WO2024057726A1 - Power storage element - Google Patents

Power storage element Download PDF

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Publication number
WO2024057726A1
WO2024057726A1 PCT/JP2023/027085 JP2023027085W WO2024057726A1 WO 2024057726 A1 WO2024057726 A1 WO 2024057726A1 JP 2023027085 W JP2023027085 W JP 2023027085W WO 2024057726 A1 WO2024057726 A1 WO 2024057726A1
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WO
WIPO (PCT)
Prior art keywords
electrode body
hole
positive electrode
electrode
separator
Prior art date
Application number
PCT/JP2023/027085
Other languages
French (fr)
Japanese (ja)
Inventor
義人 ▲高▼木
一弥 岡部
良一 奥山
Original Assignee
株式会社Ｇｓユアサ
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Publication of WO2024057726A1 publication Critical patent/WO2024057726A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/52—Separators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/66—Current collectors
    • H01G11/70—Current collectors characterised by their structure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
    • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
    • H01G11/78—Cases; Housings; Encapsulations; Mountings
    • 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
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • 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
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/70—Carriers or collectors characterised by shape or form
    • 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
    • H01M50/103—Primary casings; Jackets or wrappings characterised by their shape or physical structure prismatic or rectangular
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/411—Organic material
    • H01M50/414—Synthetic resins, e.g. thermoplastics or thermosetting resins
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/431—Inorganic material
    • H01M50/434—Ceramics
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/443—Particulate material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/409—Separators, membranes or diaphragms characterised by the material
    • H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
    • H01M50/451—Separators, membranes or diaphragms characterised by the material having a layered structure comprising layers of only organic material and layers containing inorganic material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • 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
    • H01M50/60—Arrangements or processes for filling or topping-up with liquids; Arrangements or processes for draining liquids from casings
    • H01M50/609—Arrangements or processes for filling with liquid, e.g. electrolytes
    • H01M50/627—Filling ports
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M6/00—Primary cells; Manufacture thereof
    • H01M6/14—Cells with non-aqueous electrolyte
    • H01M6/16—Cells with non-aqueous electrolyte with organic electrolyte

Definitions

  • the present invention relates to a power storage element in which an electrode body and an electrolyte are housed in a container.
  • Patent Document 1 discloses a wound-type electrode body formed by laminating and winding a positive electrode plate and a negative electrode plate with a separator interposed therebetween, and a wound-type power storage device (power storage element) in which an electrolytic solution is housed in a battery container. Disclosed.
  • a power storage element including a conventional wound-type electrode body as described above, it may be difficult to allow the electrolyte to penetrate into the electrode body when injecting the electrolyte into the container.
  • an electrolyte injection part is provided on the wall of the container that extends in the direction of the winding axis of the electrode body, it is difficult for the electrolyte to penetrate from the outside to the inside of the electrode body. becomes difficult. In particular, if the length of the electrode body in the direction of the winding axis is long, it becomes more difficult to infiltrate the electrolyte into the electrode body.
  • the present invention was made by the inventors of the present application newly paying attention to the above-mentioned problem, and an object of the present invention is to provide a power storage element in which an electrolytic solution can easily penetrate into an electrode body.
  • a power storage element includes an electrode body in which an electrode plate and a separator are wound, an electrolytic solution, and a container in which the electrode body and the electrolytic solution are housed, and the container includes the
  • the electrode body has an injection part for the electrolytic solution on a wall extending in the winding axis direction, the electrode body has a length in the winding axis direction of 500 mm or more, and the separator has a base material and a base material. and an inorganic coat layer containing inorganic particles coated on the base material.
  • the electrolyte can easily penetrate into the electrode body.
  • FIG. 1 is a perspective view showing the appearance of a power storage element according to an embodiment.
  • FIG. 2 is an exploded perspective view showing each component of the power storage device according to the embodiment.
  • FIG. 3 is a perspective view showing the structure of the electrode body according to the embodiment.
  • FIG. 4 is a perspective view and a cross-sectional view showing the structure of an electrode body according to an embodiment.
  • FIG. 5 is a front view and a cross-sectional view showing the configuration of a through hole of an electrode body according to an embodiment.
  • FIG. 6 is a front view and a cross-sectional view showing the structure of a through hole of an electrode body according to Modification 1 of the embodiment.
  • a power storage element includes an electrode body in which an electrode plate and a separator are wound, an electrolytic solution, and a container in which the electrode body and the electrolytic solution are housed, the container has an injection part for the electrolytic solution on a wall extending in the direction of the winding axis of the electrode body, the electrode body has a length of 500 mm or more in the direction of the winding axis, and the separator has: It has a base material and an inorganic coat layer containing inorganic particles coated on the base material.
  • the power storage element includes a wound electrode body, and an electrolyte injection part is provided in a wall portion of the container that extends in the direction of the winding axis of the electrode body. This makes it difficult for the electrolyte to penetrate from the outside to the inside of the electrode body when pouring the electrolyte into the container, making it difficult for the electrolyte to penetrate into the electrode body.
  • By coating the separator with the electrolyte it is possible to improve the permeability of the electrolyte into the separator.
  • the length of the electrode body in the direction of the winding axis is 500 mm or more, it becomes more difficult to penetrate the electrolyte into the electrode body, so by coating the separator with an inorganic coating layer, it is possible to The effect of improving the permeability of the electrolyte becomes remarkable. Therefore, the time required for the electrolyte to penetrate into the electrode body can be shortened, so that the electrolyte can easily penetrate into the electrode body.
  • the inorganic coat layer may have a permeation area of 80 mm 2 or more for the electrolyte at 300 seconds after the electrolyte is dropped.
  • the inorganic coating layer coated on the separator has a relatively short electrolytic solution penetration area of 80 mm 2 or more at 300 seconds after the electrolytic solution is dropped. It is an inorganic coating layer that can permeate a relatively wide area over time. In this way, by using an inorganic coating layer that allows the electrolyte to permeate a relatively wide area in a relatively short period of time, the permeability of the electrolyte into the separator can be improved.
  • the inorganic coat layer may include at least one of barium sulfate and alumina as the inorganic particles.
  • the inventors of the present invention have discovered that when an electrolyte is dropped onto an inorganic coat layer containing at least one of barium sulfate and alumina, the electrolyte can penetrate a relatively wide area of the inorganic coat layer in a relatively short time. According to the power storage element described in (3) above, by including at least one of barium sulfate and alumina in the inorganic coating layer coated on the separator, the permeability of the electrolyte into the separator can be improved.
  • the electrode body may have a length of 600 mm or more in the direction of the winding axis.
  • the inventors of the present application have found that even when using the electrode body, by coating the separator with an inorganic coating layer, the electrolytic solution can be easily penetrated into the electrode body. Therefore, when a long electrode body like the electricity storage element described in (4) above is used, the effect of adopting the configuration of the present application is high.
  • a through hole may be formed in the electrode plate.
  • the separator in which the permeability of the electrolytic solution has been improved by the inorganic coating layer, passes through the through hole to the electrode. Allows electrolytes to penetrate the body.
  • the direction in which the short sides of the container face each other is defined as the X-axis direction.
  • the direction in which the long sides of the container face each other or the thickness direction of the container is defined as the Y-axis direction.
  • the direction in which the container body and lid of the container are lined up or the vertical direction is defined as the Z-axis direction.
  • X-axis direction, Y-axis direction, and Z-axis direction are directions that intersect with each other (orthogonal in this embodiment).
  • the Z-axis direction may not be the vertical direction, but for convenience of explanation, the Z-axis direction will be described as the vertical direction below.
  • the X-axis plus direction indicates the arrow direction of the X-axis
  • the X-axis minus direction indicates the opposite direction to the X-axis plus direction.
  • the X-axis direction it refers to both or one of the X-axis plus direction and the X-axis minus direction.
  • One side and the other side in the X-axis direction refer to one and the other of the X-axis plus direction and the X-axis minus direction.
  • Expressions indicating relative directions or orientations, such as parallel and orthogonal, include cases where the directions or orientations are not strictly speaking.
  • FIG. 1 is a perspective view showing the appearance of a power storage element 10 according to the present embodiment.
  • FIG. 2 is an exploded perspective view showing each component of the power storage element 10 according to the present embodiment.
  • the power storage element 10 is a secondary battery (single battery) that can charge and discharge electricity, and more specifically, it is a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery.
  • the power storage element 10 is used as a battery for driving or starting an engine of a moving object such as an automobile, a motorcycle, a watercraft, a ship, a snowmobile, an agricultural machine, a construction machine, or a railway vehicle for an electric railway.
  • Examples of the above-mentioned vehicles include electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and fossil fuel (gasoline, diesel oil, liquefied natural gas, etc.) vehicles.
  • Examples of the above-mentioned railway vehicles for electric railways include electric trains, monorails, linear motor cars, and hybrid electric trains equipped with both a diesel engine and an electric motor.
  • the power storage element 10 can also be used as a stationary battery used for home or business use.
  • the power storage element 10 is not limited to a non-aqueous electrolyte secondary battery, and may be a secondary battery that is not a non-aqueous electrolyte secondary battery, or may be a capacitor.
  • the power storage element 10 may be not a secondary battery but a primary battery that allows the user to use the stored electricity without charging it.
  • the power storage element 10 may be a pouch type power storage element.
  • a rectangular parallelepiped-shaped (prismatic) power storage element 10 that is flat in the Y-axis direction is illustrated, but the shape of the power storage element 10 is not limited to a rectangular parallelepiped shape, and may include a polygonal prism shape other than a rectangular parallelepiped, The shape may be an elongated cylinder, an elliptical cylinder, a cylinder, or the like.
  • the power storage element 10 includes a container 100, a pair of terminals 300 (positive electrode and negative electrode), and a pair of upper gaskets 400 (positive electrode and negative electrode). As shown in FIG. 2, inside the container 100, a pair of lower gaskets 500 (positive electrode and negative electrode), a pair of current collectors 600 (positive electrode and negative electrode), and an electrode body 700 are accommodated. . In addition to the above-mentioned components, a spacer placed on the side or below the electrode body 700, an insulating film that wraps around the electrode body 700, etc. may be placed.
  • An electrolytic solution (non-aqueous electrolyte) is sealed inside the container 100, but illustration thereof is omitted.
  • the type of electrolytic solution is not particularly limited as long as it does not impair the performance of the power storage element 10, and various types can be selected.
  • the electrolytic solution includes a non-aqueous solvent and an electrolyte salt dissolved in the non-aqueous solvent.
  • the non-aqueous solvent can be appropriately selected from known non-aqueous solvents.
  • non-aqueous solvents examples include cyclic carbonates such as ethylene carbonate (EC) or propylene carbonate (PC), chain carbonates such as ethyl methyl carbonate (EMC), carboxylic acid esters, phosphoric acid esters, sulfonic acid esters, ethers, amides, Examples include nitrile.
  • cyclic carbonates such as ethylene carbonate (EC) or propylene carbonate (PC)
  • chain carbonates such as ethyl methyl carbonate (EMC)
  • carboxylic acid esters examples include phosphoric acid esters, sulfonic acid esters, ethers, amides
  • the electrolyte salt can be appropriately selected from known electrolyte salts.
  • the electrolyte salt include lithium salts such as inorganic lithium salts such as LiPF 6 , sodium salts, potassium salts, magnesium salts, onium salts, and the like. Among these, lithium salts are preferred.
  • the container 100 is a rectangular parallelepiped-shaped (prismatic or box-shaped) case that has a container body 110 with an opening formed in the positive Z-axis direction and a lid 120 that closes the opening of the container body 110.
  • the lid 120 is a flat, rectangular member that constitutes the lid of the container 100, and is arranged in the positive Z-axis direction of the container body 110.
  • the lid body 120 is an example of a wall portion extending in the direction of the winding axis of the electrode body 700.
  • the winding axis direction of the electrode body 700 is the direction in which the winding axis L of the electrode body 700, which will be described later, extends (the direction along the winding axis L, in this embodiment, the X-axis direction).
  • the container body 110 is a member that constitutes the main body of the container 100 and includes a rectangular cylindrical portion and a bottom.
  • the container body 110 has a pair of long side walls 111 on both sides in the Y-axis direction, a pair of short side walls 112 on both sides in the X-axis direction, and has a pair of short side walls 112 on both sides in the Y-axis direction. It has a bottom wall portion 113 on the surface (bottom surface).
  • the long side wall portion 111 is a flat rectangular wall portion extending in the X-axis direction (the direction of the winding axis of the electrode body 700), and constitutes the long side surface of the container 100.
  • the long side wall 111 is adjacent to the short side wall 112, the bottom wall 113, and the lid 120, and has a larger area than the short side wall 112.
  • the short side wall portion 112 is a flat rectangular wall portion extending in the Z-axis direction, and constitutes a short side surface of the container 100.
  • the short side wall 112 is adjacent to the long side wall 111, the bottom wall 113, and the lid 120, and has a smaller area than the long side wall 111.
  • the bottom wall portion 113 is a flat, rectangular wall portion that extends in the X-axis direction (the direction of the winding axis of the electrode body 700), and constitutes the bottom surface of the container 100.
  • the bottom wall portion 113 is disposed adjacent to the long side wall portion 111 and the short side wall portion 112.
  • the container main body 110 and the lid 120 are joined by welding or the like, so that the inside of the container 100 is hermetically sealed.
  • the material of the container 100 is not particularly limited, and may be a weldable (joinable) metal such as stainless steel, aluminum, aluminum alloy, iron, or plated steel plate, or resin may be used.
  • the container body 110 and the lid 120 may be made of the same material or may be made of different materials.
  • the power storage element 10 is a pouch type power storage element
  • the container 100 may be a laminate film made of multiple layers including a metal layer and a resin layer.
  • a liquid injection part 130 and a gas discharge valve 140 are formed in the container 100.
  • the liquid injection part 130 and the gas discharge valve 140 are formed on the lid 120. That is, the liquid injection part 130 and the gas discharge valve 140 are formed on a wall portion extending in the winding axis direction (X-axis direction) of the electrode body 700.
  • the gas discharge valve 140 is a safety valve that releases the pressure inside the container 100 when the pressure increases excessively.
  • the gas exhaust valve 140 is arranged at the center in the X-axis direction and the center in the Y-axis direction of the lid 120, but it may be arranged at any position on the lid 120.
  • the liquid injection part 130 is a part (electrolyte liquid injection part) for injecting the electrolytic solution into the inside of the container 100 when manufacturing the power storage element 10.
  • the liquid injection unit 130 evacuates the inside of the container 100 , injects an electrolytic solution into the container 100 to impregnate the electrode body 700 with the electrolytic solution, and performs functions such as filling the electrode body 700 with the electrolytic solution when manufacturing the power storage element 10 . It is used to evacuate gas from inside.
  • the liquid injection part 130 is arranged at the center of the lid 120 in the negative X-axis direction and the Y-axis direction, but it may be arranged at any position on the lid 120.
  • the liquid injection part 130 includes a liquid injection port 131 and a liquid injection plug 132.
  • the liquid injection port 131 is, for example, a circular through hole formed in the lid 120 for injecting the electrolyte into the container 100 .
  • the liquid injection stopper 132 is a member that closes the liquid injection port 131. Specifically, the liquid injection stopper 132 is joined to the lid body 120 after the inside of the container 100 is evacuated from the liquid injection port 131 and the electrolyte is injected into the inside of the container 100 during manufacturing of the power storage element 10. This is a closing member (lid member) that closes the liquid injection port 131.
  • the material of the liquid injection stopper 132 is not particularly limited, but any metal that can be used for the container 100 (lid 120) can be used. In particular, the liquid injection stopper 132 is preferably formed of a material that can be welded to the lid 120, such as the same material as the lid 120.
  • the terminal 300 is a terminal member (a positive terminal and a negative terminal) that is electrically connected to the electrode body 700 via the current collector 600.
  • the terminal 300 is used to lead the electricity stored in the electrode body 700 to the external space of the electricity storage element 10 and to introduce electricity into the internal space of the electricity storage element 10 in order to store electricity in the electrode body 700.
  • It is a metal member.
  • the terminal 300 is made of a conductive member such as metal such as aluminum, aluminum alloy, copper, or copper alloy.
  • the terminal 300 is connected (joined) to the current collector 600 and attached to the lid 120 by caulking, welding, or the like.
  • terminal 300 is arranged so as to protrude in the Z-axis positive direction from the outer surface (the surface in the Z-axis positive direction) of the lid body 120.
  • terminal 300 is a welding terminal that is joined to an external conductive member such as a bus bar by welding.
  • terminal 300 may also be a bolt terminal.
  • the bolt terminal has a bolt portion in which a male screw portion protruding in the positive direction of the Z-axis is formed, and is joined to the conductive member by bolt connection.
  • the current collector 600 is a conductive current collecting member (a positive electrode current collector and a negative electrode current collector) that is connected (joined) to the electrode body 700 and the terminal 300 and electrically connects the electrode body 700 and the terminal 300. ).
  • current collectors 600 are arranged on both sides of electrode body 700 in the X-axis direction.
  • the current collector 600 and an end 720 of an electrode body 700, which will be described later, are connected (joined) by welding, caulking, or the like. Further, as described above, the current collector 600 and the terminal 300 are connected (joined) by caulking, welding, or the like, and are fixed to the lid 120.
  • the positive electrode current collector 600 is formed of aluminum or an aluminum alloy, etc., like the positive electrode current collector foil 741 of the electrode body 700, which will be described later.
  • the current collector 600 is made of copper, copper alloy, or the like, like the negative electrode current collector foil 751 of the electrode body 700 described later.
  • the upper gasket 400 is a plate-shaped and rectangular insulating member that is disposed between the lid 120 of the container 100 and the terminal 300, and insulates and seals between the lid 120 and the terminal 300.
  • the lower gasket 500 is a plate-shaped and rectangular insulating member that is disposed between the lid 120 and the current collector 600 and insulates between the lid 120 and the current collector 600.
  • the upper gasket 400 and the lower gasket 500 are made of polypropylene (PP), polyethylene (PE), polystyrene (PS), polyphenylene sulfide resin (PPS), polyphenylene ether (PPE (including modified PPE)), polyethylene terephthalate (PET), Polybutylene terephthalate (PBT), polyether ether ketone (PEEK), tetrafluoroethylene perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene (PTFE), polyether sulfone (PES), polyamide (PA), ABS resin , or an insulating member such as a composite material thereof.
  • PP polypropylene
  • PE polyethylene
  • PS polystyrene
  • PPS polyphenylene sulfide resin
  • PPE polyphenylene ether
  • PET polyethylene terephthalate
  • PBT Polybutylene terephthalate
  • PEEK polyether ether ketone
  • the electrode body 700 is a power storage element (power generation element) that is formed by laminating electrode plates and separators and is capable of storing electricity.
  • the electrode body 700 is formed by winding an electrode plate and a separator.
  • the electrode body 700 has an elongated shape extending in the X-axis direction, and has an oval shape (long columnar shape) when viewed from the X-axis direction.
