二部分1112可以为第一极片11和第二极片12在弯折区域B2并位于第二部 分1112的外侧的部分提供支撑力，使得第一极片11和第二极片12在弯折区域B2的部分更为紧凑，第一极片11在弯折区域B2的部分与第二极片12在弯折区域B2的部分之间的间隙不易因受到外力作用而增大，从而降低析锂风险。
第二部分1112还可以撑开第一极片11的位于第二部分1112的外侧的部分，增大第一极片11的位于第二部分1112的外侧的部分的曲率半径，减少第一极片11的位于第二部分1112的外侧的部分的活性物质脱落，降低析锂风险。第二部分1112还可以撑开第二极片12的位于第二部分1112的外侧的部分，增大第二极片12的位于第二部分1112的外侧的部分的曲率半径，减少第二极片12的位于第二部分1112的外侧的部分的活性物质脱落，降低析锂风险。
第二部分1112超出第二极片12，其本身不参与与第二极片12的反应，第二部分1112可以不涂覆活性物质。另外，即使第二部分1112涂覆有活性物质，且第二部分1112出现活性物质脱落，第二部分1112也不会出现析锂。因此，第二部分1112可设置于弯折区域B2。
在一些实施例中，第一极片11还包括与第三部分1113连续设置的单侧反应段113，单侧反应段113与第三部分1113在交界处分界。单侧反应段113仅外侧表面上的活性物质层113a与第二极片12的活性物质层120a相对。单侧反应段113的至少一部分层叠于第二卷绕起始段111外侧，单侧反应段113的层叠于第二卷绕起始段111外侧的部分和第二卷绕起始段111之间无隔离件13和第二极片12。
在一示例中，单侧反应段113仅外表面涂覆有活性物质层113a；在另一示例中，单侧反应段113的内表面和外表面均涂覆有活性物质层113a，由于第二极片12仅布置于单侧反应段113的外侧，所以单侧反应段113的内表面的活性物质层113a基本不参与和第二极片12的电化学反应。
第二卷绕起始段111比单侧反应段113的层叠于第二卷绕起始段111外侧的部分更靠近电极组件的卷绕中心。
在本申请实施例中，单侧反应段113与第二卷绕起始段111相邻，两者之间的隔离件13可以省略，从而节约隔离件13的用量，提高电极组件10的能量密度。同时，单侧反应段113与第二卷绕起始段111极性相同，两者相邻设置可降低短路风险，提高安全性。
在一些实施例中，第二极片12为负极极片。单侧反应段113和第二卷绕起始段111之间相邻，不易引发析锂风险。
在一些实施例中，单侧反应段113卷绕一圈。
在一些实施例中，单侧反应段113的层叠于第二卷绕起始段111外侧的部分和第二卷绕起始段111接触。
第二卷绕起始段111可支撑于单侧反应段113，第二部分1112提供的支撑力可先传递给单侧反应段113，再通过单侧反应段113传递给第二极片12，使得第二卷绕起始段111对单侧反应段113和第二极片12产生更好的支撑作用。
在一些实施例中，第二极片12包括从第二极片的卷绕首端12a延伸的第三卷绕起始段121，第三卷绕起始段121整体位于平直区域B1。在第三卷绕起始段121的厚度 方向Y上，第三卷绕起始段121与第一部分1111不重叠。
在本申请实施例中，第三卷绕起始段121与第一部分1111不重叠，两者可以在厚度方向Y上共用相同的空间，从而提高空间利用率，提高电极组件10的能量密度。另外，第三卷绕起始段121的端部不易挤压第一部分1111，第一部分1111的端部也不易挤压第三卷绕起始段121，这样可以减小应力集中，降低因应力集中引发的极片断裂的风险。
在一些实施例中，第三卷绕起始段121的端部即为第二极片的卷绕首端12a，第一部分1111的端部即为第一极片的卷绕首端11a。
在一些实施例中，第三卷绕起始段121从第二极片的卷绕首端12a沿第一方向X的负方向延伸，第一部分1111从第一极片的卷绕首端11a沿第一方向X的正方向延伸。
