WO2024164308A1 - 电极组件、电池单体、电池及用电装置 - Google Patents

电极组件、电池单体、电池及用电装置 Download PDF

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Publication number
WO2024164308A1
WO2024164308A1 PCT/CN2023/075460 CN2023075460W WO2024164308A1 WO 2024164308 A1 WO2024164308 A1 WO 2024164308A1 CN 2023075460 W CN2023075460 W CN 2023075460W WO 2024164308 A1 WO2024164308 A1 WO 2024164308A1
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WO
WIPO (PCT)
Prior art keywords
pole ear
pole
foil
electrode assembly
ear portion
Prior art date
Legal status (The legal status 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 status listed.)
Ceased
Application number
PCT/CN2023/075460
Other languages
English (en)
French (fr)
Inventor
柴志生
金海族
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Contemporary Amperex Technology Co Ltd
Original Assignee
Contemporary Amperex Technology Co Ltd
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 Contemporary Amperex Technology Co Ltd filed Critical Contemporary Amperex Technology Co Ltd
Priority to CN202380044182.XA priority Critical patent/CN119343831A/zh
Priority to PCT/CN2023/075460 priority patent/WO2024164308A1/zh
Priority to EP23920516.4A priority patent/EP4597737A4/en
Publication of WO2024164308A1 publication Critical patent/WO2024164308A1/zh
Priority to US19/055,712 priority patent/US12586872B2/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50Current conducting connections for cells or batteries
    • H01M50/531Electrode connections inside a battery casing
    • H01M50/533Electrode connections inside a battery casing characterised by the shape of the leads or tabs
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00Secondary cells; Manufacture thereof
    • H01M10/04Construction or manufacture in general
    • H01M10/0431Cells with wound or folded electrodes
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00Secondary cells; Manufacture thereof
    • H01M10/05Accumulators with non-aqueous electrolyte
    • H01M10/058Construction or manufacture
    • H01M10/0587Construction or manufacture of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50Current conducting connections for cells or batteries
    • H01M50/531Electrode connections inside a battery casing
    • H01M50/536Electrode connections inside a battery casing characterised by the method of fixing the leads to the electrodes, e.g. by welding
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50Current conducting connections for cells or batteries
    • H01M50/531Electrode connections inside a battery casing
    • H01M50/538Connection of several leads or tabs of wound or folded electrode stacks
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01MPROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2220/00Batteries for particular applications
    • H01M2220/20Batteries in motive systems, e.g. vehicle, ship, plane
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10Energy storage using batteries
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02PCLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present application relates to the field of battery technology, and in particular to an electrode assembly, a battery cell, a battery and an electrical device.
  • the battery includes a battery cell, and an electrode assembly is arranged in the shell of the battery cell. By connecting the electrode assembly and the shell, the input or output of the electric energy of the battery cell can be realized.
  • the electrode assembly of the existing battery cells is often damaged during the production and assembly process, resulting in poor production quality of the battery cells, which is not conducive to improving the product qualification rate of the battery cells.
  • the embodiments of the present application provide an electrode assembly, a battery cell, a battery and an electrical device, which can effectively improve the production quality of the battery cell.
  • an embodiment of the present application provides an electrode assembly, comprising two pole pieces with opposite polarities and an isolating member for isolating the two pole pieces, wherein the two pole pieces and the isolating member are wound along a winding direction to form a main body and two pole ears; wherein the pole ears and the main body are arranged along the first direction, the pole ears comprise a plurality of pole ear portions arranged at intervals along the winding direction, the pole ear portions are bent relative to the first direction, at least a portion of the plurality of pole ear portions are stacked along the first direction, and a protrusion is formed on at least one side of the pole ear portion in its thickness direction.
  • two pole pieces with opposite polarities and a separator are wound along a winding direction to form an electrode assembly of a wound structure, so that the electrode assembly has a main body and two pole ears, and the pole ears and the main body are arranged along a first direction.
  • the pole ear is provided with a plurality of pole ear portions arranged at intervals along the winding direction, and the pole ear portion is bent relative to the first direction, so that at least a portion of the plurality of pole ear portions of the pole ear can be stacked along the first direction, and a protrusion is provided on at least one side of the pole ear portion of the pole ear to increase the thickness of the plurality of pole ear portions stacked together, and the phenomenon that the plurality of pole ear portions of the pole ear have a smaller local thickness after stacking can be alleviated, thereby improving the production quality of the pole ear, reducing the risk of the pole ear being welded through during the subsequent assembly process, thereby helping to reduce the phenomenon of damage to the electrode assembly, and helping to improve the connection stability and assembly quality between the electrode assembly and other components of the battery cell, so as to improve the production quality and use stability of the battery cell having such an electrode assembly.
  • a plurality of protrusions are formed on at least one side of the pole lug portion.
  • the pole ear portion is bent relative to the first direction and multiple pole ear portions are stacked along the first direction, so that the area with a cavity between two stacked and adjacent pole ear portions can be effectively increased, which is beneficial to further increase the overall thickness of the pole ear in the first direction, and can improve the uniformity of the thickness of the pole ear, thereby further alleviating the phenomenon of the pole ear being welded through during subsequent assembly and processing.
  • the projection area of the pole ear portion is S 1
  • the sum of the projection areas of the plurality of protrusions on the pole ear portion is S 2 , satisfying S 2 /S 1 ⁇ 0.5.
  • the pole ear portion in the thickness direction of the pole ear portion by setting the sum of the projected areas of the multiple protrusions on the pole ear portion in the thickness direction of the pole ear portion to be greater than or equal to half of the projected area of the pole ear portion in the thickness direction of the pole ear portion, that is, the area occupied by the multiple protrusions on the pole ear portion is half or more of the pole ear portion, so that there is a sufficient area on the pole ear portion to be provided with the protrusions, so that after the multiple pole ear portions of the pole ear are stacked along the first direction, the pole ear has a sufficient thickness, and the uniformity of the thickness of the pole ear can be effectively improved, so as to reduce the risk of the pole ear being welded through during the subsequent assembly process.
  • the pole ear portion includes a main body region that does not overlap with a projection of the protrusion in the thickness direction of the pole ear portion, and the protrusion protrudes from the main body region along the thickness direction of the pole ear portion; along the thickness direction of the pole ear portion, the maximum dimension of the pole ear portion is D 1 , and the thickness of the main body region is D 2 , satisfying 2 ⁇ D 1 /D 2 ⁇ 8.
  • the pole ear portion has a main body area which does not overlap with the projection of the protrusion in the thickness direction of the pole ear portion, and the protrusion protrudes from the main body area in the thickness direction of the pole ear portion, that is, the main body area of the pole ear portion is an area of the pole ear portion where the protrusion is not arranged.
  • the maximum dimension of the pole ear portion in the thickness direction of the pole ear portion is 2 to 8 times the thickness of the main body area, that is, the maximum thickness of the pole ear portion after the protrusion is arranged is 2 to 8 times the thickness of the main body area of the pole ear portion, so that after the pole ear portion is bent relative to the first direction, the thickness of multiple pole ear portions of the pole ear stacked on each other along the first direction can be effectively increased, so as to realize an increase in the thickness of the pole ear, and further can effectively alleviate the phenomenon of the pole ear being welded through during the subsequent assembly process.
  • the pole ear portion is formed with a plurality of rows of protrusions, and each row of protrusions includes a plurality of the protrusions arranged at intervals.
  • each row of protrusions includes multiple protrusions arranged at intervals, so that the multiple protrusions on the pole ear portion are arranged in an array, so that after the multiple pole ear portions of the pole ear are stacked along the first direction, the area with a cavity between two stacked and adjacent pole ear portions can be effectively increased, which is beneficial to further improve the overall thickness of the pole ear in the first direction, and can effectively improve the uniformity of the thickness of the pole ear, so as to reduce the phenomenon of the pole ear being welded through during the subsequent assembly process.
  • the maximum dimension of the protrusion in a direction perpendicular to the thickness direction of the pole ear portion is W 1 , satisfying 0.3 mm ⁇ W 1 ⁇ 2 mm.
  • the maximum dimension of the protrusion in a direction perpendicular to the thickness direction of the pole ear portion is 0.3 mm to 3 mm, that is, the maximum dimension of the protrusion in its radial direction is 0.3 mm to 3 mm, on the one hand, the phenomenon of excessive processing difficulty caused by the protrusion being too small can be alleviated, so as to reduce the processing difficulty of the pole ear portion; on the other hand, the phenomenon of the number of multiple protrusions on the pole ear portion being limited due to the protrusion being too large can be alleviated.
  • the pole ear portion is formed with a plurality of protrusions arranged at intervals, and two ends of the protrusions extend to two ends of the pole ear portion respectively along a direction perpendicular to an arrangement direction of the plurality of protrusions.
  • a plurality of protrusions are formed on the pole ear portion and arranged at intervals, and both ends of the protrusions extend to both ends of the pole ear portion, that is,
  • the protrusion is a strip structure arranged on the pole ear portion, so as to realize a structure in which a plurality of protrusions are arranged on the pole ear portion.
  • the use of such a structure is conducive to reducing the difficulty of arranging the protrusion on the pole ear portion, so as to improve the processing efficiency of the pole ear portion.
  • the width of the protrusions is W 2 , satisfying 0.3 mm ⁇ W 2 ⁇ 2 mm.
  • the width of the protrusion in the arrangement direction of the multiple protrusions to 0.3mm to 3mm, that is, the size of the protrusion in the direction perpendicular to the extension direction of the protrusion is 0.3mm to 3mm, on the one hand, it can alleviate the phenomenon of excessive processing difficulty caused by the protrusion width being too small, so as to reduce the processing difficulty of the pole ear part, and on the other hand, it can alleviate the phenomenon of the number of multiple protrusions on the pole ear part being limited due to the protrusion width being too large.
  • the pole ear portion along the thickness direction of the pole ear portion, includes a plurality of foil materials stacked together, a convex portion is formed on one side of the foil material, and a concave portion is formed on the other side at a position corresponding to the convex portion, and in two adjacent foil materials, the convex portion of one foil material is accommodated in the concave portion of the other foil material; wherein, along the thickness direction of the pole ear portion, the convex portion located on one side of the pole ear portion is the protrusion.
  • the pole ear portion is arranged as a structure in which multiple foils are stacked, and a convex portion is formed on one side of the foil and a concave portion is formed on the other side, so that after the multiple foils are stacked, the convex portions and the concave portions of two adjacent foils can be embedded in each other, so that a convex portion is formed on one side of the pole ear portion in the thickness direction of the pole ear portion.
  • the pole ear portion adopting such a structure can effectively increase the thickness and structural strength of the pole ear portion itself, so that after the multiple pole ear portions of the pole ear are stacked along the first direction, the overall thickness and structural strength of the pole ear can be further increased, so as to further reduce the risk of the pole ear being welded through during the subsequent assembly process.
  • a plurality of the foils are connected by welding to form the protrusions and the recesses on the foils.
  • welding is used to connect multiple stacked foils, and convexities and concave portions are formed at the positions where the multiple foils are welded to each other.
  • this is beneficial to improving the connection strength and connection stability between the multiple foils, and on the other hand, it is beneficial to reduce the processing difficulty of forming concave portions and convex portions on the foils, so as to optimize the production rhythm of the pole pieces, thereby effectively improving the production efficiency of the pole pieces.
  • the pole piece includes a main body, a plurality of pole ear portions are connected to the main body, the main bodies of the two pole pieces and the isolation member are wound along the winding direction to form the main body, the main body includes a substrate and an active material layer arranged on at least one side of the substrate; the plurality of foil materials include a first foil material and a second foil material stacked together, the first foil material is connected to one end of the substrate in the first direction and is integrally formed with the substrate, and the second foil material is separately arranged from the substrate.
  • the multiple foils include a first foil that is integrally formed with the substrate of the main body of the electrode piece.
  • an area without an active material layer can be reserved on the substrate, so that the first foil can be arranged on the area, and then the second foil can be stacked on one side of the first foil, so that the first foil can provide a connection support point for the second foil, so as to achieve an increase in the thickness and structural strength of the electrode ear.
  • a electrode piece with such a structure can effectively reduce the process difficulty of connecting the electrode ear to the substrate, which is beneficial to improving the production efficiency of the electrode assembly.
  • the substrate includes a coating area and a spacing area, the coating area and the spacing area are arranged along the first direction, the active material layer is disposed in the coating area, and the spacing area connects the coating area and the first foil material.
  • a coating area coated with an active material layer and a spacing area not coated with an active material layer are arranged on the substrate, so that the first foil of the pole ear portion can be connected to the coating area through the spacing area, so that the pole ear portion and the active material layer are spaced apart in the first direction.
  • the electrode assembly adopting this structure can isolate the stress generated by the pole ear portion during the bending process relative to the first direction through the spacing area, so as to reduce the risk of fracture of the active material layer arranged on the coating area.
  • the influence of the welding process on the active material layer can be reduced, thereby alleviating the phenomenon of damage to the active material layer, which is beneficial to improving the production quality of the electrode assembly.
  • the thickness of the first foil is D 3
  • the thickness of the second foil is D 4 , satisfying 0.5 ⁇ D 3 /D 4 ⁇ 2.
  • the thickness of the first foil is 0.5 to 2 of the thickness of the second foil, that is, the thickness of the first foil is 0.5 to 2 times the thickness of the second foil, the phenomenon that the assembly difficulty of the first foil and the second foil is too great due to the large difference in thickness between the first foil and the second foil can be alleviated, so as to reduce the processing difficulty of the pole ear portion of this structure.
  • the phenomenon that the second foil is damaged during the mutual welding process due to the thickness of the first foil being too large compared to the thickness of the second foil can be alleviated, and on the other hand, the phenomenon that the first foil is damaged during the mutual welding process due to the thickness of the second foil being too large compared to the thickness of the first foil can be alleviated.
  • an end of the second foil material close to the substrate does not exceed an end of the first foil material connected to the substrate.
  • the interference effect between the second foil material and the active material layer arranged on one side of the substrate can be effectively alleviated, thereby reducing the risk of the active material layer being damaged by the second foil material.
  • a distance L between an end of the first foil away from the substrate and an end of the second foil away from the substrate satisfies L ⁇ 2 mm.
  • the spacing between one end of the first foil away from the substrate and one end of the second foil away from the substrate in a direction perpendicular to the thickness direction of the pole ear portion is less than or equal to 2 mm, that is, the dimension of the end of the first foil away from the substrate exceeding the end of the second foil away from the substrate is less than or equal to 2 mm, or the dimension of the end of the second foil away from the substrate exceeding the end of the first foil away from the substrate is less than or equal to 2 mm, thereby alleviating the problem that the first foil exceeds the second foil too much or the second foil exceeds the first foil too much due to the length of the first foil or the length of the second foil being too large, thereby causing the pole ear portion to be lengthy or inverted into the electrode assembly, which is beneficial to improving the production quality and use reliability of the electrode assembly.
  • the first foil and the second foil are made of the same material.
  • the process difficulty of connecting the first foil and the second foil can be reduced.
  • the pole piece includes a main body, a plurality of pole ears are connected to one end of the main body in the first direction, and the main bodies of the two pole pieces and the separator are wound along the winding direction to form the main body; wherein the main body includes a substrate and a The active material layer on at least one side of the substrate comprises a coating area and a spacing area, the coating area and the spacing area are arranged along the first direction, the active material layer is arranged in the coating area, and the spacing area connects the coating area and the pole ear portion.
  • a coating area coated with an active material layer and a spacer area not coated with an active material layer are arranged on the substrate, so that the pole ear portion can be connected to the coating area through the spacer area, so that the pole ear portion and the active material layer are spaced apart in the first direction.
  • the electrode assembly adopting this structure can isolate the stress generated by the pole ear portion during the bending process relative to the first direction through the spacer area, so as to reduce the risk of fracture of the active material layer arranged on the coating area.
  • the impact on the active material layer caused by the welding process can be reduced, thereby alleviating the phenomenon of damage to the active material layer, which is beneficial to improving the production quality of the electrode assembly.
  • the pole ear portion and the spacer region are integrally formed.
  • the pole ear portion by setting the pole ear portion as a structure integrally formed with the spacer area of the substrate, the pole ear portion can be a part of the substrate during the actual production process. After reserving an area on the substrate where the active material layer is not set, the pole ear portion can be set on the area to reduce the process difficulty of connecting the pole ear portion to the substrate, which is beneficial to improving the production efficiency of the electrode assembly.
  • a groove is formed on a side of the pole ear portion away from the protrusion and corresponding to a position of the protrusion.
  • a groove is provided on the side of the pole ear portion away from the protrusion and at the position corresponding to the protrusion, so that the pole ear portion of this structure can be formed with a protrusion on the pole ear portion through a process such as stamping or rolling.
  • it is beneficial to reduce the processing difficulty of the pole ear portion and to improve the processing efficiency of the pole ear portion.
  • the protrusion of one pole lug portion and the groove of the other pole lug portion are staggered.
  • the thickness of the tab is D 5 , satisfying 0.2 mm ⁇ D 5 ⁇ 2.5 mm.
  • the thickness of the pole ear in the first direction to 0.2 mm to 2.5 mm
  • the risk of the pole ear being welded through due to the small thickness of the pole ear can be alleviated, so as to reduce the risk of damage to the electrode assembly during subsequent assembly.
  • the phenomenon of the pole ear occupying too much space due to the excessive thickness of the pole ear can be alleviated, which is beneficial to optimize the internal space of the battery cell with such an electrode assembly to improve the energy density of the battery cell.
  • the two tabs are respectively disposed at two ends of the main body.
  • the two pole ears of the electrode assembly are respectively formed at the two ends of the electrode assembly in the first direction, it is convenient to subsequently assemble the electrode assembly, which is beneficial to reduce the difficulty of assembling the battery cell with such an electrode assembly, and can reduce the interference or mutual contact between the two pole ears, thereby helping to reduce the risk of short circuit of the electrode assembly.
  • the body is cylindrical.
  • the main body of the electrode assembly is set to a cylindrical structure, so as to facilitate subsequent processing to form a battery cell with a cylindrical structure.
  • an embodiment of the present application further provides a battery cell, comprising a housing and the above-mentioned electrode assembly; the electrode assembly is accommodated in the housing.
  • the battery cell further includes a current collecting member; the current collecting member is disposed between the housing and the tab along the first direction, and the current collecting member connects the housing and the tab.
  • a current collecting component is provided in the shell of the battery cell to connect the shell and the pole ear of the electrode assembly through the current collecting component, thereby realizing the input or output of electric energy of the battery cell.
  • the current collecting member is connected to the tab by welding, and along the first direction, the thickness of the tab is D 5 , and the thickness of the current collecting member is D 6 , satisfying that D 6 ⁇ 1.5D 5 .
  • the thickness of the current collecting component in the first direction is less than or equal to 1.5 times the thickness of the pole lug in the first direction, the phenomenon that the welding power required for welding the current collecting component and the pole lug is too large due to the thickness of the current collecting component being too large than the thickness of the pole lug can be alleviated, thereby effectively reducing the risk of the pole lug being welded through, thereby reducing the phenomenon of damage to the electrode assembly, which is beneficial to improving the production quality of battery cells.
  • the current collecting member is connected to the electrode tab by welding to form a weld mark, and along the first direction, the weld mark covers the protrusion of at least one of the electrode tab portions.
  • the weld mark formed by welding the current collecting member and the pole ear is set to cover the protrusion of at least one pole ear part in the first direction, that is, in the first direction, the position where the current collecting member and the pole ear are welded to each other is set corresponding to the protrusion of at least one pole ear part, so that the position where the current collecting member and the pole ear are welded to each other is located in the area where the pole ear is thickened by the protrusion, which is beneficial to further reduce the risk of the pole ear being welded through during the assembly process.
  • an embodiment of the present application further provides a battery, comprising the above-mentioned battery cell.
  • an embodiment of the present application further provides an electrical device, comprising the above-mentioned battery.
  • FIG1 is a schematic diagram of the structure of a vehicle provided in some embodiments of the present application.
  • FIG2 is an exploded view of a battery structure provided in some embodiments of the present application.
  • FIG3 is an exploded view of a battery cell structure provided by some embodiments of the present application.
  • FIG4 is a cross-sectional view of an electrode assembly provided in some embodiments of the present application.
  • FIG5 is a cross-sectional view of an electrode assembly provided in some embodiments of the present application.
  • FIG6 is a schematic diagram of the structure of an electrode assembly during a winding process provided by some embodiments of the present application.
  • FIG. 7 is a schematic diagram of the structure of the electrode sheet of the electrode assembly provided in some embodiments of the present application after unfolding;
  • FIG8 is a partial cross-sectional view of a pole piece after unfolding provided in some embodiments of the present application.
  • FIG9 is a schematic diagram of the structure of a pole ear portion provided in some embodiments of the present application.
  • FIG10 is a front view of a pole ear portion provided in some embodiments of the present application.
  • FIG11 is a schematic diagram of the structure of the pole ear portion provided in some other embodiments of the present application.
  • FIG12 is a front view of a pole ear portion provided in some other embodiments of the present application.
  • FIG13 is a schematic diagram of the structure of the pole ear portion provided in some other embodiments of the present application.
  • FIG14 is a front view of a pole ear portion provided in some other embodiments of the present application.
  • FIG15 is a partial cross-sectional view of a pole piece after unfolding provided in some other embodiments of the present application.
  • FIG16 is a cross-sectional view of a pole ear portion of a pole piece provided in some other embodiments of the present application.
  • FIG. 17 is a cross-sectional view of a plurality of tab portions of an electrode tab of an electrode assembly provided in some embodiments of the present application after being stacked;
  • FIG. 18 is a schematic diagram showing the connection between the current collecting member and the electrode lug of the electrode assembly provided in some embodiments of the present application.
  • Icon 1000-vehicle; 100-battery; 10-box; 11-first box body; 12-second box body; 20-battery cell; 21-housing; 211-shell; 2111-opening; 212-end cover; 22-electrode assembly; 221-pole piece; 2211-main body; 22111-substrate; 22111a-coating area; 22111b-spacer area; 22112-active material layer; 2212-ear; 22121 -ear portion; 22121a-protrusion; 22121b-groove; 22121c-main body; 22121d-foil; 22121e-convex portion; 22121f-concave portion; 22121g-first foil; 22121h-second foil; 222-isolating member; 223-main body; 23-current collecting member; 24-weld stamp; 200-controller; 300-motor; X-first direction; Y-winding direction; Z-thickness direction of the ear portion.
  • 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.
  • a and/or B can represent: A exists alone, A and B exist at the same time, and B exists alone.
  • the character "/" in this application generally indicates that the associated objects before and after are in an "or" relationship.
  • the battery cell may be a secondary battery.
  • a secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.
  • the battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead storage battery, etc., which is not limited in the embodiments of the present application.
  • a battery cell generally includes an electrode assembly.
  • the electrode assembly includes a positive electrode, a negative electrode, and a separator.
  • active ions such as lithium ions
  • the separator is set between the positive electrode and the negative electrode to prevent the positive and negative electrodes from short-circuiting, while allowing active ions to pass through.
  • the positive electrode may be a positive electrode sheet, and the positive electrode sheet may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.
  • the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is disposed on either or both of the two facing surfaces of the positive electrode current collector.
  • the positive electrode current collector may be a metal foil or a composite current collector.
  • the metal foil aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc., treated with silver surface, may be used.
  • the composite current collector may include a polymer material base and a metal layer.
  • the composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).
  • the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds.
  • the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more.
  • lithium-containing phosphates may include, but are not limited to, lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and at least one of a composite material of lithium iron manganese phosphate and carbon.
  • the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.
  • the negative electrode current collector can be a metal foil, a foamed metal or a composite current collector.
  • a metal foil aluminum or stainless steel treated with silver, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. can be used.
  • the foamed metal can be a foamed nickel, a foamed copper, a foamed aluminum, a foamed alloy, or a foamed carbon, etc.
  • the composite current collector can include a polymer material base and a metal layer.
  • the composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).
  • a metal material copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.
  • a polymer material substrate such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.
  • the negative electrode sheet may include a negative electrode collector and a negative electrode active material disposed on at least one surface of the negative electrode collector.
  • the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is disposed on either or both of the two facing surfaces of the negative electrode current collector.
  • the negative electrode active material may be a negative electrode active material for a battery cell known in the art.
  • the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc.
  • the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.
  • the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.
  • the separator is a separator.
  • the present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical stability and mechanical stability can be selected.
  • the main material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics.
  • the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transmit ions and isolate the positive and negative electrodes.
  • the battery cell further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes.
  • an electrolyte which acts as a conductor of ions between the positive and negative electrodes.
  • the present application has no specific restrictions on the type of electrolyte, which can be selected according to needs.
  • the electrolyte can be liquid, gel or solid.
  • the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into the wound structure.
  • the electrode assembly is a laminate structure.
  • the shape of the electrode assembly can be cylindrical, flat, or polygonal.
  • the electrode assembly is provided with tabs, which can lead current out of the electrode assembly.
  • the tabs include a positive tab and a negative tab.
  • the battery cell may include a housing.
  • the housing is used to encapsulate components such as the electrode assembly and the electrolyte.
  • the housing may be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film.
  • the battery cell can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes.
  • the prismatic battery cell includes a square shell battery cell, a blade-shaped battery cell, a polygonal battery, such as a hexagonal battery, etc. There is no special limitation in this application.