  • the electrode body 700 has an electrode body body part 710 and an end part 720 protruding from the electrode body body part 710 on both sides in the X-axis direction, and as described above, the end part 720 is connected (joined) to the current collector 600. ) to be done.
  • a through hole 730 is formed in the electrode main body portion 710. The configuration of such an electrode body 700 will be described in detail below.
  • FIG. 3 is a perspective view showing the configuration of an electrode body 700 according to this embodiment.
  • FIG. 3 shows the structure of the electrode body 700 in a partially unfolded state in which the electrode plates are wound.
  • FIG. 4 is a perspective view and a cross-sectional view showing the configuration of an electrode body 700 according to this embodiment.
  • FIG. 4(a) is a perspective view showing the configuration of the electrode body 700 after winding the electrode plate, and
  • FIG. 4(b) is an enlarged cross-section of a part of the electrode body 700.
  • FIG. 4(a) is a perspective view showing the configuration of the electrode body 700 after winding the electrode plate
  • FIG. 4(b) is an enlarged cross-section of a part of the electrode body 700.
  • the electrode body 700 has two electrode plates, a positive electrode plate 740 and a negative electrode plate 750, and has two separators 760 as separators. 761 and 762.
  • the positive electrode plate 740 is an electrode plate (electrode plate) in which a positive electrode active material layer 742 is formed on the surface of a positive electrode current collector foil 741 that is a long strip-shaped current collector foil (metal foil) made of metal such as aluminum or aluminum alloy.
  • the negative electrode plate 750 is an electrode plate (electrode plate) in which a negative electrode active material layer 752 is formed on the surface of a negative electrode current collector foil 751, which is a long strip-shaped current collector foil (metal foil) made of metal such as copper or copper alloy. ).
  • the positive electrode current collector foil 741 and the negative electrode current collector foil 751 materials such as nickel, iron, stainless steel, titanium, fired carbon, conductive polymer, conductive glass, Al-Cd alloy, etc., can be used to prevent oxidation-reduction reactions during charging and discharging. Any known material may be used as long as it is stable.
  • the positive electrode active material used in the positive electrode active material layer 742 and the negative electrode active material used in the negative electrode active material layer 752 any known material can be used as long as it is a positive electrode active material and a negative electrode active material that can intercalate and extract lithium ions. can be used.
  • polyanion compounds such as LiMPO 4 , LiMSiO 4 , LiMBO 3 (M is one or more transition metal elements selected from Fe, Ni, Mn, Co, etc.), lithium titanate, LiMn 2 Spinel-type lithium manganese oxide such as O 4 or LiMn 1.5 Ni 0.5 O 4 , LiMO 2 (M is one or more transition metal elements selected from Fe, Ni, Mn, Co, etc.) Lithium transition metal oxides such as the following can be used.
  • negative electrode active materials include lithium metal, lithium alloys (lithium metal-containing alloys such as lithium-silicon, lithium-aluminum, lithium-lead, lithium-tin, lithium-aluminum-tin, lithium-gallium, and Wood alloys). , alloys that can absorb and release lithium, carbon materials (graphite, non-graphitizable carbon, easily graphitizable carbon, low-temperature firing carbon, amorphous carbon, etc.), silicon oxides, metal oxides, lithium metal oxides (Li 4 Ti 5 O 12 etc.), polyphosphoric acid compounds, or compounds of transition metals and Group 14 to Group 16 elements, such as Co 3 O 4 or Fe 2 P, which are generally called conversion negative electrodes.
  • lithium metal lithium alloys
  • lithium metal-containing alloys such as lithium-silicon, lithium-aluminum, lithium-lead, lithium-tin, lithium-aluminum-tin, lithium-gallium, and Wood alloys.
  • alloys that can absorb and release lithium include carbon materials (
  • the separator 760 (separators 761 and 762) includes a separator base material 760a and an inorganic coat layer 760b containing inorganic particles coated on the separator base material 760a (see (b) in FIG. 4).
  • the separator base material 760a is a base material of the separator 760, and is a microporous insulating sheet made of resin or the like.
  • any known material can be used as appropriate, as long as it does not impair the performance of power storage element 10. Examples of the shape of the separator base material 760a include woven fabric, nonwoven fabric, and porous resin film.
  • a porous resin film is preferred from the viewpoint of strength, and a nonwoven fabric is preferred from the viewpoint of electrolyte retention.
  • a material for the separator base material 760a polyolefins such as polyethylene and polypropylene are preferred from the viewpoint of a shutdown function, and polyimide, aramid, etc. are preferred from the viewpoint of oxidative decomposition resistance.
  • a composite material of these resins may be used as the separator base material 760a.
  • the inorganic coat layer 760b is a coat layer that is coated on the separator base material 760a.
  • the inorganic coat layer 760b includes inorganic particles and a binder (binding material), and is coated on the separator base material 760a with the binder.
  • the binder any known material can be used as appropriate.
  • the inorganic coating layer 760b is a thin film-like portion that is thinner than the separator base material 760a and covers the entire surface (one side) of the separator base material 760a.
  • the inorganic coat layer 760b is not limited to covering the entire surface of the separator base material 760a, and may not cover a part of the surface. In FIG.
  • the inorganic coat layer 760b covers the surface of the separator base material 760a in the Y-axis negative direction, but it may cover the surface of the separator base material 760a in the Y-axis positive direction, or Both sides of 760a may be covered.
  • the inorganic coat layer 760b may be thicker than the separator base material 760a. However, it is preferable that the inorganic coating layer 760b covers one side of the separator base material 760a and is thinner than the separator base material 760a because the thickness of the separator 760 can be reduced.
  • the inorganic coating layer 760b coated on the separator base material 760a has an electrolyte permeation area of 80 mm 2 or more at 300 seconds after the electrolyte is dropped.
  • Table 1 shows a comparison of the permeation area of the electrolytic solution at 300 seconds after the electrolytic solution was dropped in a separator having an organic coating layer and a separator having an inorganic coating layer.
  • the method for measuring the permeation area is as follows. The evaluation sample is placed on a glass plate so that the front side becomes the coating layer and the back side becomes the separator base material 760a, and 0.3 cc of electrolytic solution is dropped into the center of the sample.
  • the time when the electrolytic solution adheres to the organic or inorganic coating layer is defined as 0 seconds, and the area that changes color due to penetration of the solution at 300 seconds is considered to be the penetration range.
  • the electrolytic solution dropped onto the organic or inorganic coating layer spreads in a circular shape, the diameter of the permeation range is measured at three locations, and the area of the circle calculated from the average value of the diameters is defined as the permeation area. If the spread of the electrolyte is visually confirmed to be a distorted shape that is not circular, such as an ellipse, the area that has changed color due to penetration of the solution is considered the penetration range, and image processing is performed to calculate the penetration area. calculate.
  • PC propylene carbonate
  • inorganic substances such as aluminum silicate, barium sulfate, and alumina (boehmite) are The test was conducted using particles with a particle diameter of approximately 5 ⁇ m. The larger the particle size, the faster the penetration rate, so the average primary particle size of the inorganic substance (inorganic particles) is preferably 1 ⁇ m or more, more preferably 3 ⁇ m or more. The particle diameter of the inorganic substance (inorganic particles) is equal to or less than the thickness of the inorganic coat layer 760b.
  • the The permeation area of the electrolyte is 80 mm 2 or more.
  • the inorganic coat layer 760b contains inorganic particles such as aluminum silicate, barium sulfate, and alumina (boehmite), and the permeation area of the electrolyte at 300 seconds after the electrolyte is dropped is 80 mm. It is 2 or more. Since barium sulfate and alumina (boehmite) have a larger permeation area than aluminum silicate, the inorganic coat layer 760b preferably contains at least one of barium sulfate and alumina as inorganic particles. In this case, the inorganic coat layer 760b has an electrolytic solution permeation area of 90 mm 2 or more (95 mm 2 ) 300 seconds after the electrolytic solution is dropped.
  • the inorganic coat layer 760b may contain one type of these inorganic substances as inorganic particles, or may contain multiple types of inorganic substances.
  • the particle size of the inorganic particles is about 5 ⁇ m.
  • the electrode body 700 is formed by alternately stacking and winding the positive electrode plate 740 and the negative electrode plate 750 configured as described above, and the separators 761 and 762. That is, the electrode body 700 is formed by stacking a positive electrode plate 740, a separator 761, a flat negative electrode plate 750, and a separator 762 in this order and winding them (see FIG. 4B, etc.).
  • the electrode body 700 is a wound type electrode body, and is formed by winding a positive electrode plate 740, a negative electrode plate 750, etc. around a winding axis L extending in the X-axis direction.
  • the winding axis L is a virtual axis that becomes the central axis when winding the positive electrode plate 740, the negative electrode plate 750, etc. They are parallel straight lines.
  • the electrode body 700 includes a positive electrode plate 740 and a negative electrode plate 750 that is shifted from the positive electrode plate 740 in the direction along the winding axis L (the winding axis direction, in this embodiment, the X-axis direction). , are formed by laminating and then winding. Separator 761 and separator 762 are arranged to be interposed between positive electrode plate 740 and negative electrode plate 750 after winding.
  • the positive electrode active material layer 742 and the negative electrode active material layer 752 are not formed (coated) on the ends in the respective shifted directions, and the positive electrode current collector foil 741 and the negative electrode current collector foil 751 has an exposed portion (active material layer non-forming portion).
  • the electrode body 700 has a positive electrode end 720 in which the active material layer-free portion of the positive electrode plate 740 is laminated and bundled at one end in the winding axis direction, and the other end in the winding axis direction.
  • the active material layer-free portion of the negative electrode plate 750 is stacked and bundled to form a negative electrode end portion 720.
  • the end portion 720 is a portion where the positive electrode plate 740 or the negative electrode plate 750 are stacked in the stacking direction (Y-axis direction).
  • the electrode body 700 includes an electrode body body part 710 that constitutes the body of the electrode body 700, and a pair of end parts 720 (a positive electrode and a negative electrode) that protrude from the electrode body body part 710 on both sides in the X-axis direction.
  • the electrode main body portion 710 includes a portion of the positive electrode plate 740 on which the positive electrode active material layer 742 is formed (coated), and a portion of the negative electrode plate 750 on which the negative electrode active material layer 752 is formed (coated).
  • the electrode main body part 710 has a pair of curved parts 711 made up of parts on both sides in the Z-axis direction, and a pair of flat parts 712 made up of parts on both sides in the Y-axis direction ((a) in FIG. 4). reference). That is, the electrode body 700 has a curved portion 711 and a flat portion 712, which are formed by winding the positive electrode plate 740 and the negative electrode plate 750 around the winding axis L.
  • the curved portion 711 is a curved portion that is curved in a semicircular arc shape so as to protrude in the Z-axis direction when viewed from the X-axis direction, and extends in the X-axis direction, and is a curved portion that extends in the X-axis direction. It is arranged opposite to the body 120. That is, the pair of curved portions 711 are portions that are curved so as to protrude on both sides in the Z-axis direction toward the bottom wall portion 113 and the lid 120 of the container body 110 when viewed from the X-axis direction.
  • the flat portion 712 is a rectangular and flat portion that connects the ends of the pair of curved portions 711 and extends parallel to the XZ plane facing the Y-axis direction, and is a long side wall on both sides of the container body 110 in the Y-axis direction. It is arranged opposite to the section 111.
  • the curved shape of the curved portion 711 is not limited to a semicircular arc shape, but may be a part of an elliptical shape or the like, and may be curved in any manner.
  • the flat portion 712 is not limited to having a flat outer surface facing the Y-axis direction, and may be slightly recessed or slightly bulged.
  • the electrode body 700 has an elongated (horizontally elongated) shape with a long length in the X-axis direction.
  • the length of the electrode body 700 in the direction of the winding axis is 500 mm or more.
  • the length from one end edge to the other end edge of the electrode body 700 in the X-axis direction, which is the winding axis direction is 500 mm or more.
  • the length of the electrode body 700 in the direction of the winding axis is preferably longer than 500 mm, more preferably 550 mm or more, and even more preferably 600 mm or more.
  • the length from one end edge to the other end edge of the electrode main body portion 710 may be 500 mm or more, preferably longer than 500 mm, and preferably 550 mm or more. is more preferable, and even more preferably 600 mm or more.
  • one or more through holes 730 are formed in the electrode body 700. That is, one or more through holes 730 are formed in the electrode plates (positive electrode plate 740 and negative electrode plate 750) of the electrode body 700. In this embodiment, one through hole 730 is formed in the electrode body main body portion 710 of the electrode body 700. Below, the configuration of the through hole 730 will be explained in detail using FIG. 5 as well.
  • FIG. 5 is a front view and a cross-sectional view showing the configuration of the through hole 730 of the electrode body 700 according to the present embodiment.
  • 5(a) is a front view showing the configuration of the through hole 730 of the electrode body 700 when viewed from the front (Y-axis negative direction), and FIG. FIG.
  • the through hole 730 is formed at the center in the X-axis direction and at the end in the Z-axis minus direction of the flat portion 712 in the Y-axis minus direction of the electrode body 710.
  • the through hole 730 is disposed opposite to the long side wall 111 of the container body 110 of the container 100 in the negative Y-axis direction and close to the bottom wall 113 .
  • the portion of the positive electrode plate 740 where the positive electrode active material layer 742 is formed (coated) on the positive current collector foil 741 is referred to as a positive electrode active material portion 743.
  • a portion of the negative electrode plate 750 in which the negative electrode active material layer 752 is formed (coated) on the negative electrode current collector foil 751 is referred to as a negative electrode active material portion 753 .
  • the positive electrode current collector foil 741 and the positive electrode active material layer 742 excluding the portion included in the end portion 720 of the positive electrode are referred to as a positive electrode active material portion 743
  • the negative electrode collector foil 741 excluding the portion included in the end portion 720 of the negative electrode are referred to as a positive electrode active material portion 743
  • the electric foil 751 and the negative electrode active material layer 752 are referred to as a negative electrode active material portion 753.
  • the portion other than the positive electrode current collector foil 741 included in the positive electrode end 720 of the positive electrode plate 740 is referred to as the positive electrode active material portion 743
  • the negative electrode included in the negative electrode end 720 of the negative electrode plate 750 is referred to as the positive electrode active material portion 743
  • a portion other than the current collector foil 751 is referred to as a negative electrode active material portion 753.
  • positive electrode active material layers 742 are formed on both sides of a positive electrode current collector foil 741 (one layer) of the positive electrode plate 740 in the electrode body 700.
  • the three layers formed as one unit are referred to as one positive electrode active material portion 743.
  • the electrode main body part 710 is formed by laminating these plurality of positive electrode active material parts 743, plurality of negative electrode active material parts 753, and separators 761 and 762.
  • a through hole 730 is formed in at least one of the positive electrode active material portion 743 and the negative electrode active material portion 753 located on the flat portion 712 of the electrode main body portion 710.
  • through holes 730 are formed in both the positive electrode active material section 743 and the negative electrode active material section 753, as well as in the separators 761 and 762.
  • a positive electrode through hole 743a serving as the through hole 730 is formed in the positive electrode active material portion 743.
  • the positive electrode through hole 743a is a circular through hole that penetrates the positive electrode active material portion 743 in the Y-axis direction.
  • the positive electrode through hole 743a is a circular through hole that penetrates the positive electrode current collector foil 741 and the two positive electrode active material layers 742 provided on both sides of the positive electrode current collector foil 741 in the Y axis direction.
  • a negative electrode through hole 753 a serving as the through hole 730 is formed in the negative electrode active material portion 753 .
  • the negative electrode through hole 753a is a circular through hole that penetrates the negative electrode active material portion 753 in the Y-axis direction.
  • the negative electrode through hole 753a is a circular through hole that penetrates the negative electrode current collector foil 751 and the two negative electrode active material layers 752 provided on both sides of the negative electrode current collector foil 751 in the Y axis direction. be.
  • the positive electrode through hole 743a and the negative electrode through hole 753a are arranged at a position where at least a portion thereof overlaps when viewed from the penetrating direction of the through hole 730 (the direction in which the positive electrode through hole 743a and the negative electrode through hole 753a are lined up, the Y-axis direction).
  • the negative electrode through hole 753a when viewed from the Y-axis direction, is arranged at a position where the entire negative electrode through hole 743a overlaps with the positive electrode through hole 743a. That is, when viewed from the Y-axis direction, the negative electrode through hole 753a has a smaller shape than the positive electrode through hole 743a, and is arranged inside the positive electrode through hole 743a.
  • the positive electrode through hole 743a and the negative electrode through hole 753a are smaller, from the viewpoint of suppressing a decrease in the capacity of the electricity storage element 10.
  • the size is not too small, as it will be difficult to remove the electrode plate.
  • the positive electrode through hole 743a and the negative electrode through hole 753a (through hole 730) preferably have a diameter of 0.8 mm or more (opening area of 0.5 mm 2 or more), and a diameter of 1 mm or more (opening area of 0.5 mm 2 or more). is more preferably 0.785 mm 2 or more).
  • the negative electrode through hole 753a is a circular through hole with a diameter of about 0.8 mm to 3 mm, and the positive electrode through hole 743a has a diameter of about 1.5 mm to 5 mm. It is a circular through hole. That is, all the positive electrode through holes 743a and the negative electrode through holes 753a (through holes 730) have an opening area of 0.5 mm 2 or more (diameter of 0.8 mm or more).
  • the positive electrode through hole 743a and the negative electrode through hole 753a can be formed by laser processing (laser welding, laser cutting), etc. before winding the positive electrode plate 740 and the negative electrode plate 750.
  • the positive electrode through holes 743a may be formed by forming (coating) the positive electrode active material layer 742 on the positive electrode current collector foil 741 in which through holes are formed in advance, or by forming the positive electrode active material layer 742 on the positive electrode current collector foil 741.
  • the positive electrode through hole 743a may be formed by punching out the positive electrode current collector foil 741 and the positive electrode active material layer 742 after forming (coating). The same applies to the negative electrode through hole 753a.
  • the positive electrode through hole 743a and the negative electrode through hole 753a can be formed by press working, it is preferable to form them by laser working in order to process small holes at high speed.
  • the plurality of positive electrode active material parts 743 and the plurality of negative electrode active material parts 753 are stacked in the stacking direction.
  • the plurality of positive electrode active material parts 743 and the plurality of negative electrode active material parts 753 are stacked in a direction perpendicular to the flat surface of the flat part 712 (that is, in the Y-axis direction).
  • a plurality of positive electrode through holes 743a and a plurality of negative electrode through holes 753a are formed in the plurality of positive electrode active material parts 743 and the plurality of negative electrode active material parts 753, which are arranged continuously in the stacking direction.
  • a plurality of positive electrode through holes 743a and a plurality of negative electrode through holes 753a as the through holes 730 are formed in the positive electrode plate 740 and the negative electrode plate 750, respectively.