在一些实施例中，在第一方向X上，第三卷绕起始段121与第一部分1111间隔设置。
本申请实施例将第三卷绕起始段121与第一部分1111间隔设置，以降低第三卷绕起始段121与第一部分1111重叠的风险。
在一些实施例中，在第一方向X上，第三卷绕起始段121与第一部分1111之间的间距为L3，L3为5mm-20mm。可选地，L3为5mm、8mm、10mm、15mm或20mm。
在充放电过程中，电极组件10会出现膨胀变形。如果L3过小，第三卷绕起始段121和第一部分1111可能会出现重叠。L3越大，第三卷绕起始段121和第一部分1111沿第一方向X的尺寸也越小。如果L3过大，会造成空间浪费，降低电极组件10的能量密度。
通过将L3为5mm-20mm，可降低第三卷绕起始段121和第一部分1111重叠的风险，减少电极组件10的能量密度的损失。
在一些实施例中，在第一方向X上，第一部分1111的尺寸为5mm-20mm。示例性地，第一部分1111在第一方向X上的尺寸为5mm、7mm、10mm、12mm、15mm、18mm或20mm。
在一些实施例中，在第一方向X上，第三卷绕起始段121与第一部分1111之间的最小间距大于或等于第一部分1111的尺寸。
可选地，第三卷绕起始段121与第一部分1111之间的最小间距为L3。
在电极组件10的卷绕过程中，因为工艺误差，可能会造成第一部分1111沿第一方向X的尺寸偏差较大。基于第一部分1111的尺寸来限定第三卷绕起始段121与第一部分1111之间的最小间距，可有效地降低第三卷绕起始段121和第一部分1111重叠的风险。
图12为图4所示的电极组件的另一局部示意图；图13为图12所示的电极组件在展平状态下的示意图。
如图12和图13所示，在一些实施例中，第一极片的卷绕末端11b位于弯折区域B2。
本申请实施例不限制第二极片的卷绕末端12b。第二极片的卷绕末端12b可以 位于弯折区域B2，也可以位于平直区域B1。
在电池单体的充放电过程中，电极组件10的平直区域B1膨胀较大，且平直区域B1易与外壳互相挤压。如果第一极片的卷绕末端11b设置在平直区域B1，第一极片的卷绕末端11b容易产生应力集中，引发第二极片12被第一极片的卷绕末端11b压断、析锂等风险。本申请实施例将第一极片的卷绕末端11b设置于弯折区域B2，可以减小应力集中，降低第二极片12断裂、析锂等风险，提高安全性。
在一些实施例中，第一极片11包括超出第二极片的卷绕末端12b的第二卷绕收尾段112，第二卷绕收尾段112包括第一极片的卷绕末端11b。第二卷绕收尾段112整体位于弯折区域B2。
第二卷绕收尾段112整体位于弯折区域B2，可减小第二卷绕收尾段112的长度K4，减少物料浪费。
在一些实施例中，第二卷绕收尾段112的内表面近似为圆柱面的一部分。可选地，第二卷绕收尾段112的内表面沿卷绕轴向Z的投影为圆弧线，该圆弧线的圆心角为α，0°＜α＜90°。可选地，α为10°、30°、45°、60°、75°或85°。
第二卷绕收尾段112在弯折区域B2大体弯折为圆弧状。
本申请实施例可以根据需要设置第二卷绕收尾段112的长度。
在一些实施例中，30°≤α≤60°。可选地，α为40°-50°；进一步可选地，α为45°。
α越大，第二卷绕收尾段112的长度K4越大，第二卷绕收尾段112占用的空间和重量越大，电极组件10的能量密度越低。电极组件10的充放电过程中膨胀，会引发第二卷绕收尾段112偏移的风险；如果α过小，第一极片11可能会因为第二卷绕收尾段112的偏移而无法覆盖第二极片12，从而引发析锂等安全问题。
通过将α限定为30°-60°，可平衡电极组件10的安全性和能量密度。
在一些实施例中，第二卷绕收尾段112的长度K4为5mm-20mm；示例性地，第二卷绕收尾段112的长度K4为5mm、7mm、10mm、12mm、15mm、18mm或20mm。
在一些实施例中，第二极片的卷绕末端12b位于弯折区域B2。
