WO2026029030A1 - Dispositif de stockage d'énergie - Google Patents

Dispositif de stockage d'énergie

Info

Publication number
WO2026029030A1
WO2026029030A1 PCT/JP2025/026773 JP2025026773W WO2026029030A1 WO 2026029030 A1 WO2026029030 A1 WO 2026029030A1 JP 2025026773 W JP2025026773 W JP 2025026773W WO 2026029030 A1 WO2026029030 A1 WO 2026029030A1
Authority
WO
WIPO (PCT)
Prior art keywords
electrode
positive electrode
winding
cut
current collector
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.)
Pending
Application number
PCT/JP2025/026773
Other languages
English (en)
Japanese (ja)
Inventor
きよみ 神月
真一 坂本
香澄 佐藤
雅弘 井濱
真也 下司
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 Intellectual Property Management Co Ltd
Original Assignee
Panasonic Intellectual Property Management 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 Intellectual Property Management Co Ltd filed Critical Panasonic Intellectual Property Management Co Ltd
Publication of WO2026029030A1 publication Critical patent/WO2026029030A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H01M10/0587—Construction or manufacture of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/102—Primary casings; Jackets or wrappings characterised by their shape or physical structure
    • H01M50/107—Primary casings; Jackets or wrappings characterised by their shape or physical structure having curved cross-section, e.g. round or elliptic
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H01M50/533—Electrode connections inside a battery casing characterised by the shape of the leads or tabs
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H01M50/538—Connection of several leads or tabs of wound or folded electrode stacks
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/572—Means for preventing undesired use or discharge
    • H01M50/584—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries
    • H01M50/586—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries inside the batteries, e.g. incorrect connections of electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/572—Means for preventing undesired use or discharge
    • H01M50/584—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries
    • H01M50/59—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries characterised by the protection means

Definitions

  • This disclosure relates to an electricity storage device.
  • a known energy storage device includes a cylindrical case with a bottom, an electrode assembly disposed within the case, and a cap assembly (sealing body) that closes the opening of the case.
  • the electrode assembly includes a positive electrode, a negative electrode, and a separator disposed between the positive and negative electrodes, with the positive and negative electrodes being wound with the separator interposed between them.
  • a current collector plate is disposed above the electrode assembly within the case, and is fixed to and electrically connected to the axial end of the positive electrode of the electrode assembly.
  • the current collector plate is electrically connected to the cap assembly.
  • An uncoated area that is free of active material is provided at the axial end of the positive electrode, and the uncoated area has multiple independent regions separated in the winding direction by cuts. The independent regions are fixed to the current collector plate in a pressurized and deformed state.
  • Patent Document 1 The configuration described in Patent Document 1 is able to suppress the occurrence of wrinkles when the axial end of the positive electrode is bent, compared to a configuration with a plain area and no independent area, which allows for more welding points between the current collector plate and the positive electrode, potentially reducing the electrical resistance at the connection between the positive electrode and the current collector plate.
  • a narrow independent area at the outermost periphery of the plain area there is a possibility that the outermost independent area of the plain area will deform outward after the tip end portion of the plain area is bent inward. In this case, the outermost periphery of the plain area may come into contact with the inner surface of the case, causing a short circuit.
  • the energy storage device comprises a cylindrical case with a bottom, an electrode body in which the first electrode and the second electrode are wound together via the separator, and a current collector plate fixed to and electrically connected to the axial end of the electrode body.
  • the first electrode has a laminated portion in which an electrode active material layer is laminated, and an uncoated portion provided at the end on the current collector plate side and in which no electrode active material layer is laminated.
  • the uncoated portion is bent toward the inner periphery of the electrode body.
  • the uncoated portion is connected to the current collector plate in this state, and the uncoated portion has a first slit and at least one second slit located closer to the winding start than the first slit, extending from the end on the current collector plate side.
  • the uncoated portion includes an uncut portion in the region from the winding end to the first slit, where there is no slit at the middle of the winding direction, and an slit portion in the region from the first slit to the winding start end, where there is a second slit at the middle of the winding direction, and the length of the uncut portion in the winding direction is at least one full turn from the winding end of the uncoated portion.
  • a first electrode is connected to a current collector plate, and a cut portion is provided in the uncoated portion of the first electrode. This prevents wrinkles from occurring in the uncoated portion when the uncoated portion is bent inward.
  • the uncoated portion also has an uncut portion in the middle, between the first end, which is the outermost winding end, and the second end, which is the first cut.
  • the length of the uncut portion in the winding direction is at least one full turn from the uncoated portion's winding end. This prevents the outermost periphery of the uncoated portion from having a small, independent region separated in the winding direction by a cut.
  • FIG. 1 is an axial cross-sectional view of an electricity storage device according to an embodiment of the present disclosure.
  • FIG. 2 is an enlarged view of part A in FIG. 1 , showing a part in a schematic manner.
  • 2 is a perspective view showing upper and lower current collector plates and an electrode body that constitute the electricity storage device of FIG. 1, with a portion of the upper end cut away.
  • FIG. 2 is a cross-sectional view taken along the line BB in FIG. 1.
  • FIG. 2 is a schematic diagram showing a developed state of a positive electrode in an embodiment.