  • the plurality of positive electrode through holes 743a and the plurality of negative electrode through holes 753a are arranged at overlapping positions when viewed from the penetrating direction of the through hole 730.
  • the penetrating direction of the through holes 730 (the plurality of positive electrode through holes 743a and the plurality of negative electrode through holes 753a) can be defined as the Y-axis direction.
  • the plurality of positive electrode through holes 743a are formed from the positive electrode active material portion 743 located at the innermost layer (innermost circumference) in the electrode body 700 to the outermost layer (the outermost layer) so that the positive electrode plate 740 and the negative electrode plate 750 are aligned after being wound.
  • the intervals are formed such that the distance increases toward the positive electrode active material portion 743 located at the outer periphery. The same applies to the negative electrode through hole 753a.
  • the through-hole 730 is also formed in the active material portion disposed in the outermost layer (outermost periphery) of the plurality of positive electrode active material portions 743 and the plurality of negative electrode active material portions 753.
  • the negative electrode active material portion 753 is arranged in the outermost layer (outermost periphery) of the electrode body 700
  • the negative electrode through hole 753a is also formed in the outermost negative electrode active material portion 753.
  • the plurality of positive electrode through holes 743a and the plurality of negative electrode through holes 753a extend from the active material part of the outermost layer (outermost periphery) to the active material part of the innermost layer (innermost periphery) in the electrode body 700. Formed continuously.
  • all the negative electrode through holes 753a formed in the plurality of negative electrode active material parts 753 are arranged inside all the positive electrode through holes 743a formed in the plurality of positive electrode active material parts 743. be done.
  • a separator through hole 761a as the through hole 730 is formed in the separator 761 (separator base material 760a and inorganic coat layer 760b).
  • the separator through hole 761a is a circular through hole that penetrates the separator 761 in the Y-axis direction.
  • a separator through hole 762a as the through hole 730 is formed in the separator 762 (separator base material 760a and inorganic coat layer 760b).
  • the separator through hole 762a is a circular through hole that penetrates the separator 762 in the Y-axis direction.
  • the separator through holes 761a and 762a have the same shape and the same size, but they may have different shapes or different sizes.
  • Separator through-holes 761a and 762a are at least partially connected to positive electrode through-hole 743a and negative electrode through-hole 753a when viewed from the through-hole direction of through-hole 730 (line direction of positive electrode through-hole 743a and negative electrode through-hole 753a, Y-axis direction). placed in overlapping positions.
  • separator through holes 761a and 762a are arranged at positions where all of them overlap with positive electrode through hole 743a and partially overlap with negative electrode through hole 753a, when viewed from the Y-axis direction.
  • the separator through holes 761a and 762a when viewed from the Y-axis direction, have a shape smaller than the positive electrode through hole 743a and larger than the negative electrode through hole 753a, and are arranged inside the positive electrode through hole 743a. Moreover, the negative electrode through hole 753a is arranged inward.
  • the separator through holes 761a and 762a are circular through holes with a diameter of approximately 1 mm to 4 mm.
  • the separator through holes 761a and 762a can be formed by laser processing, press processing, etc. before winding the positive electrode plate 740 and the negative electrode plate 750, similarly to the positive electrode through hole 743a and the negative electrode through hole 753a.
  • the separator through holes 761a and 762a may be processed by irradiating the positions of the positive electrode through hole 743a and the negative electrode through hole 753a with a laser after winding the positive electrode plate 740 and the negative electrode plate 750.
  • the separator through holes 761a and 762a may be the same size as the negative electrode through hole 753a, or may be smaller in size than the negative electrode through hole 753a.
  • a plurality of separator through-holes 761a and 762a are formed continuously in the Y-axis direction in the separators 761 and 762 along with a plurality of positive electrode through-holes 743a and a plurality of negative electrode through-holes 753a. That is, a plurality of separator through holes 761a and 762a are continuous from the separator 761 or 762 located at the outermost layer (outermost periphery) to the separator 761 or 762 located at the innermost layer (innermost periphery) in the electrode body 700. It is formed by As a result, in the electrode body 700, all separator through holes 761a and 762a formed in separators 761 and 762 are arranged inside all positive electrode through holes 743a when viewed from the Y-axis direction.
  • “number of through holes” is the number (presence or absence) of through holes 730 formed in the electrode body 700 shown in FIG. In Examples 7 to 6, no through hole 730 was formed, and in Examples 7 and 8, one through hole 730 was formed in the electrode body 700.
  • the "length of the electrode body” is the length from one end edge to the other edge of the electrode body 700 in the X-axis direction (winding axis direction), and is 300 mm in Reference Example 1, Comparative Examples 1 and 2, and Example In Examples 1 to 3, it was 500 mm, and in Examples 4 to 8, it was 600 mm.
  • Presence or absence of coat layer refers to whether or not the separator 760 is provided with a coat layer.
  • the separator 760 is not provided with a coat layer, and in Comparative Example 2 and Example In Nos. 1 to 8, the separator 760 was provided with a coating layer.
  • “Type of coating layer” is the type of coating layer provided on the separator 760, and includes aramid fiber in Comparative Example 2, aluminum silicate in Examples 1 and 4, barium sulfate in Examples 2, 5, and 7, and barium sulfate in Examples 2, 5, and 7. In Examples 3, 6, and 8, it was alumina (boehmite).
  • the permeation area column, the values of the permeation area corresponding to the types of coating layers shown in Table 1 are listed again.
  • the "Liquid Penetration Time” column shows the experimental results of the time required for the electrolytic solution to penetrate into the entire electrode body 700 after dropping the electrolytic solution onto the target electrode body 700.
  • Table 2 in all cases of Reference Example 1, Comparative Examples 1 and 2, and Examples 1 to 8, the width of the electrode body 700 (length in the Z-axis direction) is 135.6 mm, and the width of the electrode body 700 is 135.6 mm.
  • the thickness (length in the Y-axis direction) was 19.4 mm.
  • the diameter of the negative electrode through-hole 753a was 1 mm
  • the diameter of the positive electrode through-hole 743a was 3 mm
  • the diameter of separator through-holes 761a and 762a was 2 mm.
  • the electrode body 700 can be formed in a relatively short time (within 2 hours). The electrolyte penetrates. However, as shown in Comparative Example 1, when the separator 760 is not provided with a coating layer and the length of the electrode body 700 is 500 mm, the electrode body 700 is electrolyzed even after a long period of time (6 hours). Liquid does not penetrate.
  • an inorganic coating layer 760b (aluminum silicate, barium sulfate, or alumina (boehmite)) containing an inorganic substance (inorganic particles) is provided on the separator 760, as shown in Examples 1 to 3,
  • the electrolytic solution permeates into the electrode body 700 in a short period of time (within 2 hours). Therefore, it can be seen that when the length of the electrode body 700 is 500 mm or more, it is necessary to provide the inorganic coating layer 760b on the separator 760. It is preferable that the inorganic coat layer 760b has an electrolytic solution permeation area of 80 mm 2 or more at 300 seconds after the electrolytic solution is dropped.
  • Comparative Examples 1 and 2 and Examples 1 to 3 similar results are obtained even when the length of the electrode main body portion 710 (the length from one end edge to the other end edge in the X-axis direction) is 500 mm.
  • the inorganic coat layer 760b when the length of the electrode body 700 is 600 mm, when the inorganic coat layer 760b contains aluminum silicate as inorganic particles, the time for the electrolyte to penetrate into the electrode body 700 is slightly longer (4 (within hours).
  • the inorganic coating layer 760b when the inorganic coating layer 760b contains barium sulfate or alumina (boehmite) as inorganic particles, the The electrolytic solution permeates into the electrode body 700 in a short time (within 2 hours). Therefore, the inorganic coat layer 760b preferably contains at least one of barium sulfate and alumina as inorganic particles.
  • the inorganic coat layer 760b preferably has an electrolytic solution permeation area of 90 mm 2 or more (95 mm 2 ) 300 seconds after the electrolytic solution is dropped.
  • an electrolytic solution permeation area of 90 mm 2 or more (95 mm 2 ) 300 seconds after the electrolytic solution is dropped.
  • similar results can be obtained even when the length of the electrode main body portion 710 (the length from one end edge to the other end edge in the X-axis direction) is 600 mm.
  • the length of the electrode body 700 is 500 mm or more, preferably longer than 500 mm, more preferably 550 mm or more, and even more preferably 600 mm or more.
  • the length of the electrode main body portion 710 may be 500 mm or more, preferably longer than 500 mm, more preferably 550 mm or more, and even more preferably 600 mm or more.
  • the length of the electrode body 700 (or the length of the electrode body body part 710) is 800 mm.
  • the length is preferably 700 mm or less, and more preferably 700 mm or less.
  • the length of the electrode body 700 (or the length of the electrode body main body portion 710) is preferably 1600 mm or less, and more preferably 1400 mm or less.
  • the length of the electrode body 700 is preferably 500 mm or more and 800 mm or less, and less than 500 mm.
  • the length is more preferably 800 mm or less, further preferably 550 mm or more and 700 mm or less, and particularly preferably 600 mm or more and 700 mm or less.
  • the length of the electrode body 700 (or the length of the electrode body part 710) is preferably 500 mm or more and 1600 mm or less, and is preferably longer than 500 mm and 1600 mm. It is more preferably the following, further preferably 550 mm or more and 1400 mm or less, particularly preferably 600 mm or more and 1400 mm or less.
  • the power storage element 10 includes the wound electrode body 700, and the wall portion (lid body 120) extending in the direction of the winding axis of the electrode body 700 of the container 100.
  • An electrolyte injection part 130 is provided at . Therefore, when pouring the electrolyte into the container 100, the electrolyte is difficult to penetrate from the outside to the inside of the electrode body 700, making it difficult to infiltrate the electrolyte into the electrode body 700.
  • the separator 760 is coated with an inorganic coating layer 760b.
  • the permeability (liquid wettability and capillary force) of the electrolytic solution into the separator 760 can be improved. Therefore, the time for the electrolytic solution to penetrate into the electrode body 700 can be shortened, so that the electrolytic solution can easily penetrate into the electrode body 700. If the electrolytic solution penetrates into the electrode body 700 for a long time, there is a concern that the copper of the negative electrode plate 750 will be eluted and a short circuit will occur. The occurrence can be suppressed.
  • the inorganic coating layer 760b coated on the separator 760 is an inorganic inorganic material that allows the electrolyte to penetrate a relatively wide area in a relatively short period of time. This is a coat layer 760b. In this way, by using the inorganic coating layer 760b that allows the electrolyte to permeate into a relatively wide area in a relatively short time, the permeability of the electrolyte into the separator 760 can be improved. If it takes more than 6 hours for the electrolyte to penetrate into the electrode body 700, there is a concern that the copper of the negative electrode plate 750 will be eluted and a short circuit will occur. Since we obtained experimental results that allow penetration, the occurrence of the short circuit can be suppressed.
  • the inventor of the present application has discovered that when an electrolytic solution is dropped onto an inorganic coat layer 760b containing at least one of barium sulfate and alumina, the electrolytic solution is removed in a relatively short time compared to other inorganic particles (such as aluminum silicate). It has been found that it can penetrate into a relatively wide area of the inorganic coat layer 760b. When the inorganic coating layer 760b was used, an experimental result was obtained in which the electrolytic solution could penetrate into the electrode body 700 within 2 hours. Therefore, by including at least one of barium sulfate and alumina in the inorganic coating layer 760b coated on the separator 760, the permeability of the electrolyte into the separator 760 can be improved.
  • the inventor of the present invention has found that even when the electrode body 700 is used, the electrolytic solution can be easily penetrated into the electrode body 700 by coating the separator 760 with the inorganic coating layer 760b. Therefore, when such a long electrode body 700 is used, the effect of adopting the configuration of the present application is high.
  • the longer the length of the electrode body 700 the higher the effect of adopting the configuration of the present application, so the length of the electrode body 700 is 500 mm or more, preferably longer than 500 mm, and 550 mm or more. More preferably, the length is 600 mm or more.
  • the electrolyte can permeate into the electrode body 700 through the through-hole 730 from the separator 760 whose permeability for the electrolyte has been improved by the inorganic coating layer 760b.
  • the through hole 730 can be placed close to the bottom wall 113 of the container 100, so that the electrolytic solution collected at the bottom of the container 100 can permeate into the electrode body 700. Easy to do. In particular, even when the amount of electrolytic solution in container 100 is small (such as when the container is at the end of its life), the electrolytic solution accumulated in the lower part of container 100 can be permeated into electrode body 700.
  • the electrolytic solution can be stored in the through hole 730, so that the electrolytic solution is not consumed due to reduction of the electrolytic solution (SEI film formation) during charging and discharging. This can prevent the electrolyte from running out.
  • the gas is discharged from the gas discharge valve 140 to the outside of the power storage element 10 , the gas inside the electrode body 700 can be easily discharged through the through hole 730 .
  • the through hole 730 By forming the through hole 730 in the flat portion 712 of the electrode body main body portion 710 of the electrode body 700, the through hole 730 can be easily formed.
  • FIG. 6 is a front view and a cross-sectional view showing the configuration of a through hole 730 of an electrode body 700 according to Modification 1 of the present embodiment.
  • FIG. 6 is a diagram corresponding to FIG. 5.
  • the positive electrode through hole 743a is formed to have the same size as the negative electrode through hole 753a when viewed from the Y-axis direction, and the positive electrode active material layer 742 around the positive electrode through hole 743a
  • An insulating section 744 is provided in the. That is, the positive electrode plate 740 has an insulating part 744 that is arranged around the positive electrode through hole 743a and has an outer periphery 744a larger in size than the negative electrode through hole 753a.
  • the insulating portion 744 is a portion masked by melting an insulating member such as resin into the positive electrode active material layer 742 around the positive electrode through hole 743a.
  • the insulating portion 744 is a portion having a higher content of an insulating material such as resin than other portions of the positive electrode active material layer 742.
  • the insulating portion 744 can be formed by dissolving a UV-curable epoxy resin that is cured by irradiation with ultraviolet rays into the positive electrode active material layer 742, or by dissolving a polyolefin resin such as PE or PP melted by heating. .
  • the insulating portion 744 can be easily formed by pressing a resin molding die and pouring the resin.
  • the insulating part 744 is made of a binder-modified polyolefin sheet (a sheet member in which polar groups are introduced into polyolefin to give it adhesive properties with different materials) that has been previously formed into a shape that covers the periphery of the positive electrode through hole 743a. It may be placed in the positive electrode active material layer 742 around the electrode 743a, heated, melted, and impregnated. When the insulating material such as the resin permeates into the positive electrode active material layer 742, the positive electrode active material layer 742 is deactivated (discharge capacity becomes smaller).
  • a binder-modified polyolefin sheet a sheet member in which polar groups are introduced into polyolefin to give it adhesive properties with different materials
  • the power storage element 10 can achieve the same effects as the above embodiment.
  • the negative electrode active material layer 752 is made of positive electrode active material regardless of the size of the positive electrode through hole 743a and the negative electrode through hole 753a.
  • the structure covers layer 742.
  • an insulating part 744 having an outer periphery 744a larger in size than the negative electrode through hole 753a is arranged around the positive electrode through hole 743a in the positive electrode plate 740.
  • the negative electrode active material layer 752 covers the positive electrode active material layer 742. be able to. In other words, by deactivating the positive electrode active material layer 742 around the positive electrode through hole 743a, the active positive electrode active material layer 742 can be covered with the negative electrode active material layer 752, and lithium electrodeposition onto the negative electrode plate 750 is suppressed. can.
  • the positive electrode through hole 743a may be smaller or larger than the negative electrode through hole 753a when viewed from the Y-axis direction, and the size of the outer periphery 744a of the insulating portion 744 may be larger than the negative electrode through hole 753a.
  • the separator through holes 761a and 762a may have the same size as the negative electrode through hole 753a and the positive electrode through hole 743a, or may have a smaller size than the negative electrode through hole 753a and the positive electrode through hole 743a.
  • the liquid injection part 130 is arranged on the lid 120 of the container 100, but it may be arranged on the container main body 110.
  • the liquid injection part 130 may be arranged on the long side wall part 111 of the container main body 110, or may be arranged on the bottom wall part 113.
  • the liquid injection part 130 may be disposed on a wall extending in the direction of the winding axis of the electrode body 700.
  • the gas exhaust valve 140 is arranged on the lid 120, it may be arranged on any wall of the container body 110.
  • inorganic particles contained in the inorganic coat layer 760b of the separator 760 are exemplified as inorganic particles contained in the inorganic coat layer 760b of the separator 760, but the inorganic particles are not limited thereto.
  • the inorganic coat layer 760b may contain any inorganic particles as long as the time for the electrolyte to penetrate into the electrode body 700 can be shortened.
  • the inorganic coat layer 760b of the separator 760 has an electrolyte permeation area of 80 mm 2 or more at 300 seconds after the electrolyte is dropped, but the invention is not limited to this.
  • the permeation area may be smaller than 80 mm 2 as long as the time for permeation of the electrolyte into the electrode body 700 can be shortened.
  • separators 761 and 762 may be made of the same material or may be made of different materials. That is, the separator base material 760a of the separator 761 and the separator base material 760a of the separator 762 may be formed of the same material or may be formed of different materials.
  • the inorganic coat layer 760b of the separator 761 and the inorganic coat layer 760b of the separator 762 may contain the same inorganic particles or may contain different inorganic particles.
  • the through hole 730 of the electrode body 700 is formed at the center in the X-axis direction and at the end in the negative Z-axis direction of the flat portion 712 in the Y-axis minus direction of the electrode body body 710. , may be formed at any position on the electrode body 700.
  • the through hole 730 may be formed at the end of the flat portion 712 in the X-axis direction, the center in the Z-axis direction, or the end in the positive Z-axis direction.
  • the through hole 730 may be formed in the flat portion 712 of the electrode body portion 710 in the positive Y-axis direction, or may be formed in the curved portion 711 of the electrode body portion 710. When the through hole 730 is formed in the curved portion 711, the through hole 730 is less likely to be blocked by the container 100, making it easier for the electrolyte to penetrate into the electrode body 700.
  • one through hole 730 is formed in the electrode body 700, but two or more through holes 730 may be formed.
  • the arrangement position of the through-hole 730 is not particularly limited, but if the length of the electrode body 700 in the X-axis direction becomes longer, a plurality of through-holes 730 are formed at different positions in the X-axis direction of the electrode body 700. is preferable.
  • the length of the electrode body 700 in the Z-axis direction becomes long, it is preferable to form a plurality of through holes 730 at different positions in the Z-axis direction of the electrode body 700. These allow the electrolytic solution to easily penetrate into the electrode body 700.
  • the effective electrode area of the electrode body 700 is the area of the region in the electrode plate where the active material layer is arranged (specifically, the region in the positive electrode plate 740 where the positive electrode active material layer 742 is arranged).
  • the rate at which this effective electrode area is reduced is referred to as the opening area ratio.