第二极片的卷绕末端12b和第一极片的卷绕末端11b可以位于同一个弯折区域B2，也可以分别位于两个弯折区域B2。
本申请实施例将第二极片的卷绕末端12b设置于弯折区域B2，可以减小应力集中，降低第一极片11被第二极片的卷绕末端12b压断的风险，减少析锂，提高安全性。
在一些实施例中，第二极片的卷绕末端12b和第一极片的卷绕末端11b可以位于同一个弯折区域B2。
在一些实施例中，第二极片12包括第三卷绕收尾段122，第三卷绕收尾段122从第二极片的卷绕末端12b延伸且整体位于弯折区域B2。
在一些实施例中，第三卷绕收尾段122的内表面近似为圆柱面的一部分。可选地，第三卷绕收尾段122的内表面沿卷绕轴向Z的投影为圆弧线，该圆弧线的圆心角为β，0°＜β＜45°。可选地，0°＜α＜45°。
图14为本申请一些实施例提供的电极组件的立体结构示意图；图15为图12所 示的电极组件沿线A-A作出的剖视示意图。
请一并参照图12至图15，在一些实施例中，隔离件13包括超出第二极片的卷绕末端12b的第一卷绕收尾段132，第一卷绕收尾段132包括隔离件的卷绕末端13b。电极组件10还包括束缚件14，束缚件14连接于隔离件13并用于束缚第一卷绕收尾段132。
束缚件14可以束缚第一卷绕收尾段132，以降低隔离件13散开的风险。
在一些实施例中，第一卷绕收尾段132位于第二卷绕收尾段112的外侧，束缚件14通过第一卷绕收尾段132束缚第二卷绕收尾段112，以降低第一极片11散开的风险。
在一些实施例中，第一极片11包括超出第二极片的卷绕末端12b的第二卷绕收尾段112，第二卷绕收尾段112包括第一极片的卷绕末端11b。第一卷绕收尾段132和第二卷绕收尾段112位于同一个弯折区域B2。束缚件14的一端位于第一卷绕收尾段132的外侧并连接于第一卷绕收尾段132，束缚件14的另一端超出第一极片的卷绕末端11b和隔离件的卷绕末端13b，并连接于隔离件13。
本申请实施例不限制第一极片的卷绕末端11b和隔离件的卷绕末端13b的位置。在一些示例中，第一极片的卷绕末端11b超出隔离件的卷绕末端13b；在另一些示例中，隔离件的卷绕末端13b超出第一极片的卷绕末端11b；在又一些示例中，第一极片的卷绕末端11b与隔离件的卷绕末端13b齐平。
束缚件14的另一端可以位于弯折区域B2，也可以位于平直区域B1。
束缚件14可以将第一卷绕收尾段132连接到隔离件13的其它部分，以束缚第一卷绕收尾段132，降低隔离件13散开的风险。
示例性地，束缚件14沿第二极片12的卷绕方向W延伸，束缚件14的一端为束缚件14沿卷绕方向W的首端，束缚件14的另一端为束缚件14沿卷绕方向W的末端。示例性地，第二极片12的卷绕方向W为逆时针方向。
在一些实施例中，束缚件14的另一端位于平直区域B1。平直区域B1较为平整，便于实现束缚件14与隔离件13的连接，并增大束缚件14与隔离件13的连接强度。
在一些实施例中，束缚件14包括胶带。可选地，束缚件14包括绝缘胶带。
在一些实施例中，电极组件10还包括识别标记15，识别标记15设置于束缚件14的背离平直区域B1的表面。
示例性地，识别标记15可记录该电极组件10的生产数据，以便于后续数据追溯。
电极组件10的生产设备可通过解读识别标记15来得到电极组件10的相关信息，有助于实现电极组件10的自动化生产。与在隔离件13上设置识别标记15的方案相比，在束缚件14上设置识别标记15可降低隔离件13损伤的风险。
在一些实施例中，束缚件14的厚度大于隔离件13的厚度。束缚件14具有较大的厚度和强度，既可有效地束缚隔离件13，还能够支撑识别标记15。
束缚件14的另一端超过平直区域B1的中线C，中线C平行于电极组件10的卷 绕轴向Z。识别标记15覆盖中线C的至少部分。
示例性地，卷绕轴向Z垂直于第一方向X以及第二极片12的卷绕方向W。