  • FIG. 10 is a perspective view showing upper and lower current collector plates and an electrode body that constitute a power storage device according to another embodiment, with a portion of the upper end cut away.
  • FIG. 10 is a schematic diagram showing a developed state of a positive electrode constituting an electricity storage device according to another embodiment.
  • FIG. 10 is a schematic diagram showing a developed state of a positive electrode constituting an electricity storage device according to another embodiment.
  • FIG. 5 is a diagram corresponding to FIG. 4 in a power storage device according to another embodiment.
  • 10 is a schematic diagram showing a developed state of a positive electrode constituting an electricity storage device according to another embodiment.
  • FIG. 10 is a schematic diagram showing a developed state of a positive electrode constituting an electricity storage device according to another embodiment.
  • FIG. 10 is a schematic diagram showing a developed state of a positive electrode constituting an electricity storage device according to another embodiment.
  • FIG. 10 is a schematic diagram showing a developed state of a positive electrode constituting an electricity storage device according to another embodiment.
  • the energy storage device according to the present disclosure may be a battery using an aqueous electrolyte or a battery using a non-aqueous electrolyte.
  • a cylindrical non-aqueous electrolyte secondary battery will be described as the energy storage device of the embodiment, but the energy storage device according to the present disclosure can have various configurations, such as a rectangular cylindrical shape, as long as it is an energy storage device that includes a cylindrical case with a bottom, a wound electrode assembly disposed in the case, and current collector plates fixed to and electrically connected to the axial ends of the electrode assembly.
  • the present disclosure is not limited to the following embodiments and variations thereof, and various improvements and modifications are possible within the scope of the claims of this application and their equivalents.
  • Figure 1 is an axial cross-sectional view of a secondary battery 10, which is an embodiment of the energy storage device.
  • Figure 2 is an enlarged schematic view of part A in Figure 1.
  • Figure 3 is a perspective view of the upper and lower current collector plates 18, 17 and electrode body 14 that make up the secondary battery 10, with a portion of the upper end broken away.
  • Figure 4 is a cross-sectional view taken along line B-B in Figure 1.
  • the secondary battery 10 includes a wound electrode assembly 14, a non-aqueous electrolyte (not shown), a case 15 which is a metal can, and a sealing body 16.
  • the wound electrode assembly 14 has a positive electrode 11, a negative electrode 12, and a separator 13, with the positive electrode 11 and negative electrode 12 being spirally wound with the separator 13 interposed between them.
  • the positive electrode 11, negative electrode 12, and separator 13 are all in the form of long, approximately rectangular strips.
  • the non-aqueous electrolyte includes a non-aqueous solvent and an electrolyte salt dissolved in the non-aqueous solvent.
  • the positive electrode 11 protrudes upward beyond the negative electrode 12 and separator 13
  • the negative electrode 12 protrudes downward beyond the positive electrode 11 and separator 13.
  • the positive electrode 11 has a positive electrode uncoated portion 34 where the positive electrode active material layer 32 is not provided and the positive electrode core 30 is exposed.
  • the positive electrode uncoated portion 34 is located at the upper end, which is one end of the winding axis direction (hereinafter sometimes referred to as the axial direction), from the winding start end to the winding end end in the longitudinal direction of the positive electrode 11.
  • the electrode plate longitudinal direction corresponds to the winding direction of the positive electrode 11 or negative electrode 12 in a wound state, and is the longitudinal direction of the elongated rectangle when the positive electrode 11 or negative electrode 12 is viewed in the thickness direction when the positive electrode 11 or negative electrode 12 is unfolded along a plane.
  • a positive electrode protective layer (not shown) may be provided between the positive electrode active material layer 32 and the positive electrode uncoated portion 34 at the upper end of the positive electrode 11 to prevent short-circuiting of the positive electrode core 30.
  • the positive electrode active material layer 32 corresponds to the electrode active material layer.
  • the negative electrode 12 has a negative electrode uncoated portion 44 where the negative electrode active material layer 42 ( Figure 2) is not provided and the negative electrode core 40 ( Figure 2) is exposed.
  • the negative electrode uncoated portion 44 is located at the lower end, which is the other end in the axial direction, from the end at the winding start side to the end at the winding end side in the longitudinal direction of the electrode plate of the negative electrode 12. Therefore, the upper axial end of the electrode body 14 is made up of the positive electrode uncoated portion 34, and the lower axial end of the electrode body 14 is made up of the negative electrode uncoated portion 44.
  • the positive electrode 11 corresponds to the first electrode
  • the negative electrode 12 corresponds to the second electrode having a polarity different from that of the first electrode.
  • the first electrode may be the negative electrode 12
  • the second electrode may be the positive electrode 11.
  • the non-aqueous electrolyte has ion conductivity (e.g., lithium ion conductivity).
  • the non-aqueous electrolyte includes a non-aqueous solvent and an electrolyte salt dissolved in the non-aqueous solvent.
  • the non-aqueous electrolyte is not limited to a liquid electrolyte (nonaqueous electrolytic solution) and may be a solid electrolyte using a gel-like polymer or the like.
  • the secondary battery 10 is preferably a lithium ion battery.
  • the electrolyte salt may be, for example, a lithium salt such as LiBF4 or LiPF6 .
  • the non-aqueous solvent may be, for example, an ester such as ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), or methyl propionate (MP), an ether, a nitrile, an amide, or a mixed solvent of two or more of these.