  • 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 may be a battery module.
  • the multiple battery cells are arranged and fixed to form a battery module.
  • the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are accommodated in the case.
  • the box body can be used as a part of the chassis structure of the vehicle.
  • part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.
  • the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.
  • Batteries have outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide adaptability, and low self-discharge coefficient, and are an important part of the development of new energy today.
  • a current collecting component is usually arranged in the shell of the battery cell.
  • the pole ear of the electrode assembly needs to be welded to the current collecting component, and then connected to the shell through the current collecting component to realize the input or output of the electric energy of the battery cell, so as to facilitate the assembly of the battery cell and reduce the difficulty of assembling the battery cell.
  • the electrode assembly is usually welded to the current collecting member through the pole ear to achieve electrical connection between the electrode assembly and the current collecting member, and the pole ear is usually formed by stacking multiple pole ear sheets.
  • a flattening process or a smoothing process is usually used to flatten or smooth the multiple pole ear sheets of the pole sheet to improve the flatness of the pole ear, so that the pole ear is formed at one end of the electrode assembly, which is conducive to reducing the welding difficulty between the pole ear and the current collecting member.
  • the pole ear of the existing electrode assembly is very likely to cause the pole ear to have a local thickness that is too small during the flattening or smoothing process, and it is easy to cause the overall thickness of the pole ear to be small after the multiple pole ear sheets are closely fitted, so that the pole ear is easily welded through during the welding process between the pole ear and the current collecting member, resulting in the risk of damage to the electrode assembly, thereby making the production quality of the battery cell poor, which is not conducive to improving the product qualification rate of the battery cell.
  • an embodiment of the present application provides an electrode assembly, including two pole pieces with opposite polarities and an isolating member for isolating the two pole pieces, the two pole pieces and the isolating member are wound along a winding direction to form a main body and two pole ears; wherein the pole ears and the main body are arranged along a first direction, the pole ears include a plurality of pole ear portions arranged at intervals along the winding direction, the pole ear portions are bent relative to the first direction, at least parts of the plurality of pole ear portions are stacked along the first direction, and a protrusion is formed on at least one side of the pole ear portions in the thickness direction thereof.
  • pole piece of this structure two pole pieces with opposite polarities and a separator are wound along a winding direction to form an electrode assembly of a wound structure, so that the electrode assembly has a main body and two pole ears, and the pole ears and the main body are arranged along a first direction.
  • the pole ear is provided with a plurality of pole ear portions arranged at intervals along the winding direction, and the pole ear portion is bent relative to the first direction, so that at least a portion of the plurality of pole ear portions of the pole ear can be stacked along the first direction, and a protrusion is provided on at least one side of the pole ear portion of the pole ear to increase the thickness of the plurality of pole ear portions stacked together, and the phenomenon that the plurality of pole ear portions of the pole ear have a small local thickness after stacking can be alleviated, thereby improving the production quality of the pole ear, reducing the risk of the pole ear being welded through during the subsequent assembly process, thereby helping to reduce the phenomenon of damage to the electrode assembly, and helping to improve the connection stability and assembly quality between the electrode assembly and other components of the battery cell, so as to improve the production quality and use stability of the battery cell having such an electrode assembly.
  • the pole piece disclosed in the embodiment of the present application can be used in, but not limited to, electric devices such as vehicles, ships or aircraft.
  • a power supply system comprising the electrode assembly, battery cells or batteries disclosed in the present application can be used to form the electric device, so that the phenomenon of the pole ear of the electrode assembly being welded through during the production and assembly of the battery cell can be effectively alleviated, thereby improving the production quality of the battery cell.
  • the embodiment of the present application provides an electric device using a battery as a power source
  • the electric device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc.
  • the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc.
  • the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.
  • FIG. 1 is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of the present application.
  • the vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc.
  • a battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided at the bottom of the vehicle 1000, or at the head of the vehicle 1000, or at the tail of the vehicle 1000.
  • the battery 100 may be used to power the vehicle 1000, for example, the battery 100 may be used as an operating power source or a power source for the vehicle 1000, etc.
  • the vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to power the motor 300, for example, for the starting, navigation and working power requirements of the vehicle 1000 during driving.
  • the battery 100 can not only serve as an operating power source or a use power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.
  • the battery 100 may include a housing 10 and a battery cell 20, wherein the battery cell 20 is used to be accommodated in the housing 10.
  • the box body 10 is used to provide an assembly space for the battery cell 20, and the box body 10 can adopt a variety of structures.
  • the box body 10 may include a first box body 11 and a second box body 12, the first box body 11 and the second box body 12 cover each other, and the first box body 11 and the second box body 12 jointly define an assembly space for accommodating the battery cell 20.
  • the second box body 12 can be a hollow structure with one end open, the first box body 11 can be a plate-like structure, and the first box body 11 covers the open side of the second box body 12, so that the first box body 11 and the second box body 12 jointly define an assembly space; the first box body 11 and the second box body 12 can also be hollow structures with one side open, and the open side of the first box body 11 covers the open side of the second box body 12.
  • the box body 10 formed by the first box body 11 and the second box body 12 can be in a variety of shapes, such as a cylinder, a cuboid, etc. Exemplarily, in Figure 2, the shape of the box body 10 is a cuboid.
  • the battery cell 20 disposed in the housing 10 may be one or more. When there are more than one battery cell 20 disposed in the housing 10, the multiple battery cells 20 may be connected in series, in parallel, or in a mixed connection.
  • a mixed connection means that the multiple battery cells 20 are both connected in series and in parallel.
  • the multiple battery cells 20 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 20 may be accommodated in the housing 10; of course, the battery 100 may also be a battery module formed by connecting multiple battery cells 20 in series, in parallel, or in a mixed connection, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the housing 10.
  • the battery 100 may also include other structures.
  • the battery 100 may also include a busbar component, which is used to connect the multiple battery cells 20 to achieve electrical connection between the multiple battery cells 20.
  • Each battery cell 20 may be a secondary battery or a primary battery; it may also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but the battery cell 20 is not limited thereto.
  • the battery cell 20 may be cylindrical, flat, rectangular or other shapes. For example, in FIG2 , the battery cell 20 is a cylindrical structure.
  • Fig. 3 is an exploded view of a battery cell 20 provided in some embodiments of the present application.
  • the battery cell 20 may include a housing 21 and an electrode assembly 22, wherein the electrode assembly 22 is accommodated in the housing 21.
  • the housing 21 can also be used to contain electrolytes, such as electrolytes.
  • the housing 21 can be in various structural forms, such as a cylinder, a cuboid, or a prism structure.
  • the housing 21 can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy.
  • the housing 21 may include a shell 211 and an end cap 212, wherein a accommodating cavity is formed inside the shell 211, and the accommodating cavity has an opening 2111, and the accommodating cavity is used to accommodate the electrode assembly 22, that is, the shell 211 is a hollow structure with an opening 2111 on one side, and the end cap 212 covers the opening 2111 of the shell 211 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 22 and the electrolyte.
  • the electrode assembly 22 When assembling the battery cell 20 , the electrode assembly 22 may be placed in the housing 211 first, and the housing 211 may be filled with electrolyte. The end cap 212 may then be closed on the opening 2111 of the housing 211 to complete the assembly of the battery cell 20 .
  • the shell 211 can be in various shapes, such as a cylinder, a cuboid, etc.
  • the shape of the shell 211 can be determined according to the specific shape of the electrode assembly 22. For example, if the electrode assembly 22 is a cylindrical structure, a shell 211 with a cylindrical structure can be selected; if the electrode assembly 22 is a cuboid structure, a shell 211 with a cuboid structure can be selected.
  • the end cap 212 can also be in various structures, such as the end cap 212 being a plate-like structure, a hollow structure with an opening 2111 at one end, etc.
  • the electrode assembly 22 is a cylindrical structure, and correspondingly, the shell 211 is a cylindrical structure, the end cap 212 is a cylindrical plate-like structure, and the end cap 212 covers the opening 2111 of the shell 211.
  • the outer shell 21 is not limited to the above structure, and the outer shell 21 may also be other structures.
  • the outer shell 21 includes a shell body 211 and two end caps 212.
  • the shell body 211 is a hollow structure with openings 2111 on opposite sides.
  • One end cap 212 corresponds to an opening 2111 of the shell body 211 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 22 and the electrolyte.
  • the housing 21 may further include a positive electrode terminal and a negative electrode terminal.
  • the positive electrode terminal may be mounted on the end cap 212, and the negative electrode terminal may be mounted on the end of the housing 211 opposite to the end cap 212.
  • the positive electrode terminal may be mounted on the end of the housing 211 opposite to the end cap 212, and the negative electrode terminal may be mounted on the end cap 212.
  • the positive electrode terminal and the negative electrode terminal may be mounted on the end cap 212 or both of them may be mounted on the end of the housing 211 opposite to the end cap 212.
  • the positive electrode terminal and the negative electrode terminal are both used to electrically connect to the electrode assembly 22 to achieve the input or output of the electric energy of the battery cell 20.
  • the positive electrode terminal and the negative electrode terminal may be directly connected to the electrode assembly 22, such as welding or abutting, etc., and the positive electrode terminal and the negative electrode terminal may also be indirectly connected to the electrode assembly 22, such as the positive electrode terminal and the negative electrode terminal are first connected to other components, and then abutted or welded to the electrode assembly 22 through other components.
  • the battery cell 20 may further include a current collecting member 23 , which is accommodated in the housing 21 , and is used to connect the electrode assembly 22 and the positive electrode terminal or the negative electrode terminal of the housing 21 to realize the input or output of electrical energy of the battery cell 20 .
  • the current collecting component 23 serves to connect the electrode assembly 22 and the positive electrode terminal of the outer shell 21 or to connect the electrode assembly 22 and the negative electrode terminal of the outer shell 21. There are many ways to connect the current collecting component 23 with the electrode assembly 22 and the positive electrode terminal or the negative electrode terminal of the outer shell 21, such as welding, abutment or bonding.
  • the battery cell 20 may include two current collecting components 23, and the electrode assembly 22 is respectively connected to the positive electrode terminal and the negative electrode terminal of the outer shell 21 through the two current collecting components 23, that is, the electrode assembly 22 is connected to the positive electrode terminal of the outer shell 21 through one current collecting component 23, and is connected to the negative electrode terminal of the outer shell 21 through another current collecting component 23, so that the positive and negative electrodes of the battery cell 20 can be output or input respectively.
  • the battery cell 20 may further include a pressure relief mechanism, which may be installed on the end cover 212 or the housing 211. Similarly, there may be one or more pressure relief mechanisms, which are used to release the pressure inside the battery cell 20.
  • the pressure relief mechanism may be a pressure relief component such as an explosion-proof valve, an explosion-proof disk, an air valve, a pressure relief valve or a safety valve.
  • the electrode assembly 22 is a component in the battery cell 20 where an electrochemical reaction occurs.
  • the electrode assembly 22 may have a variety of structures, for example, the electrode assembly 22 may be a winding structure formed by winding, or a laminated structure formed by stacking.
  • the electrode assembly 22 may have a variety of shapes, for example, the electrode assembly 22 may be a cylindrical structure, an elliptical structure, or a rectangular parallelepiped structure.
  • Fig. 4 is a cross-sectional view of an electrode assembly 22 provided in some embodiments of the present application
  • Fig. 5 is a cross-sectional view of an electrode assembly 22 provided in some embodiments of the present application.
  • the electrode assembly 22 is a wound structure formed by winding, and the shape of the electrode assembly 22 is a cylinder.
  • the electrode assembly 22 may include two pole pieces 221 with opposite polarities, and the two pole pieces 221 are wound around a central axis extending along the first direction X to form an electrode assembly 22 with a wound structure. That is, the two pole pieces 221 with opposite polarities are respectively the positive pole piece and the negative pole piece of the electrode assembly 22, and the positive pole piece and the negative pole piece are wound to form the electrode assembly 22 with a wound structure.
  • the electrode assembly 22 may also be a laminated structure formed by stacking two pole pieces 221 with opposite polarities.
  • the electrode assembly 22 may further include an isolating member 222 , which is disposed between the two pole pieces 221 to insulate and isolate the two pole pieces 221 , thereby effectively reducing the risk of short circuit of the electrode assembly 22 during use.
  • an isolating member 222 which is disposed between the two pole pieces 221 to insulate and isolate the two pole pieces 221 , thereby effectively reducing the risk of short circuit of the electrode assembly 22 during use.
  • the material of the isolation member 222 may be various, for example, the material of the isolation member 222 may be polypropylene or polyethylene.
  • Figure 6 is a schematic diagram of the structure of the electrode assembly 22 provided in some embodiments of the present application during the winding process
  • Figure 7 is a schematic diagram of the structure of the pole piece 221 of the electrode assembly 22 provided in some embodiments of the present application after unfolding
  • Figure 8 is a partial cross-sectional view of the pole piece 221 provided in some embodiments of the present application after unfolding.
  • the present application provides an electrode assembly 22, including two pole pieces 221 with opposite polarities and an isolating member 222 for isolating the two pole pieces 221, and the two pole pieces 221 and the isolating member 222 are wound along the winding direction Y to form a main body 223 and two pole ears 2212.
  • the pole ear 2212 and the main body 223 are arranged along the first direction X, and the pole ear 2212 includes a plurality of pole ear portions 22121 arranged at intervals along the winding direction Y, the pole ear portions 22121 are bent relative to the first direction X, at least a portion of the plurality of pole ear portions 22121 are stacked along the first direction X, and a protrusion 22121a is formed on at least one side of the pole ear portion 22121 in its thickness direction.
  • the pole piece 221 may include a main body 2211 and a pole ear 2212 connected to one end of the main body 2211 in the first direction X, and the main bodies 2211 and the isolation members 222 of the two pole pieces 221 with opposite polarities are wound along the winding direction Y to form the main body 223 of the electrode assembly 22, and the winding center axis of the electrode assembly 22 extends along the first direction X, so that the pole ear 2212 of each pole piece 221 is formed at one end of the electrode assembly 22 in the first direction X, thereby making the pole ear 2212 and the main body 223 arranged along the first direction X.
  • the two pole pieces 221 with opposite polarities each have a pole ear 2212
  • the two pole ears 2212 have opposite polarities
  • the two pole ears 2212 are located at two ends of the main body 223 in the first direction X, respectively.
  • the main body 2211 of the pole piece 221 is the area where the pole piece 221 undergoes chemical reactions in the battery cell 20, and mainly relies on the movement of metal ions between the main bodies 2211 of the two pole pieces 221 with opposite polarities to work.
  • the main body 2211 of the pole piece 221 includes a substrate 22111 and an active material layer 22112 disposed on one side of the substrate 22111, and the pole ear 2212 is connected to one end of the substrate 22111 along the first direction X.
  • the active material layer 22112 is used to perform chemical reactions in the battery cell 20 during the use of the battery cell 20.
  • the pole ear portion 22121 is bent relative to the first direction X, that is, when the pole piece 221 is not wound to form the electrode assembly 22 and is in an unfolded state, the pole ear portion 22121 is a structure extending along the first direction X. After the pole piece 221 is wound to form the electrode assembly 22, the pole ear portion 22121 needs to be bent so that the pole ear portion 22121 is set at a non-zero angle with the first direction X, so that at least a part of the pole ear portions 22121 among the multiple pole ear portions 22121 can be stacked on each other along the first direction X to form a pole ear 2212.
  • the multiple pole ear portions 22121 of the pole ear 2212 can be processed by smoothing or kneading processes, so that the pole ear portion 22121 is bent relative to the first direction X, and at least a portion of the multiple pole ear portions 22121 is stacked along the first direction X.
  • the thickness direction Z of the pole ear portion can be the same as the first direction X, or can be set at a smaller angle to the first direction X, for example, The angle between the thickness direction Z of the pole ear portion and the first direction X is less than or equal to 10°.
  • the thickness direction Z of the pole ear portion is the same as the first direction X.
  • the extension direction of the main body 2211 of the pole piece 221 is the winding direction Y, so that the multiple pole ear portions 22121 of the pole ear 2212 are arranged at intervals along the extension direction of the main body 2211.
  • the first direction X, the extension direction of the main body 2211 and the thickness direction Z of the pole ear portion are mutually perpendicular structures.
  • the thickness direction of the substrate 22111 is the same as the thickness direction Z of the pole ear portion.
  • the substrate 22111 and the tab 2212 may be an integral structure or a split structure. If the substrate 22111 and the tab 2212 are an integral structure, the multiple tab portions 22121 of the tab 2212 may be formed at one end of the substrate 22111 in the first direction X by cutting or the like; if the substrate 22111 and the tab 2212 are a split structure, the tab 2212 may be connected to one end of the substrate 22111 in the first direction X by welding or clamping or the like, wherein in the embodiment where the substrate 22111 and the tab 2212 are a split structure, the material of the substrate 22111 may be the same as the material of the tab 2212, or may be different from the material of the tab 2212.
  • the pole ear 2212 of the pole piece 221 is a component of the pole piece 221 for outputting or inputting electric energy of the pole piece 221.
  • the pole ear 2212 includes a plurality of pole ear portions 22121 spaced apart along the winding direction Y, so that after the pole piece 221 is wound to form the electrode assembly 22, it is convenient to process the plurality of pole ear portions 22121 of the pole ear 2212 by smoothing or kneading, etc., so that the plurality of pole ear portions 22121 of the pole ear 2212 can be stacked and formed at one end of the electrode assembly 22 in the first direction X, so that the positive or negative electrode of the electrode assembly 22 can be output or input after the pole ear 2212 is connected to the current collecting component 23.
  • the pole ear 2212 includes a plurality of pole ear portions 22121 spaced apart along the winding direction Y, that is, after the pole piece 221 is unfolded, as shown in FIG7 , the plurality of pole ear portions 22121 of the pole ear 2212 are spaced apart along the extension direction of the main body portion 2211; when the pole piece 221 is wound along the winding direction Y to form the electrode assembly 22, the extension direction of the main body portion 2211 is the same as the winding direction Y, and the plurality of pole ear portions 22121 are spaced apart along the winding direction Y.
  • At least a portion of the multiple pole ear portions 22121 are stacked along the first direction X, that is, after the multiple pole ear portions 22121 of the pole ear 2212 are bent relative to the first direction X through smoothing or kneading processes, some of the pole ear portions 22121 may be stacked along the first direction X, or all of the pole ear portions 22121 may be stacked along the first direction X.
  • the extension direction of the main body 2211 is the winding direction Y, so that the multiple pole ear portions 22121 of the pole ear 2212 are arranged at intervals along the winding direction of the pole piece 221, so that when the pole ear 2212 undergoes a smoothing or kneading process, the multiple pole ear portions 22121 of the pole ear 2212 are smoothed from the outer edge of the electrode assembly 22 toward the direction of the central axis of the electrode assembly 22, so that the multiple pole ear portions 22121 of the pole ear 2212 are a structure in which a part of the pole ear portions 22121 and a part of the pole ear portions 22121 are stacked along the first direction X, and another part is stacked along the first direction X with another part of the pole ear portions 22121.
  • the pole ear 2212 can also be a structure in which the multiple pole ear portions 22121 are
  • a protrusion 22121a is formed on at least one side of the pole ear portion 22121 in the thickness direction thereof, that is, in the thickness direction Z of the pole ear portion, the pole ear portion 22121 may be provided with the protrusion 22121a on only one side, or may be provided with the protrusion 22121a on both sides of the pole ear portion 22121.
  • the number of protrusions 22121a provided on the pole ear portion 22121 may be one or more.
  • the protrusion 22121a is provided on only one side of the pole ear portion 22121, and the number of the protrusions 22121a is more than one.
  • the protrusion 22121a on the pole ear portion 22121 there are multiple processing methods for forming the protrusion 22121a on the pole ear portion 22121, for example, adding material on one side of the pole ear portion 22121 by welding or extrusion molding to form the protrusion 22121a on one side of the pole ear portion 22121, or pressing or rolling the protrusion 22121a on one side of the pole ear portion 22121, and forming a groove 22121b on the side of the pole ear portion 22121 away from the protrusion 22121a and corresponding to the protrusion 22121a.
  • the protrusion 22121a is formed on one side of the pole ear portion 22121 by stamping or rolling, so that the pole ear portion 22121 is formed with a groove 22121b on the side away from the protrusion 22121a and corresponding to the protrusion 22121a.
  • the two pole pieces 221 with opposite polarities and the separator 222 are wound along the winding direction Y to form a wound electrode assembly 22, so that the electrode assembly 22 has a main body 223 and two pole tabs 2212, and the pole tabs 2212 and the main body 223 are arranged along the first direction X.
  • the pole lug 2212 is provided with a plurality of pole lug portions 22121 arranged at intervals along the winding direction Y, and the pole lug portion 22121 is bent relative to the first direction X, so that at least a portion of the plurality of pole lug portions 22121 of the pole lug 2212 can be stacked along the first direction X, and a protrusion 22121a is provided on at least one side of the pole lug portion 22121 of the pole lug 2212 to increase the thickness of the plurality of pole lug portions 22121 stacked together, and the phenomenon that the plurality of pole lug portions 22121 of the pole lug have a smaller local thickness after stacking can be alleviated, thereby improving the production quality of the pole lug 2212, reducing the risk of the pole lug 2212 being welded through during subsequent assembly processing, thereby helping to reduce the phenomenon of damage to the electrode assembly 22, and helping to improve the connection stability and assembly quality between the electrode assembly 22 and other components of the battery cell 20, so as to improve the production quality and use
  • Figure 9 is a schematic structural diagram of the pole ear portion 22121 provided in some embodiments of the present application
  • Figure 10 is a front view of the pole ear portion 22121 provided in some embodiments of the present application.
  • at least one side of the pole ear portion 22121 is formed with a plurality of protrusions 22121a.
  • multiple protrusions 22121a are formed on at least one side of the pole ear 22121, that is, in the thickness direction Z of the pole ear 22121, the pole ear 22121 can be provided with multiple protrusions 22121a only on one side, or multiple protrusions 22121a can be provided on both sides of the pole ear 22121.
  • a plurality of protrusions 22121a are provided on only one side of the pole ear 22121.
  • a plurality of protrusions 22121a are provided on only one side of the pole ear 22121.
  • the area with a cavity between two stacked and adjacent pole ear portions 22121 can be effectively increased, which is beneficial to further increase the overall thickness of the pole ear 2212 in the first direction X, and can improve the uniformity of the thickness of the pole ear 2212, thereby further alleviating the phenomenon of the pole ear 2212 being welded through during subsequent assembly and processing.
  • the projection area of the pole ear portion 22121 is S 1
  • the sum of the projection areas of the plurality of protrusions 22121a on the pole ear portion 22121 is S 2 , satisfying S 2 /S 1 ⁇ 0.5.
  • the projection area of the pole ear portion 22121 along the thickness direction Z of the pole ear portion is S 1 , that is, the area of the region defined by the projection of the pole ear portion 22121 along the thickness direction Z of the pole ear portion is S 1 .
  • the sum of the projection areas of the plurality of protrusions 22121a on the pole ear 22121 along the thickness direction Z of the pole ear is S 2 , that is, the sum of the areas defined by the projections of each protrusion 22121a in the thickness direction Z of the pole ear is S 2 .
  • S2 is the sum of the projection areas of the multiple protrusions 22121a on the thickness direction Z of the pole ear; if there are multiple protrusions 22121a on both sides of the pole ear 22121, S2 is the sum of the projection areas of the multiple protrusions 22121a on both sides of the pole ear 22121 on the thickness direction Z of the pole ear.
  • the sum S2 of the projected areas of the plurality of protrusions 22121a on the pole ear portion 22121 may be 0.5 times, 0.55 times, 0.58 times, 0.6 times, 0.65 times, 0.7 times, 0.8 times, etc., of the projected area S1 of the pole ear portion 22121 .
  • S1 and S2 that is, when measuring the projection area S1 of the pole ear 22121 and the sum of the projection areas S2 of the multiple protrusions 22121a on the pole ear 22121, it is necessary to first unfold the pole piece 221 and then measure (as shown in Figure 7) to obtain S1 and S2 , that is, S1 is the projection plane of the pole ear 22121 in the thickness direction Z of the pole ear when the pole piece 221 is in the unfolded state, and S2 is the sum of the projection areas of the multiple protrusions 22121a on the pole ear 22121 in the thickness direction Z of the pole ear when the pole piece 221 is in the unfolded state.
  • the area occupied by the multiple protrusions 22121a on the pole ear portion 22121 is half or more of the pole ear portion 22121, so that there is a sufficient area on the pole ear portion 22121 to be provided with the protrusions 22121a, so that after the multiple pole ear portions 22121 of the pole ear 2212 are stacked along the first direction X, the pole ear 2212 has a sufficient thickness, and the uniformity of the thickness of the pole ear 2212 can be effectively improved, so as to reduce the risk of the pole ear 2212 being welded through during the subsequent assembly process.
  • the pole ear portion 22121 includes a main body region 22121c that does not overlap with the projection of the protrusion 22121a in the thickness direction Z of the pole ear portion, and the protrusion 22121a protrudes from the main body region 22121c along the thickness direction Z of the pole ear portion.
  • the maximum dimension of the pole ear portion 22121 is D 1
  • the thickness of the main body region 22121c is D 2 , satisfying 2 ⁇ D 1 /D 2 ⁇ 8.
