WO2024181038A1 - 円筒形電池 - Google Patents

円筒形電池 Download PDF

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Publication number
WO2024181038A1
WO2024181038A1 PCT/JP2024/003616 JP2024003616W WO2024181038A1 WO 2024181038 A1 WO2024181038 A1 WO 2024181038A1 JP 2024003616 W JP2024003616 W JP 2024003616W WO 2024181038 A1 WO2024181038 A1 WO 2024181038A1
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WO
WIPO (PCT)
Prior art keywords
negative electrode
winding
positive electrode
cylindrical battery
electrode
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/JP2024/003616
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English (en)
French (fr)
Japanese (ja)
Inventor
大倫 若林
剛也 伊藤
崇夫 今奥
昂佑 福井
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.)
Panasonic Energy Co Ltd
Original Assignee
Panasonic Energy 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 Panasonic Energy Co Ltd filed Critical Panasonic Energy Co Ltd
Priority to CN202480013317.0A priority Critical patent/CN120660212A/zh
Priority to EP24763522.0A priority patent/EP4675724A1/en
Priority to JP2025503695A priority patent/JPWO2024181038A1/ja
Publication of WO2024181038A1 publication Critical patent/WO2024181038A1/ja
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/04—Construction or manufacture in general
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H01M10/0587—Construction or manufacture of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • This disclosure relates to cylindrical batteries.
  • Cylindrical batteries are equipped with an electrode assembly in which a positive electrode and a negative electrode are wound in a spiral shape with a separator between them.
  • the positive electrode and negative electrode expand and contract, which may cause plate deformation in which at least one of the positive electrode and negative electrode is locally deformed.
  • Patent Document 1 discloses a cylindrical battery equipped with a wound electrode body having an insulating tape attached to the negative electrode so as to straddle the surface of the negative electrode lead in the winding direction in order to suppress deformation of the joint of the negative electrode lead.
  • a step is formed along the winding direction due to the winding start end of the positive electrode, so the negative electrode portion that faces the winding start end of the positive electrode via the separator may deform as a result of the charge and discharge cycles described above. If this deformation of the negative electrode portion occurs, the distance between the positive and negative electrodes will vary, causing uneven charge and discharge reactions and possibly deteriorating cycle characteristics.
  • Patent Document 1 may not be able to sufficiently suppress deformation of the negative electrode portion that faces the winding start end of the positive electrode.
  • Patent Document 1 raises concerns that the capacity of the cylindrical battery may decrease due to the insulating tape being attached to the negative electrode.
  • the present disclosure therefore aims to provide a cylindrical battery that can suppress deformation of the negative electrode portion that faces the winding start end of the positive electrode that occurs during charge and discharge cycles.
  • the cylindrical battery according to the present disclosure is a cylindrical battery having an electrode body in which a positive electrode and a negative electrode are spirally wound with a separator interposed therebetween, the negative electrode having a core body, a negative electrode lead joined to the end of the core body at the start of winding, and a mixture layer formed on the end of the winding of the negative electrode lead, and the core body including a folded portion bent in a Z shape between the negative electrode lead and the end of the mixture layer at the start of winding.
  • the cylindrical battery disclosed herein can suppress deformation of the negative electrode portion that faces the winding start end of the positive electrode during charge and discharge cycles.
  • FIG. 2 is an axial cross-sectional view of a cylindrical battery according to an embodiment of the present invention.
  • 4 is a schematic diagram showing a radial cross section of the winding start side of the electrode body.
  • the cylindrical battery 10 has a positive electrode 11, a negative electrode 12, and a separator 13, and is equipped with an electrode body 14 in which the positive electrode 11 and the negative electrode 12 are wound with the separator 13 interposed therebetween.
  • the cylindrical battery 10 also has a cylindrical outer can 16 with a bottom that houses the electrode body 14, and a sealing body 17 that closes the opening of the outer can 16.
  • the outer can 16 houses an electrolyte together with the electrode body 14.
  • the outer can 16 has a grooved portion 22 formed in its side wall, and the sealing body 17 is supported by the grooved portion 22 to close the opening of the outer can 16.
  • the sealing body 17 side of the cylindrical battery 10 will be referred to as the top, and the bottom side of the outer can 16 will be referred to as the bottom.
  • the negative electrode 12 has a negative electrode core 40, a negative electrode lead 21 joined to the winding start end of the negative electrode core 40, and a negative electrode mixture layer 41 formed on the winding end side of the negative electrode lead 21.
  • the negative electrode core 40 core exposed portion 43
  • the folded portion 45 makes it possible to suppress deformation of the portion of the negative electrode 12 facing the winding start end of the positive electrode 11 that occurs during charge and discharge cycles.
  • the electrolyte may be an aqueous electrolyte, but in this embodiment, a non-aqueous electrolyte is used.
  • the non-aqueous electrolyte has lithium ion conductivity.
  • the non-aqueous electrolyte may be a liquid electrolyte (electrolytic solution) or a solid electrolyte.
  • the cylindrical battery 10 is, for example, a non-aqueous electrolyte secondary battery, and is preferably a lithium ion battery.
  • the liquid electrolyte includes a non-aqueous solvent and an electrolyte salt dissolved in the non-aqueous solvent.
  • a non-aqueous solvent for example, esters, ethers, nitriles, amides, and mixed solvents of two or more of these are used as the non-aqueous solvent.