  • the non-aqueous solvent may contain a halogen-substituted compound in which at least a portion of the hydrogen atoms of these solvents are substituted with halogen atoms such as fluorine.
  • halogen-substituted compounds include fluorinated cyclic carbonates such as fluoroethylene carbonate (FEC), fluorinated chain carbonates, and fluorinated chain carboxylic acid esters such as methyl fluoropropionate (FMP).
  • FEC fluoroethylene carbonate
  • FMP fluorinated chain carboxylic acid esters
  • the non-aqueous electrolyte preferably contains 5% by mass or more of FEC, and more preferably 5% to 15% by mass of FEC, based on the mass of the non-aqueous electrolyte.
  • the solid electrolyte for example, a solid or gel-like polymer electrolyte, an inorganic solid electrolyte, etc. is 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 the non-aqueous solvent and gels is used.
  • the polymer material for example, fluororesin, acrylic resin, polyether resin, etc. is used.
  • the inorganic solid electrolyte for example, a material known in all-solid-state lithium-ion secondary batteries (for example, oxide-based solid electrolytes, sulfide-based solid electrolytes, halide-based solid electrolytes, etc.) is used.
  • a material known in all-solid-state lithium-ion secondary batteries for example, oxide-based solid electrolytes, sulfide-based solid electrolytes, halide-based solid electrolytes, etc.
  • the positive electrode 11 has a positive electrode core 30 and positive electrode active material layers 32 formed on both sides of the positive electrode core 30.
  • the positive electrode core 30 can be made of a metal foil, such as aluminum or an aluminum alloy, that is stable within the potential range of the positive electrode 11, or a film with such a metal disposed on the surface.
  • the thickness of the positive electrode core 30 is, for example, 10 ⁇ m or more and 30 ⁇ m or less.
  • the positive electrode active material layer 32 contains a positive electrode active material, a conductive agent, and a binder.
  • the positive electrode 11 can be produced, for example, by applying a positive electrode mixture slurry containing a positive electrode active material, a conductive agent, a binder, etc.
  • the positive electrode active material layer 32 may be formed on only one side of the positive electrode core 30.
  • the thickness of the positive electrode active material layer 32 is, for example, 10 ⁇ m or more and 150 ⁇ m or less on one side of the positive electrode core 30.
  • the positive electrode active material is composed primarily of a lithium-containing metal composite oxide.
  • Metal elements contained in the lithium-containing metal composite oxide include Ni, Co, Mn, Al, B, Mg, Ti, V, Cr, Fe, Cu, Zn, Ga, Sr, Zr, Nb, In, Sn, Ta, and W.
  • An example of a preferred lithium-containing metal composite oxide is a composite oxide containing at least one of Ni, Co, Mn, and Al.
  • Examples of conductive agents contained in the positive electrode active material layer 32 include carbon materials such as carbon black, acetylene black, ketjen black, and graphite.
  • Examples of binders contained in the positive electrode active material layer 32 include fluororesins such as polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVdF), polyacrylonitrile (PAN), polyimide resin, acrylic resin, and polyolefin resin. These resins may be used in combination with cellulose derivatives such as carboxymethyl cellulose (CMC) or its salts, and polyethylene oxide (PEO).
  • CMC carboxymethyl cellulose
  • PEO polyethylene oxide
  • a positive electrode protective layer may be provided between the positive electrode active material layer 32 and the positive electrode uncoated portion 34 on both sides of the upper end of the positive electrode core 30.
  • the positive electrode protective layer may be an inorganic filler protective layer containing, for example, an inorganic material additive such as alumina, a resin such as a water-insoluble polymer such as polyvinylidene fluoride (PVdF), and a conductive additive such as acetylene black (AB) or carbon black (CB) in a predetermined ratio.
  • the positive electrode protective layer may be configured to contain an inorganic material such as alumina, a resin such as polyvinylidene fluoride (PVdF), and a conductive additive in a mass ratio of 100:16.7:0.5.
  • the conductive additive may be omitted from the positive electrode protective layer.
  • the negative electrode 12 has a negative electrode core 40 and a negative electrode active material layer 42 formed on both sides of the negative electrode core 40.
  • the negative electrode core 40 can be made of a metal foil, such as copper or a copper alloy, that is stable within the potential range of the negative electrode 12, or a film with such a metal disposed on the surface.
  • the thickness of the negative electrode core 40 is, for example, 5 ⁇ m or more and 30 ⁇ m or less.
  • the negative electrode active material layer 42 contains a negative electrode active material and a binder.
  • the negative electrode 12 can be produced, for example, by applying a negative electrode mixture slurry containing a negative electrode active material and a binder, etc., to the negative electrode core 40, drying the coating, and then compressing it to form a negative electrode active material layer 42 on both sides of the negative electrode core 40.
  • the negative electrode active material layer 42 may be formed on only one side of the negative electrode core 40.
  • the thickness of the negative electrode active material layer 42 is, for example, 10 ⁇ m or more and 150 ⁇ m or less on one side of the negative electrode core 40.
  • Anode active materials generally use carbon materials that reversibly absorb and release lithium ions.
  • Preferred carbon materials are graphites such as natural graphite, including flake graphite, lump graphite, and amorphous graphite, and artificial graphite, including lump artificial graphite and graphitized mesophase carbon microbeads.