  • the pole ear portion 22121 includes a main body area 22121c which does not overlap with the projection of the protrusion 22121a in the thickness direction Z of the pole ear portion, that is, the area of the pole ear portion 22121 where the protrusion 22121a is not formed is the main body area 22121c, so that the projection of the main body area 22121c in the thickness direction Z of the pole ear portion and the projection of the protrusion 22121a in the thickness direction Z of the pole ear portion do not intersect with each other, that is to say, the protrusion 22121a protrudes from one side of the main body portion 2211 in the thickness direction Z of the pole ear portion.
  • the maximum dimension of the pole ear portion 22121 is D 1 , and the thickness of the main area 22121c is D 2 , satisfying 2 ⁇ D 1 /D 2 ⁇ 8, that is, the maximum thickness of the pole ear portion 22121 in its thickness direction is 2 to 8 times the wall thickness of the main area 22121c itself, that is, the maximum thickness of the pole ear portion 22121 after the protrusion 22121a is formed by a process such as stamping or rolling is 2 to 8 times the thickness of the pole ear portion 22121 before the stamping or rolling process is performed.
  • the maximum dimension D1 of the ear portion 22121 may be 2 times, 2.5 times, 2.8 times, 3 times, 3.5 times, 4 times, 5 times, 6 times, 8 times, etc., of the thickness D2 of the main body region 22121c.
  • the pole piece 221 is a positive pole piece
  • the pole ear 2212 corresponding to the pole piece 221 is a positive pole ear
  • the thickness of the pole ear portion 22121 of the positive pole ear before stamping or rolling to form the protrusion 22121a is 10 ⁇ m-16 ⁇ m
  • the pole piece 221 is a negative pole piece
  • the pole ear 2212 corresponding to the pole piece 221 is a negative pole ear
  • the thickness of the pole ear portion 22121 of the negative pole ear before stamping or rolling to form the protrusion 22121a is 4 ⁇ m-10 ⁇ m.
  • the pole ear portion 22121 has a main body area 22121c which does not overlap with the projection of the protrusion 22121a in the thickness direction Z of the pole ear portion, and the protrusion 22121a protrudes from the main body area 22121c in the thickness direction Z of the pole ear portion, that is, the main body area 22121c of the pole ear portion 22121 is an area of the pole ear portion 22121 where the protrusion 22121a is not provided, by setting the maximum size of the pole ear portion 22121 in the thickness direction Z of the pole ear portion to twice the thickness of the main body area 22121c To 8 times, that is, the maximum thickness of the pole ear portion 22121 after being provided with the protrusion 22121a is 2 times to 8 times the thickness of the main area 22121c of the pole ear portion 22121, so that after the pole ear portion 22121 is bent relative to the first direction X, the thickness of the multiple pole ear portions 22121 of the pole ear 2212 stacked on each other along the first direction X can
  • the pole ear portion 22121 is formed with a plurality of rows of protrusions 22121 a , and each row of protrusions 22121 a includes a plurality of protrusions 22121 a arranged at intervals.
  • the pole ear portion 22121 is formed with multiple rows of protrusions 22121a, and each row of protrusions 22121a includes multiple protrusions 22121a arranged at intervals, that is, the multiple protrusions 22121a on the pole ear portion 22121 are arranged in an array, so that the multiple protrusions 22121a are arranged in multiple rows and columns.
  • the multiple protrusions 22121a in each row can be arranged at intervals along the first direction X, or can be arranged at intervals along the winding direction Y (the extension direction of the main body 2211).
  • the shape of the protrusion 22121a can be various.
  • the protrusion 22121a is a hemispherical structure.
  • Figure 11 is a schematic diagram of the structure of the pole ear portion 22121 provided in some other embodiments of the present application
  • Figure 12 is a front view of the pole ear portion 22121 provided in some other embodiments of the present application.
  • the protrusion 22121a can also be a square columnar structure.
  • the structure of the protrusion 22121a is not limited to this.
  • the protrusion 22121a can also be a cylindrical structure, a triangular columnar structure, a pentagonal columnar structure, etc.
  • each row of protrusions 22121a includes multiple protrusions 22121a arranged at intervals, so that the multiple protrusions 22121a on the pole ear portion 22121 are arranged in an array, so that after the multiple pole ear portions 22121 of the pole ear 2212 are stacked along the first direction X, the area with a cavity between two stacked and adjacent pole ear portions 22121 can be effectively increased, which is beneficial to further improve the overall thickness of the pole ear 2212 in the first direction X, and can effectively improve the uniformity of the thickness of the pole ear 2212, so as to reduce the phenomenon of the pole ear 2212 being welded through during the subsequent assembly process.
  • the maximum dimension of the protrusion 22121 a in a direction perpendicular to the thickness direction Z of the pole ear portion is W 1 , satisfying 0.3 mm ⁇ W 1 ⁇ 2 mm.
  • the maximum dimension of the protrusion 22121a in a direction perpendicular to the thickness direction Z of the pole ear portion is W 1 , that is, in any direction in a plane perpendicular to the thickness direction Z of the pole ear portion, the maximum width of the protrusion 22121a is W 1 , that is, in a plane perpendicular to the thickness direction Z of the pole ear portion, the maximum width of the protrusion 22121a in its radial direction is W 1 .
  • W 1 is the diameter of the protrusion 22121a; if the protrusion 22121a is a square columnar structure, W 1 is the length of the diagonal line of the protrusion 22121a.
  • the maximum dimension W1 of the protrusion 22121a in a direction perpendicular to the thickness direction Z of the pole ear portion may be 0.3 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm or 2 mm, etc.
  • the maximum dimension of the protrusion 22121a in the direction perpendicular to the thickness direction Z of the pole ear portion is 0.3 mm to 3 mm, that is, the maximum dimension of the protrusion 22121a in its radial direction is 0.3 mm to 3 mm
  • the phenomenon of excessive processing difficulty caused by the small size of the protrusion 22121a can be alleviated, so as to reduce the processing difficulty of the pole ear portion 22121; on the other hand, the phenomenon of the number of multiple protrusions 22121a on the pole ear portion 22121 being limited due to the large size of the protrusion 22121a can be alleviated.
  • the use of this structure can effectively alleviate the phenomenon that the protrusion 22121a and the groove 22121b of two adjacent pole ear portions 22121 of the pole ear 2212 overlap and offset each other after the multiple pole ear portions 22121 of the pole ear 2212 are stacked on each other due to the excessive size of the protrusion 22121, thereby providing a cavity between the two stacked and adjacent pole ear portions 22121 to increase the overall thickness of the pole ear 2212.
  • Figure 13 is a schematic diagram of the structure of the pole ear portion 22121 provided in some other embodiments of the present application
  • Figure 14 is a front view of the pole ear portion 22121 provided in some other embodiments of the present application.
  • the pole ear portion 22121 is formed with a plurality of protrusions 22121a arranged at intervals, and the two ends of the protrusion 22121a extend to the two ends of the pole ear portion 22121 along a direction perpendicular to the arrangement direction of the plurality of protrusions 22121a.
  • the arrangement direction of the plurality of protrusions 22121 a refers to a direction in which the plurality of protrusions 22121 a are arranged in sequence and at intervals in a plane perpendicular to the thickness direction Z of the pole ear portion.
  • the two ends of the protrusion 22121a extend to the two ends of the pole ear portion 22121 along a direction perpendicular to the arrangement direction of the multiple protrusions 22121a, that is, the protrusion 22121a is a strip structure, and the two ends of the protrusion 22121a extend to the two ends of the pole ear portion 22121 along a direction perpendicular to the arrangement direction of the multiple protrusions 22121a, so that the multiple protrusions 22121a are arranged in a spaced arrangement along the width direction of the protrusion 22121a.
  • the extension direction of the protrusion 22121a of the strip structure can be along the first direction X, or along the winding direction Y (the extension direction of the main body 2211).
  • the protrusion 22121a is a strip-shaped structure with a rectangular cross-section.
  • the protrusion 22121a may also be a strip-shaped structure with a semicircular, pentagonal, or other cross-section.
  • a structure in which a plurality of protrusions 22121a are arranged on the pole ear portion 22121 is realized.
  • the use of such a structure is beneficial to reducing the difficulty of arranging the protrusions 22121a on the pole ear portion 22121, so as to improve the processing efficiency of the pole ear portion 22121.
  • the width of the protrusions 22121 a is W 2 , satisfying 0.3 mm ⁇ W 2 ⁇ 2 mm.
  • the width of the protrusion 22121a is W 2 , that is, in the arrangement direction of the plurality of protrusions 22121a , the maximum size of the protrusion 22121a is W 2 .
  • the width W2 of the protrusion 22121a may be 0.3 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm or 2 mm, etc.
  • the width of the protrusion 22121a in the arrangement direction of the multiple protrusions 22121a is 0.3mm to 3mm, that is, the size of the protrusion 22121a in the direction perpendicular to the extension direction of the protrusion 22121a is 0.3mm to 3mm, on the one hand, the phenomenon of excessive processing difficulty caused by the small width of the protrusion 22121a can be alleviated, so as to reduce the processing difficulty of the pole ear portion 22121; on the other hand, the phenomenon of limited number of multiple protrusions 22121a on the pole ear portion 22121 caused by the excessive width of the protrusion 22121a can be alleviated.
  • the use of this structure can effectively alleviate the phenomenon that the protrusion 22121a and the groove 22121b of two adjacent pole ear portions 22121 of the pole ear 2212 overlap and offset each other after the multiple pole ear portions 22121 of the pole ear 2212 are stacked on each other due to the excessive width of the protrusion 22121a, thereby allowing a cavity to exist between the two stacked and adjacent pole ear portions 22121, so as to meet the requirement that the pole ear 2212 has sufficient thickness after being smoothed.
  • FIG. 15 is a partial cross-sectional view of a pole piece 221 provided in other embodiments of the present application after unfolding
  • FIG. 16 is a cross-sectional view of a pole ear portion 22121 of a pole piece 221 provided in other embodiments of the present application.
  • the pole ear portion 22121 may include a plurality of foils 22121d arranged in a stacked manner, a convex portion 22121e is formed on one side of the foil 22121d, and a concave portion 22121f is formed at a position corresponding to the convex portion 22121e on the other side.
  • the convex portion 22121e of one foil 22121d is accommodated in the concave portion 22121f of the other foil 22121d.
  • the convex portion 22121e located on one side of the pole ear portion 22121 is a protrusion 22121a.
  • the pole ear portion 22121 includes a plurality of foils 22121d stacked, that is, the pole ear portion 22121 is composed of a plurality of foils 22121d, and the plurality of foils 22121d are stacked along the thickness direction Z of the pole ear portion to form the pole ear portion 22121 of the pole ear 2212.
  • the pole ear portion 22121 may include two foils 22121d, one of the two foils 22121d is connected to the main body 2211, and the other foil 22121d is stacked on one side of the foil 22121d connected to the main body 2211 along the thickness direction Z of the pole ear portion.
  • the pole ear portion 22121 may be formed by stacking three, four, five or six foils 22121d. It should be noted that, in some embodiments, the pole ear portion 22121 may also include only one foil material 22121d.
  • a convex portion 22121e is formed on one side of the foil 22121d, and a concave portion 22121f is formed on the other side at a position corresponding to the convex portion 22121e. That is, in the thickness direction Z of the pole ear portion, a convex portion 22121e protruding from the foil 22121d is formed on one side of the foil 22121d, and a concave portion 22121f is formed on the other side at a position corresponding to the convex portion 22121e, so that the convex portion 22121e and the concave portion 22121f are arranged one by one in the thickness direction Z of the pole ear portion.
  • the convex portion 22121e of one foil 22121d is accommodated in the concave portion 22121f of the other foil 22121d, that is, along the thickness direction Z of the pole ear portion, in the two stacked and adjacent foils 22121d, the convex portion 22121e of one foil 22121d and the concave portion 22121b of the other foil 22121d are arranged in a one-to-one correspondence, so that the convex portion 22121e of one foil 22121d can be embedded in the concave portion 22121b of the other foil 22121d, so that the two foils 22121d can fit tightly.
  • the convex portion 22121e located on one side of the pole ear portion 22121 is the protrusion 22121a, that is, the convex portion 22121e of the foil 22121d located on one side among the multiple foils 22121d of the pole ear portion 22121 is the protrusion 22121a on one side of the pole ear portion 22121, and correspondingly, the concave portion 22121f of the foil 22121d located on the other side among the multiple foils 22121d of the pole ear portion 22121 is the groove 22121b on the other side of the pole ear portion 22121.
  • the plurality of foils 22121d of the pole ear portion 22121 may be connected in various ways, such as snap-on, adhesive or welding.
  • the pole ear portion 22121 is configured as a structure in which a plurality of foils 22121d are stacked, and a convex portion 22121e is formed on one side of the foil 22121d, and a concave portion 22121f is formed on the other side, so that after the plurality of foils 22121d are stacked, the convex portions 22121e and the concave portions 22121f of two adjacent foils 22121d are 22121f can be embedded in each other to achieve the formation of a protrusion 22121a on one side of the pole ear portion 22121 in the thickness direction Z of the pole ear portion.
  • the pole ear portion 22121 adopting this structure can effectively increase the thickness and structural strength of the pole ear portion 22121 itself, so that after the multiple pole ear portions 22121 of the pole ear 2212 are stacked along the first direction X, the overall thickness and structural strength of the pole ear 2212 can be further increased, so as to further reduce the risk of the pole ear 2212 being welded through during the subsequent assembly process.
  • a plurality of foils 22121d are welded to form a convex portion 22121e and a concave portion 22121f on the foil 22121d. That is, the convex portion 22121e and the concave portion 22121f are formed correspondingly at the positions where the plurality of foils 22121d are welded to each other, that is, the convex portion 22121e and the concave portion 22121f on the foil 22121d are structures formed by welding the plurality of foils 22121d.
  • the plurality of foils 22121d are connected by ultrasonic roller welding to form convex portions 22121e and concave portions 22121f at the positions where the foils 22121d are welded.
  • the specific connection method of ultrasonic roller welding can be found in the relevant technology and will not be described in detail here.
  • Welding is used to connect multiple stacked foils 22121d, and protrusions 22121e and recesses 22121f are formed at positions where the multiple foils 22121d are welded to each other. This is beneficial to improving the connection strength and stability between the multiple foils 22121d on one hand, and beneficial to reducing the processing difficulty of forming the recesses 22121f and protrusions 22121e on the foil 22121d on the other hand, so as to optimize the production rhythm of the pole piece 221, thereby effectively improving the production efficiency of the pole piece 221.
  • the pole piece 221 may include a main body 2211, a plurality of pole ears 22121 connected to the main body 2211, and the main bodies 2211 and the separators 222 of the two pole pieces 221 are wound along the winding direction Y to form a main body 223.
  • the main body 2211 includes a substrate 22111 and an active material layer 22112 disposed on at least one side of the substrate 22111.
  • the plurality of foils 22121d may include a first foil 22121g and a second foil 22121h that are stacked, the first foil 22121g being connected to one end of the substrate 22111 in the first direction X and being integrally formed with the substrate 22111, and the second foil 22121h being separately disposed from the substrate 22111.
  • multiple pole ear portions 22121 of the pole ear 2212 are connected to one end of the main body 2211 in the first direction X.
  • the pole piece 221 When the pole piece 221 is in an unfolded state, the pole ear 2212 and the main body 2211 are arranged along the first direction X, and the multiple pole ear portions 22121 of the pole ear 2212 are arranged at intervals along the extension direction of the main body 2211; after the pole piece 221 is wound to form the electrode assembly 22, and the pole ear portion 22121 is bent relative to the first direction X, the multiple pole ear portions 22121 of the pole ear 2212 are arranged at intervals along the winding direction Y, and the pole ear portion 22121 is connected to one end of the main body 2211 in the first direction X, and is arranged at a non-zero angle with the main body 2211.
  • An active material layer 22112 is disposed on at least one side of the substrate 22111. That is, the substrate 22111 may be disposed with an active material layer 22112 on only one side, or may be disposed with an active material layer 22112 on both sides of the substrate 22111. For example, in FIG15 , an active material layer 22112 is disposed on both sides of the substrate 22111.
  • the active material layer 22112 is the area where chemical reactions occur in the battery cell 20, and mainly relies on the movement of metal ions between the active material layers 22112 of the two pole pieces 221 to work.
  • the substrate 22111 may also be coated with an insulating protective layer, and the insulating protective layer is arranged at one end or both ends of the active material layer 22112 along the first direction X to protect and separate the active material layer 22112.
  • the insulating protective layer may not be arranged at one end of the active material layer 22112 in the first direction X, that is, only the active material layer 22112 is coated on the substrate 22111.
  • the material of the active material layer 22112 of the main body 2211 corresponding to the electrode 221 may be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc.; if the electrode 221 is a negative electrode, the material of the active material layer 22112 of the main body 2211 corresponding to the electrode 221 may be carbon or silicon, etc.
  • the first foil material 22121g is connected to one end of the substrate 22111 in the first direction X, and is formed integrally with the substrate 22111, that is, the first foil material 22121g is connected to the substrate 22111, and the first foil material 22121g is a structure formed by cutting and processing on the substrate 22111.
  • the first foil material 22121g and the substrate 22111 may also be a split structure, for example, the first foil material 22121g is connected to one end of the substrate 22111 in the first direction X by welding or the like, and similarly, the first foil material 22121g and the substrate 22111 may also be indirectly connected, for example, the first foil material 22121g and the substrate 22111 are indirectly connected through other conductive components.
  • one end of the first foil 22121g in a direction perpendicular to the thickness direction Z of the electrode ear portion is connected to one end of the substrate 22111 in the first direction X.
  • the thickness direction Z of the pole ear portion and the first direction X are perpendicular to each other. Then, one end of the first foil 22121g in a direction perpendicular to the thickness direction Z of the pole ear portion is connected to one end of the substrate 22111 in the first direction X, that is, one end of the first foil 22121g in the first direction X is connected to one end of the substrate 22111 in the first direction X (see Figure 15).
  • the second foil material 22121h is separately provided from the substrate 22111, that is, the second foil material 22121h and the substrate 22111 are two independent parts.
  • the second foil material 22121h is stacked and connected to the first foil material 22121g on one side of the thickness direction Z of the pole ear portion.
  • the first foil material 22121g may be provided with the second foil material 22121h only on one side, or may be provided with the second foil material 22121h on both sides, and the number of the second foil material 22121h provided on one side of the first foil material 22121g may be one or more.
  • the multiple foils 22121d include a first foil 22121g integrally formed with the substrate 22111 of the main body 2211 of the electrode piece 221.
  • an area without an active material layer 22112 may be reserved on the substrate 22111, so that the first foil 22121g can be set on the area, and then the second foil 22121h can be stacked on one side of the first foil 22121g, so that the first foil 22121g can provide a connection support point for the second foil 22121h, so as to achieve an increase in the thickness and structural strength of the pole ear portion 22121.
  • the pole piece 221 with such a structure can effectively reduce the process difficulty of connecting the pole ear portion 22121 to the substrate 22111, which is beneficial to improving the production efficiency of the electrode assembly 22.
  • the substrate 22111 includes a coating area 22111a and a spacer area 22111b, the coating area 22111a and the spacer area 22111b are arranged along a first direction X, the active material layer 22112 is disposed in the coating area 22111a, and the spacer area 22111b connects the coating area 22111a and the first foil material 22121g.
  • the spacer area 22111b of the substrate 22111 is an area on the substrate 22111 that is not coated with the active material layer 22112.
  • the coating area 22111a and the spacer area 22111b are arranged along the first direction X, and the spacer area 22111b connects the coating area 22111a and the first foil 22121g. That is, when the electrode 221 is unfolded Finally, in the first direction X, the spacing area 22111b is connected between the coating area 22111a and the first foil 22121g.
  • the spacer 22111b is a blank area on the substrate 22111.
  • the spacer 22111b on the substrate 22111 that is not coated with the active material layer 22112 may also be coated with an insulating protective layer, etc., to protect the active material layer 22112.
  • the substrate 22111 of the main body 2211 may not be provided with the spacer 22111b, that is, the first foil material 22121g is directly connected to the coating area 22111a of the substrate 22111, that is, the active material layer 22112 completely covers one side of the substrate 22111, so that the first foil material 22121g is connected to one end of the substrate 22111.
  • the first foil 22121g of the pole ear 22121 can be connected to the coating area 22111a through the spacer area 22111b, so that the pole ear 22121 and the active material layer 22112 are spaced apart in the first direction X.
  • the electrode assembly 22 with such a structure can, on the one hand, isolate the stress generated during the bending process of the pole ear 22121 relative to the first direction X through the spacer area 22111b, so as to reduce the risk of fracture of the active material layer 22112 arranged on the coating area 22111a.
  • the influence of the welding process on the active material layer 22112 can be reduced, thereby alleviating the phenomenon of damage to the active material layer 22112, which is beneficial to improving the production quality of the electrode assembly 22.
  • the thickness of the first foil 22121g is D 3
  • the thickness of the second foil 22121h is D 4 , satisfying 0.5 ⁇ D 3 /D 4 ⁇ 2.
  • the thickness D3 of the first foil 22121g is the wall thickness of the first foil 22121g itself, that is, the thickness D3 of the first foil 22121g is the thickness of the area of the first foil 22121g where the protrusion 22121e and the recess 22121f are not formed, that is, the thickness D3 of the first foil 22121g is the thickness of the first foil 22121g before the protrusion 22121e and the recess 22121f are formed.
  • the thickness D4 of the second foil 22121h is the wall thickness of the second foil 22121h itself, that is, the thickness D4 of the second foil 22121h is the thickness of the area of the first foil 22121g where the protrusions 22121e and the recesses 22121f are not formed, that is, the thickness D4 of the second foil 22121h is the thickness of the second foil 22121h before the protrusions 22121e and the recesses 22121f are formed.
  • the thickness D 3 of the first foil 22121 g may be 0.5 times, 0.6 times, 0.75 times, 0.8 times, 1 times, 1.2 times, 1.5 times, 2 times, etc., of the thickness D 4 of the second foil 22121 h .
  • a first foil 22121g with a thickness of 12 ⁇ m was selected for the experiment, and the thickness of the second foil 22121h was set to different sizes for the experiment, so as to measure the influence of the thickness ratio of the first foil 22121g to the second foil 22121h on the mutual welding assembly of the first foil 22121g and the second foil 22121h under different conditions.
  • the experimental results are as follows:
  • the ratio of the thickness D3 of the first foil 22121g to the thickness D4 of the second foil 22121h is set to be less than or equal to 2.
  • the ratio of the thickness D3 of the first foil 22121g to the thickness D4 of the second foil 22121h is set to be greater than or equal to 0.5.
  • the thickness of the first foil 22121g is 0.5 to 2 of the thickness of the second foil 22121h, that is, the thickness of the first foil 22121g is 0.5 to 2 times the thickness of the second foil 22121h, the problem of the difficulty of assembling the first foil 22121g and the second foil 22121h being too difficult due to the large difference between the thickness of the first foil 22121g and the thickness of the second foil 22121h can be alleviated, so as to reduce the difficulty of processing the pole ear portion 22121 of this structure.
  • the problem of the second foil 22121h being damaged during the mutual welding process due to the thickness of the first foil 22121g being too large compared to the thickness of the second foil 22121h can be alleviated
  • the problem of the first foil 22121g being damaged during the mutual welding process due to the thickness of the second foil 22121h being too large compared to the thickness of the first foil 22121g can be alleviated.
  • the end of the second foil 22121h close to the substrate 22111 does not exceed the end of the first foil 22121g connected to the substrate 22111. It should be noted that when the pole piece 221 is in an unfolded state, in the first direction X, the end of the second foil 22121h close to the substrate 22111 does not exceed the end of the first foil 22121g connected to the substrate 22111.
  • the end of the second foil 22121h close to the substrate 22111 does not exceed the end of the first foil 22121g connected to the substrate 22111. That is, the end of the first foil 22121g connected to the substrate 22111 may be flush with the second foil 22121h, or may extend out of the second foil.
  • the first foil 22121 g is connected to one end of the substrate 22111 and extends out from the second foil 22121 h to one end of the substrate 22111 .
  • the second foil 22121h is an end close to the substrate 22111 in the first direction X and does not exceed the end of the first foil 22121g connected to the substrate 22111 in the first direction X. If the pole piece 221 is wound to form the electrode assembly 22, and the multiple pole ear portions 22121 of the pole ear are flattened or kneaded and stacked on one end of the electrode assembly 22, the second foil 22121h is perpendicular to the first direction X and points to the end of the first foil 22121g connected to the substrate 22111 along the end of the first foil 22121g away from the substrate 22111 and does not exceed the end of the first foil 22121g connected to the substrate 22111.
  • the interference effect between the second foil 22121h and the active material layer 22112 arranged on one side of the substrate 22111 can be effectively alleviated, thereby reducing the risk of the active material layer 22112 being damaged by the second foil 22121h.
  • the distance between the end of the first foil 22121g away from the substrate 22111 and the end of the second foil 22121h away from the substrate 22111 is L, satisfying that L ⁇ 2mm. It should be noted that when the pole piece 221 is in the unfolded state, L is the distance between the end of the first foil 22121g away from the substrate 22111 and the end of the second foil 22121h away from the substrate 22111 in the first direction X.