  • the opening area ratio is the ratio of the total opening area of one or more through holes 730 located within the region to the area of the region in the electrode plate where the active material layer is arranged.
  • the opening area ratio is the ratio of the total opening area of the positive electrode through holes 743a located within the region to the area of the region in the positive electrode plate 740 where the positive electrode active material layer 742 is arranged.
  • the opening area ratio is the ratio of the total opening area of the positive electrode through holes 743a located in the region where the positive electrode active material layer 742 is disposed to the area of the region when the wound state of the electrode body 700 is unfolded to spread the positive electrode plate 740 and the positive electrode plate 740 is viewed in a plan view.
  • the opening area ratio is preferably 3% or less, and more than 0.1%, from the viewpoint of suppressing a decrease in the capacity of the power storage element 10. It is more preferably small, and even more preferably smaller than 0.05%. As described above, the opening area ratio can also be said to be the ratio of the amount of capacity reduction (capacity loss) of the power storage element 10 due to the through hole 730. Therefore, the rate of capacity reduction (capacity loss) of the electricity storage element 10 is also preferably 3% or less, more preferably less than 0.1%, and even more preferably less than 0.05%. .
  • the through holes 730 are formed in all of the plurality of stacked positive electrode active material parts 743 and the plurality of negative electrode active material parts 753. , but not limited to.
  • the through hole 730 may not be formed in any of the positive electrode active material portions 743 or any of the negative electrode active material portions 753.
  • the separators 761 and 762 the portions where the through holes 730 (separator through holes 761a and 762a) are not formed between the outermost layer separators 761 and 762 and the innermost layer separators 761 and 762 in the electrode body 700 There may be.
  • the through holes 730 are formed in both the positive electrode active material portion 743 and the negative electrode active material portion 753, but the present invention is not limited thereto.
  • the through hole 730 may be formed only in either one of the positive electrode active material portion 743 and the negative electrode active material portion 753.
  • the through hole 730 (separator through holes 761a, 762a) may be formed only in either one of the separators 761 and 762, or the through hole 730 may be formed in both the separators 761 and 762. It does not have to be formed.
  • a structure in which the through hole 730 is not formed in the electrode body 700 may also be used.
  • the negative electrode through hole 753a has a smaller shape than the positive electrode through hole 743a when viewed from the Y-axis direction, and is arranged inside the positive electrode through hole 743a. is not limited to.
  • the negative electrode through hole 753a may not be placed inside the positive electrode through hole 743a, but may be placed at a position slightly shifted from the positive electrode through hole 743a, or may be placed at a position that does not overlap with the positive electrode through hole 743a.
  • the shape, size relationship, and arrangement position of the negative electrode through hole 753a are not particularly limited.
  • separator through holes 761a and 762a may be arranged at positions slightly shifted from positive electrode through holes 743a and negative electrode through holes 753a, or may be arranged at positions that do not overlap with positive electrode through holes 743a and negative electrode through holes 753a. You can.
  • the shape, size relationship, and arrangement position of the separator through holes 761a and 762a, the positive electrode through hole 743a, and the negative electrode through hole 753a are not particularly limited. However, even in this case, it is preferable that all of the positive electrode active material layer 742 (active positive electrode active material layer 742) face the separators 761 and 762.
  • both of the pair of terminals 300 are arranged to protrude from the container 100 in the positive Z-axis direction, but the direction in which the terminals 300 protrude is not particularly limited.
  • the pair of terminals 300 may protrude from the container 100 in either one of the X-axis directions, or may protrude in both X-axis directions.
  • the electrode body 700 has an elongated cylindrical shape (flat shape) having a curved part 711 and a flat part 712, but it may also have a cylindrical shape, an elliptical cylindrical shape, etc., or a wound type electrode body. If so, its shape is not particularly limited.
  • the end portion 720 may be a tab portion (a portion where a plurality of tabs of the electrode plate are stacked) projecting from a part of the electrode body main body portion 710.
  • the electrode body 700 does not have to have a long shape in the X-axis direction.
  • the present invention can be applied to power storage elements such as lithium ion secondary batteries.

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Abstract

This power storage element is provided with: an electrode body which is obtained by winding an electrode plate and a separator; an electrolyte solution; and a container in which the electrode body and the electrolyte solution are contained. The container has a liquid injection part for the electrolyte solution on a wall part that extends in the winding axis direction of the electrode body; the electrode body has a length of 500 mm or more in the winding axis direction; and the separator comprises a separator base material and an inorganic coat layer that contains inorganic particles and is coated on the separator base material.

Description

蓄電素子Energy storage element
　本発明は、電極体及び電解液が容器に収容された蓄電素子に関する。 The present invention relates to a power storage element in which an electrode body and an electrolyte are housed in a container.
　従来、極板及びセパレータが巻回された巻回型の電極体と、電解液と、電極体及び電解液が収容される容器と、を備える蓄電素子が広く知られている。特許文献１には、正極板と負極板とをセパレータを介して積層し捲回してなる捲回型電極体、及び、電解液が電池容器に収容された捲回型蓄電装置（蓄電素子）が開示されている。 BACKGROUND ART Conventionally, power storage elements are widely known that include a wound-type electrode body in which an electrode plate and a separator are wound, an electrolyte, and a container in which the electrode body and the electrolyte are housed. Patent Document 1 discloses a wound-type electrode body formed by laminating and winding a positive electrode plate and a negative electrode plate with a separator interposed therebetween, and a wound-type power storage device (power storage element) in which an electrolytic solution is housed in a battery container. Disclosed.
特開２００６－２１００３１号公報JP2006-210031A
　上記のような従来の巻回型の電極体を備える蓄電素子では、容器内への電解液の注入時に、電極体に電解液を浸透させるのが困難な場合がある。容器のうちの電極体の巻回軸方向に延びる壁部に電解液の注液部が設けられる場合、電極体の外部から内部に電解液が浸透しにくいため、電極体に電解液を浸透させるのが困難になる。特に、電極体の当該巻回軸方向における長さが長いと、電極体に電解液を浸透させるのがさらに困難になる。 In a power storage element including a conventional wound-type electrode body as described above, it may be difficult to allow the electrolyte to penetrate into the electrode body when injecting the electrolyte into the container. When an electrolyte injection part is provided on the wall of the container that extends in the direction of the winding axis of the electrode body, it is difficult for the electrolyte to penetrate from the outside to the inside of the electrode body. becomes difficult. In particular, if the length of the electrode body in the direction of the winding axis is long, it becomes more difficult to infiltrate the electrolyte into the electrode body.
　本発明は、本願発明者が上記課題に新たに着目することによってなされたものであり、電極体に電解液を容易に浸透できる蓄電素子を提供することを目的とする。 The present invention was made by the inventors of the present application newly paying attention to the above-mentioned problem, and an object of the present invention is to provide a power storage element in which an electrolytic solution can easily penetrate into an electrode body.
　本発明の一態様に係る蓄電素子は、極板及びセパレータが巻回された電極体と、電解液と、前記電極体及び前記電解液が収容される容器と、を備え、前記容器は、前記電極体の巻回軸方向に延びる壁部に、前記電解液の注液部を有し、前記電極体は、前記巻回軸方向における長さが５００ｍｍ以上であり、前記セパレータは、基材と、前記基材にコートされた無機粒子を含む無機コート層と、を有している。 A power storage element according to one aspect of the present invention includes an electrode body in which an electrode plate and a separator are wound, an electrolytic solution, and a container in which the electrode body and the electrolytic solution are housed, and the container includes the The electrode body has an injection part for the electrolytic solution on a wall extending in the winding axis direction, the electrode body has a length in the winding axis direction of 500 mm or more, and the separator has a base material and a base material. and an inorganic coat layer containing inorganic particles coated on the base material.
　本発明における蓄電素子によれば、電極体に電解液を容易に浸透できる。 According to the electricity storage element of the present invention, the electrolyte can easily penetrate into the electrode body.
図１は、実施の形態に係る蓄電素子の外観を示す斜視図である。FIG. 1 is a perspective view showing the appearance of a power storage element according to an embodiment. 図２は、実施の形態に係る蓄電素子を分解して各構成要素を示す分解斜視図である。FIG. 2 is an exploded perspective view showing each component of the power storage device according to the embodiment. 図３は、実施の形態に係る電極体の構成を示す斜視図である。FIG. 3 is a perspective view showing the structure of the electrode body according to the embodiment. 図４は、実施の形態に係る電極体の構成を示す斜視図及び断面図である。FIG. 4 is a perspective view and a cross-sectional view showing the structure of an electrode body according to an embodiment. 図５は、実施の形態に係る電極体の貫通孔の構成を示す正面図及び断面図である。FIG. 5 is a front view and a cross-sectional view showing the configuration of a through hole of an electrode body according to an embodiment. 図６は、実施の形態の変形例１に係る電極体の貫通孔の構成を示す正面図及び断面図である。FIG. 6 is a front view and a cross-sectional view showing the structure of a through hole of an electrode body according to Modification 1 of the embodiment.
　（１）本発明の一態様に係る蓄電素子は、極板及びセパレータが巻回された電極体と、電解液と、前記電極体及び前記電解液が収容される容器と、を備え、前記容器は、前記電極体の巻回軸方向に延びる壁部に、前記電解液の注液部を有し、前記電極体は、前記巻回軸方向における長さが５００ｍｍ以上であり、前記セパレータは、基材と、前記基材にコートされた無機粒子を含む無機コート層と、を有している。 (1) A power storage element according to one aspect of the present invention includes an electrode body in which an electrode plate and a separator are wound, an electrolytic solution, and a container in which the electrode body and the electrolytic solution are housed, the container has an injection part for the electrolytic solution on a wall extending in the direction of the winding axis of the electrode body, the electrode body has a length of 500 mm or more in the direction of the winding axis, and the separator has: It has a base material and an inorganic coat layer containing inorganic particles coated on the base material.
　本発明の一態様に係る蓄電素子によれば、蓄電素子は、巻回型の電極体を備え、容器のうちの電極体の巻回軸方向に延びる壁部に電解液の注液部が設けられているため、容器内への電解液の注液時に、電極体の外部から内部に電解液が浸透しにくく、電極体に電解液を浸透させるのが困難になるが、セパレータを無機コート層でコートすることにより、セパレータへの電解液の浸透性を向上させることができる。特に、電極体の巻回軸方向の長さが５００ｍｍ以上である場合には、電極体に電解液を浸透させるのがさらに困難になるため、セパレータを無機コート層でコートすることで、セパレータへの電解液の浸透性を向上させる効果が顕著となる。したがって、電極体への電解液の浸透時間を短くできるため、電極体に電解液を容易に浸透できる。 According to the power storage element according to one aspect of the present invention, the power storage element includes a wound electrode body, and an electrolyte injection part is provided in a wall portion of the container that extends in the direction of the winding axis of the electrode body. This makes it difficult for the electrolyte to penetrate from the outside to the inside of the electrode body when pouring the electrolyte into the container, making it difficult for the electrolyte to penetrate into the electrode body. By coating the separator with the electrolyte, it is possible to improve the permeability of the electrolyte into the separator. In particular, when the length of the electrode body in the direction of the winding axis is 500 mm or more, it becomes more difficult to penetrate the electrolyte into the electrode body, so by coating the separator with an inorganic coating layer, it is possible to The effect of improving the permeability of the electrolyte becomes remarkable. Therefore, the time required for the electrolyte to penetrate into the electrode body can be shortened, so that the electrolyte can easily penetrate into the electrode body.
　（２）上記（１）に記載の蓄電素子において、前記無機コート層は、前記電解液が滴下されて３００秒目における前記電解液の浸透面積が８０ｍｍ２以上であってもよい。 (2) In the electricity storage element according to (1) above, the inorganic coat layer may have a permeation area of 80 mm 2 or more for the electrolyte at 300 seconds after the electrolyte is dropped.
　上記（２）に記載の蓄電素子によれば、セパレータにコートされる無機コート層は、電解液が滴下されて３００秒目における電解液の浸透面積が８０ｍｍ２以上という、電解液が比較的短時間で比較的広い面積に浸透可能な無機コート層である。このように、電解液が比較的短時間で比較的広い面積に浸透可能な無機コート層を用いることで、セパレータへの電解液の浸透性を向上できる。 According to the energy storage element described in (2) above, the inorganic coating layer coated on the separator has a relatively short electrolytic solution penetration area of 80 mm 2 or more at 300 seconds after the electrolytic solution is dropped. It is an inorganic coating layer that can permeate a relatively wide area over time. In this way, by using an inorganic coating layer that allows the electrolyte to permeate a relatively wide area in a relatively short period of time, the permeability of the electrolyte into the separator can be improved.
　（３）上記（１）または（２）に記載の蓄電素子において、前記無機コート層は、前記無機粒子として、硫酸バリウム及びアルミナの少なくとも一方を含んでもよい。 (3) In the electricity storage element according to (1) or (2) above, the inorganic coat layer may include at least one of barium sulfate and alumina as the inorganic particles.
　本願発明者は、硫酸バリウム及びアルミナの少なくとも一方を含む無機コート層に電解液を滴下した場合、電解液が、比較的短時間で、無機コート層の比較的広い面積に浸透できることを見出した。上記（３）に記載の蓄電素子によれば、セパレータにコートされる無機コート層に、硫酸バリウム及びアルミナの少なくとも一方を含ませることで、セパレータへの電解液の浸透性を向上できる。 The inventors of the present invention have discovered that when an electrolyte is dropped onto an inorganic coat layer containing at least one of barium sulfate and alumina, the electrolyte can penetrate a relatively wide area of the inorganic coat layer in a relatively short time. According to the power storage element described in (3) above, by including at least one of barium sulfate and alumina in the inorganic coating layer coated on the separator, the permeability of the electrolyte into the separator can be improved.
　（４）上記（１）から（３）のいずれかひとつに記載の蓄電素子において、前記電極体は、前記巻回軸方向における長さが６００ｍｍ以上でもよい。 (4) In the electricity storage element according to any one of (1) to (3) above, the electrode body may have a length of 600 mm or more in the direction of the winding axis.
　巻回軸方向における長さが６００ｍｍ以上という長い電極体を用いた場合には、電極体に電解液を浸透させるのがさらに困難になる。これに対し、本願発明者は、当該電極体を用いた場合でも、セパレータを無機コート層でコートすることで、電極体に電解液を容易に浸透できることを見出した。このため、上記（４）に記載の蓄電素子ような長い電極体を用いた場合に、本願の構成を採用することによる効果が高い。 When using a long electrode body with a length of 600 mm or more in the direction of the winding axis, it becomes more difficult to penetrate the electrolyte into the electrode body. On the other hand, the inventors of the present application have found that even when using the electrode body, by coating the separator with an inorganic coating layer, the electrolytic solution can be easily penetrated into the electrode body. Therefore, when a long electrode body like the electricity storage element described in (4) above is used, the effect of adopting the configuration of the present application is high.
　（５）上記（１）から（４）のいずれかひとつに記載の蓄電素子において、前記極板には、貫通孔が形成されてもよい。 (5) In the electricity storage element according to any one of (1) to (4) above, a through hole may be formed in the electrode plate.
　上記（５）に記載の蓄電素子によれば、電極体の極板に貫通孔を形成することで、無機コート層によって電解液の浸透性が向上されたセパレータから、当該貫通孔を介して電極体に電解液を浸透できる。 According to the electricity storage element described in (5) above, by forming a through hole in the electrode plate of the electrode body, the separator, in which the permeability of the electrolytic solution has been improved by the inorganic coating layer, passes through the through hole to the electrode. Allows electrolytes to penetrate the body.
　以下、図面を参照しながら、本発明の実施の形態（その変形例も含む）に係る蓄電素子について説明する。以下で説明する実施の形態は、いずれも包括的または具体的な例を示すものである。以下の実施の形態で示される数値、形状、材料、構成要素、構成要素の配置位置及び接続形態、製造工程、製造工程の順序等は、一例であり、本発明を限定する主旨ではない。各図において、寸法等は厳密に図示したものではない。各図において、同一または同様な構成要素については同じ符号を付している。 Hereinafter, a power storage element according to an embodiment of the present invention (including variations thereof) will be described with reference to the drawings. The embodiments described below are all inclusive or specific examples. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components, manufacturing steps, order of manufacturing steps, etc. shown in the following embodiments are merely examples, and do not limit the present invention. In each figure, dimensions etc. are not strictly illustrated. In each figure, the same or similar components are designated by the same reference numerals.
　以下の説明及び図面中において、蓄電素子が有する一対（正極及び負極、以下同様）の端子の並び方向、一対の集電体の並び方向、電極体の巻回軸方向、電極体の延びる方向、または、容器の短側面の対向方向を、Ｘ軸方向と定義する。容器の長側面の対向方向、または、容器の厚み方向を、Ｙ軸方向と定義する。容器の容器本体と蓋体との並び方向、または、上下方向を、Ｚ軸方向と定義する。これらＸ軸方向、Ｙ軸方向及びＺ軸方向は、互いに交差（本実施の形態では直交）する方向である。使用態様によってはＺ軸方向が上下方向にならない場合も考えられるが、以下では説明の便宜のため、Ｚ軸方向を上下方向として説明する。 In the following description and drawings, the direction in which a pair of terminals (positive electrode and negative electrode, the same applies hereinafter) of a power storage element are arranged, the direction in which a pair of current collectors are arranged, the direction of the winding axis of the electrode body, the direction in which the electrode body extends, Alternatively, the direction in which the short sides of the container face each other is defined as the X-axis direction. The direction in which the long sides of the container face each other or the thickness direction of the container is defined as the Y-axis direction. The direction in which the container body and lid of the container are lined up or the vertical direction is defined as the Z-axis direction. These X-axis direction, Y-axis direction, and Z-axis direction are directions that intersect with each other (orthogonal in this embodiment). Depending on the mode of use, the Z-axis direction may not be the vertical direction, but for convenience of explanation, the Z-axis direction will be described as the vertical direction below.
　以下の説明において、Ｘ軸プラス方向とは、Ｘ軸の矢印方向を示し、Ｘ軸マイナス方向とは、Ｘ軸プラス方向とは反対方向を示す。単にＸ軸方向という場合は、Ｘ軸プラス方向及びＸ軸マイナス方向の双方向またはいずれか一方の方向を示す。Ｘ軸方向の一方側及び他方側という場合は、Ｘ軸プラス方向及びＸ軸マイナス方向のうちの一方及び他方を示す。Ｙ軸方向及びＺ軸方向についても同様である。平行及び直交等の、相対的な方向または姿勢を示す表現は、厳密には、その方向または姿勢ではない場合も含む。例えば、２つの方向が平行であるとは、当該２つの方向が完全に平行であることを意味するだけでなく、実質的に平行であること、すなわち、例えば数％程度の差異を含むことも意味する。以下の説明において、「絶縁」と表現する場合、「電気的な絶縁」を意味する。 In the following description, the X-axis plus direction indicates the arrow direction of the X-axis, and the X-axis minus direction indicates the opposite direction to the X-axis plus direction. When simply referred to as the X-axis direction, it refers to both or one of the X-axis plus direction and the X-axis minus direction. One side and the other side in the X-axis direction refer to one and the other of the X-axis plus direction and the X-axis minus direction. The same applies to the Y-axis direction and the Z-axis direction. Expressions indicating relative directions or orientations, such as parallel and orthogonal, include cases where the directions or orientations are not strictly speaking. For example, when two directions are parallel, it does not only mean that the two directions are completely parallel, but also that they are substantially parallel, that is, they may differ by a few percent, for example. means. In the following description, when the expression "insulation" is used, it means "electrical insulation".