  • the anode active material layer 42 may contain a silicon (Si) material as the anode active material.
  • Si silicon
  • metals other than Si that alloy with lithium, alloys containing such metals, compounds containing such metals, etc. may also be used as the anode active material.
  • the binder contained in the negative electrode active material layer 42 may be fluororesin, PAN, polyimide resin, acrylic resin, polyolefin resin, etc., but styrene-butadiene rubber (SBR) or a modified version thereof is preferred.
  • SBR styrene-butadiene rubber
  • the negative electrode active material layer 42 may also contain, for example, CMC or a salt thereof, polyacrylic acid (PAA) or a salt thereof, polyvinyl alcohol, etc.
  • Separator 13 is made of a porous sheet that is ion permeable and insulating. Specific examples of porous sheets include microporous thin films, woven fabrics, and nonwoven fabrics. Preferred materials for separator 13 include polyolefin resins such as polyethylene and polypropylene, and cellulose. Separator 13 may have either a single-layer structure or a laminated structure. A heat-resistant layer or the like may be formed on the surface of separator 13.
  • the secondary battery 10 has a metallic negative electrode current collector 17 made of nickel, nickel alloy, or the like, located axially below the electrode body 14.
  • An uncoated negative electrode portion 44 protruding from the electrode body 14 is joined to the negative electrode current collector 17, which is joined to the inner surface of the bottom plate of the case 15.
  • the case 15, to which the uncoated negative electrode portion 44 is electrically connected via the negative electrode current collector 17, serves as the negative electrode terminal.
  • the secondary battery 10 has a positive electrode current collector 18 placed inside the case 15.
  • the positive electrode current collector 18 is a circular metal plate made of aluminum, aluminum alloy, or the like, and is placed axially above the electrode body 14.
  • the positive electrode uncoated portion 34 protruding from the electrode body 14 is joined to the positive electrode current collector 18.
  • the positive electrode current collector 18 is fixed to and electrically connected to the axial upper end of the electrode body 14.
  • the secondary battery 10 has a circular insulating plate 19 axially above the positive electrode current collector 18.
  • the positive electrode connection lead 20 is joined to the top surface of the positive electrode current collector 18 by welding or the like.
  • the positive electrode connection lead 20 passes through a through-hole in the insulating plate 19 and extends toward the sealing body 16, and the other end of the positive electrode connection lead 20 is connected to the underside of the filter 22 of the sealing body 16 by welding or the like.
  • the cap 26 that forms the top plate of the sealing body 16 is electrically connected to the filter 22.
  • the positive electrode current collector 18 is electrically connected to the cap 26, and the cap 26 serves as the positive electrode terminal.
  • the positive electrode connection lead 20 is a conductive member made of a metal primarily composed of aluminum or the like.
  • the secondary battery 10 further includes a resin gasket 27 placed between the case 15 and the sealing body 16.
  • the gasket 27 is sandwiched between the case 15 and the sealing body 16, and insulates the sealing body 16 from the case 15.
  • the gasket 27 serves as a sealing material to maintain airtightness inside the battery, and as an insulating material to insulate the case 15 and the sealing body 16.
  • the case 15 has an annular groove 21 along part of its axial direction.
  • the grooved portion 21 can be formed, for example, by spinning a portion of the side surface radially inward to create a recess radially inward.
  • the case 15 has a bottomed cylindrical portion including the grooved portion 21, and an annular shoulder portion.
  • the bottomed cylindrical portion houses the electrode assembly 14 and non-aqueous electrolyte, and the shoulder portion is bent radially inward from the end of the open side of the bottomed cylindrical portion and extends inward.
  • the shoulder portion is formed when the upper end of the case 15 is bent inward and crimped onto the peripheral edge of the sealing body 16.
  • the sealing body 16 is crimped and fixed to the case 15 with a gasket 27 interposed between the shoulder portion and the grooved portion 21. In this way, the internal space of the secondary battery 10 is sealed.
  • the sealing body 16 has a structure in which, from the electrode body 14 side, a filter 22, a lower valve body 23, an insulating member 24, an upper valve body 25, and a cap 26 are stacked.
  • Each member constituting the sealing body 16 has, for example, a disk or ring shape, and all members except for the insulating member 24 are electrically connected to each other.
  • the filter 22 has at least one through-hole.
  • the lower valve body 23 and the upper valve body 25 are connected at their respective centers, with the insulating member 24 interposed between their respective peripheral edges.
  • the lower valve body 23 deforms and breaks, pushing the upper valve body 25 toward the cap 26, cutting off the current path between the lower valve body 23 and the upper valve body 25. If the internal pressure rises further, the upper valve body 25 breaks and gas is released from the through-hole 26a of the cap 26. This gas release prevents the internal pressure of the secondary battery 10 from rising excessively, which could cause the secondary battery 10 to deform or explode, thereby improving the safety of the secondary battery 10. It also reduces the impact of deformation or explosion of the secondary battery 10 on adjacent components (not shown).
  • Figure 5 is a schematic diagram showing the expanded state of the positive electrode 11.
  • the positive electrode 11 has a laminated portion 35 in which positive electrode active material layers 32 are laminated on both sides of the positive electrode core 30, and a positive electrode uncoated portion 34 located above the laminated portion 35 and closer to the positive electrode collector plate 18.