  • the non-aqueous solvent include ethylene carbonate (EC), ethyl methyl carbonate (EMC), dimethyl carbonate (DMC), diethyl carbonate (DEC), and mixed solvents of these.
  • the non-aqueous solvent may contain a halogen-substituted product (e.g., fluoroethylene carbonate, etc.) in which at least a part of the hydrogen of these solvents is replaced with a halogen atom such as fluorine.
  • a halogen-substituted product e.g., fluoroethylene carbonate, etc.
  • a lithium salt such as LiPF6 is used as the electrolyte salt.
  • the solid electrolyte for example, a solid or gel-like polymer electrolyte, an inorganic solid electrolyte, etc. can be used.
  • the inorganic solid electrolyte a material known in all-solid-state lithium ion secondary batteries, etc. (for example, an oxide-based solid electrolyte, a sulfide-based solid electrolyte, a halogen-based solid electrolyte, etc.) can be used.
  • the polymer electrolyte includes, for example, a lithium salt and a matrix polymer, or a non-aqueous solvent, a lithium salt, and a matrix polymer.
  • the matrix polymer for example, a polymer material that absorbs a non-aqueous solvent and gels is used.
  • the polymer material for example, a fluororesin, an acrylic resin, a polyether resin, etc. can be used.
  • the electrode body 14 has a wound structure in which the positive electrode 11 and the negative electrode 12 are wound in a spiral shape with the separator 13 interposed therebetween.
  • the positive electrode 11, the negative electrode 12, and the separator 13 are all long strip-shaped bodies, and are wound in a spiral shape so that they are alternately stacked in the radial direction of the electrode body 14.
  • the negative electrode 12 is formed with dimensions slightly larger than the positive electrode 11 to prevent lithium precipitation. In other words, the negative electrode 12 is formed to be longer in the length direction and width direction than the positive electrode 11.
  • the separator 13 is formed with dimensions at least slightly larger than the positive electrode 11, and for example, two separators 13 are arranged to sandwich the positive electrode 11.
  • the electrode body 14 has a positive electrode lead 20 joined to the positive electrode 11 and a negative electrode lead 21 joined to the negative electrode 12.
  • the positive electrode lead 20 is provided in the center of the positive electrode 11 in the longitudinal direction, away from the winding start end and winding end end of the electrode body 14.
  • the negative electrode lead 21 is provided at one longitudinal end of the negative electrode 12 located at the winding start side of the electrode body 14.
  • the negative electrode 12 has a first core exposed portion 43 (see Figure 2) where the negative electrode mixture layer 41 is not present.
  • the negative electrode lead 21 is joined to the core exposed portion 43.
  • the positive electrode 11 has a positive electrode core 30 and a positive electrode mixture layer 31 formed on at least one surface of the core.
  • the positive electrode core 30 can be made of a foil of a metal such as aluminum or an aluminum alloy that is stable in the potential range of the positive electrode 11, or a film with the metal disposed on the surface.
  • the positive electrode mixture layer 31 contains a positive electrode active material, a conductive agent such as acetylene black, and a binder such as polyvinylidene fluoride (PVdF), and is preferably formed on both sides of the positive electrode core 30.
  • the thickness of the positive electrode mixture layer 31 is, for example, 40 ⁇ m or more and 100 ⁇ m or less.
  • the positive electrode active material for example, a lithium transition metal composite oxide containing Ni, Co, Mn, Al, etc. is used.
  • the positive electrode lead 20 is preferably directly bonded to the positive electrode core 30 by ultrasonic welding or the like.
  • the negative electrode 12 has a negative electrode core 40 and a negative electrode mixture layer 41 formed on at least one surface of the core.
  • a foil of a metal stable in the potential range of the negative electrode 12, such as copper or a copper alloy, or a film with the metal disposed on the surface layer can be used.
  • the negative electrode mixture layer 41 contains a negative electrode active material and a binder such as styrene-butadiene rubber (SBR), and is preferably formed on both sides of the negative electrode core 40.
  • the thickness of the negative electrode mixture layer 41 is, for example, 40 ⁇ m or more and 100 ⁇ m or less.
  • graphite, a material containing Si, etc. is used as the negative electrode active material.
  • the negative electrode lead 21 is preferably directly bonded to the negative electrode core 40 by ultrasonic welding or the like.
  • the cylindrical battery 10 is provided with an upper insulating plate 18 that is disposed between the sealing body 17 and the electrode group and has an opening through which the positive electrode lead 20 passes.
  • the electrode group refers to the portion of the electrode body 14 that is composed of the positive electrode 11, the negative electrode 12, and the separator 13, excluding the positive electrode lead 20 and the negative electrode lead 21.
  • the cylindrical battery 10 also has a lower insulating plate 19 that is disposed between the inner bottom surface of the outer can 16 and the electrode group and has an opening through which the negative electrode lead 21 passes.
  • the positive electrode lead 20 extends through the opening of the upper insulating plate 18 toward the sealing body 17, and the negative electrode lead 21 extends through the opening of the lower insulating plate 19 toward the bottom side of the outer can 16.
  • the positive electrode lead 20 is connected to the underside of the bottom plate 23 of the sealing body 17 by welding or the like, and the sealing body 17 serves as the positive electrode terminal.
  • the negative electrode lead 21 is connected to the inner bottom surface of the outer can 16 by welding or the like, and the outer can 16 serves as the negative electrode terminal.
  • the negative electrode 12 is disposed on the outermost surface of the electrode body 14, and a second core exposed portion 44 is provided where the surface of the negative electrode core 40 is exposed.
  • the core exposed portion 44 abuts against the inner surface of the exterior can 16.