　（実施の形態）
　［１ 蓄電素子１０の全般的な説明］
　まず、図１及び図２を用いて、本実施の形態における蓄電素子１０の全般的な説明を行う。図１は、本実施の形態に係る蓄電素子１０の外観を示す斜視図である。図２は、本実施の形態に係る蓄電素子１０を分解して各構成要素を示す分解斜視図である。 (Embodiment)
[1 General description of power storage element 10]
First, a general description of the power storage element 10 in this embodiment will be given using FIGS. 1 and 2. FIG. 1 is a perspective view showing the appearance of a power storage element 10 according to the present embodiment. FIG. 2 is an exploded perspective view showing each component of the power storage element 10 according to the present embodiment.
　蓄電素子１０は、電気を充電し、また、電気を放電できる二次電池（単電池）であり、より具体的には、リチウムイオン二次電池等の非水電解質二次電池である。蓄電素子１０は、自動車、自動二輪車、ウォータークラフト、船舶、スノーモービル、農業機械、建設機械、または、電気鉄道用の鉄道車両等の移動体の駆動用またはエンジン始動用等のバッテリ等として用いられる。上記の自動車としては、電気自動車（ＥＶ）、ハイブリッド電気自動車（ＨＥＶ）、プラグインハイブリッド電気自動車（ＰＨＥＶ）、及び、化石燃料（ガソリン、軽油、液化天然ガス等）自動車が例示される。上記の電気鉄道用の鉄道車両としては、電車、モノレール、リニアモーターカー、並びに、ディーゼル機関及び電気モーターの両方を備えるハイブリッド電車が例示される。蓄電素子１０は、家庭用または事業用等に使用される定置用のバッテリ等としても用いることができる。 The power storage element 10 is a secondary battery (single battery) that can charge and discharge electricity, and more specifically, it is a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery. The power storage element 10 is used as a battery for driving or starting an engine of a moving object such as an automobile, a motorcycle, a watercraft, a ship, a snowmobile, an agricultural machine, a construction machine, or a railway vehicle for an electric railway. . Examples of the above-mentioned vehicles include electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and fossil fuel (gasoline, diesel oil, liquefied natural gas, etc.) vehicles. Examples of the above-mentioned railway vehicles for electric railways include electric trains, monorails, linear motor cars, and hybrid electric trains equipped with both a diesel engine and an electric motor. The power storage element 10 can also be used as a stationary battery used for home or business use.
　蓄電素子１０は、非水電解質二次電池には限定されず、非水電解質二次電池でない二次電池であってもよいし、キャパシタでもよい。蓄電素子１０は、二次電池ではなく、使用者が充電をしなくても蓄えられている電気を使用できる一次電池でもよい。蓄電素子１０は、パウチタイプの蓄電素子でもよい。本実施の形態では、Ｙ軸方向に扁平な直方体形状（角形）の蓄電素子１０を図示しているが、蓄電素子１０の形状は、直方体形状には限定されず、直方体以外の多角柱形状、長円柱形状、楕円柱形状または円柱形状等でもよい。 The power storage element 10 is not limited to a non-aqueous electrolyte secondary battery, and may be a secondary battery that is not a non-aqueous electrolyte secondary battery, or may be a capacitor. The power storage element 10 may be not a secondary battery but a primary battery that allows the user to use the stored electricity without charging it. The power storage element 10 may be a pouch type power storage element. In the present embodiment, a rectangular parallelepiped-shaped (prismatic) power storage element 10 that is flat in the Y-axis direction is illustrated, but the shape of the power storage element 10 is not limited to a rectangular parallelepiped shape, and may include a polygonal prism shape other than a rectangular parallelepiped, The shape may be an elongated cylinder, an elliptical cylinder, a cylinder, or the like.
　図１に示すように、蓄電素子１０は、容器１００と、一対（正極及び負極）の端子３００と、一対（正極及び負極）の上部ガスケット４００と、を備えている。図２に示すように、容器１００の内方には、一対（正極及び負極）の下部ガスケット５００と、一対（正極及び負極）の集電体６００と、電極体７００と、が収容されている。上記の構成要素の他、電極体７００の側方または下方等に配置されるスペーサ、電極体７００等を包み込む絶縁フィルム等が配置されてもよい。 As shown in FIG. 1, the power storage element 10 includes a container 100, a pair of terminals 300 (positive electrode and negative electrode), and a pair of upper gaskets 400 (positive electrode and negative electrode). As shown in FIG. 2, inside the container 100, a pair of lower gaskets 500 (positive electrode and negative electrode), a pair of current collectors 600 (positive electrode and negative electrode), and an electrode body 700 are accommodated. . In addition to the above-mentioned components, a spacer placed on the side or below the electrode body 700, an insulating film that wraps around the electrode body 700, etc. may be placed.
　容器１００の内部には、電解液（非水電解質）が封入されているが、図示は省略する。当該電解液としては、蓄電素子１０の性能を損なうものでなければその種類に特に制限はなく、様々なものを選択できる。電解液は、非水溶媒と、非水溶媒に溶解されている電解質塩と、を含んでいる。非水溶媒としては、公知の非水溶媒の中から適宜選択できる。非水溶媒としては、エチレンカーボネート（ＥＣ）またはプロピレンカーボネート（ＰＣ）等の環状カーボネート、エチルメチルカーボネート（ＥＭＣ）等の鎖状カーボネート、カルボン酸エステル、リン酸エステル、スルホン酸エステル、エーテル、アミド、ニトリル等が挙げられる。非水溶媒として、これらの化合物に含まれる水素原子の一部がハロゲンに置換されたものを用いてもよい。電解質塩としては、公知の電解質塩から適宜選択できる。電解質塩としては、ＬｉＰＦ６等の無機リチウム塩等のリチウム塩、ナトリウム塩、カリウム塩、マグネシウム塩、オニウム塩等が挙げられる。これらの中でもリチウム塩が好ましい。電解液は、非水溶媒と電解質塩以外に、ビフェニル等の添加剤を含んでもよい。 An electrolytic solution (non-aqueous electrolyte) is sealed inside the container 100, but illustration thereof is omitted. The type of electrolytic solution is not particularly limited as long as it does not impair the performance of the power storage element 10, and various types can be selected. The electrolytic solution includes a non-aqueous solvent and an electrolyte salt dissolved in the non-aqueous solvent. The non-aqueous solvent can be appropriately selected from known non-aqueous solvents. Examples of non-aqueous solvents include cyclic carbonates such as ethylene carbonate (EC) or propylene carbonate (PC), chain carbonates such as ethyl methyl carbonate (EMC), carboxylic acid esters, phosphoric acid esters, sulfonic acid esters, ethers, amides, Examples include nitrile. As the non-aqueous solvent, compounds in which some of the hydrogen atoms contained in these compounds are replaced with halogens may be used. The electrolyte salt can be appropriately selected from known electrolyte salts. Examples of the electrolyte salt include lithium salts such as inorganic lithium salts such as LiPF 6 , sodium salts, potassium salts, magnesium salts, onium salts, and the like. Among these, lithium salts are preferred. The electrolytic solution may contain additives such as biphenyl in addition to the nonaqueous solvent and electrolyte salt.
　容器１００は、Ｚ軸プラス方向側に開口が形成された容器本体１１０と、容器本体１１０の当該開口を閉塞する蓋体１２０と、を有する直方体形状（角形または箱形）のケースである。蓋体１２０は、容器１００の蓋部を構成する平板状かつ矩形状の部材であり、容器本体１１０のＺ軸プラス方向に配置される。蓋体１２０は、電極体７００の巻回軸方向に延びる壁部の一例である。電極体７００の巻回軸方向とは、後述する電極体７００の巻回軸Ｌが延びる方向（巻回軸Ｌに沿う方向、本実施の形態ではＸ軸方向）である。 The container 100 is a rectangular parallelepiped-shaped (prismatic or box-shaped) case that has a container body 110 with an opening formed in the positive Z-axis direction and a lid 120 that closes the opening of the container body 110. The lid 120 is a flat, rectangular member that constitutes the lid of the container 100, and is arranged in the positive Z-axis direction of the container body 110. The lid body 120 is an example of a wall portion extending in the direction of the winding axis of the electrode body 700. The winding axis direction of the electrode body 700 is the direction in which the winding axis L of the electrode body 700, which will be described later, extends (the direction along the winding axis L, in this embodiment, the X-axis direction).
　容器本体１１０は、容器１００の本体部を構成する、矩形筒状の部分と底とを備える部材である。容器本体１１０は、Ｙ軸方向両側の面（側面）に一対の長側壁部１１１を有し、Ｘ軸方向両側の面（側面）に一対の短側壁部１１２を有し、Ｚ軸マイナス方向の面（底面）に底壁部１１３を有する。長側壁部１１１は、Ｘ軸方向（電極体７００の巻回軸方向）に延びる平板状かつ矩形状の壁部であり、容器１００の長側面を構成する。長側壁部１１１は、短側壁部１１２、底壁部１１３及び蓋体１２０に隣接し、かつ、短側壁部１１２よりも面積が大きい。短側壁部１１２は、Ｚ軸方向に延びる平板状かつ矩形状の壁部であり、容器１００の短側面を構成する。短側壁部１１２は、長側壁部１１１、底壁部１１３及び蓋体１２０に隣接し、かつ、長側壁部１１１よりも面積が小さい。底壁部１１３は、Ｘ軸方向（電極体７００の巻回軸方向）に延びる平板状かつ矩形状の壁部であり、容器１００の底面を構成する。底壁部１１３は、長側壁部１１１及び短側壁部１１２に隣接して配置される。 The container body 110 is a member that constitutes the main body of the container 100 and includes a rectangular cylindrical portion and a bottom. The container body 110 has a pair of long side walls 111 on both sides in the Y-axis direction, a pair of short side walls 112 on both sides in the X-axis direction, and has a pair of short side walls 112 on both sides in the Y-axis direction. It has a bottom wall portion 113 on the surface (bottom surface). The long side wall portion 111 is a flat rectangular wall portion extending in the X-axis direction (the direction of the winding axis of the electrode body 700), and constitutes the long side surface of the container 100. The long side wall 111 is adjacent to the short side wall 112, the bottom wall 113, and the lid 120, and has a larger area than the short side wall 112. The short side wall portion 112 is a flat rectangular wall portion extending in the Z-axis direction, and constitutes a short side surface of the container 100. The short side wall 112 is adjacent to the long side wall 111, the bottom wall 113, and the lid 120, and has a smaller area than the long side wall 111. The bottom wall portion 113 is a flat, rectangular wall portion that extends in the X-axis direction (the direction of the winding axis of the electrode body 700), and constitutes the bottom surface of the container 100. The bottom wall portion 113 is disposed adjacent to the long side wall portion 111 and the short side wall portion 112.
　電極体７００等を容器本体１１０の内部に収容後、容器本体１１０と蓋体１２０とが溶接等によって接合されることにより、容器１００の内部が密閉（密封）される。容器１００（容器本体１１０及び蓋体１２０）の材質は特に限定されず、ステンレス鋼、アルミニウム、アルミニウム合金、鉄、メッキ鋼板など溶接可能（接合可能）な金属でもよく、樹脂を用いてもよい。容器本体１１０及び蓋体１２０は、同じ材質で形成されてもよいし、異なる材質で形成されてもよい。蓄電素子１０がパウチタイプの蓄電素子の場合、容器１００は、金属層と樹脂層とを含む複数層からなるラミネートフィルムでもよい。 After the electrode body 700 and the like are housed inside the container main body 110, the container main body 110 and the lid 120 are joined by welding or the like, so that the inside of the container 100 is hermetically sealed. The material of the container 100 (container main body 110 and lid body 120) is not particularly limited, and may be a weldable (joinable) metal such as stainless steel, aluminum, aluminum alloy, iron, or plated steel plate, or resin may be used. The container body 110 and the lid 120 may be made of the same material or may be made of different materials. When the power storage element 10 is a pouch type power storage element, the container 100 may be a laminate film made of multiple layers including a metal layer and a resin layer.
　容器１００には、注液部１３０と、ガス排出弁１４０とが形成されている。本実施の形態では、注液部１３０及びガス排出弁１４０は、蓋体１２０に形成されている。つまり、注液部１３０及びガス排出弁１４０は、電極体７００の巻回軸方向（Ｘ軸方向）に延びる壁部に形成されている。ガス排出弁１４０は、容器１００内方の圧力が過度に上昇した場合に当該圧力を開放する安全弁である。本実施の形態では、ガス排出弁１４０は、蓋体１２０のＸ軸方向中央部かつＹ軸方向中央部に配置されているが、蓋体１２０のどの位置に配置されてもよい。 A liquid injection part 130 and a gas discharge valve 140 are formed in the container 100. In this embodiment, the liquid injection part 130 and the gas discharge valve 140 are formed on the lid 120. That is, the liquid injection part 130 and the gas discharge valve 140 are formed on a wall portion extending in the winding axis direction (X-axis direction) of the electrode body 700. The gas discharge valve 140 is a safety valve that releases the pressure inside the container 100 when the pressure increases excessively. In this embodiment, the gas exhaust valve 140 is arranged at the center in the X-axis direction and the center in the Y-axis direction of the lid 120, but it may be arranged at any position on the lid 120.
　注液部１３０は、蓄電素子１０の製造時に容器１００の内方に電解液を注入するための部位（電解液の注液部）である。注液部１３０は、蓄電素子１０の製造時に、容器１００内を真空引きしたり、容器１００内に電解液を注入して、電極体７００内への電解液の含浸を行ったり、電極体７００内からのガスを脱気したりするために用いられる。本実施の形態では、注液部１３０は、蓋体１２０のＸ軸マイナス方向、かつ、Ｙ軸方向の中央部に配置されているが、蓋体１２０のどの位置に配置されてもよい。 The liquid injection part 130 is a part (electrolyte liquid injection part) for injecting the electrolytic solution into the inside of the container 100 when manufacturing the power storage element 10. The liquid injection unit 130 evacuates the inside of the container 100 , injects an electrolytic solution into the container 100 to impregnate the electrode body 700 with the electrolytic solution, and performs functions such as filling the electrode body 700 with the electrolytic solution when manufacturing the power storage element 10 . It is used to evacuate gas from inside. In this embodiment, the liquid injection part 130 is arranged at the center of the lid 120 in the negative X-axis direction and the Y-axis direction, but it may be arranged at any position on the lid 120.
　注液部１３０は、注液口１３１と、注液栓１３２とを備えている。注液口１３１は、容器１００の内方に電解液を注液するために、蓋体１２０に形成された例えば円形状の貫通孔である。注液栓１３２は、注液口１３１を閉塞する部材である。具体的には、注液栓１３２は、蓄電素子１０の製造時に、注液口１３１から容器１００内を真空引きして容器１００の内方に電解液を注入した後に、蓋体１２０に接合されて注液口１３１を閉塞する閉塞部材（蓋部材）である。注液栓１３２の材質は特に限定されないが、容器１００（蓋体１２０）に採用可能ないずれかの金属等を用いることができる。特に、注液栓１３２は、蓋体１２０と同じ材質等、蓋体１２０と溶接可能な素材で形成されることが好ましい。 The liquid injection part 130 includes a liquid injection port 131 and a liquid injection plug 132. The liquid injection port 131 is, for example, a circular through hole formed in the lid 120 for injecting the electrolyte into the container 100 . The liquid injection stopper 132 is a member that closes the liquid injection port 131. Specifically, the liquid injection stopper 132 is joined to the lid body 120 after the inside of the container 100 is evacuated from the liquid injection port 131 and the electrolyte is injected into the inside of the container 100 during manufacturing of the power storage element 10. This is a closing member (lid member) that closes the liquid injection port 131. The material of the liquid injection stopper 132 is not particularly limited, but any metal that can be used for the container 100 (lid 120) can be used. In particular, the liquid injection stopper 132 is preferably formed of a material that can be welded to the lid 120, such as the same material as the lid 120.
　端子３００は、集電体６００を介して、電極体７００に電気的に接続される端子部材（正極端子及び負極端子）である。つまり、端子３００は、電極体７００に蓄えられている電気を蓄電素子１０の外部空間に導出し、また、電極体７００に電気を蓄えるために蓄電素子１０の内部空間に電気を導入するための金属製の部材である。端子３００は、アルミニウム、アルミニウム合金、銅または銅合金等の金属等の導電部材で形成されている。端子３００は、かしめ接合または溶接等によって、集電体６００に接続（接合）され、かつ、蓋体１２０に取り付けられる。端子３００は、蓋体１２０の外面（Ｚ軸プラス方向の面）からＺ軸プラス方向に突出した状態で配置される。本実施の形態では、端子３００は、外部のバスバー等の導電部材と溶接で接合される溶接端子である。しかし、端子３００は、ボルト端子でもよい。ボルト端子は、Ｚ軸プラス方向に突出する雄ネジ部が形成されたボルト部を有し、ボルト結合によって当該導電部材と接合される。 The terminal 300 is a terminal member (a positive terminal and a negative terminal) that is electrically connected to the electrode body 700 via the current collector 600. In other words, the terminal 300 is used to lead the electricity stored in the electrode body 700 to the external space of the electricity storage element 10 and to introduce electricity into the internal space of the electricity storage element 10 in order to store electricity in the electrode body 700. It is a metal member. The terminal 300 is made of a conductive member such as metal such as aluminum, aluminum alloy, copper, or copper alloy. The terminal 300 is connected (joined) to the current collector 600 and attached to the lid 120 by caulking, welding, or the like. The terminal 300 is arranged so as to protrude in the Z-axis positive direction from the outer surface (the surface in the Z-axis positive direction) of the lid body 120. In this embodiment, terminal 300 is a welding terminal that is joined to an external conductive member such as a bus bar by welding. However, terminal 300 may also be a bolt terminal. The bolt terminal has a bolt portion in which a male screw portion protruding in the positive direction of the Z-axis is formed, and is joined to the conductive member by bolt connection.