  • the positive electrode uncoated portion 34 has an axial extension portion 37 extending approximately parallel to the axial direction of the electrode body 14, and a current collector weld portion 38 bent in a bent or curved state from the upper end of the axial extension portion 37 toward the inner circumference and extending parallel to the underside of the positive electrode collector plate 18.
  • the current collector weld portion 38 is welded to the underside of the positive electrode collector plate 18.
  • a positive electrode protective layer may be provided on both sides of the portion of the axial extension portion 37 near the upper end of the laminated portion 35.
  • the current collector weld 38 and the underside of the positive current collector 18 are shown separated from each other, but in reality, the upper surfaces of all current collector welds 38 on each circumference of the positive electrode 11 are welded in contact with the underside of the positive current collector 18.
  • the positive electrode uncoated portion 34 is located at the upper axial end of the positive electrode 11 on the positive current collector 18 side, and no positive electrode active material layer is laminated on it.
  • the tip of the positive electrode uncoated portion 34 is connected to the positive current collector 18 in a state where it is bent toward the inner periphery of the electrode body 14.
  • the current collector welds 38 of adjacent positive electrodes 11 partially overlap each other. This reduces the electrical resistance between the positive electrodes 11 and the positive current collector plates 18. Note that the current collector welds 38 in adjacent circumferential portions of the positive electrodes 11 may be configured not to overlap.
  • the positive electrode uncoated portion 34 has an uncut portion 50 provided at the outer peripheral end on the end on the positive electrode current collector plate 18 side, and a cut portion 51 provided in the remaining portion in the winding direction of the positive electrode 11.
  • the uncut portion 50 of the positive electrode uncoated portion 34 is shown by a solid line, and the cut portion 51 is shown by a dashed line.
  • the positive electrode uncoated portion 34 has multiple straight, thin slits 52, 53 formed along substantially the entire short side direction (the vertical direction in Figure 5) of the positive electrode 11, extending from one end (the end (top end) on the positive electrode current collector 18 side) to the other end (the boundary between the positive electrode uncoated portion 34 and the laminated portion 35).
  • the multiple slits 52, 53 do not have to be formed along substantially the entire short side direction of the positive electrode uncoated portion 34, but may be formed at a position including the end on the positive electrode current collector 18 side, for example, only at the tip end where bending toward the inner circumference occurs.
  • the multiple slits 52, 53 include a first slit 52 and a second slit 53.
  • the second slits are multiple slits.
  • the first slit 52 is located at the end of the slits, including the second slit 53, closest to the end of the winding in the winding direction.
  • the second cut 53 is located closer to the start of winding than the first cut 52.
  • the first cut 52 is shown as being wider in the winding direction than the second cut 53, but the first cut 52 and the second cut 53 may be thin cuts of the same width. There may also be only one second cut 53.
  • the uninterrupted portion 50 of the positive electrode uncoated portion 34 is a portion in which the first end is the outer peripheral winding end 54, the second end is the first slit 52, and there is no intermission between the first and second ends.
  • the uninterrupted portion 50 of the positive electrode uncoated portion 34 is a region in which there is no intermission at the midpoint in the winding direction.
  • the interrupted portion 51 of the positive electrode uncoated portion 34 is a region in which the first slit 52 is the third end, the inner peripheral winding start end 55 is the fourth end, and a second slit 53 is provided between the third and fourth ends.
  • the interrupted portion 51 of the positive electrode uncoated portion 34 is a region in which the second slit 53 is provided at the midpoint in the winding direction. Furthermore, the winding length of the uninterrupted portion 50 (the horizontal length in FIG. 5 ) is at least one full turn from the winding end 54 of the positive electrode uncoated portion 34.
  • the positive electrode 11 is spirally wound together with the negative electrode 12 and separator 13, and the tip of the positive electrode uncoated portion 34 is bent toward the inner periphery, thereby forming the electrode body 14 shown in Figures 3 and 4.
  • the tip of the negative electrode uncoated portion 44 shown in Figure 1 is also bent or curved toward the inner periphery of the electrode body 14.
  • the positive electrode uncoated portion 34 of the electrode body 14 has an uncut portion 50 located in at least the outermost circumferential portion, and a cut portion 51 having multiple second cuts 53 is located inside the uncut portion 50.
  • the positive electrode uncoated portion 34 connected to the positive electrode current collector plate 18 has a slit portion 51 with a second slit 53. This prevents the positive electrode uncoated portion 34 from wrinkling when bent inward.
  • the positive electrode uncoated portion 34 also has an unslit portion 50 between the first end, which is the outer winding end 54, and the second end, which is the first slit 52.
  • the winding length of the unslit portion 50 is at least one full turn from the winding end 54 of the positive electrode uncoated portion 34. This prevents a small, independent region separated by a slit in the winding direction at the outermost periphery of the positive electrode uncoated portion 34.
  • multiple second cuts 53 are provided in the cut portion 51.
  • the winding direction length of each independent region 56 separated in the winding direction by the second cuts 53 can be reduced in the cut portion 51, making it easier for the independent regions 56 to orient in a direction that does not cause wrinkles when bent. This further reduces the occurrence of wrinkles when the positive electrode uncoated portion 34 is bent.