  • the distance between one end of the first foil 22121g away from the substrate 22111 and one end of the second foil 22121h away from the substrate 22111 is L, that is, one end of the first foil 22121g away from the substrate 22111 and one end of the second foil 22121h away from the substrate 22111 can be flush with each other or staggered with each other. If the end of the first foil 22121g away from the substrate 22111 and the end of the second foil 22121h away from the substrate 22111 are staggered, then the distance between the end of the first foil 22121g away from the substrate 22111 and the end of the second foil 22121h away from the substrate 22111 is less than or equal to 2 mm.
  • the distance between the end of the first foil 22121g away from the substrate 22111 and the end of the second foil 22121h away from the substrate 22111 is L, and the end of the first foil 22121g away from the substrate 22111 may exceed the end of the second foil 22121h away from the substrate 22111, and the dimension of the first foil 22121g exceeding the second foil 22121h is less than or equal to 2mm; or the end of the second foil 22121h away from the substrate 22111 exceeds the end of the first foil 22121g away from the substrate 22111, and the dimension of the second foil 22121h exceeding the first foil 22121g is less than or equal to 2mm.
  • L can be 0mm, 0.2mm, 0.5mm, 1mm, 1.5mm or 2mm, etc.
  • one end of the first foil 22121g away from the substrate 22111 exceeds one end of the second foil 22121h away from the substrate 22111, and a size L is defined as the portion of the first foil 22121g that exceeds the second foil 22121h.
  • the distance between the end of the first foil 22121g away from the substrate 22111 and the end of the second foil 22121h away from the substrate 22111 in the direction perpendicular to the thickness direction Z of the pole ear portion is less than or equal to 2 mm, that is, the dimension of the end of the first foil 22121g away from the substrate 22111 exceeding the end of the second foil 22121h away from the substrate 22111 by less than or equal to 2 mm, or the end of the second foil 22121h away from the substrate 22111 exceeding the first foil 22121g by less than or equal to 2 mm.
  • the dimension of the end of the foil 22121g away from the substrate 22111 is less than or equal to 2 mm, thereby alleviating the phenomenon that the first foil 22121g exceeds the second foil 22121h too much or the second foil 22121h exceeds the first foil too much due to the length of the first foil 22121g or the length of the second foil 22121h being too large, resulting in the ear portion 22121 being too long or being inverted into the electrode assembly 22, which is beneficial to improving the production quality and reliability of the electrode assembly 22.
  • the first foil 22121g and the second foil 22121h are made of the same material. In other words, the first foil 22121g and the second foil 22121h are made of the same material.
  • the material of the first foil 22121g and the material of the second foil 22121h can be various, for example, copper, iron, aluminum, steel, aluminum alloy, etc.
  • the process difficulty of connecting the first foil 22121g and the second foil 22121h can be reduced.
  • the main body 2211 includes a substrate 22111 and an active material layer 22112 disposed on at least one side of the substrate 22111, the substrate 22111 includes a coating area 22111a and a spacing area 22111b, the coating area 22111a and the spacing area 22111b are arranged along the first direction X, the active material layer 22112 is disposed in the coating area 22111a, and the spacing area 22111b connects the coating area 22111a and the pole ear portion 22121.
  • multiple pole ear portions 22121 of the pole ear 2212 are connected to one end of the main body 2211 in the first direction X.
  • the pole piece 221 When the pole piece 221 is in an unfolded state, the pole ear 2212 and the main body 2211 are arranged along the first direction X, and the multiple pole ear portions 22121 of the pole ear 2212 are arranged at intervals along the extension direction of the main body 2211; after the pole piece 221 is wound to form the electrode assembly 22, and the pole ear portion 22121 is bent relative to the first direction X, the multiple pole ear portions 22121 of the pole ear 2212 are arranged at intervals along the winding direction Y, and the pole ear portion 22121 is connected to one end of the main body 2211 in the first direction X, and is arranged at a non-zero angle with the main body 2211.
  • An active material layer 22112 is disposed on at least one side of the substrate 22111, that is, the substrate 22111 may be provided with an active material layer 22112 on one side or on both sides.
  • active material layers 22112 are disposed on both sides of the substrate 22111.
  • the spacer 22111b of the substrate 22111 is an area on the substrate 22111 that is not coated with the active material layer 22112.
  • the coating area 22111a and the spacer 22111b are arranged along the first direction X, and the spacer 22111b connects the coating area 22111a and the pole ear portion 22121, that is, in the first direction X, the spacer 22111b is connected between the coating area 22111a and the pole ear portion 22121.
  • the pole ear portion 22121 may be a structure including only one foil material 22121d, or the pole ear portion 22121 may be a structure including a plurality of foil materials 22121d stacked.
  • the spacer 22111b is a blank area on the substrate 22111. It should be noted that, in some embodiments, the spacer 22111b on the substrate 22111 that is not coated with the active material layer 22112 may also be coated with an insulating protective layer, etc., to protect the active material layer 22112. Of course, in other embodiments, the spacer 22111b may not be provided on the substrate 22111 of the main body 2211, that is, the pole ear 22121 is directly connected to the coating area 22111a of the substrate 22111, that is, the active material layer 22112 completely covers one side of the substrate 22111, so that the pole ear 22121 is connected to one end of the substrate 22111.
  • the pole ear portion 22121 can be connected to the coating area 22111a through the spacer area 22111b, so that the pole ear portion 22121 and the active material layer 22112 are spaced apart in the first direction X.
  • the electrode assembly 22 with such a structure can, on the one hand, isolate the stress generated during the bending process of the pole ear portion 22121 relative to the first direction X through the spacer area 22111b, so as to reduce the risk of fracture of the active material layer 22112 arranged on the coating area 22111a.
  • the influence of the welding process on the active material layer 22112 can be reduced, thereby alleviating the phenomenon of damage to the active material layer 22112, which is beneficial to improving the production quality of the electrode assembly 22.
  • the pole ear portion 22121 and the spacer region 22111 b are integrally formed.
  • the pole ear portion 22121 and the spacer 22111b are integrally formed, that is, the pole ear portion 22121 includes only one foil material 22121d, and the pole ear portion 22121 is a structure formed by cutting and processing on the substrate 22111.
  • the pole ear portion 22121 and the substrate 22111 may also be a split structure, for example, the pole ear portion 22121 is connected to one end of the substrate 22111 in the first direction X by welding or the like.
  • the pole ear portion 22121 may also be a structure integrally formed with the substrate 22111, that is, the pole ear portion 22121 is integrally formed with the coating area 22111a of the substrate 22111.
  • the pole ear portion 22121 By setting the pole ear portion 22121 as a structure that is integrally formed with the spacer area 22111b of the substrate 22111, the pole ear portion 22121 can be a part of the substrate 22111 during the actual production process. After reserving an area on the substrate 22111 where the active material layer 22112 is not set, the pole ear portion 22121 can be set in the area, thereby reducing the process difficulty of connecting the pole ear portion 22121 to the substrate 22111, which is beneficial to improving the production efficiency of the electrode assembly 22.
  • a groove 22121 b is formed on a side of the pole ear portion 22121 away from the protrusion 22121 a and corresponding to the position of the protrusion 22121 a .
  • a groove 22121b is formed on the side of the pole ear portion 22121 away from the protrusion 22121a and corresponding to the position of the protrusion 22121a. That is to say, a protrusion 22121a is formed on one side of the pole ear portion 22121, and a groove 22121b is formed on the other side corresponding to the position of the protrusion 22121a, so that the protrusion 22121a and the groove 22121b are arranged one by one in the thickness direction Z of the pole ear portion.
  • the ear portion 22121 of this structure may be processed in a variety of ways, such as stamping or rolling.
  • the pole ear 22121 of this structure can be formed with the protrusion 22121a on the pole ear 22121 through a process such as stamping or rolling.
  • a process such as stamping or rolling.
  • it is beneficial to reduce the processing difficulty of the pole ear 22121 and to improve the processing efficiency of the pole ear 22121.
  • FIG17 is a cross-sectional view of a plurality of pole ear portions 22121 of a pole ear 2212 of an electrode assembly 22 provided in some embodiments of the present application after being stacked.
  • the protrusion 22121a of one pole ear portion 22121 is staggered with the groove 22121b of the other pole ear portion 22121.
  • the protrusion 22121a of one pole ear portion 22121 and the groove 22121b of the other pole ear portion 22121 are staggered, that is, in two adjacent pole ear portions 22121, the protrusion 22121a of one pole ear portion 22121 and the groove 22121b of the other pole ear portion 22121 are not aligned in the first direction X.
  • the protrusion 22121a of one pole ear portion 22121 and the groove 22121b of the other pole ear portion 22121 in two adjacent pole ear portions 22121 in the first direction X as mutually staggered structures, the phenomenon of mutual offsetting of the protrusion 22121a and the groove 22121b after overlapping can be effectively alleviated, so that the pole ear 2212 has sufficient thickness in the first direction X, which is beneficial to reduce the risk of the pole ear 2212 of the electrode assembly 22 being welded through during the subsequent assembly process.
  • the thickness of the tab 2212 is D 5 , satisfying 0.2 mm ⁇ D 5 ⁇ 2.5 mm.
  • the thickness of the tab 2212 is D 5 , that is, after the multiple tab portions 22121 of the tab 2212 are bent relative to the first direction X and stacked on one end of the main body 223 of the electrode assembly 22 in the first direction X through smoothing or kneading processes, the size of the tab 2212 in the first direction X is D 5 .
  • the thickness D5 of the tab 2212 may be 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.8 mm, 1 mm, 1.5 mm, 2 mm, or 2.5 mm, etc.
  • the thickness of the pole lug 2212 in the first direction X is set to 0.2 mm to 2.5 mm, on the one hand, the risk of the pole lug 2212 being welded through due to the pole lug 2212 being too thin can be alleviated, thereby reducing the risk of the electrode assembly 22 being damaged during subsequent assembly.
  • the phenomenon of the pole lug 2212 occupying too much space due to the pole lug 2212 being too thick can be alleviated, which is beneficial for optimizing the internal space of the battery cell 20 having such an electrode assembly 22, thereby improving the energy density of the battery cell 20.
  • two electrode tabs 2212 are respectively disposed at two ends of the main body 223 of the electrode assembly 22 .
  • the polarities of the two pole pieces 221 are opposite, that is, the two pole pieces 221 are respectively the positive pole piece and the negative pole piece of the electrode assembly 22 .
  • the two pole ears 2212 are respectively arranged at the two ends of the main body 223 of the electrode assembly 22, that is, the pole ears 2212 of the two pole pieces 221 with opposite polarities are respectively formed at the two ends of the electrode assembly 22 in the first direction X, so that the positive pole ear and the negative pole ear are respectively formed at the two ends of the electrode assembly 22 in the first direction X to output or input the positive and negative poles of the electrode assembly 22.
  • the electrode assembly 22 By respectively arranging the two pole ears 2212 of the electrode assembly 22 at the two ends of the main body 223 of the electrode assembly 22 in the first direction X, so that the two pole ears 2212 are respectively formed at the two ends of the electrode assembly 22 in the first direction X, it is convenient to assemble the electrode assembly 22 later, which is beneficial to reduce the difficulty of assembling the battery cell 20 with such an electrode assembly 22, and can reduce the interference or mutual contact between the two pole ears 2212, thereby helping to reduce the risk of short circuit of the electrode assembly 22.
  • the main body 223 of the electrode assembly 22 is cylindrical.
  • the structure of the main body 223 of the electrode assembly 22 is not limited thereto.
  • the main body 223 of the electrode assembly 22 may also be a columnar structure with an elliptical cross section.
  • the electrode assembly 22 is arranged in a cylindrical structure, so that the battery cell 20 with a cylindrical structure can be formed in the subsequent processing.
  • the present application also provides a battery cell 20, including a housing 21 and a The electrode assembly 22 of any of the above solutions is accommodated in the housing 21.
  • the housing 21 may include a shell 211 and an end cover 212 .
  • the shell 211 is a hollow structure with an opening 2111 on one side.
  • the end cover 212 closes the opening 2111 of the shell 211 to form a sealed space for accommodating the electrode assembly 22 .
  • the shell 211 may be in various shapes, such as a cylinder, a cuboid, etc.
  • the shape of the shell 211 may be determined according to the specific shape of the electrode assembly 22.
  • the electrode assembly 22 is cylindrical, and correspondingly, may be a cylindrical structure.
  • the housing 21 may further include a positive electrode terminal and a negative electrode terminal, wherein the positive electrode terminal is mounted on the end cap 212, and the negative electrode terminal is mounted on the end of the housing 211 opposite to the end cap 212.
  • the positive electrode terminal may be mounted on the end of the housing 211 opposite to the end cap 212, and the negative electrode terminal may be mounted on the end cap 212.
  • the positive electrode terminal and the negative electrode terminal are respectively used to electrically connect to the pole ears 2212 at both ends of the electrode assembly 22 in the first direction X, so as to output or input the electrical energy of the battery cell 20.
  • the materials of the positive electrode terminal and the negative electrode terminal can be various, such as copper, iron, aluminum, steel or aluminum alloy.
  • the positive electrode terminal and the negative electrode terminal may be directly connected to the tab 2212 of the electrode assembly 22, for example, by welding or abutting, or the positive electrode terminal and the negative electrode terminal may be indirectly connected to the tab 2212 of the electrode assembly 22, for example, by abutting or welding the positive electrode terminal and the negative electrode terminal to the electrode assembly 22 through other components.
  • the battery cell 20 may further include a current collecting member 23 , which is disposed between the housing 21 and the tab 2212 along the first direction X, and the current collecting member 23 connects the housing 21 and the tab 2212 .
  • the current collecting component 23 serves to connect the electrode ear 2212 of the electrode assembly 22 with the positive electrode terminal or the negative electrode terminal to achieve electrical connection between the electrode assembly 22 and the positive electrode terminal or the negative electrode terminal.
  • the material of the current collecting component 23 can be various, such as copper, iron, aluminum, steel or aluminum alloy.
  • the battery cell 20 includes two current collecting members 23 , which are respectively arranged at both ends of the electrode assembly 22 in the first direction X, one current collecting member 23 connecting the positive electrode terminal and one pole ear 2212 of the electrode assembly 22 , and the other current collecting member 23 connecting the negative electrode terminal and the other pole ear 2212 of the electrode assembly 22 , so as to realize the input or output of electrical energy of the battery cell 20 .
  • the current collecting component 23 and the pole tab 2212 may be connected in various ways, such as welding, bonding or abutting.
  • the current collecting component 23 and the pole tab 2212 are connected by welding.
  • the outer shell 21 and the pole ear 2212 of the electrode assembly 22 are connected through the current collecting component 23, so that the input or output of electric energy of the battery cell 20 can be realized.
  • This structure is simple, easy to implement, and helps to reduce the difficulty of assembly between the pole ear 2212 and the outer shell 21.
  • FIG. 18 is a schematic diagram of the connection between the current collecting member 23 and the pole tab 2212 of the electrode assembly 22 provided in some embodiments of the present application.
  • the current collecting member 23 is welded to the pole tab 2212, and along the first direction X, the thickness of the pole tab 2212 is D5 , and the thickness of the current collecting member 23 is D6 , satisfying that D6 ⁇ 1.5D5 .
  • the current collecting member 23 is disposed at one end of the electrode assembly 22 in the first direction X, so that the current collecting member 23 can be welded to the electrode tab 2212 at one end of the electrode assembly 22 in the first direction X.
  • the thickness of the tab 2212 is D 5 , that is, after the multiple tab portions 22121 of the tab 2212 are bent relative to the first direction X by smoothing or kneading processes and stacked on one end of the main body 223 of the electrode assembly 22 in the first direction X, the size of the tab 2212 in the first direction X is D 5 .
  • the thickness of the current collecting member 23 is D 6 , that is, the dimension of the current collecting member 23 in the first direction X is D 6 .
  • the thickness of the current collecting member 23 is less than or equal to 1.5 times the thickness of the tab 2212.
  • the thickness D 6 of the current collecting member 23 may be 1.5 times, 1.4 times, 1.2 times, 1.25 times, 1 times, 0.9 times, 0.8 times, 0.75 times, or 0.5 times the thickness D 5 of the tab 2212.
  • the thickness of the current collecting member 23 and the thickness of the tab 2212 were set to different sizes, so that the ratio of the thickness of the current collecting member 23 to the thickness of the tab 2212 was different, so as to measure the influence of the ratio of the thickness of the current collecting member 23 to the thickness of the tab 2212 on the welding assembly process of the current collecting member 23 and the tab 2212 under different conditions.
  • the experimental results are as follows:
  • the pole lug 2212 may be welded through, resulting in poor assembly quality of the current collecting component 23 and the pole lug 2212, which cannot meet assembly requirements.
  • the ratio of the thickness of the current collecting component 23 to the thickness of the pole lug 2212 is less than or equal to 1.5, the phenomenon of the pole lug 2212 being welded through can be alleviated, which is beneficial to improving the assembly quality of the current collecting component 23 and the pole lug 2212. Therefore, the ratio of the thickness of the current collecting component 23 to the thickness of the pole lug 2212 is set to be less than or equal to 1.5, that is, D 6 ⁇ 1.5D 5 .
  • the thickness of the current collecting component 23 in the first direction X is less than or equal to 1.5 times the thickness of the pole tab 2212 in the first direction X, the phenomenon of excessive welding power required for welding the current collecting component 23 and the pole tab 2212 due to the thickness of the current collecting component 23 being too large than the thickness of the pole tab 2212 can be alleviated, thereby effectively reducing the risk of the pole tab 2212 being welded through, thereby reducing the phenomenon of damage to the electrode assembly 22, which is beneficial to improving the production quality of the battery cell 20.
  • the current collecting member 23 is welded to the pole lug 2212 to form a weld mark 24 .
  • the weld mark 24 covers the protrusion 22121 a of at least one pole lug portion 22121 .
  • the weld mark 24 covers the protrusion 22121a of at least one pole ear portion 22121 , that is, in the first direction X, the position where the current collecting component 23 and the pole ear 2212 are welded to each other is arranged corresponding to the protrusion 22121a of at least one pole ear portion 22121 .
  • the weld mark 24 formed by welding the current collecting component 23 and the pole lug 2212 to each other is set to cover the protrusion 22121a of at least one pole lug portion 22121 in the first direction X, so that the position where the current collecting component 23 and the pole lug 2212 are welded to each other is located in the area of the pole lug 2212 thickened by the protrusion 22121a, which helps to further reduce the risk of the pole lug 2212 being welded through during the assembly process.
  • a battery 100 is further provided, and the battery 100 includes a battery cell 20 of any of the above schemes.
  • the battery 100 may further include a box body 10 , in which the battery cells 20 are accommodated.
  • the battery cell 20 contained in the box body 10 may be one or more.
  • the battery 100 includes a plurality of battery cells 20, and the plurality of battery cells 20 are contained in the box body 10.
  • the plurality of battery cells 20 may be connected in series, in parallel, or in mixed connection.
  • Mixed connection means that the plurality of battery cells 20 are both connected in series and in parallel.
  • the plurality of battery cells 20 may be directly connected in series, in parallel, or in mixed connection, and then the whole formed by the plurality of battery cells 20 is contained in the box body 10.
  • an electric device is further provided, the electric device comprises a battery 100 according to any of the above schemes, and the battery 100 is used to provide electric energy to the electric device.
  • the power-consuming device may be any of the aforementioned devices or systems using the battery 100 .
  • the present application provides an electrode assembly 22, which is a winding structure, and includes two pole pieces 221 with opposite polarities and a separator 222 for isolating the two pole pieces 221, and the two pole pieces 221 and the separator 222 are wound along a winding direction Y to form a main body 223 and two pole ears 2212, and the pole ears 2212 of the two pole pieces 221 are respectively arranged at two ends of the main body 223 in the first direction X.
  • the pole piece 221 includes a main body 2211 and a pole ear 2212, and the extension direction of the main body 2211 is consistent with the winding direction Y.
  • the main body 2211 includes a substrate 22111 and an active material layer 22112 arranged on both sides of the substrate 22111.
  • the substrate 22111 includes a coating area 22111a and a spacing area 22111b.
  • the coating area 22111a and the spacing area 22111b are arranged along a first direction X, and the active material layer 22112 is arranged in the coating area 22111a.
  • the pole lug 2212 includes a plurality of pole lug portions 22121, the pole lug portion 22121 is connected to one end of the spacing area 22111b away from the coating area 22111a in the first direction X, and the plurality of pole lug portions 22121 are spaced apart along the winding direction Y, and at least a portion of the plurality of pole lug portions 22121 are stacked along the first direction X to form a pole lug 2212 at one end of the electrode assembly 22 along the first direction X, and the thickness of the pole lug 2212 in the first direction X is D 5 , satisfying 0.2 mm ⁇ D 5 ⁇ 2.5 mm.
  • a plurality of protrusions 22121a are formed on one side of the pole ear portion 22121, and a groove 22121b is formed on the side of the pole ear portion 22121 away from the protrusion 22121a and corresponding to the position of the protrusion 22121a.
  • the protrusion 22121a of one pole ear portion 22121 and the groove 22121b of the other pole ear portion 22121 are staggered.
  • the projection area of the pole ear portion 22121 is S 1
  • the sum of the projection areas of the multiple protrusions 22121a on the pole ear portion 22121 is S 2 , satisfying S 2 /S 1 ⁇ 0.5
  • the pole ear portion 22121 includes a main body area 22121c that does not overlap with the projection of the protrusion 22121a in the thickness direction Z of the pole ear portion, and along the thickness direction Z of the pole ear portion, the maximum size of the pole ear portion 22121 is D 1
  • the thickness of the main body area 22121c is D 2 , satisfying 2 ⁇ D 1 /D 2 ⁇ 8.
  • the protrusions 22121a are hemispherical structures, the multiple protrusions 22121a include multiple rows of protrusions 22121a arranged at intervals, each row of protrusions 22121a includes multiple protrusions 22121a arranged at intervals, and the diameter of the protrusions 22121a in a direction perpendicular to the thickness direction Z of the pole ear portion is W 1 , satisfying 0.3mm ⁇ W 1 ⁇ 2mm.
  • the present application provides a battery cell 20, which includes a housing 21, an electrode assembly 22, and a current collecting member 23.
  • the electrode assembly 22 is accommodated in the housing 21.
  • the current collecting member 23 is disposed between the housing 21 and the pole tab 2212.
  • the current collecting member 23 is welded to the pole tab 2212 to form a weld mark 24.
  • the weld mark 24 covers the protrusion 22121a of at least one pole tab portion 22121.
  • the thickness of the pole tab 2212 is D 5
  • the thickness of the current collecting member 23 is D 6 , satisfying that D 6 ⁇ 1.5D 5 .