在本申请实施例中，中线C为一个虚拟的直线。在平行于第一方向X和卷绕轴向Z的平面内，平直区域B1的投影大体为矩形；中线C可为矩形投影的平行于卷绕轴向Z的中心线。
在本申请实施例中，识别标记15靠近平直区域B1沿第一方向X的中心设置，以便于外部设备检测。
在一些实施例中，在平行于第一方向X和卷绕轴向Z的平面内，平直区域B1的投影大体为矩形；识别标记15位于矩形投影的中心处。本实施例可便于读码器识别识别标记15。
在一些实施例中，在电极组件10的卷绕轴向Z上，束缚件14的两个边缘均超出第一极片11。
在本申请实施例中，束缚件14的两个边缘均超出第一极片11是指：束缚件14的两个边缘均超出第一极片11的活性物质层。
在本申请实施例中，束缚件14可以覆盖第一极片11，减少第一极片11的活性物质层外露的风险，提高安全性。
在一些实施例中，在实际生产过程中，因为受到卷绕过程的张力作用，切断后的隔离件13可能会发生弹性收缩，造成第一卷绕收尾段132的长度K3小于第二卷绕收尾段112的长度K4，导致第二卷绕收尾段112的一部分外露。束缚件14可以覆盖第二卷绕收尾段112的未被第一卷绕收尾段132覆盖的部分，从而减少第一极片11外露的风险，提高安全性。
图16为本申请另一些实施例提供的电极组件的局部示意图。
如图16所示，在一些实施例中，束缚件14的另一端位于另一个弯折区域B2。
束缚件14沿第二极片12的卷绕方向W的两端分别位于两个弯折区域B2。示例性地，束缚件14沿第二极片12的卷绕方向W，从一个弯折区域B2，跨过平直区域B1并延伸至另个一弯折区域B2。
本申请实施例将束缚件14的两端设置于弯折区域B2，可在电极组件10膨胀时减小束缚件14的端部受到的压力，减小应力集中，降低极片被压断的风险，减少析锂，提高安全性。
图17为本申请另一些实施例提供的电极组件的结构示意图。
如图17所示，在一些实施例中，第一极片11包括超出第二极片的卷绕首端12a的第二卷绕起始段111。第二卷绕起始段111整体位于平直区域B1。
第二卷绕起始段111在平直区域B1被夹持，可提高第二卷绕起始段111的稳定性，降低第二卷绕起始段111在电极组件10受到外部冲击时偏移的风险，提高安全性.
本申请实施例还可减小第二卷绕起始段111的长度K2，节约物料，提高电极组件10的能量密度。
在一些实施例中，第一卷绕起始段131整体位于平直区域B1。
在一些实施例中，第一卷绕起始段131的长度K1等于第二卷绕起始段111的长 度K2。
在一些实施例中，第三卷绕起始段121整体位于平直区域B1。
根据本申请的一些实施例，本申请还提供了一种电池单体，其包括外壳和以上任一实施例的电极组件，电极组件容纳于外壳内。
根据本申请的一些实施例，本申请还提供了一种电池，包括多个以上任一实施例的电池单体。
根据本申请的一些实施例，本申请还提供了一种用电装置，包括以上任一实施例的电池，电池用于为用电装置提供电能。用电装置可以是前述任一应用电池的设备或系统。
根据本申请的一些实施例，参照图4和图5，本申请实施例提供了一种卷绕式电极组件10，其包括第一极片11、第二极片12和两个隔离件13。第一极片11为负极极片，第二极片12为正极极片，两个隔离件13用于隔离第一极片11和第二极片12。
第一极片11、第二极片12和两个隔离件13卷绕设置。各隔离件13的长度为L1，第一极片11的长度为L2，L1＝L2。
隔离件13包括超出第二极片的卷绕首端12a的第一卷绕起始段131，第一极片11包括超出第二极片的卷绕首端12a的第二卷绕起始段111。第一卷绕起始段131的长度K1等于第二卷绕起始段111的长度K2。
隔离件13包括超出第二极片的卷绕末端12b的第一卷绕收尾段132，第一极片11包括超出第二极片的卷绕末端12b的第二卷绕收尾段112。第一卷绕收尾段132的长度K3等于第二卷绕收尾段112的长度K4。
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 (38)