  • the core exposed portion 44 abuts against the inner surface of the exterior can 16, which is the negative electrode terminal, electrically connecting both ends in the length direction of the negative electrode 12 to the exterior can 16, ensuring good current collection.
  • the core exposed portion 44 may be provided on a part of the outermost surface of the electrode body 14, but is preferably provided over the entire outermost surface. For example, a portion where the negative electrode mixture layer 41 is not present is provided on the outer surface of the negative electrode core 40 for a length of one revolution or more from the end of the winding of the negative electrode 12.
  • the outer can 16 is a cylindrical metal container with a bottom.
  • a gasket 28 is provided between the outer can 16 and the sealing body 17 to seal the inside of the battery.
  • the outer can 16 has a grooved portion 22 formed, for example, by pressing the side portion from the outside.
  • the grooved portion 22 is preferably formed in an annular shape along the circumferential direction of the outer can 16, and supports the sealing body 17 on its upper surface.
  • the upper end of the outer can 16 is bent inward and crimped to the peripheral edge of the sealing body 17.
  • the sealing body 17 has a structure in which, in order from the electrode body 14 side, a bottom plate 23, a lower valve body 24, an insulating member 25, an upper valve body 26, and a cap 27 are stacked.
  • Each member constituting the sealing body 17 has, for example, a disk or ring shape, and each member except for the insulating member 25 is electrically connected to each other.
  • the lower valve body 24 and the upper valve body 26 are connected to each other at their respective centers, and the insulating member 25 is interposed between their respective peripheral edges.
  • Fig. 2 is a schematic diagram showing a radial cross section of the winding start side of the electrode body 14.
  • the separator 13 is omitted from illustration in order to clarify the drawing.
  • the folded portion 45 is a portion where the negative electrode core 40 is folded in a Z shape between the negative electrode lead 21 and the winding start end 41A of the negative electrode mixture layer 41.
  • the length of the core exposed portion 43 is, for example, approximately 1.25 and a half turns.
  • positive electrode 11 and negative electrode 12 expand and contract, and at least one of positive electrode 11 and negative electrode 12 may deform locally, resulting in plate deformation.
  • a step is formed in the winding direction at a position that straddles winding start end 11A of positive electrode 11, so that the portion of negative electrode 12 facing the winding start end of positive electrode 11 may deform with charge/discharge cycles. If this portion of negative electrode 12 deforms, the distance between the positive and negative electrodes may vary, causing uneven charge/discharge reactions and deteriorating cycle characteristics.
  • the winding start end of positive electrode 11 means winding start end 11A and its vicinity.
  • the folded portion 45 when the charge/discharge cycle is repeated and the portion of the negative electrode 12 facing the winding start end of the positive electrode 11 is subjected to stress, the folded portion 45 deforms preferentially, alleviating the stress and suppressing deformation of the portion of the negative electrode 12 facing the winding start end of the positive electrode 11. This prevents variation in the distance between the positive and negative electrodes, makes the charge/discharge reaction uniform, and maintains good cycle characteristics. Note that since the folded portion 45 is formed in a portion of the negative electrode 11 that does not face the positive electrode via the separator 13, deformation of the folded portion 45 has little effect on the distance between the positive and negative electrodes.
  • the folded portion 45 has a bent portion 45A and a bent portion 45B at both ends in the winding direction.
  • the bent portion 45A is located at the start of winding of the folded portion 45
  • the bent portion 45B is located at the end of winding of the folded portion 45.
  • the folded portion 45 is formed so that the bent portion 45A at the start of winding faces the inside of the winding and the bent portion 45B at the end of winding faces the outside of the winding. This makes it easier for the folded portion 45 to deform toward the hollow portion of the electrode body 14, as will be described in detail later, and therefore the effect that deformation of the folded portion 45 has on the distance between the positive and negative electrodes can be further reduced.
  • the fold-over part 45 is formed so that the bent part 45A on the winding start side faces the inside of the winding and the bent part 45B on the winding end side faces the outside of the winding, the fold-over part 45 is easily deformed towards the hollow part of the electrode body 14.
  • the folded portion 45 is formed on the negative electrode 12 at the end of the winding from the position where the negative electrode 12 faces the winding start end 11A of the positive electrode 11 toward the winding start side. This makes it easier for the folded portion 45 to deform to absorb stress when the part of the negative electrode 12 facing the winding start end of the positive electrode 11 is subjected to stress.
  • the winding start end 41A of the negative electrode mixture layer 41 is located closer to the winding start side than the inside of the winding start end 11A of the positive electrode 11.
  • the folded-over portion 45 is formed in a position that does not face the positive electrode 11 via the separator 13.
  • the joining position of the negative electrode lead 21 is not particularly limited, but can be, for example, in the range of 0.5 to 1.5 turns from the winding start end 41 of the negative electrode mixture layer 41 to the winding start side.
  • Configuration 3 The cylindrical battery according to configuration 1 or 2, wherein the folded portion is formed on the negative electrode at a position on the end side of the winding of the negative electrode that is one turn away from a position facing the inner side of the winding start end of the positive electrode toward the winding start side.