  • the radius of curvature of the uncoated positive electrode portion during winding decreases as it moves from the outermost periphery toward the inner periphery.
  • wrinkles are more likely to occur on the inner periphery of the uncoated positive electrode portion when the tip is bent toward the inner periphery.
  • the length of the uninterrupted portion 50 in the winding direction can be two or more and six or fewer revolutions from the winding end 54 of the positive electrode uncoated portion 34.
  • the radius of curvature in the winding direction of the positive electrode uncoated portion 34 is larger the closer it is to the outermost periphery. Therefore, wrinkles are less likely to occur even when the tip is bent inward.
  • the uninterrupted portion 50 is formed as a portion of the positive electrode uncoated portion 34 six or fewer revolutions from the winding end 54, wrinkles are less likely to occur.
  • the uninterrupted portion 50 in the winding direction is two or more revolutions from the winding end 54 of the positive electrode uncoated portion 34
  • the uninterrupted portion 50 is provided not only at the outermost periphery during winding, but also at a portion of the circumference that is inward from the outermost periphery.
  • the winding length of the seamless portion 50 may be greater than or equal to one circumference around the inner circumference of the case 15 and less than two circumferences around the inner circumference of the case 15.
  • Figure 6 is a perspective view showing the upper and lower positive and negative electrode current collector plates 18 and 17, and the electrode body 14a, which constitute a secondary battery according to another embodiment, with a portion of the upper end broken away.
  • Figure 7 is a schematic diagram showing the expanded state of the positive electrode 11a, which constitutes a secondary battery according to another embodiment.
  • the orientation of the second slits 53a is inclined with respect to the winding direction at the tip portion of the positive electrode uncoated portion 34a bent inward.
  • the extension line L1 extending from each second slit 53a toward the tip of the positive electrode uncoated portion 34a intersects with the extension line L2 extending toward the tip of the edge of the winding axis direction of the winding start end 55 of the slit portion 51 (in the direction from the stacked portion 35 toward the positive electrode uncoated portion 34a). This makes it easier to bend the positive electrode uncoated portion 34a inward while overlapping adjacent independent regions 56a more smoothly in the winding direction. This further reduces the occurrence of wrinkles when the positive electrode uncoated portion 34a is bent.
  • each second cut 53a extends from the boundary 57 between the positive electrode uncoated portion 34a and the laminated portion 35 toward the tip of the positive electrode uncoated portion 34a.
  • the boundary 57-side end T1 which is the innermost end of the second cut 53a, is located closer to the end of the winding than the tip end T2 of the positive electrode uncoated portion 34a of the second cut 53a. This makes it easier for the highly rigid boundary 57-side end (e.g., part P in FIG. 7) of the independent region 56a at the start of the winding to overlap the boundary 57-side end (e.g., part Q in FIG. 7) of the independent region 56a at the end of the winding.
  • the positive electrode uncoated portion 34a can be easily bent or nearly bent toward the inner periphery and wound while preventing wrinkles from forming in the positive electrode uncoated portion 34a. This makes it easier to reduce the vertical height of the bent positive electrode uncoated portion 34a.
  • each second cut 53a may be inclined in the opposite direction to the configuration shown in FIG. 7, i.e., the edge of the second cut 53a on the boundary 57 side may be inclined closer to the start of winding than the tip end of the positive electrode uncoated portion 34a of the second cut 53a.
  • the acute-angled tip of the low-rigidity independent region on the start of winding side (for example, the portion corresponding to portion R in FIG. 7) may overlap the obtuse-angled tip of the high-rigidity independent region on the end of winding side (for example, the portion corresponding to portion S in FIG. 7). This results in a lower effect of suppressing the rising of the independent region 56a on the end of winding of the cut portion 51 compared to the configuration shown in FIG. 7.
  • each second slit 53a is inclined at an angle ⁇ of 30 degrees or more and 80 degrees or less with respect to the boundary 57 between the positive electrode uncoated portion 34a and the laminated portion 35. This makes it easier to bend the positive electrode uncoated portion 34a inward or in a nearly bent state and wind it while suppressing the occurrence of wrinkles in the positive electrode uncoated portion 34a.
  • the angle ⁇ is greater than 80 degrees, it becomes difficult to smoothly overlap adjacent independent regions 56a, thereby reducing the effect of suppressing the occurrence of wrinkles when bending.
  • the angle ⁇ is less than 30 degrees, the length of the second slit 53a becomes excessively large compared to the width of the end of the independent region 56a on the laminated portion 35 side in the winding direction. This makes the independent region 56a elongated and reduced rigidity, making it difficult to hold the adjacent independent region bent inward.
  • each second cut 53a be between 30 degrees and 60 degrees.
  • the inventors conducted an experiment in which the angle ⁇ was changed to several different angles in the range of 40 degrees to 90 degrees, and the folded height (height in the vertical direction) was compared when the uncoated positive electrode portion was bent inward to prevent wrinkles from forming in the uncoated positive electrode portion.
  • the results of this experiment showed that the folded height could be significantly reduced when the angle ⁇ was 60 degrees or less.
  • the other configurations and functions are the same as those in Figures 1 to 5.
  • Figure 8 is a schematic diagram showing the expanded state of the positive electrode 11b constituting a secondary battery in another example of the embodiment.