  1. 一种电极组件，包括第一极片、第二极片和用于隔离所述第一极片和所述第二极片的至少一个隔离件，所述第一极片和所述第二极片极性相反，所述第一极片、所述第二极片和所述至少一个隔离件卷绕设置；
    其中，至少一个所述隔离件的长度为L1，所述第一极片的长度为L2，|L1-L2|≤50mm。
  2. 根据权利要求1所述的电极组件，其中，L1和L2满足：|L1-L2|≤30mm。
  3. 根据权利要求2所述的电极组件，其中，L1和L2满足：|L1-L2|≤10mm。
  4. 根据权利要求1-3任一项所述的电极组件，其中，L1＝L2。
  5. 根据权利要求1-3任一项所述的电极组件，其中，L1＞L2。
  6. 根据权利要求1-5任一项所述的电极组件，其中，所述隔离件包括超出所述第二极片的卷绕首端的第一卷绕起始段，所述第一极片包括超出所述第二极片的卷绕首端的第二卷绕起始段；
    所述第一卷绕起始段包括所述隔离件的卷绕首端，所述第二卷绕起始段包括所述第一极片的卷绕首端，所述隔离件的卷绕首端和所述第一极片的卷绕首端的最小间距为D1，D1≤20mm。
  7. 根据权利要求6所述的电极组件，其中，D1≤10mm。
  8. 根据权利要求6或7所述的电极组件，其中，所述第一卷绕起始段的长度大于所述第二卷绕起始段的长度，且所述第一卷绕起始段覆盖所述第一极片的卷绕首端。
  9. 根据权利要求6或7所述的电极组件，其中，所述第一卷绕起始段的长度等于所述第二卷绕起始段的长度，且所述隔离件的卷绕首端和所述第一极片的卷绕首端对齐。
  10. 根据权利要求1-9任一项所述的电极组件，其中，所述隔离件包括超出所述第二极片的卷绕末端的第一卷绕收尾段，所述第一极片包括超出所述第二极片的卷绕末端的第二卷绕收尾段；
    所述第一卷绕收尾段包括所述隔离件的卷绕末端，所述第二卷绕收尾段包括所述第一极片的卷绕末端，所述隔离件的卷绕末端和所述第一极片的卷绕末端的间距为D2，D2≤20mm。
  11. 根据权利要求10所述的电极组件，其中，D2≤10mm。
  12. 根据权利要求10或11所述的电极组件，其中，所述第一卷绕收尾段的长度大于所述第二卷绕收尾段的长度，且所述第一卷绕收尾段覆盖所述第一极片的卷绕末端。
  13. 根据权利要求10或11所述的电极组件，其中，所述第一卷绕收尾段的长度等于所述第二卷绕收尾段的长度，且所述第一卷绕收尾段和所述第一极片的卷绕末端对齐。
  14. 根据权利要求1-13任一项所述的电极组件，其中，所述隔离件的数量为两个，两个所述隔离件的长度相等。
  15. 根据权利要求1-14任一项所述的电极组件，其中，所述第一极片、所述隔离件 和所述第二极片经过卷绕形成平直区域和两个弯折区域，两个所述弯折区域分别位于所述平直区域沿第一方向的两侧。
  16. 根据权利要求15所述的电极组件，其中，所述第一极片包括超出所述第二极片的卷绕首端的第二卷绕起始段；
    所述第二卷绕起始段整体位于所述平直区域。
  17. 根据权利要求15所述的电极组件，其中，所述第一极片包括超出所述第二极片的卷绕首端的第二卷绕起始段；
    所述第二卷绕起始段的至少一部分位于所述弯折区域。
  18. 根据权利要求17所述的电极组件，其中，所述第二卷绕起始段包括连续设置的第一部分、第二部分和第三部分，所述第一部分包括所述第一极片的卷绕首端，所述第三部分具有与所述第二极片的卷绕首端对齐的交界处，所述第三部分从所述交界处延伸，所述第一部分和所述第三部分均位于所述平直区域，所述第二部分位于所述弯折区域，并用于连接所述第一部分和所述第三部分。
  19. 根据权利要求18所述的电极组件，其中，所述第二部分支撑所述第一极片和所述第二极片在所述弯折区域并位于所述第二部分的外侧的部分。