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Abstract

本申请提供了一种电极组件、电池单体、电池及用电装置,属于电池技术领域。其中,电极组件包括极性相反的两个极片和用于隔离两个极片的隔离件,两个极片和隔离件沿卷绕方向卷绕后形成主体和两个极耳。极耳和主体沿第一方向设置,极耳包括沿卷绕方向间隔设置的多个极耳部,极耳部相对于第一方向弯折,多个极耳部的至少一部分沿第一方向层叠设置,且极耳部在其厚度方向上的至少一侧形成有凸起。通过在极耳部上设置凸起,使得极耳部弯折后能够增加层叠在一起的多个极耳部的厚度,且能够缓解极耳的局部厚度较小的现象,以降低极耳在后续装配过程中被焊穿的风险,有利于减少电极组件被损坏的现象,以提升具有这种电极组件的电池单体的生产质量。

Description

电极组件、电池单体、电池及用电装置 技术领域
本申请涉及电池技术领域,具体而言,涉及一种电极组件、电池单体、电池及用电装置。
背景技术
近些年,新能源汽车有了飞跃式的发展,在电动汽车领域,动力电池作为电动汽车的动力源,起着不可替代的重要作用。随着新能源汽车的大力推广,对动力电池产品的需求也日益增长。其中,电池包括电池单体,电池单体的外壳内设置有电极组件,通过将电极组件和外壳相连后能够实现电池单体的电能的输入或输出。但是,现有的电池单体在生产装配的过程中常常会出现电极组件被损坏的现象,从而导致电池单体的生产质量较差,不利于提高电池单体的产品合格率。
发明内容
本申请实施例提供一种电极组件、电池单体、电池及用电装置,能够有效电池单体的生产质量。
第一方面,本申请实施例提供一种电极组件,包括极性相反的两个极片和用于隔离两个所述极片的隔离件,两个所述极片以及所述隔离件沿卷绕方向卷绕后形成主体和两个极耳;其中,所述极耳和所述主体沿所述第一方向设置,所述极耳包括沿所述卷绕方向间隔设置的多个极耳部,所述极耳部相对于所述第一方向弯折设置,所述多个极耳部的至少一部分沿所述第一方向层叠设置,且所述极耳部在其厚度方向上的至少一侧形成有凸起。
在上述技术方案中,极性相反的两个极片和隔离件沿卷绕方向卷绕形成卷绕式结构的电极组件,以使电极组件具有主体和两个极耳,且极耳和主体沿第一方向设置。其中,极耳设置有沿卷绕方向间隔排布的多个极耳部,且极耳部相对于第一方向弯折设置,以使极耳的多个极耳部中的至少一部分能够沿第一方向层叠,通过在极耳的极耳部的至少一侧设置凸起,以增加层叠在一起的多个极耳部的厚度,且能够缓解极耳的多个极耳部在层叠后出现局部厚度较小的现象,从而能够改善极耳的生产质量,以降低极耳在后续装配加工的过程中出现被焊穿的风险,进而有利于减少电极组件被损坏的现象,且有利于提升电极组件与电池单体的其他部件之间的连接稳定性和装配质量,以提升具有这种电极组件的电池单体的生产质量和使用稳定性。
在一些实施例中,沿所述极耳部的厚度方向,所述极耳部的至少一侧形成有多个所述凸起。
在上述技术方案中,通过在极耳部的至少一侧上设置多个凸起,从而在极耳部相对于第一方向弯折并使得多个极耳部沿第一方向层叠设置后能够有效增加相互层叠且相邻的两个极耳部之间具有空腔的区域,有利于进一步提升极耳在第一方向上的整体厚度,且能够提升极耳厚度的均匀性,进而能够进一步缓解极耳在后续装配加工的过程中出现被焊穿的现象。
在一些实施例中,沿所述极耳部的厚度方向,所述极耳部的投影面积为S1,所述极耳部上的多个所述凸起的投影面积之和为S2,满足,S2/S1≥0.5。
在上述技术方案中,通过将极耳部上的多个凸起在极耳部的厚度方向上的投影面积之和设置为大于或等于极耳部在极耳部的厚度方向上的投影面积的一半,即多个凸起在极耳部上占用的面积为极耳部的一半或一半以上,以使极耳部上具有足够的区域设置有凸起,从而在极耳的多个极耳部沿第一方向层叠后使得极耳具有足够的厚度,且能够有效提升极耳厚度的均匀性,以降低极耳在后续装配过程中存在被焊穿的风险。
在一些实施例中,所述极耳部包括在所述极耳部的厚度方向上与所述凸起的投影不重叠的主体区,所述凸起沿所述极耳部的厚度方向凸出于所述主体区;沿所述极耳部的厚度方向,所述极耳部的最大尺寸为D1,所述主体区的厚度为D2,满足,2≤D1/D2≤8。
在上述技术方案中,极耳部具有在极耳部的厚度方向上与凸起的投影不重叠的主体区,且凸起在极耳部的厚度方向上凸出于主体区,即极耳部的主体区为极耳部未设置凸起的区域,通过将极耳部在极耳部的厚度方向上的最大尺寸设置为主体区的厚度的2倍到8倍,也就是说,极耳部设置有凸起后的最大厚度为极耳部的主体区的厚度的2倍到8倍,从而在极耳部相对于第一方向弯折后能够有效提升极耳的多个极耳部沿第一方向相互层叠的厚度,以实现极耳的厚度的增加,进而能够有效缓解极耳在后续装配过程中出现被焊穿的现象。
在一些实施例中,所述极耳部形成有多排凸起,每排凸起包括间隔设置多个所述凸起。
在上述技术方案中,通过在极耳部上设置多排凸起,且每排凸起包括间隔设置的多个凸起,以使极耳部上的多个凸起呈排列方式设置,从而在极耳的多个极耳部沿第一方向层叠后能够有效增加相互层叠且相邻的两个极耳部之间具有空腔的区域,进而有利于进一步提升极耳在第一方向上的整体厚度,且能够有效提升极耳厚度的均匀性,以减少极耳在后续装配过程中出现被焊穿的现象。
在一些实施例中,所述凸起在垂直于所述极耳部的厚度方向的方向上的最大尺寸为W1,满足,0.3mm≤W1≤2mm。
在上述技术方案中,通过将凸起在垂直于极耳部的厚度方向的方向上的最大尺寸设置在0.3mm到3mm,即凸起在其径向上的最大尺寸为0.3mm到3mm,一方面能够缓解因凸起的尺寸过小而导致加工难度过大的现象,以降低极耳部的加工难度,另一方面能够缓解因凸起的尺寸过大而造成极耳部上的多个凸起的数量设置受限的现象。
在一些实施例中,所述极耳部形成有间隔排布的多个所述凸起,所述凸起的两端沿垂直于多个所述凸起的排布方向的方向分别延伸至所述极耳部的两端。
在上述技术方案中,通过在极耳部上形成间隔设置的多个凸起,且凸起的两端延伸至极耳部的两端,即 凸起为设置于极耳部上的条状结构,以实现在极耳部上设置多个凸起的结构,采用这种结构有利于降低在极耳部上设置凸起的难度,以提升极耳部的加工效率。
在一些实施例中,沿多个所述凸起的排布方向,所述凸起的宽度为W2,满足,0.3mm≤W2≤2mm。
在上述技术方案中,通过将凸起在多个凸起的排布方向上的宽度设置在0.3mm到3mm,即凸起在垂直于凸起的延伸方向的方向上的尺寸为0.3mm到3mm,一方面能够缓解因凸起的宽度过小而导致加工难度过大的现象,以降低极耳部的加工难度,另一方面能够缓解因凸起的宽度过大而造成极耳部上的多个凸起的数量设置受限的现象。
在一些实施例中,沿所述极耳部的厚度方向,所述极耳部包括层叠设置的多个箔材,所述箔材的一侧形成有凸部,另一侧与所述凸部对应的位置形成有凹部,在相邻的两个所述箔材中,一个所述箔材的所述凸部容纳于另一个所述箔材的所述凹部内;其中,沿所述极耳部的厚度方向,位于所述极耳部的一侧的所述凸部为所述凸起。
在上述技术方案中,通过将极耳部设置为多个箔材层叠设置的结构,且箔材的一侧形成有凸部,另一侧形成有凹部,使得多个箔材层叠后相邻的两个箔材的凸部和凹部能够相互嵌设,以实现极耳部在极耳部的厚度方向上的一侧形成有凸起,采用这种结构的极耳部能够有效增加极耳部自身的厚度和结构强度,从而在极耳的多个极耳部沿第一方向层叠后能够进一步增加极耳的整体厚度和结构强度,以进一步降低极耳在后续装配过程中出现被焊穿的风险。
在一些实施例中,多个所述箔材焊接连接,以在所述箔材上形成所述凸部和所述凹部。
在上述技术方案中,采用焊接的方式连接层叠设置的多个箔材,并通过焊接的方式在多个箔材相互焊接的位置形成凸部和凹部,一方面有利于提升多个箔材之间的连接强度和连接稳定性,另一方面有利于降低在箔材上形成凹部和凸部的加工难度,以优化极片的生产节拍,从而能够有效提升极片的生产效率。
在一些实施例中,所述极片包括主体部,多个所述极耳部连接于所述主体部,两个所述极片的所述主体部和所述隔离件沿所述卷绕方向卷绕形成所述主体,所述主体部包括基材和设置于所述基材的至少一侧的活性物质层;多个所述箔材包括层叠设置的第一箔材和第二箔材,所述第一箔材连接于所述基材在所述第一方向上的一端,并与所述基材一体成型,所述第二箔材与所述基材分体设置。
在上述技术方案中,多个箔材中包括与极片的主体部的基材一体成型的第一箔材,在实际生产中,可在基材上预留未设置活性物质层的区域,从而能够在该区域上设置第一箔材,再将第二箔材层叠设置于第一箔材的一侧即可,使得第一箔材的能够为第二箔材提供连接支撑点,以实现极耳部的厚度和结构强度的提升,采用这种结构的极片能够有效降低极耳部连接于基材的工艺难度,有利于提高电极组件的生产效率。
在一些实施例中,所述基材包括涂覆区和间隔区,所述涂覆区与所述间隔区沿所述第一方向排布,所述活性物质层设置于所述涂覆区,所述间隔区连接所述涂覆区和所述第一箔材。
在上述技术方案中,通过在基材上设置涂覆有活性物质层的涂覆区和未涂覆有活性物质层的间隔区,使得极耳部的第一箔材能够通过间隔区与涂覆区相连,以实现极耳部与活性物质层在第一方向上间隔设置,采用这种结构的电极组件一方面通过间隔区能够间隔极耳部在相对于第一方向弯折加工的过程中产生的应力,以减少设置于涂覆区上的活性物质层出现断裂的风险,另一方面在极耳后续与其他部件焊接的过程中能够减少焊接过程中对活性物质层造成的影响,从而能够缓解活性物质层被损坏的现象,进而有利于提高电极组件的生产质量。
在一些实施例中,沿所述极耳部的厚度方向,所述第一箔材的厚度为D3,所述第二箔材的厚度为D4,满足,0.5≤D3/D4≤2。
在上述技术方案中,通过将第一箔材的厚度设置为第二箔材的厚度的0.5到2,即第一箔材的厚度为第二箔材的厚度的0.5倍到2倍,从而能够缓解因第一箔材的厚度与第二箔材的厚度相差过大而造成第一箔材与第二箔材相互连接的装配难度过大的现象,以降低这种结构的极耳部的加工难度。此外,一方面能够缓解因第一箔材的厚度相较于第二箔材的厚度过大时造成第二箔材在相互焊接的过程中出现损坏的现象,另一方面能够缓解因第二箔材的厚度相较于第一箔材的厚度过大时造成第一箔材在相互焊接的过程中出现损坏的现象。
在一些实施例中,沿垂直于所述极耳部的厚度方向的方向,所述第二箔材靠近所述基材的一端不超出所述第一箔材连接于所述基材的一端。
在上述技术方案中,通过将第二箔材在垂直于所述极耳部的厚度方向的方向上设置为不超出第一箔材连接于基材的一端,从而能够有效缓解第二箔材与设置于基材的一侧上的活性物质层之间的干涉影响,以降低活性物质层被第二箔材损坏的风险。
在一些实施例中,沿所述垂直于所述极耳部的厚度方向的方向,所述第一箔材远离所述基材的一端与所述第二箔材远离所述基材的一端之间的距离为L,满足,L≤2mm。
在上述技术方案中,通过将第一箔材远离基材的一端和第二箔材远离基材的一端在垂直于所述极耳部的厚度方向的方向上的间距设置为小于或等于2mm,也就是说,第一箔材远离基材的一端超出第二箔材远离基材的一端的尺寸为小于或等于2mm,或第二箔材远离基材的一端超出第一箔材远离基材的一端的尺寸为小于或等于2mm,从而能够缓解因第一箔材的长度或第二箔材的长度过大而出现第一箔材超出第二箔材过多或第二箔材超出第一箔材过多,以导致极耳部存在冗长或倒插至电极组件内的现象,从而有利于提升电极组件的生产质量和使用可靠性。
在一些实施例中,所述第一箔材与所述第二箔材的材质相同。
在上述技术方案中,通过将第一箔材与第二箔材设置为相同材质,一方面能够实现极耳部的极性稳定,另一方面能够降低第一箔材与第二箔材相互连接的工艺难度。
在一些实施例中,所述极片包括主体部,多个所述极耳部连接于所述主体部在所述第一方向上的一端,两个所述极片的所述主体部和所述隔离件沿所述卷绕方向卷绕形成所述主体;其中,所述主体部包括基材和设置于 所述基材的至少一侧的活性物质层,所述基材包括涂覆区和间隔区,所述涂覆区与所述间隔区沿所述第一方向排布,所述活性物质层设置于所述涂覆区,所述间隔区连接所述涂覆区和所述极耳部。
在上述技术方案中,通过在基材上设置涂覆有活性物质层的涂覆区和未涂覆有活性物质层的间隔区,使得极耳部能够通过间隔区与涂覆区相连,以实现极耳部与活性物质层在第一方向上间隔设置,采用这种结构的电极组件一方面通过间隔区能够间隔极耳部在相对于第一方向弯折加工的过程中产生的应力,以减少设置于涂覆区上的活性物质层出现断裂的风险,另一方面在极耳后续与其他部件焊接的过程中能够减少焊接过程中对活性物质层造成的影响,从而能够缓解活性物质层被损坏的现象,进而有利于提高电极组件的生产质量。
在一些实施例中,所述极耳部与所述间隔区一体成型。
在上述技术方案中,通过将极耳部设置为与基材的间隔区一体成型的结构,使得在实际生产过程中极耳部可以为基材的一部分,可在基材上预留未设置活性物质层的区域后便能够在该区域上设置极耳部,以降低极耳部连接于基材上的工艺难度,有利于提高电极组件的生产效率。
在一些实施例中,沿所述极耳部的厚度方向,所述极耳部背离所述凸起的一侧且对应所述凸起的位置形成有凹槽。
在上述技术方案中,通过在极耳部背离凸起的一侧且对应凸起的位置设置有凹槽,使得这种结构的极耳部能够通过冲压或辊压等工艺便能够实现在极耳部上形成有凸起,一方面有利于降低极耳部的加工难度,且有利于提升极耳部的加工效率,另一方面无需通过增加材料的方式在极耳部的一侧设置凸起,从而有利于降低极耳部的生产成本,且有利于减轻极耳部的重量。
在一些实施例中,沿所述第一方向,在相邻的两个所述极耳部中,一个所述极耳部的所述凸起与另一个所述极耳部的所述凹槽错位设置。
在上述技术方案中,通过在第一方向上相邻的两个极耳部中将一个极耳部的凸起与另一个极耳部的凹槽设置为相互错位的结构,从而能够有效缓解凸起与凹槽重叠后出现相互抵消的现象,以使极耳在第一方向上具有足够的厚度,进而有利于降低电极组件的极耳在后续装配过程中出现被焊穿的风险。
在一些实施例中,沿所述第一方向,所述极耳的厚度为D5,满足,0.2mm≤D5≤2.5mm。
在上述技术方案中,通过将极耳在第一方向上的厚度设置在0.2mm到2.5mm,一方面能够缓解因极耳的厚度过小而容易出现极耳被焊穿的风险,以降低电极组件在后续装配过程中出现被损坏的风险,另一方面能够缓解因极耳的厚度过大而造成极耳的占用空间过大的现象,从而有利于优化具有这种电极组件的电池单体的内部空间,以提升电池单体的能量密度。
在一些实施例中,沿所述第一方向,两个所述极耳分别设置于所述主体的两端。
在上述技术方案中,通过将电极组件的两个极耳分别设置于主体在第一方向上的两端,即两个极耳分别形成于电极组件在第一方向上的两端,从而便于后续对电极组件进行装配,有利于降低具有这种电极组件的电池单体的装配难度,且能够减少两个极耳之间的出现干涉或相互接触的现象,进而有利于降低电极组件的短接风险。
在一些实施例中,所述主体呈圆柱状。
在上述技术方案中,通过将电极组件的主体设置为圆柱状的结构,以便于后续加工形成圆柱体结构的电池单体。
第二方面,本申请实施例还提供一种电池单体,包括外壳和上述的电极组件;所述电极组件容纳于外壳内。
在一些实施例中,所述电池单体还包括集流构件;所述集流构件沿所述第一方向设置于所述外壳与所述极耳之间,所述集流构件连接所述外壳与所述极耳。
在上述技术方案中,通过在电池单体的外壳内设置集流构件,以通过集流构件连接外壳和电极组件的极耳,从而能够实现电池单体的电能的输入或输出,这种结构简单,便于实现,且有利于降低极耳与外壳之间的装配难度。
在一些实施例中,所述集流构件与所述极耳焊接连接,沿所述第一方向,所述极耳的厚度为D5,所述集流构件的厚度为D6,满足,D6≤1.5D5
在上述技术方案中,通过将集流构件在第一方向上的厚度设置为小于或等于极耳在第一方向上的厚度的1.5倍,从而能够缓解因集流构件的厚度比极耳的厚度过大而造成焊接集流构件与极耳的所需焊接功率过大的现象,进而能够有效降低极耳出现被焊穿的风险,以减少电极组件被损坏的现象,有利于提升电池单体的生产质量。
在一些实施例中,所述集流构件与所述极耳焊接连接并形成焊印,沿所述第一方向,所述焊印覆盖至少一个所述极耳部的所述凸起。
在上述技术方案中,通过将集流构件和极耳相互焊接形成的焊印设置为在第一方向上覆盖至少一个极耳部的凸起,即在第一方向上,集流构件与极耳相互焊接的位置与至少一个极耳部的凸起对应设置,从而使得集流构件与极耳相互焊接的位置位于极耳被凸起加厚的区域,进而有利于进一步降低极耳在装配过程中出现被焊穿的风险。
第三方面,本申请实施例还提供一种电池,包括上述的电池单体。
第四方面,本申请实施例还提供一种用电装置,包括上述的电池。
附图说明
为了更清楚地说明本申请实施例的技术方案,下面将对实施例中所需要使用的附图作简单地介绍,应当理解,以下附图仅示出了本申请的某些实施例,因此不应被看作是对范围的限定,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,还可以根据这些附图获得其他相关的附图。
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结构爆炸图;
图3为本申请一些实施例提供的电池单体的结构爆炸图;
图4为本申请一些实施例提供的电极组件的截面图;
图5为本申请一些实施例提供的电极组件的剖视图;
图6为本申请一些实施例提供的电极组件在卷绕过程中的结构示意图;
图7为本申请一些实施例提供的电极组件的极片在展开后的结构示意图;
图8为本申请一些实施例提供的极片在展开后的局部剖视图;
图9为本申请一些实施例提供的极耳部的结构示意图;
图10为本申请一些实施例提供的极耳部的正视图;
图11为本申请又一些实施例提供的极耳部的结构示意图;
图12为本申请又一些实施例提供的极耳部的正视图;
图13为本申请再一些实施例提供的极耳部的结构示意图;
图14为本申请再一些实施例提供的极耳部的正视图;
图15为本申请另一些实施例提供的极片在展开后的局部剖视图;
图16为本申请另一些实施例提供的极片的极耳部的剖视图;
图17为本申请一些实施例提供的电极组件的极耳的多个极耳部在层叠后的剖视图;
图18为本申请一些实施例提供的集流构件与电极组件的极耳的连接示意图。
图标:1000-车辆;100-电池;10-箱体;11-第一箱本体;12-第二箱本体;20-电池单体;21-外壳;211-壳体;2111-开口;212-端盖;22-电极组件;221-极片;2211-主体部;22111-基材;22111a-涂覆区;22111b-间隔区;22112-活性物质层;2212-极耳;22121-极耳部;22121a-凸起;22121b-凹槽;22121c-主体区;22121d-箔材;22121e-凸部;22121f-凹部;22121g-第一箔材;22121h-第二箔材;222-隔离件;223-主体;23-集流构件;24-焊印;200-控制器;300-马达;X-第一方向;Y-卷绕方向;Z-极耳部的厚度方向。
具体实施方式
为使本申请实施例的目的、技术方案和优点更加清楚,下面将结合本申请实施例中的附图,对本申请实施例中的技术方案进行清楚地描述,显然,所描述的实施例是本申请一部分实施例,而不是全部的实施例。基于本申请中的实施例,本领域普通技术人员在没有作出创造性劳动前提下所获得的所有其他实施例,都属于本申请保护的范围。
除非另有定义,本申请所使用的所有的技术和科学术语与属于本申请的技术领域的技术人员通常理解的含义相同;本申请中在申请的说明书中所使用的术语只是为了描述具体的实施例的目的,不是旨在于限制本申请;本申请的说明书和权利要求书及上述附图说明中的术语“包括”和“具有”以及它们的任何变形,意图在于覆盖不排他的包含。本申请的说明书和权利要求书或上述附图中的术语“第一”、“第二”等是用于区别不同对象,而不是用于描述特定顺序或主次关系。
在本申请中提及“实施例”意味着,结合实施例描述的特定特征、结构或特性可以包含在本申请的至少一个实施例中。在说明书中的各个位置出现该短语并不一定均是指相同的实施例,也不是与其它实施例互斥的独立的或备选的实施例。
在本申请的描述中,需要说明的是,除非另有明确的规定和限定,术语“安装”、“相连”、“连接”、“附接”应做广义理解,例如,可以是固定连接,也可以是可拆卸连接,或一体地连接;可以是直接相连,也可以通过中间媒介间接相连,可以是两个元件内部的连通。对于本领域的普通技术人员而言,可以根据具体情况理解上述术语在本申请中的具体含义。
本申请中术语“和/或”,仅仅是一种描述关联对象的关联关系,表示可以存在三种关系,例如,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,本申请中字符“/”,一般表示前后关联对象是一种“或”的关系。
在本申请的实施例中,相同的附图标记表示相同的部件,并且为了简洁,在不同实施例中,省略对相同部件的详细说明。应理解,附图示出的本申请实施例中的各种部件的厚度、长宽等尺寸,以及集成装置的整体厚度、长宽等尺寸仅为示例性说明,而不应对本申请构成任何限定。
本申请中出现的“多个”指的是两个以上(包括两个)。
本申请实施例中,电池单体可以为二次电池,二次电池是指在电池单体放电后可通过充电的方式使活性材料激活而继续使用的电池单体。
电池单体可以为锂离子电池、钠离子电池、钠锂离子电池、锂金属电池、钠金属电池、锂硫电池、镁离子电池、镍氢电池、镍镉电池、铅蓄电池等,本申请实施例对此并不限定。
电池单体一般包括电极组件。电极组件包括正极、负极以及隔离件。在电池单体充放电过程中,活性离子(例如锂离子)在正极和负极之间往返嵌入和脱出。隔离件设置在正极和负极之间,可以起到防止正负极短路的作用,同时可以使活性离子通过。
在一些实施例中,正极可以为正极片,正极片可以包括正极集流体以及设置在正极集流体至少一个表面的正极活性材料。
作为示例,正极集流体具有在其自身厚度方向相对的两个表面,正极活性材料设置在正极集流体相对的两个表面的任意一者或两者上。
作为示例,正极集流体可采用金属箔片或复合集流体。例如,作为金属箔片,可采用银表面处理的铝或不锈钢、不锈钢、铜、铝、镍、炭精电极、碳、镍或钛等。复合集流体可包括高分子材料基层和金属层。复合集流体可通过将金属材料(铝、铝合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子材料基材(如聚丙烯、聚对苯二甲酸乙二醇酯、聚对苯二甲酸丁二醇酯、聚苯乙烯、聚乙烯等的基材)上而形成。
作为示例,正极活性材料可包括以下材料中的至少一种:含锂磷酸盐、锂过渡金属氧化物及其各自的改性化合物。但本申请并不限定于这些材料,还可以使用其他可被用作电池正极活性材料的传统材料。这些正极活性材料可以仅单独使用一种,也可以将两种以上组合使用。其中,含锂磷酸盐的示例可包括但不限于磷酸铁锂(如LiFePO4(也可以简称为LFP))、磷酸铁锂与碳的复合材料、磷酸锰锂(如LiMnPO4)、磷酸锰锂与碳的复合材料、磷酸锰铁锂、磷酸锰铁锂与碳的复合材料中的至少一种。
在一些实施例中,负极可以为负极片,负极片可以包括负极集流体。
作为示例,负极集流体可采用金属箔片、泡沫金属或复合集流体。例如,作为金属箔片,可以采用银表面处理的铝或不锈钢、不锈钢、铜、铝、镍、炭精电极、用碳、镍或钛等。泡沫金属可以为泡沫镍、泡沫铜、泡沫铝、泡沫合金、或泡沫碳等。复合集流体可包括高分子材料基层和金属层。复合集流体可通过将金属材料(铜、铜合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子材料基材(如聚丙烯、聚对苯二甲酸乙二醇酯、聚对苯二甲酸丁二醇酯、聚苯乙烯、聚乙烯等的基材)上而形成。
作为示例,负极片可以包括负极集流体以及设置在负极集流体至少一个表面上的负极活性材料。
作为示例,负极集流体具有在其自身厚度方向相对的两个表面,负极活性材料设置在负极集流体相对的两个表面中的任意一者或两者上。
作为示例,负极活性材料可采用本领域公知的用于电池单体的负极活性材料。作为示例,负极活性材料可包括以下材料中的至少一种:人造石墨、天然石墨、软炭、硬炭、硅基材料、锡基材料和钛酸锂等。
在一些实施例中,正极集流体的材料可以为铝,负极集流体的材料可以为铜。
在一些实施方式中,电极组件还包括隔离件,隔离件设置在正极和负极之间。
在一些实施方式中,隔离件为隔离膜。本申请对隔离膜的种类没有特别的限制,可以选用任意公知的具有良好的化学稳定性和机械稳定性的多孔结构隔离膜。
作为示例,隔离膜的主要材质可选自玻璃纤维、无纺布、聚乙烯、聚丙烯及聚偏二氟乙烯,陶瓷中的至少一种。
在一些实施方式中,隔离件为固态电解质。固态电解质设于正极和负极之间,同时起到传输离子和隔离正负极的作用。
在一些实施方式中,电池单体还包括电解质,电解质在正、负极之间起到传导离子的作用。本申请对电解质的种类没有具体的限制,可根据需求进行选择。电解质可以是液态的、凝胶态的或固态的。
在一些实施方式中,电极组件为卷绕结构。正极片、负极片卷绕成卷绕结构。
在一些实施方式中,电极组件为叠片结构。
在一些实施方式中,电极组件的形状可以为圆柱状,扁平状或多棱柱状等。
在一些实施方式中,电极组件设有极耳,极耳可以将电流从电极组件导出。极耳包括正极耳和负极耳。
在一些实施方式中,电池单体可以包括外壳。外壳用于封装电极组件及电解质等部件。外壳可以为钢壳、铝壳、塑料壳(如聚丙烯)、复合金属壳(如铜铝复合外壳)或铝塑膜等。
作为示例,电池单体可以为圆柱形电池单体、棱柱电池单体、软包电池单体或其它形状的电池单体,棱柱电池单体包括方壳电池单体、刀片形电池单体、多棱柱电池,多棱柱电池例如为六棱柱电池等,本申请没有特别的限制。