　集電体６００は、電極体７００と端子３００とに接続（接合）されて、電極体７００と端子３００とを電気的に接続する導電性の集電部材（正極集電体及び負極集電体）である。本実施の形態では、集電体６００は、電極体７００のＸ軸方向両側に配置されている。集電体６００と後述する電極体７００の端部７２０とは、溶接またはかしめ接合等により接続（接合）される。さらに、上述の通り、集電体６００と端子３００とは、かしめ接合または溶接等により接続（接合）され、かつ、蓋体１２０に固定される。集電体６００の材質は特に限定されないが、本実施の形態では、正極の集電体６００は、後述する電極体７００の正極集電箔７４１と同様、アルミニウムまたはアルミニウム合金等で形成され、負極の集電体６００は、後述する電極体７００の負極集電箔７５１と同様、銅または銅合金等で形成されている。 The current collector 600 is a conductive current collecting member (a positive electrode current collector and a negative electrode current collector) that is connected (joined) to the electrode body 700 and the terminal 300 and electrically connects the electrode body 700 and the terminal 300. ). In this embodiment, current collectors 600 are arranged on both sides of electrode body 700 in the X-axis direction. The current collector 600 and an end 720 of an electrode body 700, which will be described later, are connected (joined) by welding, caulking, or the like. Further, as described above, the current collector 600 and the terminal 300 are connected (joined) by caulking, welding, or the like, and are fixed to the lid 120. Although the material of the current collector 600 is not particularly limited, in this embodiment, the positive electrode current collector 600 is formed of aluminum or an aluminum alloy, etc., like the positive electrode current collector foil 741 of the electrode body 700, which will be described later. The current collector 600 is made of copper, copper alloy, or the like, like the negative electrode current collector foil 751 of the electrode body 700 described later.
　上部ガスケット４００は、容器１００の蓋体１２０と端子３００との間に配置され、蓋体１２０と端子３００との間を絶縁し、かつ封止する板状かつ矩形状の絶縁部材である。下部ガスケット５００は、蓋体１２０と集電体６００との間に配置され、蓋体１２０と集電体６００との間を絶縁する板状かつ矩形状の絶縁部材である。上部ガスケット４００及び下部ガスケット５００は、ポリプロピレン（ＰＰ）、ポリエチレン（ＰＥ）、ポリスチレン（ＰＳ）、ポリフェニレンサルファイド樹脂（ＰＰＳ）、ポリフェニレンエーテル（ＰＰＥ（変性ＰＰＥを含む））、ポリエチレンテレフタラート（ＰＥＴ）、ポリブチレンテレフタレート（ＰＢＴ）、ポリエーテルエーテルケトン（ＰＥＥＫ）、テトラフルオロエチレン・パーフルオロアルキルビニルエーテル（ＰＦＡ）、ポリテトラフルオロエチレン（ＰＴＦＥ）、ポリエーテルサルフォン（ＰＥＳ）、ポリアミド（ＰＡ）、ＡＢＳ樹脂、または、それらの複合材料等の絶縁部材等によって形成されている。 The upper gasket 400 is a plate-shaped and rectangular insulating member that is disposed between the lid 120 of the container 100 and the terminal 300, and insulates and seals between the lid 120 and the terminal 300. The lower gasket 500 is a plate-shaped and rectangular insulating member that is disposed between the lid 120 and the current collector 600 and insulates between the lid 120 and the current collector 600. The upper gasket 400 and the lower gasket 500 are made of polypropylene (PP), polyethylene (PE), polystyrene (PS), polyphenylene sulfide resin (PPS), polyphenylene ether (PPE (including modified PPE)), polyethylene terephthalate (PET), Polybutylene terephthalate (PBT), polyether ether ketone (PEEK), tetrafluoroethylene perfluoroalkyl vinyl ether (PFA), polytetrafluoroethylene (PTFE), polyether sulfone (PES), polyamide (PA), ABS resin , or an insulating member such as a composite material thereof.
　電極体７００は、極板及びセパレータが積層されて形成された、電気を蓄えることができる蓄電要素（発電要素）である。本実施の形態では、電極体７００は、極板及びセパレータが巻回されて形成される。電極体７００は、Ｘ軸方向に延びる長尺な形状であって、Ｘ軸方向から見て長円形状（長円柱形状）である。電極体７００は、電極体本体部７１０と、電極体本体部７１０からＸ軸方向両側に突出する端部７２０と、を有し、上述の通り、端部７２０が集電体６００に接続（接合）される。電極体本体部７１０には、貫通孔７３０が形成されている。このような電極体７００の構成について、以下に詳細に説明する。 The electrode body 700 is a power storage element (power generation element) that is formed by laminating electrode plates and separators and is capable of storing electricity. In this embodiment, the electrode body 700 is formed by winding an electrode plate and a separator. The electrode body 700 has an elongated shape extending in the X-axis direction, and has an oval shape (long columnar shape) when viewed from the X-axis direction. The electrode body 700 has an electrode body body part 710 and an end part 720 protruding from the electrode body body part 710 on both sides in the X-axis direction, and as described above, the end part 720 is connected (joined) to the current collector 600. ) to be done. A through hole 730 is formed in the electrode main body portion 710. The configuration of such an electrode body 700 will be described in detail below.
　［２ 電極体７００の構成の説明］
　図３は、本実施の形態に係る電極体７００の構成を示す斜視図である。図３は、電極体７００における極板の巻回状態を一部展開した状態での構成を示している。図４は、本実施の形態に係る電極体７００の構成を示す斜視図及び断面図である。図４の（ａ）は、極板を巻回した後の電極体７００の構成を示す斜視図であり、図４の（ｂ）は、電極体７００の一部の断面を拡大して極板の積層状態を示す断面図である。 [2 Description of configuration of electrode body 700]
FIG. 3 is a perspective view showing the configuration of an electrode body 700 according to this embodiment. FIG. 3 shows the structure of the electrode body 700 in a partially unfolded state in which the electrode plates are wound. FIG. 4 is a perspective view and a cross-sectional view showing the configuration of an electrode body 700 according to this embodiment. FIG. 4(a) is a perspective view showing the configuration of the electrode body 700 after winding the electrode plate, and FIG. 4(b) is an enlarged cross-section of a part of the electrode body 700. FIG.
　［２．１ 電極体７００の全般的な説明］
　図３及び図４に示すように、電極体７００は、極板として、２枚の極板である正極板７４０及び負極板７５０を有し、かつ、セパレータとして、２枚のセパレータ７６０であるセパレータ７６１及び７６２を有している。 [2.1 General description of electrode body 700]
As shown in FIGS. 3 and 4, the electrode body 700 has two electrode plates, a positive electrode plate 740 and a negative electrode plate 750, and has two separators 760 as separators. 761 and 762.
　正極板７４０は、アルミニウムまたはアルミニウム合金等の金属からなる長尺帯状の集電箔（金属箔）である正極集電箔７４１の表面に、正極活物質層７４２が形成された極板（電極板）である。負極板７５０は、銅または銅合金等の金属からなる長尺帯状の集電箔（金属箔）である負極集電箔７５１の表面に、負極活物質層７５２が形成された極板（電極板）である。正極集電箔７４１及び負極集電箔７５１として、ニッケル、鉄、ステンレス鋼、チタン、焼成炭素、導電性高分子、導電性ガラス、Ａｌ－Ｃｄ合金など、充放電時の酸化還元反応に対して安定な材料であれば適宜公知の材料を用いることもできる。正極活物質層７４２に用いられる正極活物質、及び、負極活物質層７５２に用いられる負極活物質としては、リチウムイオンを吸蔵放出可能な正極活物質及び負極活物質であれば、適宜公知の材料を使用できる。 The positive electrode plate 740 is an electrode plate (electrode plate) in which a positive electrode active material layer 742 is formed on the surface of a positive electrode current collector foil 741 that is a long strip-shaped current collector foil (metal foil) made of metal such as aluminum or aluminum alloy. ). The negative electrode plate 750 is an electrode plate (electrode plate) in which a negative electrode active material layer 752 is formed on the surface of a negative electrode current collector foil 751, which is a long strip-shaped current collector foil (metal foil) made of metal such as copper or copper alloy. ). As the positive electrode current collector foil 741 and the negative electrode current collector foil 751, materials such as nickel, iron, stainless steel, titanium, fired carbon, conductive polymer, conductive glass, Al-Cd alloy, etc., can be used to prevent oxidation-reduction reactions during charging and discharging. Any known material may be used as long as it is stable. As the positive electrode active material used in the positive electrode active material layer 742 and the negative electrode active material used in the negative electrode active material layer 752, any known material can be used as long as it is a positive electrode active material and a negative electrode active material that can intercalate and extract lithium ions. can be used.
　正極活物質として、ＬｉＭＰＯ４、ＬｉＭＳｉＯ４、ＬｉＭＢＯ３（ＭはＦｅ、Ｎｉ、Ｍｎ、Ｃｏ等から選択される１種または２種以上の遷移金属元素）等のポリアニオン化合物、チタン酸リチウム、ＬｉＭｎ２Ｏ４またはＬｉＭｎ１．５Ｎｉ０．５Ｏ４等のスピネル型リチウムマンガン酸化物、ＬｉＭＯ２（ＭはＦｅ、Ｎｉ、Ｍｎ、Ｃｏ等から選択される１種または２種以上の遷移金属元素）等のリチウム遷移金属酸化物等を用いることができる。負極活物質としては、リチウム金属、リチウム合金（リチウム－ケイ素、リチウム－アルミニウム、リチウム－鉛、リチウム－錫、リチウム－アルミニウム－錫、リチウム－ガリウム、及びウッド合金等のリチウム金属含有合金）の他、リチウムを吸蔵・放出可能な合金、炭素材料（黒鉛、難黒鉛化炭素、易黒鉛化炭素、低温焼成炭素、非晶質カーボン等）、ケイ素酸化物、金属酸化物、リチウム金属酸化物（Ｌｉ４Ｔｉ５Ｏ１２等）、ポリリン酸化合物、あるいは、一般にコンバージョン負極と呼ばれる、Ｃｏ３Ｏ４またはＦｅ２Ｐ等の、遷移金属と第１４族乃至第１６族元素との化合物などが挙げられる。 As the positive electrode active material, polyanion compounds such as LiMPO 4 , LiMSiO 4 , LiMBO 3 (M is one or more transition metal elements selected from Fe, Ni, Mn, Co, etc.), lithium titanate, LiMn 2 Spinel-type lithium manganese oxide such as O 4 or LiMn 1.5 Ni 0.5 O 4 , LiMO 2 (M is one or more transition metal elements selected from Fe, Ni, Mn, Co, etc.) Lithium transition metal oxides such as the following can be used. Examples of negative electrode active materials include lithium metal, lithium alloys (lithium metal-containing alloys such as lithium-silicon, lithium-aluminum, lithium-lead, lithium-tin, lithium-aluminum-tin, lithium-gallium, and Wood alloys). , alloys that can absorb and release lithium, carbon materials (graphite, non-graphitizable carbon, easily graphitizable carbon, low-temperature firing carbon, amorphous carbon, etc.), silicon oxides, metal oxides, lithium metal oxides (Li 4 Ti 5 O 12 etc.), polyphosphoric acid compounds, or compounds of transition metals and Group 14 to Group 16 elements, such as Co 3 O 4 or Fe 2 P, which are generally called conversion negative electrodes.
　セパレータ７６０（セパレータ７６１及び７６２）は、セパレータ基材７６０ａと、セパレータ基材７６０ａにコートされた無機粒子を含む無機コート層７６０ｂと、を有している（図４の（ｂ）参照）。セパレータ基材７６０ａは、セパレータ７６０の基材であり、樹脂等からなる微多孔性の絶縁シートである。セパレータ基材７６０ａの素材としては、蓄電素子１０の性能を損なうものでなければ、適宜公知の材料を使用できる。セパレータ基材７６０ａの形状としては、織布、不織布、多孔質樹脂フィルム等が挙げられる。これらの形状の中でも、強度の観点から多孔質樹脂フィルムが好ましく、電解液の保液性の観点から不織布が好ましい。セパレータ基材７６０ａの材料としては、シャットダウン機能の観点からポリエチレン、ポリプロピレン等のポリオレフィンが好ましく、耐酸化分解性の観点からはポリイミド、アラミド等が好ましい。セパレータ基材７６０ａとして、これらの樹脂を複合した材料を用いてもよい。 The separator 760 (separators 761 and 762) includes a separator base material 760a and an inorganic coat layer 760b containing inorganic particles coated on the separator base material 760a (see (b) in FIG. 4). The separator base material 760a is a base material of the separator 760, and is a microporous insulating sheet made of resin or the like. As the material for separator base material 760a, any known material can be used as appropriate, as long as it does not impair the performance of power storage element 10. Examples of the shape of the separator base material 760a include woven fabric, nonwoven fabric, and porous resin film. Among these shapes, a porous resin film is preferred from the viewpoint of strength, and a nonwoven fabric is preferred from the viewpoint of electrolyte retention. As the material for the separator base material 760a, polyolefins such as polyethylene and polypropylene are preferred from the viewpoint of a shutdown function, and polyimide, aramid, etc. are preferred from the viewpoint of oxidative decomposition resistance. A composite material of these resins may be used as the separator base material 760a.
　無機コート層７６０ｂは、セパレータ基材７６０ａにコート（コーティング）されるコート層である。無機コート層７６０ｂは、無機粒子とバインダ（結着材）とを含んでおり、当該バインダによってセパレータ基材７６０ａにコート（コーティング）される。当該バインダとしては、適宜公知の材料を使用できる。本実施の形態では、無機コート層７６０ｂは、セパレータ基材７６０ａの表面（片面）の全体を覆う、セパレータ基材７６０ａよりも厚みの薄い薄膜状の部位である。無機コート層７６０ｂは、セパレータ基材７６０ａの表面の全面を覆うことには限定されず、当該表面の一部を覆っていなくてもよい。図４の（ｂ）では、無機コート層７６０ｂは、セパレータ基材７６０ａのＹ軸マイナス方向の面を覆うが、セパレータ基材７６０ａのＹ軸プラス方向の面を覆ってもよいし、セパレータ基材７６０ａの両面を覆ってもよい。無機コート層７６０ｂは、セパレータ基材７６０ａよりも厚みが厚くてもよい。ただし、無機コート層７６０ｂは、セパレータ基材７６０ａの片面を覆い、かつ、セパレータ基材７６０ａよりも厚みが薄い方が、セパレータ７６０の厚みを薄くできるため好ましい。 The inorganic coat layer 760b is a coat layer that is coated on the separator base material 760a. The inorganic coat layer 760b includes inorganic particles and a binder (binding material), and is coated on the separator base material 760a with the binder. As the binder, any known material can be used as appropriate. In this embodiment, the inorganic coating layer 760b is a thin film-like portion that is thinner than the separator base material 760a and covers the entire surface (one side) of the separator base material 760a. The inorganic coat layer 760b is not limited to covering the entire surface of the separator base material 760a, and may not cover a part of the surface. In FIG. 4B, the inorganic coat layer 760b covers the surface of the separator base material 760a in the Y-axis negative direction, but it may cover the surface of the separator base material 760a in the Y-axis positive direction, or Both sides of 760a may be covered. The inorganic coat layer 760b may be thicker than the separator base material 760a. However, it is preferable that the inorganic coating layer 760b covers one side of the separator base material 760a and is thinner than the separator base material 760a because the thickness of the separator 760 can be reduced.
　本実施の形態では、セパレータ基材７６０ａにコートされる無機コート層７６０ｂは、電解液が滴下されて３００秒目における電解液の浸透面積が８０ｍｍ２以上である。表１に、有機のコート層を有するセパレータ及び無機のコート層を有するセパレータにおける、電解液が滴下されて３００秒目における電解液の浸透面積の比較を示す。浸透面積の測定方法は、以下の通りである。評価サンプルの表面をコート層、裏面をセパレータ基材７６０ａとなるようにガラス板の上に載せ、サンプルの中心に０．３ｃｃの電解液を滴下する。有機又は無機のコート層に電解液が付着したときを０秒とし、３００秒目における液の浸透により変色した部分を浸透範囲とみなす。有機又は無機のコート層に滴下した電解液が円形状に広がった場合、浸透範囲の直径を３箇所で測定し、直径の平均値から算出した円の面積を浸透面積とする。電解液の広がった形状が、楕円形状等の円形状でない歪な形状であると目視で確認される場合には、液の浸透により変色した部分を浸透範囲みなし、画像処理することで浸透面積を算出する。表１においては、電解液として、プロピレンカーボネート（ＰＣ）を用い、無機物質（無機粒子）であるケイ酸アルミニウム、硫酸バリウム、及び、アルミナ（べーマイト）は、平均一次粒子径（一次粒子の平均粒子径）が５μｍ程度のものを用いて試験を行った。粒子径が大きいほど浸透速度が速くなるため、無機物質（無機粒子）の平均一次粒子径は、１μｍ以上が好ましく、３μｍ以上がさらに好ましい。無機物質（無機粒子）の粒子径は、無機コート層７６０ｂの厚み以下である。 In this embodiment, the inorganic coating layer 760b coated on the separator base material 760a has an electrolyte permeation area of 80 mm 2 or more at 300 seconds after the electrolyte is dropped. Table 1 shows a comparison of the permeation area of the electrolytic solution at 300 seconds after the electrolytic solution was dropped in a separator having an organic coating layer and a separator having an inorganic coating layer. The method for measuring the permeation area is as follows. The evaluation sample is placed on a glass plate so that the front side becomes the coating layer and the back side becomes the separator base material 760a, and 0.3 cc of electrolytic solution is dropped into the center of the sample. The time when the electrolytic solution adheres to the organic or inorganic coating layer is defined as 0 seconds, and the area that changes color due to penetration of the solution at 300 seconds is considered to be the penetration range. When the electrolytic solution dropped onto the organic or inorganic coating layer spreads in a circular shape, the diameter of the permeation range is measured at three locations, and the area of the circle calculated from the average value of the diameters is defined as the permeation area. If the spread of the electrolyte is visually confirmed to be a distorted shape that is not circular, such as an ellipse, the area that has changed color due to penetration of the solution is considered the penetration range, and image processing is performed to calculate the penetration area. calculate. In Table 1, propylene carbonate (PC) is used as the electrolyte, and inorganic substances (inorganic particles) such as aluminum silicate, barium sulfate, and alumina (boehmite) are The test was conducted using particles with a particle diameter of approximately 5 μm. The larger the particle size, the faster the penetration rate, so the average primary particle size of the inorganic substance (inorganic particles) is preferably 1 μm or more, more preferably 3 μm or more. The particle diameter of the inorganic substance (inorganic particles) is equal to or less than the thickness of the inorganic coat layer 760b.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　表１に示すように、無機物質（無機粒子）であるケイ酸アルミニウム、硫酸バリウム、及び、アルミナ（べーマイト）のいずれかのコート層を有するセパレータでは、電解液を滴下して３００秒目における電解液の浸透面積が８０ｍｍ２以上となっている。有機物質（有機繊維）であるアラミド繊維のコート層を有するセパレータでは、電解液を滴下してから３００秒が経過した時点で、電解液が浸透した面積が５８ｍｍ２であったのに対し、無機物質（無機粒子）であるケイ酸アルミニウムのコート層を有するセパレータでは、電解液を滴下してから３００秒が経過した時点で、電解液が浸透した面積は８０ｍｍ２であった。無機物質（無機粒子）である硫酸バリウム及びアルミナ（べーマイト）のコート層を有するセパレータについては、電解液を滴下してから３００秒が経過した時点で、電解液が浸透した面積は９５ｍｍ２であった。 As shown in Table 1, in a separator having a coating layer of any of the inorganic materials (inorganic particles), such as aluminum silicate, barium sulfate, or alumina (boehmite), the The permeation area of the electrolyte is 80 mm 2 or more. In the case of a separator having a coat layer of aramid fiber, which is an organic substance (organic fiber), the area penetrated by the electrolyte was 58 mm 2 after 300 seconds had passed since the electrolyte was dropped, whereas inorganic In the separator having a coating layer of aluminum silicate, which is a substance (inorganic particles), the area penetrated by the electrolyte was 80 mm 2 after 300 seconds had passed since the electrolyte was dropped. For separators that have a coating layer of barium sulfate and alumina (boehmite), which are inorganic substances (inorganic particles), the area penetrated by the electrolyte is 95 mm 2 after 300 seconds have passed since the electrolyte was dropped. there were.