  20. 根据权利要求18或19所述的电极组件，其中，所述第一极片还包括与所述第三部分连续设置的单侧反应段，所述单侧反应段与所述第三部分在所述交界处分界，所述单侧反应段仅外侧表面上的活性物质层与所述第二极片的活性物质层相对；
    所述单侧反应段的至少一部分层叠于所述第二卷绕起始段外侧，所述单侧反应段层叠于所述第二卷绕起始段外侧的部分和所述第二卷绕起始段之间无所述隔离件和所述第二极片。
  21. 根据权利要求20所述的电极组件，其中，所述单侧反应段层叠于所述第二卷绕起始段外侧的部分和所述第二卷绕起始段接触。
  22. 根据权利要求18-21任一项所述的电极组件，其中，所述第二极片包括从所述第二极片的卷绕首端延伸的第三卷绕起始段，所述第三卷绕起始段整体位于所述平直区域；在所述第三卷绕起始段的厚度方向上，所述第三卷绕起始段与所述第一部分不重叠。
  23. 根据权利要求22所述的电极组件，其中，在所述第一方向上，所述第三卷绕起始段与所述第一部分间隔设置。
  24. 根据权利要求23所述的电极组件，其中，在所述第一方向上，所述第三卷绕起始段与所述第一部分之间的最小间距大于或等于所述第一部分的尺寸。
  25. 根据权利要求23或24所述的电极组件，其中，在所述第一方向上，所述第三卷绕起始段与所述第一部分之间的间距为L3，L3为5mm-20mm。
  26. 根据权利要求15-25任一项所述的电极组件，其中，所述第一极片的卷绕末端位于所述弯折区域。
  27. 根据权利要求26所述的电极组件，其中，所述第一极片包括超出所述第二极片的卷绕末端的第二卷绕收尾段，所述第二卷绕收尾段包括所述第一极片的卷绕末端；
    所述第二卷绕收尾段整体位于所述弯折区域。
  28. 根据权利要求26或27所述的电极组件，其中，所述第二极片的卷绕末端位于所述弯折区域。
  29. 根据权利要求15-28任一项所述的电极组件，其中，
    所述隔离件包括超出所述第二极片的卷绕末端的第一卷绕收尾段，所述第一卷绕收尾段包括所述隔离件的卷绕末端；
    所述电极组件还包括束缚件，所述束缚件连接于所述隔离件并用于束缚所述第一卷绕收尾段。
  30. 根据权利要求29所述的电极组件，其中，所述第一极片包括超出所述第二极片的卷绕末端的第二卷绕收尾段，所述第二卷绕收尾段包括所述第一极片的卷绕末端；
    所述第一卷绕收尾段和所述第二卷绕收尾段位于同一个所述弯折区域；
    所述束缚件的一端位于所述第一卷绕收尾段的外侧并连接于所述第一卷绕收尾段，所述束缚件的另一端超出所述第一极片的卷绕末端和所述隔离件的卷绕末端，并连接于所述隔离件。
  31. 根据权利要求30所述的电极组件，其中，所述束缚件的所述另一端位于所述平直区域。
  32. 根据权利要求30所述的电极组件，其中，所述束缚件的所述另一端位于另一个所述弯折区域。
  33. 根据权利要求31或32所述的电极组件，还包括识别标记，所述识别标记设置于所述束缚件的背离所述平直区域的表面。
  34. 根据权利要求29-33任一项所述的电极组件，其中，所述束缚件的所述另一端超过所述平直区域的中线，所述中线平行于所述电极组件的卷绕轴向。
  35. 根据权利要求29-34任一项所述的电极组件，其中，在所述电极组件的卷绕轴向上，所述束缚件的两个边缘均超出所述第一极片。
  36. 一种电池单体，包括外壳和根据权利要求1-35任一项所述的电极组件，所述电极组件容纳于所述外壳内。
  37. 一种电池，包括多个根据权利要求36所述的电池单体。
  38. 一种用电装置，包括根据权利要求37所述的电池，所述电池用于提供电能。
PCT/CN2022/140213 2022-12-20 2022-12-20 电极组件、电池单体、电池以及用电装置 WO2024130525A1 (zh)