  • the second slit 53b in the configuration shown in Figures 6 and 7 has a triangular concave shape including a first linear portion 58 inclined with respect to the winding direction and a second linear portion 59 aligned along the short side of the positive electrode 11b.
  • the direction of the first linear portion 58 is the same as the direction of the second slit 53a in the configuration of Figure 7.
  • Adjacent independent regions 56b are separated by the second slit 53b.
  • the first slit 52b has the same shape as the second slit 53b.
  • the second cut and the first cut may also be V-shaped, including a first straight portion 58 and a second straight portion that is inclined in the opposite direction to the first straight portion 58 with respect to the winding direction.
  • the other configurations and functions are the same as those in Figures 1 to 5 or Figures 6 and 7.
  • FIG 9 is a diagram corresponding to Figure 4 of a secondary battery 10a according to another embodiment.
  • the seamless portion 50a in the uncoated positive electrode portion 34c of the positive electrode 11c includes multiple peaks 60 that protrude upward in the direction from the laminated portion 35 (see Figure 2) toward the positive current collector 18 (see Figure 2), and a valley 61 that is located between two of the multiple peaks 60 and recessed downward in the direction from the positive current collector 18 toward the laminated portion 35.
  • the peaks 60 and valleys 61 are alternately arranged in the winding direction.
  • the positive electrode current collector plate 18 and the two peaks 60 are joined by welding.
  • the tops of the peaks 60 are shown within the dashed-line frame U1
  • the bottoms of the valleys 61 are shown within the dash-dotted-line frame U2.
  • the winding length of the peaks 60 be greater than the winding length of the valleys 61.
  • the other configurations and functions are the same as those in Figures 1 to 5.
  • Figure 10 is a schematic diagram showing the expanded state of a positive electrode 11d constituting a secondary battery of another example of an embodiment.
  • the length d1 of the entire unslit portion 50b of the positive electrode uncoated portion 34d along the short side of the positive electrode 11d, including the winding end end 54a of the unslit portion 50b is smaller than the length d2 of the slit portion 51 along the short side, including the winding end end 62 of the slit portion 51.
  • a portion of the winding end end 62 forms a first slit 52c.
  • the configuration of this example makes it possible to reduce the vertical length of the unbroken portion 50b of the positive electrode 11d in its unfolded state. This further reduces the occurrence of wrinkles on the outer periphery when the portion near the winding end 54a, which forms the outer periphery of the positive electrode uncoated portion 34d, is bent or curved toward the inner periphery during winding. This increases the bonding strength between the positive electrode 11d and the positive electrode current collector plate.
  • Other configurations and functions of this example are the same as those of the configurations in Figures 1 to 5.
  • FIG 11 is a schematic diagram showing the expanded state of the positive electrode 11e constituting a secondary battery in another example of an embodiment.
  • the winding end 54b of the seamless portion 50c is located closer to the winding start side of the positive electrode 11e than the winding end 35a of the laminated portion 35.
  • the positive electrode uncoated portion 34e does not extend to the upper end, which is the end on the positive electrode current collector plate side, and a stepped uncoated portion cut portion 63 is formed.
  • the winding direction length of the seamless portion 50c is at least one revolution from the winding end of the positive electrode uncoated portion 34e.
  • the configuration of this example makes it easier to provide the positive electrode uncoated portion 34e on the inner side of the outermost periphery of the positive electrode 11e, which includes the winding end 35a of the laminated portion 35. This places the positive electrode uncoated portion 34e significantly away from the inner periphery of the case 15 (see Figure 1), more reliably preventing short circuits.
  • Configuration 1 A cylindrical case (15) with a bottom, A first electrode (11, 11a, 11b, 11c, 11d, 11e, 12) is disposed in the case (15), and a second electrode (12, 11, 11a, 11b, 11c, 11d, 11e) has a polarity different from that of the first electrode (11, 11a, 11b, 11c, 11d, 11e, 12), and the first electrode (11, 11a, 11b, 11c, 11d, 11e, 12) and the second electrodes (12, 11, 11a, 11b, 11c, 11d, 11e), and a separator (13) arranged between the first electrodes (11, 11a, 11b, 11c, 11d, 11e), wherein the first electrodes (11, 11a, 11b, 11c, 11d, 11e, 12) and the second electrodes (12, 11, 11a, 11b, 11c, 11d, 11e) are wound with the separator (13) interposed therebetween;
  • Configuration 2 The at least one second cut (53, 53a, 53b) is a plurality of second cuts (53, 53a, 53b) provided in the cut portion (51).
  • the electricity storage device (10, 10a) according to configuration 1.
  • Configuration 3 the length of the unbroken portion (50, 50a, 50b, 50c) in the winding direction is a length of two or more and six or less revolutions from the winding end (54, 54a, 54b) of the uncoated portion (34, 34a, 34b, 34c, 34d, 34e);
  • the electricity storage device (10, 10a) according to configuration 1 or 2.
  • Configuration 4 When the first electrodes (11a, 11b, 12) are in an expanded state, an extension line (L1) of the second slits (53a, 53b) extending toward the tip end of the uncoated portion (34a, 34b) intersects with an extension line (L2) extending toward the tip end of the winding start end (55) of the slit portion (51).
  • the electricity storage device (10) according to any one of configurations 1 to 3.