　このように、無機コート層７６０ｂは、ケイ酸アルミニウム、硫酸バリウム、及び、アルミナ（べーマイト）等の無機粒子を含んでおり、電解液が滴下されて３００秒目における電解液の浸透面積が８０ｍｍ２以上である。ケイ酸アルミニウムに比べて硫酸バリウム及びアルミナ（べーマイト）が、上記浸透面積が大きいため、無機コート層７６０ｂは、無機粒子として、硫酸バリウム及びアルミナの少なくとも一方を含むのが好ましい。この場合、無機コート層７６０ｂは、電解液が滴下されて３００秒目における電解液の浸透面積が９０ｍｍ２以上（９５ｍｍ２）である。無機コート層７６０ｂは、無機粒子として、これらの１種類の無機物質を含んでいてもよいし、複数種類の無機物質を含んでいてもよい。当該無機粒子の粒径は、５μｍ程度である。 In this way, the inorganic coat layer 760b contains inorganic particles such as aluminum silicate, barium sulfate, and alumina (boehmite), and the permeation area of the electrolyte at 300 seconds after the electrolyte is dropped is 80 mm. It is 2 or more. Since barium sulfate and alumina (boehmite) have a larger permeation area than aluminum silicate, the inorganic coat layer 760b preferably contains at least one of barium sulfate and alumina as inorganic particles. In this case, the inorganic coat layer 760b has an electrolytic solution permeation area of 90 mm 2 or more (95 mm 2 ) 300 seconds after the electrolytic solution is dropped. The inorganic coat layer 760b may contain one type of these inorganic substances as inorganic particles, or may contain multiple types of inorganic substances. The particle size of the inorganic particles is about 5 μm.
　電極体７００は、以上のような構成の正極板７４０及び負極板７５０と、セパレータ７６１及び７６２とが交互に積層されかつ巻回されることで形成されている。つまり、電極体７００は、正極板７４０と、セパレータ７６１と蓁負極板７５０と、セパレータ７６２とがこの順に積層され、巻回されることで形成される（図４の（ｂ）等参照）。本実施の形態では、電極体７００は巻回型の電極体であり、正極板７４０及び負極板７５０等が、Ｘ軸方向に延びる巻回軸Ｌまわりに巻回されて形成される。巻回軸Ｌとは、正極板７４０及び負極板７５０等を巻回する際の中心軸となる仮想的な軸であり、本実施の形態では、電極体７００の中心を通る、Ｘ軸方向に平行な直線である。 The electrode body 700 is formed by alternately stacking and winding the positive electrode plate 740 and the negative electrode plate 750 configured as described above, and the separators 761 and 762. That is, the electrode body 700 is formed by stacking a positive electrode plate 740, a separator 761, a flat negative electrode plate 750, and a separator 762 in this order and winding them (see FIG. 4B, etc.). In this embodiment, the electrode body 700 is a wound type electrode body, and is formed by winding a positive electrode plate 740, a negative electrode plate 750, etc. around a winding axis L extending in the X-axis direction. The winding axis L is a virtual axis that becomes the central axis when winding the positive electrode plate 740, the negative electrode plate 750, etc. They are parallel straight lines.
　具体的には、電極体７００は、正極板７４０と、正極板７４０に対して巻回軸Ｌに沿う方向（巻回軸方向、本実施の形態ではＸ軸方向）にずれた負極板７５０と、が積層し、その後巻回することによって形成される。セパレータ７６１及びセパレータ７６２は、巻回後の正極板７４０と負極板７５０との間に介在するように配置される。正極板７４０及び負極板７５０は、それぞれのずらされた方向の端部に、正極活物質層７４２及び負極活物質層７５２が形成（塗工）されず正極集電箔７４１及び負極集電箔７５１が露出した部分（活物質層非形成部）を有している。これにより、電極体７００は、巻回軸方向の一端部に、正極板７４０の活物質層非形成部が積層されて束ねられた正極の端部７２０を有し、巻回軸方向の他端部に、負極板７５０の活物質層非形成部が積層されて束ねられた負極の端部７２０を有している。 Specifically, the electrode body 700 includes a positive electrode plate 740 and a negative electrode plate 750 that is shifted from the positive electrode plate 740 in the direction along the winding axis L (the winding axis direction, in this embodiment, the X-axis direction). , are formed by laminating and then winding. Separator 761 and separator 762 are arranged to be interposed between positive electrode plate 740 and negative electrode plate 750 after winding. In the positive electrode plate 740 and the negative electrode plate 750, the positive electrode active material layer 742 and the negative electrode active material layer 752 are not formed (coated) on the ends in the respective shifted directions, and the positive electrode current collector foil 741 and the negative electrode current collector foil 751 has an exposed portion (active material layer non-forming portion). As a result, the electrode body 700 has a positive electrode end 720 in which the active material layer-free portion of the positive electrode plate 740 is laminated and bundled at one end in the winding axis direction, and the other end in the winding axis direction. The active material layer-free portion of the negative electrode plate 750 is stacked and bundled to form a negative electrode end portion 720.
　端部７２０は、正極板７４０または負極板７５０が積層方向（Ｙ軸方向）に積層された部位である。つまり、電極体７００は、電極体７００の本体を構成する電極体本体部７１０と、電極体本体部７１０からＸ軸方向両側に突出した一対（正極及び負極）の端部７２０と、を有している。電極体本体部７１０は、正極板７４０のうちの正極活物質層７４２が形成（塗工）された部分と、負極板７５０のうちの負極活物質層７５２が形成（塗工）された部分と、セパレータ７６１と、セパレータ７６１７６２と、が巻回されて形成された長円柱形状の部位（活物質層形成部）である。電極体本体部７１０は、Ｚ軸方向両側の部位から構成される一対の湾曲部７１１を有し、Ｙ軸方向両側の部位から構成される一対の平坦部７１２を有する（図４の（ａ）参照）。つまり、電極体７００は、正極板７４０及び負極板７５０が巻回軸Ｌまわりに巻回されて形成された、湾曲状の湾曲部７１１と平坦状の平坦部７１２とを有している。 The end portion 720 is a portion where the positive electrode plate 740 or the negative electrode plate 750 are stacked in the stacking direction (Y-axis direction). In other words, the electrode body 700 includes an electrode body body part 710 that constitutes the body of the electrode body 700, and a pair of end parts 720 (a positive electrode and a negative electrode) that protrude from the electrode body body part 710 on both sides in the X-axis direction. ing. The electrode main body portion 710 includes a portion of the positive electrode plate 740 on which the positive electrode active material layer 742 is formed (coated), and a portion of the negative electrode plate 750 on which the negative electrode active material layer 752 is formed (coated). , a separator 761 and a separator 761762 are wound together to form an elongated cylindrical portion (active material layer forming portion). The electrode main body part 710 has a pair of curved parts 711 made up of parts on both sides in the Z-axis direction, and a pair of flat parts 712 made up of parts on both sides in the Y-axis direction ((a) in FIG. 4). reference). That is, the electrode body 700 has a curved portion 711 and a flat portion 712, which are formed by winding the positive electrode plate 740 and the negative electrode plate 750 around the winding axis L.
　湾曲部７１１は、Ｘ軸方向から見てＺ軸方向に突出するように半円の円弧形状に湾曲し、Ｘ軸方向に延びる湾曲状の部位であり、容器本体１１０の底壁部１１３と蓋体１２０とに対向して配置される。つまり、一対の湾曲部７１１は、Ｘ軸方向から見て、容器本体１１０の底壁部１１３及び蓋体１２０に向けてＺ軸方向両側に突出するように湾曲した部位である。平坦部７１２は、一対の湾曲部７１１の端部同士を繋ぐ、Ｙ軸方向に向いたＸＺ平面に平行に広がる矩形状かつ平坦状の部位であり、容器本体１１０のＹ軸方向両側の長側壁部１１１に対向して配置される。湾曲部７１１の湾曲形状は、半円の円弧形状には限定されず、楕円形状の一部等でもよく、どのように湾曲していてもよい。平坦部７１２は、Ｙ軸方向に向く外面が平面であることには限定されず、当該外面が少し凹んでいたり、少し膨らんでいたりしていてもよい。 The curved portion 711 is a curved portion that is curved in a semicircular arc shape so as to protrude in the Z-axis direction when viewed from the X-axis direction, and extends in the X-axis direction, and is a curved portion that extends in the X-axis direction. It is arranged opposite to the body 120. That is, the pair of curved portions 711 are portions that are curved so as to protrude on both sides in the Z-axis direction toward the bottom wall portion 113 and the lid 120 of the container body 110 when viewed from the X-axis direction. The flat portion 712 is a rectangular and flat portion that connects the ends of the pair of curved portions 711 and extends parallel to the XZ plane facing the Y-axis direction, and is a long side wall on both sides of the container body 110 in the Y-axis direction. It is arranged opposite to the section 111. The curved shape of the curved portion 711 is not limited to a semicircular arc shape, but may be a part of an elliptical shape or the like, and may be curved in any manner. The flat portion 712 is not limited to having a flat outer surface facing the Y-axis direction, and may be slightly recessed or slightly bulged.
　以上のような構成により、電極体７００は、Ｘ軸方向の長さが長い長尺な（横長の）形状を有している。具体的には、電極体７００の巻回軸方向における長さが、５００ｍｍ以上である。言い換えると、巻回軸方向であるＸ軸方向において、電極体７００の一端縁から他端縁までの長さが、５００ｍｍ以上である。電極体７００の巻回軸方向における長さは、５００ｍｍよりも長いのが好ましく、５５０ｍｍ以上であるのがより好ましく、６００ｍｍ以上であるのがさらに好ましい。巻回軸方向であるＸ軸方向において、電極体本体部７１０の一端縁から他端縁までの長さは、５００ｍｍ以上であってもよく、５００ｍｍよりも長いのが好ましく、５５０ｍｍ以上であるのがより好ましく、６００ｍｍ以上であるのがさらに好ましい。 With the above configuration, the electrode body 700 has an elongated (horizontally elongated) shape with a long length in the X-axis direction. Specifically, the length of the electrode body 700 in the direction of the winding axis is 500 mm or more. In other words, the length from one end edge to the other end edge of the electrode body 700 in the X-axis direction, which is the winding axis direction, is 500 mm or more. The length of the electrode body 700 in the direction of the winding axis is preferably longer than 500 mm, more preferably 550 mm or more, and even more preferably 600 mm or more. In the X-axis direction, which is the winding axis direction, the length from one end edge to the other end edge of the electrode main body portion 710 may be 500 mm or more, preferably longer than 500 mm, and preferably 550 mm or more. is more preferable, and even more preferably 600 mm or more.
　さらに、電極体７００には、１以上の貫通孔７３０が形成されている。つまり、電極体７００の極板（正極板７４０及び負極板７５０）には、１以上の貫通孔７３０が形成されている。本実施の形態では、電極体７００の電極体本体部７１０に、１つの貫通孔７３０が形成されている。以下に、貫通孔７３０の構成について、図５も用いて詳細に説明する。 Furthermore, one or more through holes 730 are formed in the electrode body 700. That is, one or more through holes 730 are formed in the electrode plates (positive electrode plate 740 and negative electrode plate 750) of the electrode body 700. In this embodiment, one through hole 730 is formed in the electrode body main body portion 710 of the electrode body 700. Below, the configuration of the through hole 730 will be explained in detail using FIG. 5 as well.
　［２．２ 貫通孔７３０の説明］
　図５は、本実施の形態に係る電極体７００の貫通孔７３０の構成を示す正面図及び断面図である。図５の（ａ）は、電極体７００の貫通孔７３０を正面（Ｙ軸マイナス方向）から見た場合の構成を示す正面図であり、図５の（ｂ）は、図５の（ａ）の断面を示す断面図である。 [2.2 Description of through hole 730]
FIG. 5 is a front view and a cross-sectional view showing the configuration of the through hole 730 of the electrode body 700 according to the present embodiment. 5(a) is a front view showing the configuration of the through hole 730 of the electrode body 700 when viewed from the front (Y-axis negative direction), and FIG. FIG.
　図２～図４に示すように、貫通孔７３０は、電極体本体部７１０のＹ軸マイナス方向の平坦部７１２のうち、Ｘ軸方向中央部かつＺ軸マイナス方向端部に形成されている。つまり、貫通孔７３０は、容器１００の容器本体１１０が有するＹ軸マイナス方向の長側壁部１１１に対向し、かつ、底壁部１１３に近い位置に配置される。 As shown in FIGS. 2 to 4, the through hole 730 is formed at the center in the X-axis direction and at the end in the Z-axis minus direction of the flat portion 712 in the Y-axis minus direction of the electrode body 710. In other words, the through hole 730 is disposed opposite to the long side wall 111 of the container body 110 of the container 100 in the negative Y-axis direction and close to the bottom wall 113 .
　図４の（ｂ）及び図５に示すように、正極板７４０のうちの正極集電箔７４１に正極活物質層７４２が形成（塗工）された部分を、正極活物質部７４３と称する。負極板７５０のうちの負極集電箔７５１に負極活物質層７５２が形成（塗工）された部分を、負極活物質部７５３と称する。つまり、正極の端部７２０に含まれる部分を除いた正極集電箔７４１と正極活物質層７４２とを、正極活物質部７４３と称し、負極の端部７２０に含まれる部分を除いた負極集電箔７５１と負極活物質層７５２とを、負極活物質部７５３と称する。言い換えれば、正極板７４０のうちの正極の端部７２０に含まれる正極集電箔７４１以外の部分を、正極活物質部７４３と称し、負極板７５０のうちの負極の端部７２０に含まれる負極集電箔７５１以外の部分を、負極活物質部７５３と称する。 As shown in FIG. 4B and FIG. 5, the portion of the positive electrode plate 740 where the positive electrode active material layer 742 is formed (coated) on the positive current collector foil 741 is referred to as a positive electrode active material portion 743. A portion of the negative electrode plate 750 in which the negative electrode active material layer 752 is formed (coated) on the negative electrode current collector foil 751 is referred to as a negative electrode active material portion 753 . That is, the positive electrode current collector foil 741 and the positive electrode active material layer 742 excluding the portion included in the end portion 720 of the positive electrode are referred to as a positive electrode active material portion 743, and the negative electrode collector foil 741 excluding the portion included in the end portion 720 of the negative electrode are referred to as a positive electrode active material portion 743. The electric foil 751 and the negative electrode active material layer 752 are referred to as a negative electrode active material portion 753. In other words, the portion other than the positive electrode current collector foil 741 included in the positive electrode end 720 of the positive electrode plate 740 is referred to as the positive electrode active material portion 743, and the negative electrode included in the negative electrode end 720 of the negative electrode plate 750 is referred to as the positive electrode active material portion 743. A portion other than the current collector foil 751 is referred to as a negative electrode active material portion 753.
　具体的には、図４の（ｂ）及び図５において、電極体７００における正極板７４０のうちの、正極集電箔７４１（１層）の両面に正極活物質層７４２（２層）が形成された３層分を１単位として、１つの正極活物質部７４３と称する。電極体７００における負極板７５０のうちの、負極集電箔７５１（１層）の両面に負極活物質層７５２（２層）が形成された３層分を１単位として、１つの負極活物質部７５３と称する。つまり、正極板７４０と負極板７５０とが巻回されることで、正極活物質部７４３及び負極活物質部７５３の間にセパレータ７６１及び７６２が配置された状態で、複数の正極活物質部７４３と複数の負極活物質部７５３とが積層される。電極体本体部７１０は、これら複数の正極活物質部７４３と複数の負極活物質部７５３とセパレータ７６１及び７６２とが積層されて形成されたものである。 Specifically, in FIG. 4B and FIG. 5, positive electrode active material layers 742 (two layers) are formed on both sides of a positive electrode current collector foil 741 (one layer) of the positive electrode plate 740 in the electrode body 700. The three layers formed as one unit are referred to as one positive electrode active material portion 743. Three layers of the negative electrode plate 750 in the electrode body 700, in which the negative electrode active material layers 752 (two layers) are formed on both sides of the negative electrode current collector foil 751 (one layer), are considered as one unit, and one negative electrode active material part. It is called 753. That is, by winding the positive electrode plate 740 and the negative electrode plate 750, a plurality of positive electrode active material parts 743 and a plurality of negative electrode active material portions 753 are stacked. The electrode main body part 710 is formed by laminating these plurality of positive electrode active material parts 743, plurality of negative electrode active material parts 753, and separators 761 and 762.
　電極体本体部７１０の平坦部７１２に位置する正極活物質部７４３及び負極活物質部７５３の少なくとも一方には、貫通孔７３０が形成されている。本実施の形態では、正極活物質部７４３及び負極活物質部７５３の双方、並びに、セパレータ７６１及び７６２に、貫通孔７３０が形成されている。 A through hole 730 is formed in at least one of the positive electrode active material portion 743 and the negative electrode active material portion 753 located on the flat portion 712 of the electrode main body portion 710. In this embodiment, through holes 730 are formed in both the positive electrode active material section 743 and the negative electrode active material section 753, as well as in the separators 761 and 762.