Priority Applications (3)

Application Number Priority Date Filing Date Title
EP22964629.4A EP4418402A1 (en) 2022-12-20 2022-12-20 Electrode assembly, battery cell, battery, and electric apparatus
PCT/CN2022/140213 WO2024130525A1 (zh) 2022-12-20 2022-12-20 电极组件、电池单体、电池以及用电装置
US18/638,655 US20240266586A1 (en) 2022-12-20 2024-04-17 Electrode assembly, battery cell, battery, and electric apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2022/140213 WO2024130525A1 (zh) 2022-12-20 2022-12-20 电极组件、电池单体、电池以及用电装置

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US18/638,655 Continuation US20240266586A1 (en) 2022-12-20 2024-04-17 Electrode assembly, battery cell, battery, and electric apparatus

Publications (1)

Publication Number Publication Date
WO2024130525A1 true WO2024130525A1 (zh) 2024-06-27

Family

ID=91587320

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/140213 WO2024130525A1 (zh) 2022-12-20 2022-12-20 电极组件、电池单体、电池以及用电装置

Country Status (3)

Country Link
US (1) US20240266586A1 (zh)
EP (1) EP4418402A1 (zh)
WO (1) WO2024130525A1 (zh)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN2648615Y (zh) * 2003-09-01 2004-10-13 比亚迪股份有限公司 圆柱形锂离子二次电池
CN1591960A (zh) * 2003-09-01 2005-03-09 比亚迪股份有限公司 圆柱形锂离子二次电池
JP2006260904A (ja) * 2005-03-16 2006-09-28 Sony Corp 巻回型電池およびその製造方法
CN106063021A (zh) * 2014-02-25 2016-10-26 株式会社东芝 卷绕型电极组及非水电解质电池
CN106299444A (zh) * 2015-06-25 2017-01-04 丰田自动车株式会社 非水电解质二次电池和电池组
US20170301959A1 (en) * 2015-06-09 2017-10-19 Sony Corporation Battery, battery pack, electronic device, electric vehicle, electricity storage device, and power system

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN2648615Y (zh) * 2003-09-01 2004-10-13 比亚迪股份有限公司 圆柱形锂离子二次电池
CN1591960A (zh) * 2003-09-01 2005-03-09 比亚迪股份有限公司 圆柱形锂离子二次电池
JP2006260904A (ja) * 2005-03-16 2006-09-28 Sony Corp 巻回型電池およびその製造方法
CN106063021A (zh) * 2014-02-25 2016-10-26 株式会社东芝 卷绕型电极组及非水电解质电池
US20170301959A1 (en) * 2015-06-09 2017-10-19 Sony Corporation Battery, battery pack, electronic device, electric vehicle, electricity storage device, and power system
CN106299444A (zh) * 2015-06-25 2017-01-04 丰田自动车株式会社 非水电解质二次电池和电池组

Also Published As

Publication number Publication date
US20240266586A1 (en) 2024-08-08
EP4418402A1 (en) 2024-08-21

Similar Documents

Publication Publication Date Title
EP4131631A1 (en) Electrode assembly, battery cell, battery and power-consuming apparatus
WO2024099177A1 (zh) 端盖组件、储能装置以及用电设备
EP3477728B1 (en) Battery pack
CN212161993U (zh) 电极组件、电池、电池模块、电池组、使用电池的装置和电极组件的制造装置
US11955658B2 (en) Battery cell and manufacturing method and manufacturing system thereof, battery and power consumption apparatus
KR20140069419A (ko) 열수축성 튜브를 포함하는 이차전지
CN114503334A (zh) 电极组件及其相关电池、装置、制造方法和制造装置
CN215896616U (zh) 电极组件、电池单体、电池及用电设备
WO2022199152A1 (zh) 电极组件、电池单体、电池以及用电设备
CN219123356U (zh) 电极组件、电池单体、电池以及用电装置
WO2024082271A1 (zh) 电极组件、电池单体、电池及用电装置
WO2023168954A1 (zh) 电芯、电芯的制造方法、电池单体、电池及用电设备
WO2024130525A1 (zh) 电极组件、电池单体、电池以及用电装置
WO2023004822A1 (zh) 电池单体、电池、用电设备、电池单体的制造方法及设备
WO2024138707A1 (zh) 电极组件、电池单体、电池以及用电装置
WO2024092638A1 (zh) 电极组件及其制造方法、电池单体、电池及用电装置
WO2024193025A1 (zh) 电池单体、电池及用电设备
EP4099461A1 (en) Battery cell, battery, electric device, and method and apparatus for manufacturing battery cell
WO2024077557A1 (zh) 电池单体、电池及用电设备
WO2024103533A1 (zh) 用电装置、电池、电池单体及极片组件
WO2024130675A1 (zh) 电池单体、电池、用电装置和电池单体的制备方法及装置
WO2024082112A1 (zh) 电池单体、电池以及用电装置
WO2024103201A1 (zh) 端盖组件、电池单体、电池和用电装置
WO2024138576A1 (zh) 电极组件、电池单体、电池以及用电装置
CN220065739U (zh) 极片单元、电芯、电池、电池装置

Legal Events

Date Code Title Description
ENP Entry into the national phase

Ref document number: 2022964629

Country of ref document: EP

Effective date: 20240514