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。
在一些实施例中,电池可以为电池模块,电池单体有多个时,多个电池单体排列并固定形成一个电池模块。
在一些实施例中,电池可以为电池包,电池包包括箱体和电池单体,电池单体或电池模块容纳于箱体中。
在一些实施例中,箱体可以作为车辆的底盘结构的一部分。例如,箱体的部分可以成为车辆的地板的至少一部分,或者,箱体的部分可以成为车辆的横梁和纵梁的至少一部分。
在一些实施例中,电池可以为储能装置。储能装置包括储能集装箱、储能电柜等。
电池具有能量密度高、环境污染小、功率密度大、使用寿命长、适应范围广、自放电系数小等突出的优点,是现今新能源发展的重要组成部分。其中,电池单体的外壳内通常设置有集流构件,在电池单体的装配过程中,需要将电极组件的极耳与集流构件相互焊接后,再通过集流构件与外壳相连能够实现电池单体的电能的输入或输出,从而便于对电池单体进行装配,以降低电池单体的装配难度。
对于一般的电池单体而言,电极组件通常通过极耳与集流构件相互焊接,以实现电极组件与集流构件的电连接,而极耳通常由多个极耳片层叠形成,为了降低电极组件与集流构件之间的装配难度,特别是圆柱结构的电极组件,在电池单体的生产装配过程中,通常采用揉平工艺或抚平工艺对极片的多个极耳片进行揉平或抚平处理,以提升极耳的平整度,使得极耳形成于电极组件的一端,从而有利于降低极耳与集流构件之间的焊接难度。但是,现有的电极组件的极耳在揉平或抚平的过程中极容易造成极耳出现局部的厚度过小的现象,且容易造成多个极耳片紧密贴合后使得极耳的整体厚度较小的现象,使得在极耳与集流构件相互焊接的过程中容易出现极耳被焊穿的情况,以导致电极组件存在被损坏的风险,从而使得电池单体的生产质量较差,不利于提升电池单体的产品合格率。
基于上述考虑,为了解决电池单体的生产质量较差的问题,本申请实施例提供了一种电极组件,包括极性相反的两个极片和用于隔离两个极片的隔离件,两个极片以及隔离件沿卷绕方向卷绕后形成主体和两个极耳;其中,极耳和主体沿第一方向的设置,极耳包括沿卷绕方向间隔设置的多个极耳部,极耳部相对于第一方向弯折设置,多个极耳部的至少部分沿第一方向层叠设置,且极耳部在其厚度方向上的至少一侧形成有凸起。
在这种结构的极片中,极性相反的两个极片和隔离件沿卷绕方向卷绕形成卷绕式结构的电极组件,以使电极组件具有主体和两个极耳,且极耳和主体沿第一方向设置。其中,极耳设置有沿卷绕方向间隔排布的多个极耳部,且极耳部相对于第一方向弯折设置,以使极耳的多个极耳部中的至少一部分能够沿第一方向层叠,通过在极耳的极耳部的至少一侧设置凸起,以增加层叠在一起的多个极耳部的厚度,且能够缓解极耳的多个极耳部在层叠后出现局部厚度较小的现象,从而能够改善极耳的生产质量,以降低极耳在后续装配加工的过程中出现被焊穿的风险,进而有利于减少电极组件被损坏的现象,且有利于提升电极组件与电池单体的其他部件之间的连接稳定性和装配质量,以提升具有这种电极组件的电池单体的生产质量和使用稳定性。
本申请实施例公开的极片可以但不限用于车辆、船舶或飞行器等用电装置中。可以使用具备本申请公开的电极组件、电池单体或电池等组成该用电装置的电源系统,这样,能够有效缓解电池单体在生产装配的过程中出现电极组件的极耳被焊穿的现象,以提升电池单体的生产质量。
本申请实施例提供一种使用电池作为电源的用电装置,用电装置可以为但不限于手机、平板、笔记本电脑、电动玩具、电动工具、电瓶车、电动汽车、轮船、航天器等等。其中,电动玩具可以包括固定式或移动式的电动玩具,例如,游戏机、电动汽车玩具、电动轮船玩具和电动飞机玩具等等,航天器可以包括飞机、火箭、航天飞机和宇宙飞船等等。
以下实施例为了方便说明,以本申请一实施例的一种用电装置为车辆1000为例进行说明。
请参照图1,图1为本申请一些实施例提供的车辆1000的结构示意图。车辆1000可以为燃油汽车、燃气汽车或新能源汽车,新能源汽车可以是纯电动汽车、混合动力汽车或增程式汽车等。车辆1000的内部设置有电池100,电池100可以设置在车辆1000的底部,也可以设置在车辆1000的头部,还可以设置在车辆1000的尾部。电池100可以用于车辆1000的进行供电,例如,电池100可以作为车辆1000的操作电源或使用电源等。车辆1000还可以包括控制器200和马达300,控制器200用来控制电池100为马达300供电,例如,用于车辆1000的启动、导航和行驶时的工作用电需求。
在本申请一些实施例中,电池100不仅可以作为车辆1000的操作电源或使用电源,还可以作为车辆1000的驱动电源,代替或部分地代替燃油或天然气为车辆1000提供驱动动力。
请参照图2,图2为本申请一些实施例提供的电池100的结构爆炸图。电池100可以包括箱体10和电池单体20,电池单体20用于容纳于箱体10内。
其中,箱体10用于为电池单体20提供装配空间,箱体10可以采用多种结构。在一些实施例中,箱体10可以包括第一箱本体11和第二箱本体12,第一箱本体11与第二箱本体12相互盖合,第一箱本体11和第二箱本体12共同限定出用于容纳电池单体20的装配空间。第二箱本体12可以为一端开放的空心结构,第一箱本体11可以为板状结构,第一箱本体11盖合于第二箱本体12的开放侧,以使第一箱本体11与第二箱本体12共同限定出装配空间;第一箱本体11和第二箱本体12也可以是均为一侧开放的空心结构,第一箱本体11的开放侧盖合于第二箱本体12的开放侧。当然,第一箱本体11和第二箱本体12形成的箱体10可以是多种形状,比如,圆柱体、长方体等。示例性的,在图2中箱体10的形状为长方体。
在电池100中,设置于箱体10内的电池单体20可以是一个,也可以是多个。当设置于箱体10内的电池单体20为多个时,多个电池单体20之间可串联或并联或混联,混联是指多个电池单体20中既有串联又有并联。多个电池单体20之间可直接串联或并联或混联在一起,再将多个电池单体20构成的整体容纳于箱体10内;当然,电池100也可以是多个电池单体20先串联或并联或混联组成电池模块形式,多个电池模块再串联或并联或混联形成一个整体,并容纳于箱体10内。电池100还可以包括其他结构,例如,该电池100还可以包括汇流部件,汇流部件用于连接多个电池单体20,以实现多个电池单体20之间的电连接。
其中,每个电池单体20可以为二次电池或一次电池;还可以是锂硫电池、钠离子电池或镁离子电池,但电池单体20并不局限于此。电池单体20可呈圆柱体、扁平体、长方体或其它形状等。示例性的,在图2中,电池单体20为圆柱体结构。
参照图2,并请进一步参照图3,图3为本申请一些实施例提供的电池单体20的结构爆炸图。电池单体20可以包括外壳21和电极组件22,电极组件22容纳于外壳21内。
其中,外壳21还可以用于容纳电解质,例如电解液。外壳21可以是多种结构形式,比如,圆柱体、长方体或棱柱结构等。同样的,外壳21的材质也可以是多种,比如,铜、铁、铝、钢或铝合金等。
在一些实施例中,外壳21可以包括壳体211和端盖212,壳体211的内部形成有容纳腔,且容纳腔具有开口2111,容纳腔用于容纳电极组件22,即壳体211为一侧开口2111的空心结构,端盖212盖合于壳体211的开口2111处并形成密封连接,以形成用于容纳电极组件22和电解质的密封空间。
在组装电池单体20时,可以先将电极组件22放入壳体211内,并向壳体211内填充电解质,之后再将端盖212盖合于壳体211的开口2111,以完成电池单体20的组装。
壳体211可以是多种形状,比如,圆柱体、长方体等。壳体211的形状可根据电极组件22的具体形状来确定。比如,若电极组件22为圆柱体结构,则可选用为圆柱体结构的壳体211;若电极组件22为长方体结构,则可选用长方体结构的壳体211。当然,端盖212也可以是多种结构,比如,端盖212为板状结构、一端开口2111的空心结构等。示例性的,在图3中,电极组件22为圆柱体结构,对应的,壳体211为圆柱体结构,端盖212为圆柱形板状结构,端盖212盖合于壳体211的开口2111处。
当然,可理解的,外壳21并不仅仅局限于上述结构,外壳21也可以是其他结构,比如,外壳21包括壳体211和两个端盖212,壳体211为相对的两侧开口2111的空心结构,一个端盖212对应盖合于壳体211的一个开口2111处并形成密封连接,以形成用于容纳电极组件22和电解质的密封空间。
在一些实施例中,外壳21还可以包括正极电极端子和负极电极端子,正极电极端子可以是安装于端盖212上,负极电极端子可以是安装于壳体211与端盖212相对的一端上,当然,也可以是正极电极端子安装于壳体211与端盖212相对的一端上,负极电极端子安装于端盖212上,还可以是正极电极端子和负极电极端子均安装于端盖212上或均安装于壳体211与端盖212相对的一端上。正极电极端子和负极电极端子均用于与电极组件22电连接,以实现电池单体20的电能的输入或输出。其中,正极电极端子和负极电极端子可以是与电极组件22直接相连,比如,焊接或抵接等,正极电极端子和负极电极端子也可以是与电极组件22间接相连,比如,正极电极端子和负极电极端子先与其他部件相连后,再通过其他部件与电极组件22抵接或焊接等。
其中,在图3中,电池单体20还可以包括集流构件23,集流构件23容纳于外壳21内,集流构件23用于连接电极组件22和外壳21的正极电极端子或负极电极端子,以实现电池单体20的电能的输入或输出。
集流构件23起到连接电极组件22和外壳21的正极电极端子或起到连接电极组件22和外壳21的负极电极端子的作用,集流构件23与电极组件22以及与外壳21的正极电极端子或负极电极端子之间的连接方式可以是多种,比如,焊接、抵接或粘接等。
示例性的,电池单体20可以包括两个集流构件23,电极组件22通过两个集流构件23分别与外壳21的正极电极端子和负极电极端子相连,即电极组件22通过一个集流构件23与外壳21的正极电极端子相连,并通过另一个集流构件23与外壳21的负极电极端子相连,从而能够分别输出或输入电池单体20的正极和负极。
在一些实施例中,电池单体20还可以包括泄压机构,泄压机构可以是安装于端盖212上,也可以是安装于壳体211上。同样的,泄压机构可以是一个,也可以是多个。泄压机构用于泄放电池单体20内部的压力。
示例性的,泄压机构可以是诸如防爆阀、防爆片、气阀、泄压阀或安全阀等泄压部件。
需要说明的是,电极组件22是电池单体20中发生电化学反应的部件。电极组件22的结构可以是多种,比如,电极组件22可以是通过卷绕方式形成的卷绕式结构,也可以是通过层叠方式形成的叠片式结构。同样的,电极组件22的形状也可以是多种,比如,电极组件22的形状可以是圆柱体结构、椭圆形结构或长方体结构等。
在一些实施例中,参照图3,并请进一步参照图4和图5,图4为本申请一些实施例提供的电极组件22的截面图,图5为本申请一些实施例提供的电极组件22的剖视图。电极组件22为通过卷绕形成的卷绕式结构,且电极组件22的形状为圆柱体。
其中,电极组件22可以包括极性相反的两个极片221,两个极片221绕沿第一方向X延伸的中心轴线卷绕形成卷绕式结构的电极组件22。也就是说,极性相反的两个极片221分别为电极组件22的正极片和负极片,正极片和负极片卷绕形成卷绕式结构的电极组件22。当然,在其他实施例中,电极组件22也可以是极性相反的两个极片221层叠设置形成的叠片式结构。
可选地,电极组件22还可以包括隔离件222,隔离件222设置于两个极片221之间,以绝缘隔离两个极片221,从而能够有效降低电极组件22在使用过程中出现短路的风险。
示例性的,隔离件222的材质可以是多种,比如,隔离件222的材质可以为聚丙烯或聚乙烯等。
根据本申请的一些实施例,参照图4和图5,并请进一步参照图6、图7和图8,图6为本申请一些实施例提供的电极组件22在卷绕过程中的结构示意图,图7为本申请一些实施例提供的电极组件22的极片221在展开后的结构示意图,图8为本申请一些实施例提供的极片221在展开后的局部剖视图。本申请提供了一种电极组件22,包括极性相反的两个极片221和用于隔离两个极片221的隔离件222,两个极片221以及隔离件222沿卷绕方向Y卷绕后形成主体223和两个极耳2212。极耳2212和主体223沿第一方向X的设置,极耳2212包括沿卷绕方向Y间隔设置的多个极耳部22121,极耳部22121相对于第一方向X弯折设置,多个极耳部22121的至少一部分沿第一方向X层叠设置,且极耳部22121在其厚度方向上的至少一侧形成有凸起22121a。
其中,极片221可以包括主体部2211和在第一方向X上连接于主体部2211的一端的极耳2212,极性相反的两个极片221的主体部2211和隔离件222沿卷绕方向Y卷绕后形成电极组件22的主体223,且电极组件22的卷绕中心轴线沿第一方向X延伸,以使每个极片221的极耳2212形成于电极组件22在第一方向X上的一端,从而使得极耳2212和主体223沿第一方向X的设置。
示例性的,在图3中,极性相反的两个极片221分别具有一个极耳2212,两个极耳2212的极性相反,且两个极耳2212在第一方向X上分别位于主体223的两端。
极片221的主体部2211是极片221在电池单体20内发生化学反应的区域,主要依靠金属离子在极性相反的两个极片221的主体部2211之间移动来工作。极片221的主体部2211包括基材22111和设置于基材22111的一侧上活性物质层22112,极耳2212沿第一方向X连接于基材22111的一端,活性物质层22112用于在电池单体20的使用过程中在电池单体20内进行化学反应。
极耳部22121相对于第一方向X弯折设置,即在极片221未卷绕形成电极组件22且处于展开状态时,极耳部22121为沿第一方向X延伸的结构,当极片221卷绕形成电极组件22后,极耳部22121需要进行弯折,使得极耳部22121与第一方向X呈非零夹角设置,以使多个极耳部22121中的至少一部分极耳部22121能够沿第一方向X相互层叠形成极耳2212。
在一些实施例中,在两个极片221的主体部2211和隔离件222卷绕形成电极组件22的主体223后,可以通过抚平或揉平等工艺对极耳2212的多个极耳部22121进行加工,以使极耳部22121相对于第一方向X弯折设置,并使多个极耳部22121的至少一部分沿第一方向X层叠设置。需要说明的是,在极耳部22121相对于第一方向X弯折设置后,极耳部的厚度方向Z可以是与第一方向X相同,也可以是与第一方向X呈较小的夹角设置,比如, 极耳部的厚度方向Z与第一方向X之间的夹角小于或等于10°。示例性的,在图5中,极耳部的厚度方向Z与第一方向X相同。当极片221展开后,即如图7所示,极片221的主体部2211的延伸方向即为卷绕方向Y,使得极耳2212的多个极耳部22121为沿主体部2211的延伸方向间隔设置,同时,在极片221展开后,第一方向X、主体部2211的延伸方向和极耳部的厚度方向Z为两两相互垂直的结构,此时,基材22111的厚度方向与极耳部的厚度方向Z相同。
可选地,基材22111与极耳2212可以是一体式结构,也可以是分体式结构。如果基材22111与极耳2212为一体式结构,则极耳2212的多个极耳部22121可以通过裁切等方式形成于基材22111在第一方向X上的一端;如果基材22111与极耳2212为分体式结构,则极耳2212可以通过焊接或卡接等方式连接于基材22111在第一方向X上的一端,其中,在基材22111与极耳2212为分体式结构的实施例中,基材22111的材质可以是与极耳2212的材质相同,也可以是与极耳2212的材质不同。
极片221的极耳2212为极片221用于输出或输入极片221的电能的部件,极耳2212包括沿卷绕方向Y间隔设置的多个极耳部22121,使得极片221在卷绕形成电极组件22后便于对极耳2212的多个极耳部22121通过抚平或揉平等工艺进行加工,以使极耳2212的多个极耳部22121能够层叠后形成于电极组件22在第一方向X上的一端,从而在极耳2212与集流构件23相连后能够输出或输入电极组件22的正极或负极。
极耳2212包括沿卷绕方向Y间隔设置的多个极耳部22121,即在极片221展开后,如图7所示,极耳2212的多个极耳部22121为沿主体部2211的延伸方向间隔设置,当极片221沿卷绕方向Y卷绕形成电极组件22后,主体部2211的延伸方向与卷绕方向Y相同,则多个极耳部22121沿卷绕方向Y间隔设置。
多个极耳部22121的至少一部分沿第一方向X层叠设置,即极耳2212的多个极耳部22121在通过抚平或揉平等工艺相对于第一方向X弯折设置后,可以是多个极耳部22121中的一部分极耳部22121沿第一方向X层叠设置,也可以是所有的极耳部22121均沿第一方向X层叠设置。需要说明的是,在极片221卷绕形成卷绕式结构的电极组件22后,主体部2211的延伸方向即为卷绕方向Y,使得极耳2212的多个极耳部22121沿极片221的卷绕方向间隔排布,从而在极耳2212通过抚平或揉平等工艺时,由于是将极耳2212的多个极耳部22121从电极组件22的外边缘往电极组件22的中心轴线的方向抚平,使得极耳2212的多个极耳部22121为一部分极耳部22121与一部分极耳部22121沿第一方向X层叠设置,另一部分与另一部分极耳部22121沿第一方向X层叠设置的结构,当然,在一些实施例中,极耳2212也可以是多个极耳部22121整体均沿第一方向X层叠设置的结构。
极耳部22121在其厚度方向上的至少一侧形成有凸起22121a,即在极耳部的厚度方向Z上,极耳部22121可以是仅一侧设置有凸起22121a,也可以是极耳部22121的两侧均设置有凸起22121a。同样的,设置于极耳部22121上的凸起22121a的数量可以是一个,也可以是多个。示例性的,在图7和图8中,沿极耳部的厚度方向Z,极耳部22121的仅一侧设置有凸起22121a,且凸起22121a的数量为多个。
可选地,在极耳部22121上形成凸起22121a的加工方式可以是多种,比如,通过焊接或挤出成型等工艺在极耳部22121的一侧增加材料,以在极耳部22121的一侧形成凸起22121a,也可以是通过冲压或辊压等方式在极耳部22121上的一侧压出凸起22121a,并在极耳部22121背离凸起22121a的一侧且对应凸起22121a的位置形成凹槽22121b。示例性的,在图8中,凸起22121a为通过冲压或辊压等方式在极耳部22121上的一侧形成凸起22121a,以使极耳部22121在背离凸起22121a的一侧且对应凸起22121a的位置形成有凹槽22121b。极性相反的两个极片221和隔离件222沿卷绕方向Y卷绕形成卷绕式结构的电极组件22,以使电极组件22具有主体223和两个极耳2212,且极耳2212和主体223沿第一方向X设置。其中,极耳2212设置有沿卷绕方向Y间隔排布的多个极耳部22121,且极耳部22121相对于第一方向X弯折设置,以使极耳2212的多个极耳部22121中的至少一部分能够沿第一方向X层叠,通过在极耳2212的极耳部22121的至少一侧设置凸起22121a,以增加层叠在一起的多个极耳部22121的厚度,且能够缓解极耳的多个极耳部22121在层叠后出现局部厚度较小的现象,从而能够改善极耳2212的生产质量,以降低极耳2212在后续装配加工的过程中出现被焊穿的风险,进而有利于减少电极组件22被损坏的现象,且有利于提升电极组件22与电池单体20的其他部件之间的连接稳定性和装配质量,以提升具有这种电极组件22的电池单体20的生产质量和使用稳定性。
根据本申请的一些实施例,参照图7和图8,并请进一步参照图9和图10,图9为本申请一些实施例提供的极耳部22121的结构示意图,图10为本申请一些实施例提供的极耳部22121的正视图。沿极耳部的厚度方向Z,极耳部22121的至少一侧形成有多个凸起22121a。
其中,极耳部22121的至少一侧形成有多个凸起22121a,即在极耳部的厚度方向Z上,极耳部22121可以是仅一侧设置有多个凸起22121a,也可以是极耳部22121的两侧均设置有多个凸起22121a。
示例性的,在图9和图10中,极耳部22121的仅一侧设置有多个凸起22121a。通过仅在极耳部22121的一侧设置多个凸起22121a,有利于降低在极耳部22121上设置凸起22121a的加工难度,以提升生产效率。
通过在极耳部22121的至少一侧上设置多个凸起22121a,从而在极耳部22121相对于第一方向X弯折并使得多个极耳部22121沿第一方向X层叠设置后能够有效增加相互层叠且相邻的两个极耳部22121之间具有空腔的区域,有利于进一步提升极耳2212在第一方向X上的整体厚度,且能够提升极耳2212厚度的均匀性,进而能够进一步缓解极耳2212在后续装配加工的过程中出现被焊穿的现象。
根据本申请的一些实施例,请继续参见图9和图10所示,沿极耳部的厚度方向Z,极耳部22121的投影面积为S1,极耳部22121上的多个凸起22121a的投影面积之和为S2,满足,S2/S1≥0.5。
其中,沿极耳部的厚度方向Z,极耳部22121的投影面积为S1,即极耳部22121在极耳部的厚度方向Z上的投影所限定的区域的面积大小为S1
沿极耳部的厚度方向Z,极耳部22121上的多个凸起22121a的投影面积之和为S2,即每个凸起22121a在极耳部的厚度方向Z上的投影限定的区域的面积相加后为S2。需要说明的是,若极耳部22121只有一侧设置有凸 起22121a,则S2为极耳部22121的一侧的多个凸起22121a在极耳部的厚度方向Z上的投影面积之和;若极耳部22121的两侧均设置有多个凸起22121a,则S2为极耳部22121的两侧的多个凸起22121a在极耳部的厚度方向Z上的投影面积之和。
示例性的,极耳部22121上的多个凸起22121a的投影面积之和S2可以是极耳部22121的投影面积S1的0.5倍、0.55倍、0.58倍、0.6倍、0.65倍、0.7倍或0.8倍等。
需要说明的是,在获取S1和S2时,也就是说,在测量极耳部22121的投影面积S1以及极耳部22121上的多个凸起22121a的投影面积之和S2时,需要先将极片221展开后进行测量(如图7所示),以获得S1和S2,即S1为极耳部22121在极片221处于展开状态时在极耳部的厚度方向Z上的投影面向,S2为极耳部22121上的多个凸起22121a在极片221处于展开状态时在极耳部的厚度方向Z上的投影面积之和。
通过将极耳部22121上的多个凸起22121a在极耳部的厚度方向Z上的投影面积之和设置为大于或等于极耳部22121在极耳部的厚度方向Z上的投影面积的一半,使得多个凸起22121a在极耳部22121上占用的面积为极耳部22121的一半或一半以上,以使极耳部22121上具有足够的区域设置有凸起22121a,从而在极耳2212的多个极耳部22121沿第一方向X层叠后使得极耳2212具有足够的厚度,且能够有效提升极耳2212厚度的均匀性,以降低极耳2212在后续装配过程中存在被焊穿的风险。
根据本申请的一些实施例,参见图8和图10所示,极耳部22121包括在极耳部的厚度方向Z上与凸起22121a的投影不重叠的主体区22121c,凸起22121a沿极耳部的厚度方向Z凸出于主体区22121c。沿极耳部的厚度方向Z,极耳部22121的最大尺寸为D1,主体区22121c的厚度为D2,满足,2≤D1/D2≤8。
其中,极耳部22121包括在极耳部的厚度方向Z上与凸起22121a的投影不重叠的主体区22121c,即极耳部22121未形成有凸起22121a的区域则为主体区22121c,使得主体区22121c在极耳部的厚度方向Z上的投影与凸起22121a在极耳部的厚度方向Z上的投影互不相交,也就是说,凸起22121a在极耳部的厚度方向Z上凸出于主体部2211的一侧。
极耳部22121的最大尺寸为D1,主体区22121c的厚度为D2,满足,2≤D1/D2≤8,即极耳部22121在其厚度方向上的最大厚度为主体区22121c自身壁厚的2倍到8倍,也就是说,极耳部22121在冲压或辊压等工艺形成凸起22121a后的最大厚度为极耳部22121在未进行冲压或辊压等工艺之前的厚度的2倍到8倍。
示例性的,极耳部22121的最大尺寸D1可以是主体区22121c的厚度D2的2倍、2.5倍、2.8倍、3倍、3.5倍、4倍、5倍、6倍或8倍等。
需要说明的是,如果极片221为正极片,则极片221对应的极耳2212为正极耳,而正极耳的极耳部22121在冲压或辊压形成凸起22121a之前的厚度为10μm-16μm;如果极片221为负极片,则极片221对应的极耳2212为负极耳,而负极耳的极耳部22121在冲压或辊压形成凸起22121a之前的厚度为4μm-10μm。
极耳部22121具有在极耳部的厚度方向Z上与凸起22121a的投影不重叠的主体区22121c,且凸起22121a在极耳部的厚度方向Z上凸出于主体区22121c,即极耳部22121的主体区22121c为极耳部22121未设置凸起22121a的区域,通过将极耳部22121在极耳部的厚度方向Z上的最大尺寸设置为主体区22121c的厚度的2倍到8倍,也就是说,极耳部22121设置有凸起22121a后的最大厚度为极耳部22121的主体区22121c的厚度的2倍到8倍,从而在极耳部22121相对于第一方向X弯折后能够有效提升极耳2212的多个极耳部22121沿第一方向X相互层叠的厚度,以实现极耳2212的厚度的增加,进而能够有效缓解极耳2212在后续装配过程中出现被焊穿的现象。