  • Configuration 5 the second cuts (53a, 53b) extend from a boundary (57) between the uncoated portions (34a, 34b) and the laminated portion (35) toward the tips of the uncoated portions (34a, 34b), an end (T1) of the second cut (53a, 53b) on the boundary (57) side is located closer to the winding end side than an end (T2) of the second cut (57) on the tip side of the uncoated portion (34a, 34b);
  • the electricity storage device (10) according to configuration 4.
  • Configuration 6 the second cuts (53a, 53b) are provided at an angle of 30 degrees or more and 80 degrees or less with respect to a boundary (57) between the uncoated portion (34a, 34b) and the laminated portion (35); The electricity storage device (10) according to configuration 5.
  • Configuration 7 The seamless portion (50a) is two peaks (60) protruding from the laminated portion (35) in a direction toward the current collector plate (18); a valley portion (61) located between the two peak portions (60) and recessed in a direction from the current collector plate (18) toward the stack portion (35), The current collector plate (18) and the two peaks (60) are joined together.
  • the electricity storage device (10a) according to any one of configurations 1 to 6.
  • Configuration 8 In the deployed state of the first electrode (11d), a length (d1) along the short side direction of the first electrode (11d) at the winding end (54a) of the unslit portion (50b) is smaller than a length (d2) along the short side direction of the winding end (62) of the slit portion (51).
  • the electricity storage device (10) according to any one of configurations 1 to 3 and 7.
  • Configuration 9 When the first electrode (11e) is in a deployed state, the winding end (54b) of the seamless portion (50c) is located closer to the winding start side of the first electrode (11e) than the winding end end (35a) of the laminated portion (35).
  • the electricity storage device (10) according to any one of configurations 1 to 8.

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

Ce dispositif de stockage d'énergie comprend un corps d'électrode (14) et une plaque collectrice de courant (18) qui est fixée à une extrémité de direction axiale du corps d'électrode (14). Une première électrode (11) du corps d'électrode présente une partie non revêtue (34) qui est disposée sur une extrémité positionnée plus près du côté de la plaque collectrice de courant (18) qu'une partie stratifiée (35) et dans laquelle une couche de matériau actif d'électrode n'a pas été stratifiée. La partie non revêtue (34) est connectée à la plaque collectrice de courant (18) dans un état dans lequel la partie non revêtue (34) est courbée en direction du côté périphérique interne du corps d'électrode. La partie non revêtue (34) est dotée d'une première découpe et d'une seconde découpe. La partie non revêtue (34) présente : une partie non découpée (50) présentant une première extrémité qui est une extrémité d'extrémité d'enroulement et une deuxième extrémité qui est la première découpe, aucune découpe n'étant présente entre la première extrémité et la deuxième extrémité ; et une partie avec découpe (51) dotée d'une seconde découpe entre une troisième extrémité qui est la première découpe et une quatrième extrémité qui est une extrémité de début d'enroulement. La longueur dans la direction d'enroulement de la partie dans découpe (50) est au moins une spire à partir de l'extrémité d'extrémité d'enroulement de la partie non revêtue (34).
PCT/JP2025/026773 2024-07-31 2025-07-29 Dispositif de stockage d'énergie Pending WO2026029030A1 (fr)

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Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000251871A (ja) * 1999-03-02 2000-09-14 Toshiba Battery Co Ltd アルカリ二次電池
JP2004095487A (ja) * 2002-09-04 2004-03-25 Matsushita Electric Ind Co Ltd 蓄電池およびその製造方法
JP2008123848A (ja) * 2006-11-13 2008-05-29 Gs Yuasa Corporation:Kk 電池
JP2013218804A (ja) * 2012-04-04 2013-10-24 Gs Yuasa Corp 電極体、蓄電素子及び電極体の製造方法
CN113488746A (zh) * 2021-07-06 2021-10-08 湖北亿纬动力有限公司 一种多极耳电芯的制作工艺及多极耳电芯
JP2024500131A (ja) * 2021-01-19 2024-01-04 エルジー エナジー ソリューション リミテッド 電極組立体、バッテリー、それを含むバッテリーパック及び自動車
JP2024088323A (ja) * 2022-12-20 2024-07-02 トヨタ自動車株式会社 蓄電セルの製造方法及び蓄電セル

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000251871A (ja) * 1999-03-02 2000-09-14 Toshiba Battery Co Ltd アルカリ二次電池
JP2004095487A (ja) * 2002-09-04 2004-03-25 Matsushita Electric Ind Co Ltd 蓄電池およびその製造方法
JP2008123848A (ja) * 2006-11-13 2008-05-29 Gs Yuasa Corporation:Kk 電池
JP2013218804A (ja) * 2012-04-04 2013-10-24 Gs Yuasa Corp 電極体、蓄電素子及び電極体の製造方法
JP2024500131A (ja) * 2021-01-19 2024-01-04 エルジー エナジー ソリューション リミテッド 電極組立体、バッテリー、それを含むバッテリーパック及び自動車
CN113488746A (zh) * 2021-07-06 2021-10-08 湖北亿纬动力有限公司 一种多极耳电芯的制作工艺及多极耳电芯
JP2024088323A (ja) * 2022-12-20 2024-07-02 トヨタ自動車株式会社 蓄電セルの製造方法及び蓄電セル

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