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  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Secondary Cells (AREA)
  • Connection Of Batteries Or Terminals (AREA)
PCT/JP2024/003616 2023-02-27 2024-02-05 円筒形電池 Ceased WO2024181038A1 (ja)

Priority Applications (3)

Application Number Priority Date Filing Date Title
CN202480013317.0A CN120660212A (zh) 2023-02-27 2024-02-05 圆筒形电池
EP24763522.0A EP4675724A1 (en) 2023-02-27 2024-02-05 Cylindrical battery
JP2025503695A JPWO2024181038A1 (https=) 2023-02-27 2024-02-05

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2023-028126 2023-02-27
JP2023028126 2023-02-27

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Publication Number Publication Date
WO2024181038A1 true WO2024181038A1 (ja) 2024-09-06

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PCT/JP2024/003616 Ceased WO2024181038A1 (ja) 2023-02-27 2024-02-05 円筒形電池

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EP (1) EP4675724A1 (https=)
JP (1) JPWO2024181038A1 (https=)
CN (1) CN120660212A (https=)
WO (1) WO2024181038A1 (https=)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018180748A1 (ja) 2017-03-28 2018-10-04 三洋電機株式会社 非水電解質二次電池
WO2018180828A1 (ja) * 2017-03-29 2018-10-04 三洋電機株式会社 円筒形電池
JP2020080250A (ja) * 2018-11-13 2020-05-28 三洋電機株式会社 円筒形二次電池

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2018180748A1 (ja) 2017-03-28 2018-10-04 三洋電機株式会社 非水電解質二次電池
WO2018180828A1 (ja) * 2017-03-29 2018-10-04 三洋電機株式会社 円筒形電池
JP2020080250A (ja) * 2018-11-13 2020-05-28 三洋電機株式会社 円筒形二次電池

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JPWO2024181038A1 (https=) 2024-09-06
EP4675724A1 (en) 2026-01-07
CN120660212A (zh) 2025-09-16

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