根据本申请的一些实施例,参见图7、图9和图10所示,极耳部22121形成有多排凸起22121a,每排凸起22121a包括间隔设置多个凸起22121a。
其中,极耳部22121形成有多排凸起22121a,每排凸起22121a包括间隔设置多个凸起22121a,也就是说,极耳部22121上的多个凸起22121a呈排列方式设置,使得多个凸起22121a为多排和多列的布置方式。在极片221未被卷绕之前,即在极片221展开的结构中,每排的多个凸起22121a可以是沿第一方向X间隔设置,也可以是沿卷绕方向Y(主体部2211的延伸方向)间隔设置。
在这种结构的极耳部22121中,凸起22121a的形状可以是多种,示例性的,在图9和图10中,凸起22121a为半球形结构,参照图11和图12所示,图11为本申请又一些实施例提供的极耳部22121的结构示意图,图12为本申请又一些实施例提供的极耳部22121的正视图,凸起22121a还可以为方形柱状结构。当然,凸起22121a的结构并不局限于此,在其他实施例中,凸起22121a还可以是圆柱状结构、三角形柱状结构、五边形柱状结构等。
通过在极耳部22121上设置多排凸起22121a,且每排凸起22121a包括间隔设置的多个凸起22121a,以使极耳部22121上的多个凸起22121a呈排列方式设置,从而在极耳2212的多个极耳部22121沿第一方向X层叠后能够有效增加相互层叠且相邻的两个极耳部22121之间具有空腔的区域,进而有利于进一步提升极耳2212在第一方向X上的整体厚度,且能够有效提升极耳2212厚度的均匀性,以减少极耳2212在后续装配过程中出现被焊穿的现象。
在一些实施例中,参见图10和图12所示,凸起22121a在垂直于极耳部的厚度方向Z的方向上的最大尺寸为W1,满足,0.3mm≤W1≤2mm。
其中,凸起22121a在垂直于极耳部的厚度方向Z的方向上的最大尺寸为W1,即在垂直于极耳部的厚度方向Z的平面内的任意方向上,凸起22121a的最大宽度为W1,也就是说,在垂直于极耳部的厚度方向Z的平面内,凸起22121a在其径向上的最大宽度为W1。比如,若凸起22121a为半球形结构或圆柱状结构,则W1为凸起22121a的直径;若凸起22121a为方形柱状结构,则W1为凸起22121a的对角线的长度。
示例性的,凸起22121a在垂直于极耳部的厚度方向Z的方向上的最大尺寸W1可以是0.3mm、0.5mm、0.8mm、1mm、1.2mm、1.5mm或2mm等。
通过将凸起22121a在垂直于极耳部的厚度方向Z的方向上的最大尺寸设置在0.3mm到3mm,即凸起22121a在其径向上的最大尺寸为0.3mm到3mm,一方面能够缓解因凸起22121a的尺寸过小而导致加工难度过大的现象,以降低极耳部22121的加工难度,另一方面能够缓解因凸起22121a的尺寸过大而造成极耳部22121上的多个凸起22121a的数量设置受限的现象。此外,在极耳部22121背离凸起22121a的一侧且对应凸起22121a的位置设置有凹槽22121b的实施例中,采用这种结构能够有效缓解因凸起22121a的尺寸过大而造成极耳2212的多个极耳部22121在相互层叠后相邻的两个极耳部22121的凸起22121a和凹槽22121b出现相互重叠抵消的现象,从而使得相互层叠且相邻的两个极耳部22121之间存在空腔,以提升极耳2212的整体厚度。
根据本申请的一些实施例,参照图13和图14,图13为本申请再一些实施例提供的极耳部22121的结构示意图,图14为本申请再一些实施例提供的极耳部22121的正视图。极耳部22121形成有间隔排布的多个凸起22121a,凸起22121a的两端沿垂直于多个凸起22121a的排布方向的方向分别延伸至极耳部22121的两端。
其中,多个凸起22121a的排布方向是指在垂直于极耳部的厚度方向Z的平面内多个凸起22121a依次间隔排布的方向。
凸起22121a的两端沿垂直于多个凸起22121a的排布方向的方向分别延伸至极耳部22121的两端,也就是说,凸起22121a为条状结构,且凸起22121a的两端分别沿垂直于多个凸起22121a的排布方向的方向延伸至极耳部22121的两端,使得多个凸起22121a为沿凸起22121a的宽度方向间隔排布的布置方式。需要说明的是,在极片221处于展开状态时,条状结构的凸起22121a的延伸方向可以是沿第一方向X,也可以是沿卷绕方向Y(主体部2211的延伸方向)。
示例性的,在图13和图14中,凸起22121a为横截面为矩形的条状结构,当然,在其他实施例中,凸起22121a也可以是横截面为半圆形、五边形等形状的条状结构。
通过在极耳部22121上形成间隔设置的多个凸起22121a,且凸起22121a的两端延伸至极耳部22121的两端,以实现在极耳部22121上设置多个凸起22121a的结构,采用这种结构有利于降低在极耳部22121上设置凸起22121a的难度,以提升极耳部22121的加工效率。
在一些实施例中,参见图14所示,沿多个凸起22121a的排布方向,凸起22121a的宽度为W2,满足,0.3mm≤W2≤2mm。
其中,凸起22121a的宽度为W2,即在多个凸起22121a的排布方向上,凸起22121a的最大尺寸为W2
示例性的,凸起22121a的宽度为W2可以是0.3mm、0.5mm、0.8mm、1mm、1.2mm、1.5mm或2mm等。
通过将凸起22121a在多个凸起22121a的排布方向上的宽度设置在0.3mm到3mm,即凸起22121a在垂直于凸起22121a的延伸方向的方向上的尺寸为0.3mm到3mm,一方面能够缓解因凸起22121a的宽度过小而导致加工难度过大的现象,以降低极耳部22121的加工难度,另一方面能够缓解因凸起22121a的宽度过大而造成极耳部22121上的多个凸起22121a的数量设置受限的现象。此外,在极耳部22121背离凸起22121a的一侧且对应凸起22121a的位置设置有凹槽22121b的实施例中,采用这种结构能够有效缓解因凸起22121a的宽度过大而造成极耳2212的多个极耳部22121在相互层叠后相邻的两个极耳部22121的凸起22121a和凹槽22121b出现相互重叠抵消的现象,从而使得相互层叠且相邻的两个极耳部22121之间存在空腔,以满足抚平后的极耳2212具有足够的厚度需求。
根据本申请的一些实施例,参照图15和图16,图15为本申请另一些实施例提供的极片221在展开后的局部剖视图,图16为本申请另一些实施例提供的极片221的极耳部22121的剖视图。沿极耳部的厚度方向Z,极耳部22121可以包括层叠设置的多个箔材22121d,箔材22121d的一侧形成有凸部22121e,另一侧与凸部22121e对应的位置形成有凹部22121f,在相邻的两个箔材22121d中,一个箔材22121d的凸部22121e容纳于另一个箔材22121d的凹部22121f内。沿极耳部的厚度方向Z,位于极耳部22121的一侧的凸部22121e为凸起22121a。
其中,沿极耳部的厚度方向Z,极耳部22121包括层叠设置的多个箔材22121d,即极耳部22121由多个箔材22121d组成,且多个箔材22121d沿极耳部的厚度方向Z层叠设置,以形成极耳2212的极耳部22121。示例性的,在图15和图16中,极耳部22121可以包括两个箔材22121d,两个箔材22121d中的一个箔材22121d与主体部2211相连,另一个箔材22121d沿极耳部的厚度方向Z层叠于连接在主体部2211上的箔材22121d的一侧。当然,在其他实施例中,极耳部22121可以是由三个、四个、五个或六个等箔材22121d层叠而成。需要说明的是,在一些实施例中,极耳部22121也可以仅包括一个箔材22121d。
箔材22121d的一侧形成有凸部22121e,另一侧与凸部22121e对应的位置形成有凹部22121f,也就是说,在极耳部的厚度方向Z,箔材22121d的一侧形成有凸出于箔材22121d的凸部22121e,另一侧在对应凸部22121e的位置形成有凹部22121f,使得凸部22121e和凹部22121f在极耳部的厚度方向Z上一一对应设置。
在相邻的两个箔材22121d中,一个箔材22121d的凸部22121e容纳于另一个箔材22121d的凹部22121f内,也就是说,沿极耳部的厚度方向Z,在层叠设置且相邻的两个箔材22121d中,一个箔材22121d的凸部22121e与另一个箔材22121d的凹槽22121b一一对应设置,使得一个箔材22121d的凸部22121e能够嵌设于另一个箔材22121d的凹槽22121b内,以实现两个箔材22121d能够紧密贴合。
沿极耳部的厚度方向Z,位于极耳部22121的一侧的凸部22121e为凸起22121a,也就是说,极耳部22121的多个箔材22121d中位于一侧的箔材22121d的凸部22121e即为极耳部22121的一侧的凸起22121a,对应的,极耳部22121的多个箔材22121d中位于另一侧的箔材22121d的凹部22121f即为极耳部22121的另一侧的凹槽22121b。
示例性的,极耳部22121的多个箔材22121d之间的连接方式可以是多种,比如,卡接、粘接或焊接等。
通过将极耳部22121设置为多个箔材22121d层叠设置的结构,且箔材22121d的一侧形成有凸部22121e,另一侧形成有凹部22121f,使得多个箔材22121d层叠后相邻的两个箔材22121d的凸部22121e和凹部 22121f能够相互嵌设,以实现极耳部22121在极耳部的厚度方向Z上的一侧形成有凸起22121a,采用这种结构的极耳部22121能够有效增加极耳部22121自身的厚度和结构强度,从而在极耳2212的多个极耳部22121沿第一方向X层叠后能够进一步增加极耳2212的整体厚度和结构强度,以进一步降低极耳2212在后续装配过程中出现被焊穿的风险。
根据本申请的一些实施例,参见图16所示,多个箔材22121d焊接连接,以在箔材22121d上形成凸部22121e和凹部22121f。也就是说,多个箔材22121d在相互焊接的过程中且在相互焊接的位置对应形成有凸部22121e和凹部22121f,即箔材22121d上的凸部22121e和凹部22121f为多个箔材22121d焊接形成的结构。
示例性的,多个箔材22121d通过超声波辊焊连接,以实现在箔材22121d焊接的位置形成凸部22121e和凹部22121f。超声波辊焊的具体连接方式可参见相关技术,在此不再赘述。
采用焊接的方式连接层叠设置的多个箔材22121d,并通过焊接的方式在多个箔材22121d相互焊接的位置形成凸部22121e和凹部22121f,一方面有利于提升多个箔材22121d之间的连接强度和连接稳定性,另一方面有利于降低在箔材22121d上形成凹部22121f和凸部22121e的加工难度,以优化极片221的生产节拍,从而能够有效提升极片221的生产效率。
根据本申请的一些实施例,参见图5、图15和图16所示,极片221可以包括主体部2211,多个极耳部22121连接于主体部2211,两个极片221的主体部2211和隔离件222沿卷绕方向Y卷绕形成主体223。主体部2211包括基材22111和设置于基材22111的至少一侧的活性物质层22112。多个箔材22121d可以包括层叠设置的第一箔材22121g和第二箔材22121h,第一箔材22121g连接于基材22111在第一方向X上的一端,并与基材22111一体成型,第二箔材22121h与基材22111分体设置。
其中,极耳2212的多个极耳部22121连接于主体部2211在第一方向X上的一端,在极片221处于展开状态时,极耳2212与主体部2211沿第一方向X排布,且极耳2212的多个极耳部22121沿主体部2211的延伸方向间隔设置;在极片221卷绕形成电极组件22,且极耳部22121相对于第一方向X弯折设置后,极耳2212的多个极耳部22121沿卷绕方向Y间隔设置,极耳部22121连接于主体部2211在第一方向X上的一端,并与主体部2211呈非零夹角设置。
基材22111的至少一侧设置有活性物质层22112,也就是说,基材22111可以是仅一侧设置有活性物质层22112,也可以是基材22111的两侧均设置有活性物质层22112。示例性的,在图15中,基材22111的两侧均设置有活性物质层22112。
活性物质层22112是电池单体20内发生化学反应的区域,主要依靠金属离子两个极片221的活性物质层22112之间移动来工作。当然,在一些实施例中,基材22111上还可以涂覆有绝缘保护层,绝缘保护层沿第一方向X设置于活性物质层22112的一端或两端,以对活性物质层22112起到保护和分隔的作用。当然,在其他实施例中,活性物质层22112在第一方向X上的一端也可以不设置绝缘保护层,即基材22111上只涂覆有活性物质层22112。
需要说明的是,如果极片221为正极片,则极片221对应的主体部2211的活性物质层22112的材质可以为钴酸锂、磷酸铁锂、三元锂或锰酸锂等;如果极片221为负极片,则极片221对应的主体部2211的活性物质层22112的材质可以为碳或硅等。
第一箔材22121g连接于基材22111在第一方向X上的一端,并与基材22111一体成型,即第一箔材22121g与基材22111相连,且第一箔材22121g为基材22111上通过裁切和加工形成的结构。当然,在其他实施例中,第一箔材22121g与基材22111也可以是分体式结构,比如,第一箔材22121g通过焊接等方式连接于基材22111在第一方向X上的一端,同样的,第一箔材22121g与基材22111也可以是间接连接,比如,第一箔材22121g与基材22111通过其他导电部件间接连接。
示例性的,第一箔材22121g在垂直于极耳部的厚度方向Z的方向上的一端连接于基材22111在第一方向X上的一端。
需要说明的是,在极片221展开后,极耳部的厚度方向Z与第一方向X为相互垂直的结构,则第一箔材22121g在垂直于极耳部的厚度方向Z的方向上的一端连接于基材22111在第一方向X上的一端即为第一箔材22121g在第一方向X上的一端与基材22111在第一方向X上的一端相连(参见图15所示)。
第二箔材22121h与基材22111分体设置,也就是说,第二箔材22121h与基材22111为相互独立的两个部件。示例性的,在图15中,第二箔材22121h层叠并连接于第一箔材22121g在极耳部的厚度方向Z的一侧。需要说明的是,在其他实施例中,在极耳部的厚度方向Z上,第一箔材22121g可以是仅在一侧设置有第二箔材22121h,也可以是在两侧均设置有第二箔材22121h,且设置于第一箔材22121g的一侧的第二箔材22121h的数量可以是一个,也可以是多个。
多个箔材22121d中包括与极片221的主体部2211的基材22111一体成型的第一箔材22121g,在实际生产中,可在基材22111上预留未设置活性物质层22112的区域,从而能够在该区域上设置第一箔材22121g,再将第二箔材22121h层叠设置于第一箔材22121g的一侧即可,使得第一箔材22121g的能够为第二箔材22121h提供连接支撑点,以实现极耳部22121的厚度和结构强度的提升,采用这种结构的极片221能够有效降低极耳部22121连接于基材22111的工艺难度,有利于提高电极组件22的生产效率。
根据本申请的一些实施例,参见图5和图15所示,基材22111包括涂覆区22111a和间隔区22111b,涂覆区22111a与间隔区22111b沿第一方向X排布,活性物质层22112设置于涂覆区22111a,间隔区22111b连接涂覆区22111a和第一箔材22121g。
其中,基材22111的间隔区22111b为基材22111上未涂覆有活性物质层22112的区域。涂覆区22111a与间隔区22111b沿第一方向X排布,且间隔区22111b连接涂覆区22111a和第一箔材22121g,即当极片221展开 后,在第一方向X上,间隔区22111b连接于涂覆区22111a和第一箔材22121g之间。
在图15中,间隔区22111b为基材22111上空白的区域,需要说明的是,在一些实施例中,基材22111上未涂覆有活性物质层22112的间隔区22111b上也可以涂覆绝缘保护层等,以对活性物质层22112起到保护作用。当然,在其他实施例中,主体部2211的基材22111还可以不设置间隔区22111b,即第一箔材22121g直接与基材22111的涂覆区22111a相连,也就是说,活性物质层22112完全覆盖基材22111的一侧,以使第一箔材22121g连接于基材22111的一端。
通过在基材22111上设置涂覆有活性物质层22112的涂覆区22111a和未涂覆有活性物质层22112的间隔区22111b,使得极耳部22121的第一箔材22121g能够通过间隔区22111b与涂覆区22111a相连,以实现极耳部22121与活性物质层22112在第一方向X上间隔设置,采用这种结构的电极组件22一方面通过间隔区22111b能够间隔极耳部22121在相对于第一方向X弯折加工的过程中产生的应力,以减少设置于涂覆区22111a上的活性物质层22112出现断裂的风险,另一方面在极耳2212后续与其他部件焊接的过程中能够减少焊接过程中对活性物质层22112造成的影响,从而能够缓解活性物质层22112被损坏的现象,进而有利于提高电极组件22的生产质量。
根据本申请的一些实施例,参见图16所示,沿极耳部的厚度方向Z,第一箔材22121g的厚度为D3,第二箔材22121h的厚度为D4,满足,0.5≤D3/D4≤2。
其中,第一箔材22121g的厚度D3为第一箔材22121g的自身的壁厚,也就是说,第一箔材22121g的厚度D3为第一箔材22121g未形成有凸部22121e和凹部22121f的区域的厚度,即第一箔材22121g的厚度D3为第一箔材22121g在加工形成凸部22121e和凹部22121f之前的厚度。
第二箔材22121h的厚度D4为第二箔材22121h的自身的壁厚,也就是说,第二箔材22121h的厚度D4为第一箔材22121g未形成有凸部22121e和凹部22121f的区域的厚度,即第二箔材22121h的厚度D4为第二箔材22121h在加工形成凸部22121e和凹部22121f之前的厚度。
示例性的,第一箔材22121g的厚度D3可以是第二箔材22121h的厚度D4的0.5倍、0.6倍、0.75倍、0.8倍、1倍、1.2倍、1.5倍或2倍等。
在实验过程中,选用厚度为12μm的第一箔材22121g进行实验,并将第二箔材22121h的厚度设置为不同大小的情况下进行实验,以测量第一箔材22121g的厚度与第二箔材22121h的厚度比值在不同情况下对第一箔材22121g和第二箔材22121h相互焊接装配造成的影响,实验结果如下:
从上面的实验数据可以看出,在第一箔材22121g的厚度D3与第二箔材22121h的厚度D4的比值大于2时,第二箔材22121h会在焊接的过程中出现焊裂的现象,从而产生碎屑,无法满足第一箔材22121g和第二箔材22121h相互焊接装配的需求,在第一箔材22121g的厚度D3与第二箔材22121h的厚度D4的比值小于或等于2时,第一箔材22121g和第二箔材22121h在相互焊接的过程中均未出现焊裂的现象,因此,将第一箔材22121g的厚度D3与第二箔材22121h的厚度D4的比值设置为小于或等于2。
同样的,在第一箔材22121g的厚度D3与第二箔材22121h的厚度D4的比值小于0.5时,第一箔材22121g会在焊接的过程中出现焊裂的现象,从而产生碎屑,无法满足第一箔材22121g和第二箔材22121h相互焊接装配的需求,在第一箔材22121g的厚度D3与第二箔材22121h的厚度D4的比值大于或等于0.5时,第一箔材22121g和第二箔材22121h在相互焊接的过程中均未出现焊裂的现象,因此,将第一箔材22121g的厚度D3与第二箔材22121h的厚度D4的比值设置为大于或等于0.5。
通过将第一箔材22121g的厚度设置为第二箔材22121h的厚度的0.5到2,即第一箔材22121g的厚度为第二箔材22121h的厚度的0.5倍到2倍,从而能够缓解因第一箔材22121g的厚度与第二箔材22121h的厚度相差过大而造成第一箔材22121g与第二箔材22121h相互连接的装配难度过大的现象,以降低这种结构的极耳部22121的加工难度。此外,一方面能够缓解因第一箔材22121g的厚度相较于第二箔材22121h的厚度过大时造成第二箔材22121h在相互焊接的过程中出现损坏的现象,另一方面能够缓解因第二箔材22121h的厚度相较于第一箔材22121g的厚度过大时造成第一箔材22121g在相互焊接的过程中出现损坏的现象。
根据本申请的一些实施例,请参见图15和图16所示,沿垂直于极耳部的厚度方向Z的方向,第二箔材22121h靠近基材22111的一端不超出第一箔材22121g连接于基材22111的一端。需要说明的是,在极片221为展开的状态时,则为在第一方向X上,第二箔材22121h靠近基材22111的一端不超出第一箔材22121g连接于基材22111的一端。
其中,第二箔材22121h靠近基材22111的一端不超出第一箔材22121g连接于基材22111的一端,也就是说,第一箔材22121g连接于基材22111的一端可以是与第二箔材22121h相互平齐,也可以是延伸出第二箔材 22121h。示例性的,在图15和图16中,第一箔材22121g连接于基材22111的一端延伸出第二箔材22121h靠近基材22111的一端。
需要说明的是,在极片221处于展开的状态时,则是第二箔材22121h为在第一方向X上靠近基材22111的一端不超出第一箔材22121g在第一方向X上连接于基材22111的一端。若极片221卷绕形成电极组件22,且极耳的多个极耳部22121被抚平或揉平并层叠于电极组件22的一端之后,则是第二箔材22121h在垂直于第一方向X上沿第一箔材22121g远离基材22111的一端指向第一箔材22121g连接于基材22111的一端的方向不超出第一箔材22121g连接于基材22111的一端。
通过将第二箔材22121h在垂直于极耳部的厚度方向Z的方向上设置为不超出第一箔材22121g连接于基材22111的一端,从而能够有效缓解第二箔材22121h与设置于基材22111的一侧上的活性物质层22112之间的干涉影响,以降低活性物质层22112被第二箔材22121h损坏的风险。
根据本申请的一些实施例,请继续参见图15和图16所示,沿垂直于极耳部的厚度方向Z的方向,第一箔材22121g远离基材22111的一端与第二箔材22121h远离基材22111的一端之间的距离为L,满足,L≤2mm。需要说明的是,在极片221为展开的状态时,则L为在第一方向X上,第一箔材22121g远离基材22111的一端与第二箔材22121h远离基材22111的一端之间的距离。
其中,第一箔材22121g远离基材22111的一端与第二箔材22121h远离基材22111的一端之间的距离为L,即第一箔材22121g远离基材22111的一端与第二箔材22121h远离基材22111的一端可以是相互平齐,也可以是相互错位设置,若第一箔材22121g远离基材22111的一端与第二箔材22121h远离基材22111的一端为错位设置,则第一箔材22121g远离基材22111的一端与第二箔材22121h远离基材22111的一端的间距小于或等于2mm。
需要说明的是,第一箔材22121g远离基材22111的一端与第二箔材22121h远离基材22111的一端之间的距离为L,可以是第一箔材22121g远离基材22111的一端超出第二箔材22121h远离基材22111的一端,且第一箔材22121g超出第二箔材22121h的尺寸小于或等于2mm;也可以是第二箔材22121h远离基材22111的一端超出第一箔材22121g远离基材22111的一端,且第二箔材22121h超出第一箔材22121g的尺寸小于或等于2mm。同样的,L可以为0mm、0.2mm、0.5mm、1mm、1.5mm或2mm等。
示例性的,在图16中,第一箔材22121g远离基材22111的一端超出第二箔材22121h远离基材22111的一端,第一箔材22121g超出第二箔材22121h的部分的尺寸为L。
通过将第一箔材22121g远离基材22111的一端和第二箔材22121h远离基材22111的一端在垂直于极耳部的厚度方向Z的方向上的间距设置为小于或等于2mm,也就是说,第一箔材22121g远离基材22111的一端超出第二箔材22121h远离基材22111的一端的尺寸为小于或等于2mm,或第二箔材22121h远离基材22111的一端超出第一箔材22121g远离基材22111的一端的尺寸为小于或等于2mm,从而能够缓解因第一箔材22121g的长度或第二箔材22121h的长度过大而出现第一箔材22121g超出第二箔材22121h过多或第二箔材22121h超出第一箔材过多,以导致极耳部22121存在冗长或倒插至电极组件22内的现象,从而有利于提升电极组件22的生产质量和使用可靠性。
在一些实施例中,第一箔材22121g与第二箔材22121h的材质相同。也就是说,第一箔材22121g和第二箔材22121h均由同一种材质制成。
示例性的,第一箔材22121g的材质和第二箔材22121h的材质可以多种,比如,铜、铁、铝、钢、铝合金等。
通过将第一箔材22121g与第二箔材22121h设置为相同材质,一方面能够实现极耳部22121的极性稳定,另一方面能够降低第一箔材22121g与第二箔材22121h相互连接的工艺难度。
根据本申请的一些实施例,参见图5、图7和图8所示,极片221可以包括主体部2211,多个极耳部22121连接于主体部2211在第一方向X上的一端,两个极片221的主体部2211和隔离件222沿卷绕方向Y卷绕形成主体223。主体部2211包括基材22111和设置于基材22111的至少一侧的活性物质层22112,基材22111包括涂覆区22111a和间隔区22111b,涂覆区22111a与间隔区22111b沿第一方向X排布,活性物质层22112设置于涂覆区22111a,间隔区22111b连接涂覆区22111a和极耳部22121。
其中,极耳2212的多个极耳部22121连接于主体部2211在第一方向X上的一端,在极片221处于展开状态时,极耳2212与主体部2211沿第一方向X排布,且极耳2212的多个极耳部22121沿主体部2211的延伸方向间隔设置;在极片221卷绕形成电极组件22,且极耳部22121相对于第一方向X弯折设置后,极耳2212的多个极耳部22121沿卷绕方向Y间隔设置,极耳部22121连接于主体部2211在第一方向X上的一端,并与主体部2211呈非零夹角设置。
基材22111的至少一侧设置有活性物质层22112,即基材22111可以是一侧设置有活性物质层22112,也可以是两侧均设置有活性物质层22112。示例性的,在图8中,基材22111的两侧均设置有活性物质层22112。
基材22111的间隔区22111b为基材22111上未涂覆有活性物质层22112的区域,涂覆区22111a与间隔区22111b沿第一方向X排布,且间隔区22111b连接涂覆区22111a和极耳部22121,即在第一方向X上,间隔区22111b连接于涂覆区22111a和极耳部22121之间。需要说明的是,在这种实施例中,极耳部22121可以是只包括一个箔材22121d的结构,极耳部22121也可以是包括层叠设置的多个箔材22121d的结构。
在图8中,间隔区22111b为基材22111上空白的区域,需要说明的是,在一些实施例中,基材22111上未涂覆有活性物质层22112的间隔区22111b上也可以涂覆绝缘保护层等,以对活性物质层22112起到保护作用。当然,在其他实施例中,主体部2211的基材22111上也可以不设置间隔区22111b,即极耳部22121直接与基材22111的涂覆区22111a相连,也就是说,活性物质层22112完全覆盖基材22111的一侧,以使极耳部22121连接于基材22111的一端。
通过在基材22111上设置涂覆有活性物质层22112的涂覆区22111a和未涂覆有活性物质层22112的间隔区22111b,使得极耳部22121能够通过间隔区22111b与涂覆区22111a相连,以实现极耳部22121与活性物质层22112在第一方向X上间隔设置,采用这种结构的电极组件22一方面通过间隔区22111b能够间隔极耳部22121在相对于第一方向X弯折加工的过程中产生的应力,以减少设置于涂覆区22111a上的活性物质层22112出现断裂的风险,另一方面在极耳2212后续与其他部件焊接的过程中能够减少焊接过程中对活性物质层22112造成的影响,从而能够缓解活性物质层22112被损坏的现象,进而有利于提高电极组件22的生产质量。
在一些实施例中,参见图5所示,极耳部22121与间隔区22111b一体成型。
其中,极耳部22121与间隔区22111b一体成型,即极耳部22121只包括一个箔材22121d,且极耳部22121为基材22111上通过裁切和加工形成的结构。当然,在其他实施例中,极耳部22121与基材22111也可以是分体式结构,比如,极耳部22121通过焊接等方式连接于基材22111在第一方向X上的一端。
需要说明的是,在主体部2211的基材22111上未设置间隔区22111b的实施例中,极耳部22121也可以是与基材22111一体成型的结构,也就是说,极耳部22121与基材22111的涂覆区22111a一体成型。
通过将极耳部22121设置为与基材22111的间隔区22111b一体成型的结构,使得在实际生产过程中极耳部22121可以为基材22111的一部分,可在基材22111上预留未设置活性物质层22112的区域后便能够在该区域上设置极耳部22121,以降低极耳部22121连接于基材22111上的工艺难度,有利于提高电极组件22的生产效率。
根据本申请的一些实施例,参见图5和图8所示,沿极耳部的厚度方向Z,极耳部22121背离凸起22121a的一侧且对应凸起22121a的位置形成有凹槽22121b。
其中,沿极耳部的厚度方向Z,极耳部22121背离凸起22121a的一侧且对应凸起22121a的位置形成有凹槽22121b,也就是说,极耳部22121的一侧形成有凸起22121a,另一侧对应凸起22121a的位置形成有凹槽22121b,使得凸起22121a和凹槽22121b在极耳部的厚度方向Z一一对应设置。
示例性的,这种结构的极耳部22121的加工方式可以是多种,比如,冲压或辊压等。
通过在极耳部22121背离凸起22121a的一侧且对应凸起22121a的位置设置有凹槽22121b,使得这种结构的极耳部22121能够通过冲压或辊压等工艺便能够实现在极耳部22121上形成有凸起22121a,一方面有利于降低极耳部22121的加工难度,且有利于提升极耳部22121的加工效率,另一方面无需通过增加材料的方式在极耳部22121的一侧设置凸起22121a,从而有利于降低极耳部22121的生产成本,且有利于减轻极耳部22121的重量。
根据本申请的一些实施例,参照5和图8,并请进一步参照图17,图17为本申请一些实施例提供的电极组件22的极耳2212的多个极耳部22121在层叠后的剖视图。沿第一方向X,在相邻的两个极耳部22121中,一个极耳部22121的凸起22121a与另一个极耳部22121的凹槽22121b错位设置。
其中,在相邻的两个极耳部22121中,一个极耳部22121的凸起22121a与另一个极耳部22121的凹槽22121b错位设置,即相邻的两个极耳部22121中,一个极耳部22121的凸起22121a与另一个极耳部22121的凹槽22121b在第一方向X上未对齐。
通过在第一方向X上相邻的两个极耳部22121中将一个极耳部22121的凸起22121a与另一个极耳部22121的凹槽22121b设置为相互错位的结构,从而能够有效缓解凸起22121a与凹槽22121b重叠后出现相互抵消的现象,以使极耳2212在第一方向X上具有足够的厚度,进而有利于降低电极组件22的极耳2212在后续装配过程中出现被焊穿的风险。
在一些实施例中,请参见图17所示,沿第一方向X,极耳2212的厚度为D5,满足,0.2mm≤D5≤2.5mm。
其中,极耳2212的厚度为D5,即极耳2212的多个极耳部22121通过抚平或揉平等工艺相对于第一方向X弯折设置并层叠于电极组件22的主体223在第一方向X上的一端后,极耳2212在第一方向X上的尺寸为D5
示例性的,极耳2212的厚度D5可以为0.2mm、0.3mm、0.4mm、0.5mm、0.8mm、1mm、1.5mm、2mm或2.5mm等。
通过将极耳2212在第一方向X上的厚度设置在0.2mm到2.5mm,一方面能够缓解因极耳2212的厚度过小而容易出现极耳2212被焊穿的风险,以降低电极组件22在后续装配过程中出现被损坏的风险,另一方面能够缓解因极耳2212的厚度过大而造成极耳2212的占用空间过大的现象,从而有利于优化具有这种电极组件22的电池单体20的内部空间,以提升电池单体20的能量密度。
根据本申请的一些实施例,参见图4、图5和图6所示,沿第一方向X,两个极耳2212分别设置于电极组件22的主体223的两端。
其中,两个极片221的极性相反,即两个极片221分别为电极组件22的正极片和负极片。
两个极耳2212分别设置于电极组件22的主体223的两端,即极性相反的两个极片221的极耳2212分别形成于电极组件22在第一方向X上的两端,从而使得电极组件22在第一方向X上的两端分别形成正极耳和负极耳,以输出或输入电极组件22的正极和负极。
通过将电极组件22的两个极耳2212分别设置于电极组件22的主体223在第一方向X上的两端,以使两个极耳2212分别形成于电极组件22在第一方向X上的两端,从而便于后续对电极组件22进行装配,有利于降低具有这种电极组件22的电池单体20的装配难度,且能够减少两个极耳2212之间出现的干涉或相互接触的现象,进而有利于降低电极组件22的短接风险。
在一些实施例中,参见图3、图4和图5所示,电极组件22的主体223呈圆柱状。当然,电极组件22的主体223的结构并不局限于此,在其他实施例中,电极组件22的主体223也可以为横截面为椭圆形的柱状结构。
通过将电极组件22设置为圆柱形结构,以便于后续加工形成圆柱体结构的电池单体20。
根据本申请的一些实施例,参见图3所示,本申请实施例还提供了一种电池单体20,包括外壳21和以 上任一方案的电极组件22,电极组件22容纳于外壳21内。
其中,外壳21可以包括壳体211和端盖212,壳体211为一侧开口2111的空心结构,端盖212封闭壳体211的开口2111,以形成用于容纳电极组件22的密封空间。
壳体211可以是多种形状,比如,圆柱体、长方体等。壳体211的形状可根据电极组件22的具体形状来确定。示例性的,在图3中,电极组件22呈圆柱状,对应的,可以为圆柱体结构。
在一些实施例中,外壳21还可以包括正极电极端子和负极电极端子,正极电极端子安装于端盖212上,负极电极端子安装于壳体211与端盖212相对的一端上。当然,在其他实施例中,也可以是正极电极端子安装于壳体211与端盖212相对的一端上,负极电极端子安装于端盖212上。
其中,正极电极端子和负极电极端子分别用于与电极组件22在第一方向X上的两端的极耳2212电连接,以起到输出或输入电池单体20的电能的作用,示例性的,正极电极端子和负极电极端子的材质可以是多种,比如,铜、铁、铝、钢或铝合金等。
正极电极端子和负极电极端子可以是与电极组件22的极耳2212直接相连,比如,焊接或抵接等,正极电极端子和负极电极端子也可以是与电极组件22的极耳2212间接相连,比如,正极电极端子和负极电极端子通过其他部件与电极组件22抵接或焊接等。
根据本申请的一些实施例,请继续参见图3所示,电池单体20还可以包括集流构件23,集流构件23沿第一方向X设置于外壳21与极耳2212之间,集流构件23连接外壳21与极耳2212。
其中,集流构件23起到连接电极组件22的极耳2212与正极电极端子或负极电极端子的作用,以实现电极组件22与正极电极端子或负极电极端子之间的电连接,集流构件23的材质可以是多种,比如,铜、铁、铝、钢或铝合金等。
示例性的,在图3中,电池单体20包括两个集流构件23,两个集流构件23在第一方向X上分别设置于电极组件22的两端,一个集流构件23连接正极电极端子和电极组件22的一个极耳2212,另一个集流构件23连接负极段极端子和电极组件22的另一个极耳2212,以实现电池单体20的电能的输入或输出。
可选地,集流构件23与极耳2212的连接方式可以是多种,比如,焊接、粘接或抵接等,示例性的,在本申请实施例中,集流构件23与极耳2212焊接连接。
通过在电池单体20的外壳21内设置集流构件23,以通过集流构件23连接外壳21和电极组件22的极耳2212,从而能够实现电池单体20的电能的输入或输出,这种结构简单,便于实现,且有利于降低极耳2212与外壳21之间的装配难度。
根据本申请的一些实施例,参照图3,并请进一步参照图18,图18为本申请一些实施例提供的集流构件23与电极组件22的极耳2212的连接示意图。集流构件23与极耳2212焊接连接,沿第一方向X,极耳2212的厚度为D5,集流构件23的厚度为D6,满足,D6≤1.5D5
其中,集流构件23在第一方向X上设置于电极组件22的一端,以使集流构件23能够与位于电极组件22在第一方向X上的一端的极耳2212相互焊接。
沿第一方向X,极耳2212的厚度为D5,即极耳2212的多个极耳部22121通过抚平或揉平等工艺相对于第一方向X弯折设置并层叠于电极组件22的主体223在第一方向X上的一端后,极耳2212在第一方向X上的尺寸为D5
沿第一方向X,集流构件23的厚度为D6,即集流构件23在第一方向X上的尺寸为D6
D6≤1.5D5,即集流构件23的厚度小于或等于极耳2212的厚度的1.5倍。示例性的,集流构件23的厚度D6可以是极耳2212的厚度D5的1.5倍、1.4倍、1.2倍、1.25倍、1倍、0.9倍、0.8倍、0.75倍或0.5倍等。
在实验过程中,将集流构件23的厚度和极耳2212的厚度设置为不同大小的情况下进行实验,以使集流构件23的厚度和极耳2212的厚度的比值不同进行实验,以测量集流构件23的厚度和极耳2212的厚度的比值在不同情况下对集流构件23和极耳2212在焊接装配过程中造成的影响,实验结果如下:
从上面的实验数据可以看出,在集流构件23的厚度与极耳2212的厚度的比值大于1.5时,极耳2212存在被焊穿的现象,以造成集流构件23与极耳2212的装配质量较差,无法满足装配需求,在集流构件23的厚度与极耳2212的厚度的比值小于或等于1.5时,就可以缓解极耳2212被焊穿的现象,有利于提高集流构件23与极耳2212的装配质量,因此,将集流构件23的厚度与极耳2212的厚度的比值设置为小于或等于1.5,即D6≤1.5D5
通过将集流构件23在第一方向X上的厚度设置为小于或等于极耳2212在第一方向X上的厚度的1.5倍,从而能够缓解因集流构件23的厚度比极耳2212的厚度过大而造成焊接集流构件23与极耳2212的所需焊接功率过大的现象,进而能够有效降低极耳2212出现被焊穿的风险,以减少电极组件22被损坏的现象,有利于提升电池单体20的生产质量。
在一些实施例中,请参见图18所示,集流构件23与极耳2212焊接连接并形成焊印24,沿第一方向X,焊印24覆盖至少一个极耳部22121的凸起22121a。
其中,沿第一方向X,焊印24覆盖至少一个极耳部22121的凸起22121a,即在第一方向X上,集流构件23与极耳2212相互焊接的位置与至少一个极耳部22121的凸起22121a对应设置。
通过将集流构件23和极耳2212相互焊接形成的焊印24设置为在第一方向X上覆盖至少一个极耳部22121的凸起22121a,从而使得集流构件23与极耳2212相互焊接的位置位于极耳2212被凸起22121a加厚的区域,进而有利于进一步降低极耳2212在装配过程中出现被焊穿的风险。
根据本申请的一些实施例,本申请实施例还提供了一种电池100,电池100包括以上任一方案的电池单体20。
其中,电池100还可以包括箱体10,电池单体20容纳于箱体10内。
可选地,容纳于箱体10内的电池单体20可以是一个,也可以是多个,示例性的,在图2中,电池100包括多个电池单体20,且多个电池单体20均容纳于箱体10内。多个电池单体20之间可以是串联或并联或混联,混联是指多个电池单体20中既有串联又有并联。多个电池单体20之间可直接串联或并联或混联在一起,再将多个电池单体20构成的整体容纳于箱体10内。
根据本申请的一些实施例,本申请实施例还提供了一种用电装置,用电装置包括以上任一方案的电池100,并且电池100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100的设备或系统。
根据本申请的一些实施例,参见图4至图10所示,本申请提供了一种电极组件22,电极组件22为卷绕式结构,电极组件22包括极性相反的两个极片221和用于隔离两个极片221的隔离件222,两个极片221以及隔离件222沿卷绕方向Y卷绕形成主体223和两个极耳2212,且两个极片221的极耳2212分别设置于主体223在第一方向X上的两端。极片221包括主体部2211和极耳2212,主体部2211的延伸方向与卷绕方向Y一致。主体部2211包括基材22111和设置于基材22111的两侧的活性物质层22112,基材22111包括涂覆区22111a和间隔区22111b,涂覆区22111a与间隔区22111b沿第一方向X排布,活性物质层22112设置于涂覆区22111a。极耳2212包括多个极耳部22121,极耳部22121连接于间隔区22111b在第一方向X上远离涂覆区22111a的一端,且多个极耳部22121沿卷绕方向Y间隔设置,多个极耳部22121的至少一部分沿第一方向X层叠设置,以在电极组件22沿第一方向X的一端形成极耳2212,极耳2212在第一方向X上的厚度为D5,满足,0.2mm≤D5≤2.5mm。沿极耳部的厚度方向Z,极耳部22121的一侧形成有多个凸起22121a,极耳部22121背离凸起22121a的一侧且对应凸起22121a的位置形成有凹槽22121b,沿第一方向X,在相邻的两个极耳部22121中,一个极耳部22121的凸起22121a与另一个极耳部22121的凹槽22121b错位设置。沿极耳部的厚度方向Z,极耳部22121的投影面积为S1,极耳部22121上的多个凸起22121a的投影面积之和为S2,满足,S2/S1≥0.5,极耳部22121包括在极耳部的厚度方向Z上与凸起22121a的投影不重叠的主体区22121c,沿极耳部的厚度方向Z,极耳部22121的最大尺寸为D1,主体区22121c的厚度为D2,满足,2≤D1/D2≤8。其中,凸起22121a为半球形结构,多个凸起22121a包括间隔设置的多排凸起22121a,每排凸起22121a包括间隔设置的多个凸起22121a,凸起22121a在垂直于极耳部的厚度方向Z的方向上的直径为W1,满足,0.3mm≤W1≤2mm。
根据本申请的一些实施例,参见图3以及图18所示,本申请提供了一种电池单体20,电池单体20包括外壳21、电极组件22和集流构件23。电极组件22容纳于外壳21内,沿第一方向X,集流构件23设置于外壳21与极耳2212之间,集流构件23连接外壳21与极耳2212。集流构件23与极耳2212焊接连接并形成焊印24,沿第一方向X,焊印24覆盖至少一个极耳部22121的凸起22121a。其中,沿第一方向X,极耳2212的厚度为D5,集流构件23的厚度为D6,满足,D6≤1.5D5
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结合。
以上仅为本申请的优选实施例而已,并不用于限制本申请,对于本领域的技术人员来说,本申请可以有各种更改和变化。凡在本申请的精神和原则之内,所作的任何修改、等同替换、改进等,均应包含在本申请的保护范围之内。

Claims (29)

  1. 一种电极组件,包括:
    极性相反的两个极片和用于隔离两个所述极片的隔离件,两个所述极片以及所述隔离件沿卷绕方向卷绕后形成主体和两个极耳;
    其中,所述极耳和所述主体沿所述第一方向设置,所述极耳包括沿所述卷绕方向间隔设置的多个极耳部,所述极耳部相对于所述第一方向弯折设置,所述多个极耳部的至少一部分沿所述第一方向层叠设置,且所述极耳部在其厚度方向上的至少一侧形成有凸起。
  2. 根据权利要求1所述的电极组件,其中,沿所述极耳部的厚度方向,所述极耳部的至少一侧形成有多个所述凸起。
  3. 根据权利要求2所述的电极组件,其中,沿所述极耳部的厚度方向,所述极耳部的投影面积为S1,所述极耳部上的多个所述凸起的投影面积之和为S2,满足,S2/S1≥0.5。
  4. 根据权利要求1-3任一项所述的电极组件,其中,所述极耳部包括在所述极耳部的厚度方向上与所述凸起的投影不重叠的主体区,所述凸起沿所述极耳部的厚度方向凸出于所述主体区;
    沿所述极耳部的厚度方向,所述极耳部的最大尺寸为D1,所述主体区的厚度为D2,满足,2≤D1/D2≤8。
  5. 根据权利要求1-4任一项所述的电极组件,其中,所述极耳部形成有多排凸起,每排凸起包括间隔设置的多个所述凸起。
  6. 根据权利要求5所述的电极组件,其中,所述凸起在垂直于所述极耳部的厚度方向的方向上的最大尺寸为W1,满足,0.3mm≤W1≤2mm。
  7. 根据权利要求1-4任一项所述的电极组件,其中,所述极耳部形成有间隔排布的多个所述凸起,所述凸起的两端沿垂直于多个所述凸起的排布方向的方向分别延伸至所述极耳部的两端。
  8. 根据权利要求7所述的电极组件,其中,沿多个所述凸起的排布方向,所述凸起的宽度为W2,满足,0.3mm≤W2≤2mm。
  9. 根据权利要求1-8任一项所述的电极组件,其中,沿所述极耳部的厚度方向,所述极耳部包括层叠设置的多个箔材,所述箔材的一侧形成有凸部,另一侧与所述凸部对应的位置形成有凹部,在相邻的两个所述箔材中,一个所述箔材的所述凸部容纳于另一个所述箔材的所述凹部内;
    其中,沿所述极耳部的厚度方向,位于所述极耳部的一侧的所述凸部为所述凸起。
  10. 根据权利要求9所述的电极组件,其中,多个所述箔材焊接连接,以在所述箔材上形成所述凸部和所述凹部。
  11. 根据权利要求9或10所述的电极组件,其中,所述极片包括主体部,多个所述极耳部连接于所述主体部,两个所述极片的所述主体部和所述隔离件沿所述卷绕方向卷绕形成所述主体,所述主体部包括基材和设置于所述基材的至少一侧的活性物质层;
    多个所述箔材包括层叠设置的第一箔材和第二箔材,所述第一箔材连接于所述基材在所述第一方向上的一端,并与所述基材一体成型,所述第二箔材与所述基材分体设置。
  12. 根据权利要求11所述的电极组件,其中,所述基材包括涂覆区和间隔区,所述涂覆区与所述间隔区沿所述第一方向排布,所述活性物质层设置于所述涂覆区,所述间隔区连接所述涂覆区和所述第一箔材。
  13. 根据权利要求11或12所述的电极组件,其中,沿所述极耳部的厚度方向,所述第一箔材的厚度为D3,所述第二箔材的厚度为D4,满足,0.5≤D3/D4≤2。
  14. 根据权利要求11-13任一项所述的电极组件,其中,沿垂直于所述极耳部的厚度方向的方向,所述第二箔材靠近所述基材的一端不超出所述第一箔材连接于所述基材的一端。
  15. 根据权利要求11-14任一项所述的电极组件,其中,沿垂直于所述极耳部的厚度方向的方向,所述第一箔材远离所述基材的一端与所述第二箔材远离所述基材的一端之间的距离为L,满足,L≤2mm。
  16. 根据权利要求11-15任一项所述的电极组件,其中,所述第一箔材与所述第二箔材的材质相同。
  17. 根据权利要求1-16任一项所述的电极组件,其中,所述极片包括主体部,多个所述极耳部连接于所述主体部在所述第一方向上的一端,两个所述极片的所述主体部和所述隔离件沿所述卷绕方向卷绕形成所述主体;
    其中,所述主体部包括基材和设置于所述基材的至少一侧的活性物质层,所述基材包括涂覆区和间隔区,所述涂覆区与所述间隔区沿所述第一方向排布,所述活性物质层设置于所述涂覆区,所述间隔区连接所述涂覆区和所述极耳部。
  18. 根据权利要求17所述的电极组件,其中,所述极耳部与所述间隔区一体成型。
  19. 根据权利要求1-18任一项所述的电极组件,其中,沿所述极耳部的厚度方向,所述极耳部背离所述凸起的一侧且对应所述凸起的位置形成有凹槽。
  20. 根据权利要求19所述的电极组件,其中,沿所述第一方向,在相邻的两个所述极耳部中,一个所述极耳部的所述凸起与另一个所述极耳部的所述凹槽错位设置。
  21. 根据权利要求1-20任一项所述的电极组件,其中,沿所述第一方向,所述极耳的厚度为D5,满足,0.2mm≤D5≤2.5mm。
  22. 根据权利要求1-21任一项所述的电极组件,其中,沿所述第一方向,两个所述极耳分别设置于所述主体的两端。
  23. 根据权利要求1-22任一项所述的电极组件,其中,所述主体呈圆柱状。
  24. 一种电池单体,包括:
    外壳;以及
    如权利要求1-23任一项所述的电极组件,所述电极组件容纳于所述外壳内。
  25. 根据权利要求24所述的电池单体,其中,所述电池单体还包括:
    集流构件,沿所述第一方向设置于所述外壳与所述极耳之间,所述集流构件连接所述外壳与所述极耳。
  26. 根据权利要求25所述的电池单体,其中,所述集流构件与所述极耳焊接连接,沿所述第一方向,所述极耳的厚度为D5,所述集流构件的厚度为D6,满足,D6≤1.5D5
  27. 根据权利要求25或26所述的电池单体,其中,所述集流构件与所述极耳焊接连接并形成焊印,沿所述第一方向,所述焊印覆盖至少一个所述极耳部的所述凸起。
  28. 一种电池,包括如权利要求24-27任一项所述的电池单体。
  29. 一种用电装置,包括如权利要求28所述的电池。
PCT/CN2023/075460 2023-02-10 2023-02-10 电极组件、电池单体、电池及用电装置 Ceased WO2024164308A1 (zh)

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EP23920516.4A EP4597737A4 (en) 2023-02-10 2023-02-10 ELECTRODE ASSEMBLY, BATTERY ELEMENT, BATTERY AND ELECTRICAL DEVICE
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