　具体的には、図５に示すように、正極活物質部７４３には、貫通孔７３０としての正極貫通孔７４３ａが形成されている。正極貫通孔７４３ａは、正極活物質部７４３をＹ軸方向に貫通する円形状の貫通孔である。つまり、正極貫通孔７４３ａは、正極集電箔７４１と、正極集電箔７４１のＹ軸方向両面に設けられた２つの正極活物質層７４２とをＹ軸方向に貫通する円形状の貫通孔である。負極活物質部７５３には、貫通孔７３０としての負極貫通孔７５３ａが形成されている。負極貫通孔７５３ａは、負極活物質部７５３をＹ軸方向に貫通する円形状の貫通孔である。つまり、負極貫通孔７５３ａは、負極集電箔７５１と、負極集電箔７５１のＹ軸方向両面に設けられた２つの負極活物質層７５２とをＹ軸方向に貫通する円形状の貫通孔である。 Specifically, as shown in FIG. 5, a positive electrode through hole 743a serving as the through hole 730 is formed in the positive electrode active material portion 743. The positive electrode through hole 743a is a circular through hole that penetrates the positive electrode active material portion 743 in the Y-axis direction. In other words, the positive electrode through hole 743a is a circular through hole that penetrates the positive electrode current collector foil 741 and the two positive electrode active material layers 742 provided on both sides of the positive electrode current collector foil 741 in the Y axis direction. be. A negative electrode through hole 753 a serving as the through hole 730 is formed in the negative electrode active material portion 753 . The negative electrode through hole 753a is a circular through hole that penetrates the negative electrode active material portion 753 in the Y-axis direction. In other words, the negative electrode through hole 753a is a circular through hole that penetrates the negative electrode current collector foil 751 and the two negative electrode active material layers 752 provided on both sides of the negative electrode current collector foil 751 in the Y axis direction. be.
　正極貫通孔７４３ａ及び負極貫通孔７５３ａは、貫通孔７３０の貫通方向（正極貫通孔７４３ａ及び負極貫通孔７５３ａの並び方向、Ｙ軸方向）から見て、少なくとも一部が重なる位置に配置される。本実施の形態では、Ｙ軸方向から見て、負極貫通孔７５３ａは、全部が正極貫通孔７４３ａと重なる位置に配置される。つまり、Ｙ軸方向から見て、負極貫通孔７５３ａは、正極貫通孔７４３ａよりも小さな形状を有しており、正極貫通孔７４３ａの内方に配置される。 The positive electrode through hole 743a and the negative electrode through hole 753a are arranged at a position where at least a portion thereof overlaps when viewed from the penetrating direction of the through hole 730 (the direction in which the positive electrode through hole 743a and the negative electrode through hole 753a are lined up, the Y-axis direction). In this embodiment, when viewed from the Y-axis direction, the negative electrode through hole 753a is arranged at a position where the entire negative electrode through hole 743a overlaps with the positive electrode through hole 743a. That is, when viewed from the Y-axis direction, the negative electrode through hole 753a has a smaller shape than the positive electrode through hole 743a, and is arranged inside the positive electrode through hole 743a.
　正極貫通孔７４３ａ及び負極貫通孔７５３ａのサイズは、蓄電素子１０の容量の低下を抑制する観点から、小さいほどよいが、小さすぎると、孔部の加工が困難になったり、加工後に孔部の極板を取り除くのが困難になるため、小さすぎないサイズであるのが好ましい。具体的には、正極貫通孔７４３ａ及び負極貫通孔７５３ａ（貫通孔７３０）は、径が０．８ｍｍ以上（開口面積が０．５ｍｍ２以上）であるのが好ましく、径が１ｍｍ以上（開口面積が０．７８５ｍｍ２以上）であるのがより好ましい。本実施の形態では、負極貫通孔７５３ａは、径（直径、以下同様）が０．８ｍｍ～３ｍｍ程度の円形状の貫通孔であり、正極貫通孔７４３ａは、径が１．５ｍｍ～５ｍｍ程度の円形状の貫通孔である。つまり、全ての正極貫通孔７４３ａ及び負極貫通孔７５３ａ（貫通孔７３０）が、開口面積が０．５ｍｍ２以上（径が０．８ｍｍ以上）である。 The smaller the size of the positive electrode through hole 743a and the negative electrode through hole 753a is, the better, from the viewpoint of suppressing a decrease in the capacity of the electricity storage element 10. However, if the size is too small, it may become difficult to process the hole, or the hole may be damaged after processing. It is preferable that the size is not too small, as it will be difficult to remove the electrode plate. Specifically, the positive electrode through hole 743a and the negative electrode through hole 753a (through hole 730) preferably have a diameter of 0.8 mm or more (opening area of 0.5 mm 2 or more), and a diameter of 1 mm or more (opening area of 0.5 mm 2 or more). is more preferably 0.785 mm 2 or more). In the present embodiment, the negative electrode through hole 753a is a circular through hole with a diameter of about 0.8 mm to 3 mm, and the positive electrode through hole 743a has a diameter of about 1.5 mm to 5 mm. It is a circular through hole. That is, all the positive electrode through holes 743a and the negative electrode through holes 753a (through holes 730) have an opening area of 0.5 mm 2 or more (diameter of 0.8 mm or more).
　正極貫通孔７４３ａ及び負極貫通孔７５３ａは、正極板７４０及び負極板７５０を巻回する前に、レーザによる加工（レーザ溶接、レーザ切断）等で形成することができる。予め貫通孔を形成した正極集電箔７４１に正極活物質層７４２を形成（塗工）することにより正極貫通孔７４３ａを形成してもよいし、正極集電箔７４１に正極活物質層７４２を形成（塗工）した後に正極集電箔７４１及び正極活物質層７４２を打ち抜くことにより正極貫通孔７４３ａを形成してもよい。負極貫通孔７５３ａについても同様である。正極貫通孔７４３ａ及び負極貫通孔７５３ａは、プレス加工で形成することもできるが、小さい孔を高速で加工するために、レーザによる加工で形成するのが好ましい。 The positive electrode through hole 743a and the negative electrode through hole 753a can be formed by laser processing (laser welding, laser cutting), etc. before winding the positive electrode plate 740 and the negative electrode plate 750. The positive electrode through holes 743a may be formed by forming (coating) the positive electrode active material layer 742 on the positive electrode current collector foil 741 in which through holes are formed in advance, or by forming the positive electrode active material layer 742 on the positive electrode current collector foil 741. The positive electrode through hole 743a may be formed by punching out the positive electrode current collector foil 741 and the positive electrode active material layer 742 after forming (coating). The same applies to the negative electrode through hole 753a. Although the positive electrode through hole 743a and the negative electrode through hole 753a can be formed by press working, it is preferable to form them by laser working in order to process small holes at high speed.
　本実施の形態では、正極板７４０と負極板７５０とが巻回されることで、複数の正極活物質部７４３と複数の負極活物質部７５３とが積層方向に積層される。複数の正極活物質部７４３と複数の負極活物質部７５３とは、平坦部７１２の平坦面と直交する方向（つまりＹ軸方向）に積層される。この際、複数の正極活物質部７４３及び複数の負極活物質部７５３には、当該積層方向に連続して配置される複数の正極貫通孔７４３ａ及び複数の負極貫通孔７５３ａが形成されている。つまり、正極板７４０及び負極板７５０には、貫通孔７３０としての複数の正極貫通孔７４３ａ及び複数の負極貫通孔７５３ａがそれぞれ形成されている。複数の正極貫通孔７４３ａ及び複数の負極貫通孔７５３ａは、貫通孔７３０の貫通方向から見て重なる位置に配置される。本実施の形態では、貫通孔７３０（複数の正極貫通孔７４３ａ及び複数の負極貫通孔７５３ａ）は、平坦部７１２に形成されているため、貫通孔７３０の貫通方向（複数の正極活物質部７４３及び複数の負極活物質部７５３の積層方向）は、Ｙ軸方向と定義できる。 In this embodiment, by winding the positive electrode plate 740 and the negative electrode plate 750, the plurality of positive electrode active material parts 743 and the plurality of negative electrode active material parts 753 are stacked in the stacking direction. The plurality of positive electrode active material parts 743 and the plurality of negative electrode active material parts 753 are stacked in a direction perpendicular to the flat surface of the flat part 712 (that is, in the Y-axis direction). At this time, a plurality of positive electrode through holes 743a and a plurality of negative electrode through holes 753a are formed in the plurality of positive electrode active material parts 743 and the plurality of negative electrode active material parts 753, which are arranged continuously in the stacking direction. That is, a plurality of positive electrode through holes 743a and a plurality of negative electrode through holes 753a as the through holes 730 are formed in the positive electrode plate 740 and the negative electrode plate 750, respectively. The plurality of positive electrode through holes 743a and the plurality of negative electrode through holes 753a are arranged at overlapping positions when viewed from the penetrating direction of the through hole 730. In this embodiment, since the through holes 730 (the plurality of positive electrode through holes 743a and the plurality of negative electrode through holes 753a) are formed in the flat part 712, the penetrating direction of the through holes 730 (the plurality of positive electrode active material parts 743 and the stacking direction of the plurality of negative electrode active material parts 753) can be defined as the Y-axis direction.
　複数の正極貫通孔７４３ａは、正極板７４０及び負極板７５０を巻回した後に位置が合うように、電極体７００における最内層（最内周）に位置する正極活物質部７４３から最外層（最外周）に位置する正極活物質部７４３に向かうほど間隔が大きくなるように形成されている。負極貫通孔７５３ａについても同様である。 The plurality of positive electrode through holes 743a are formed from the positive electrode active material portion 743 located at the innermost layer (innermost circumference) in the electrode body 700 to the outermost layer (the outermost layer) so that the positive electrode plate 740 and the negative electrode plate 750 are aligned after being wound. The intervals are formed such that the distance increases toward the positive electrode active material portion 743 located at the outer periphery. The same applies to the negative electrode through hole 753a.
　貫通孔７３０は、複数の正極活物質部７４３及び複数の負極活物質部７５３のうちの最外層（最外周）に配置される活物質部にも形成される。電極体７００の最外層（最外周）に負極活物質部７５３が配置される場合、最外の負極活物質部７５３にも負極貫通孔７５３ａが形成される。これにより、電極体７００において、複数の正極貫通孔７４３ａ及び複数の負極貫通孔７５３ａは、電極体７００における最外層（最外周）の活物質部から最内層（最内周）の活物質部まで連続して形成される。つまり、Ｙ軸方向から見て、複数の負極活物質部７５３に形成された全ての負極貫通孔７５３ａが、複数の正極活物質部７４３に形成された全ての正極貫通孔７４３ａの内方に配置される。 The through-hole 730 is also formed in the active material portion disposed in the outermost layer (outermost periphery) of the plurality of positive electrode active material portions 743 and the plurality of negative electrode active material portions 753. When the negative electrode active material portion 753 is arranged in the outermost layer (outermost periphery) of the electrode body 700, the negative electrode through hole 753a is also formed in the outermost negative electrode active material portion 753. Thereby, in the electrode body 700, the plurality of positive electrode through holes 743a and the plurality of negative electrode through holes 753a extend from the active material part of the outermost layer (outermost periphery) to the active material part of the innermost layer (innermost periphery) in the electrode body 700. Formed continuously. That is, when viewed from the Y-axis direction, all the negative electrode through holes 753a formed in the plurality of negative electrode active material parts 753 are arranged inside all the positive electrode through holes 743a formed in the plurality of positive electrode active material parts 743. be done.
　セパレータ７６１（セパレータ基材７６０ａ及び無機コート層７６０ｂ）には、貫通孔７３０としてのセパレータ貫通孔７６１ａが形成されている。セパレータ貫通孔７６１ａは、セパレータ７６１をＹ軸方向に貫通する円形状の貫通孔である。セパレータ７６２（セパレータ基材７６０ａ及び無機コート層７６０ｂ）には、貫通孔７３０としてのセパレータ貫通孔７６２ａが形成されている。セパレータ貫通孔７６２ａは、セパレータ７６２をＹ軸方向に貫通する円形状の貫通孔である。本実施の形態では、セパレータ貫通孔７６１ａ及び７６２ａは、同じ形状及び同じ大きさの貫通孔であるが、異なる形状または異なる大きさの貫通孔でもよい。 A separator through hole 761a as the through hole 730 is formed in the separator 761 (separator base material 760a and inorganic coat layer 760b). The separator through hole 761a is a circular through hole that penetrates the separator 761 in the Y-axis direction. A separator through hole 762a as the through hole 730 is formed in the separator 762 (separator base material 760a and inorganic coat layer 760b). The separator through hole 762a is a circular through hole that penetrates the separator 762 in the Y-axis direction. In this embodiment, the separator through holes 761a and 762a have the same shape and the same size, but they may have different shapes or different sizes.
　セパレータ貫通孔７６１ａ及び７６２ａは、貫通孔７３０の貫通方向（正極貫通孔７４３ａ及び負極貫通孔７５３ａの並び方向、Ｙ軸方向）から見て、少なくとも一部が正極貫通孔７４３ａ及び負極貫通孔７５３ａと重なる位置に配置される。本実施の形態では、Ｙ軸方向から見て、セパレータ貫通孔７６１ａ及び７６２ａは、全部が正極貫通孔７４３ａと重なり、一部が負極貫通孔７５３ａと重なる位置に配置される。つまり、Ｙ軸方向から見て、セパレータ貫通孔７６１ａ及び７６２ａは、正極貫通孔７４３ａよりも小さく、負極貫通孔７５３ａよりも大きな形状を有しており、正極貫通孔７４３ａの内方に配置され、かつ、負極貫通孔７５３ａを内方に配置する。セパレータ貫通孔７６１ａ及び７６２ａは、径が１ｍｍ～４ｍｍ程度の円形状の貫通孔である。 Separator through-holes 761a and 762a are at least partially connected to positive electrode through-hole 743a and negative electrode through-hole 753a when viewed from the through-hole direction of through-hole 730 (line direction of positive electrode through-hole 743a and negative electrode through-hole 753a, Y-axis direction). placed in overlapping positions. In this embodiment, separator through holes 761a and 762a are arranged at positions where all of them overlap with positive electrode through hole 743a and partially overlap with negative electrode through hole 753a, when viewed from the Y-axis direction. That is, when viewed from the Y-axis direction, the separator through holes 761a and 762a have a shape smaller than the positive electrode through hole 743a and larger than the negative electrode through hole 753a, and are arranged inside the positive electrode through hole 743a. Moreover, the negative electrode through hole 753a is arranged inward. The separator through holes 761a and 762a are circular through holes with a diameter of approximately 1 mm to 4 mm.
　セパレータ貫通孔７６１ａ及び７６２ａは、正極貫通孔７４３ａ及び負極貫通孔７５３ａと同様に、正極板７４０及び負極板７５０を巻回する前に、レーザによる加工またはプレス加工等で形成できる。セパレータ貫通孔７６１ａ及び７６２ａは、正極板７４０及び負極板７５０を巻回した後に、正極貫通孔７４３ａ及び負極貫通孔７５３ａの位置にレーザを照射することにより加工してもよい。この場合、セパレータ貫通孔７６１ａ及び７６２ａは、負極貫通孔７５３ａと同じサイズ、または、負極貫通孔７５３ａよりも小さなサイズの貫通孔であってもよい。 The separator through holes 761a and 762a can be formed by laser processing, press processing, etc. before winding the positive electrode plate 740 and the negative electrode plate 750, similarly to the positive electrode through hole 743a and the negative electrode through hole 753a. The separator through holes 761a and 762a may be processed by irradiating the positions of the positive electrode through hole 743a and the negative electrode through hole 753a with a laser after winding the positive electrode plate 740 and the negative electrode plate 750. In this case, the separator through holes 761a and 762a may be the same size as the negative electrode through hole 753a, or may be smaller in size than the negative electrode through hole 753a.
　これにより、セパレータ７６１及び７６２には、複数のセパレータ貫通孔７６１ａ及び７６２ａが、Ｙ軸方向に、複数の正極貫通孔７４３ａ及び複数の負極貫通孔７５３ａとともに連続して形成される。つまり、電極体７００における最外層（最外周）に位置するセパレータ７６１または７６２から最内層（最内周）に位置するセパレータ７６１または７６２までに亘って、複数のセパレータ貫通孔７６１ａ及び７６２ａが連続して形成される。これにより、電極体７００において、Ｙ軸方向から見て、セパレータ７６１及び７６２に形成された全てのセパレータ貫通孔７６１ａ及び７６２ａが、全ての正極貫通孔７４３ａの内方に配置される。 Thereby, a plurality of separator through-holes 761a and 762a are formed continuously in the Y-axis direction in the separators 761 and 762 along with a plurality of positive electrode through-holes 743a and a plurality of negative electrode through-holes 753a. That is, a plurality of separator through holes 761a and 762a are continuous from the separator 761 or 762 located at the outermost layer (outermost periphery) to the separator 761 or 762 located at the innermost layer (innermost periphery) in the electrode body 700. It is formed by As a result, in the electrode body 700, all separator through holes 761a and 762a formed in separators 761 and 762 are arranged inside all positive electrode through holes 743a when viewed from the Y-axis direction.
　［３ 実験結果の説明］
　以上の構成の電極体７００において、貫通孔７３０の数、電極体７００の長さ（Ｘ軸方向の長さ）、セパレータ７６０のコート層の有無、及び、コート層の種類を変化させて、電極体７００への電解液の浸透時間を測定した結果を、表２に示す。 [3 Explanation of experimental results]
In the electrode body 700 having the above configuration, the number of through holes 730, the length of the electrode body 700 (the length in the X-axis direction), the presence or absence of the coat layer of the separator 760, and the type of the coat layer are changed. Table 2 shows the results of measuring the permeation time of the electrolyte into the body 700.
　表２において、「貫通孔の数」は、図４に示した電極体７００に形成される貫通孔７３０の数（有無）であり、参考例１、比較例１、２、及び、実施例１～６では、貫通孔７３０は形成されておらず、実施例７、８では、電極体７００に１つの貫通孔７３０が形成されていた。「電極体の長さ」は、電極体７００のＸ軸方向（巻回軸方向）における一端縁から他端縁までの長さであり、参考例１では３００ｍｍ、比較例１、２及び実施例１～３では５００ｍｍ、実施例４～８では６００ｍｍであった。「コート層の有無」は、セパレータ７６０にコート層が設けられているか否かであり、参考例１及び比較例１では、セパレータ７６０にコート層が設けられておらず、比較例２及び実施例１～８では、セパレータ７６０にコート層が設けられていた。「コート層の種類」は、セパレータ７６０に設けられたコート層の種類であり、比較例２ではアラミド繊維、実施例１、４ではケイ酸アルミニウム、実施例２、５、７では硫酸バリウム、実施例３、６、８ではアルミナ（べーマイト）であった。「浸透面積」の欄には、表１に示したコート層の種類に対応する浸透面積の値を再掲している。「液浸透時間」の欄には、対象となる電極体７００に電解液を滴下してから、電極体７００の全体に電解液が浸透するまでに要した時間の実験結果を示している。表２において、参考例１、比較例１、２、及び、実施例１～８の全てのケースで、電極体７００の幅（Ｚ軸方向の長さ）は１３５．６ｍｍであり、電極体７００の厚み（Ｙ軸方向の長さ）は１９．４ｍｍであった。貫通孔７３０においては、負極貫通孔７５３ａの径は１ｍｍであり、正極貫通孔７４３ａの径は３ｍｍであり、セパレータ貫通孔７６１ａ及び７６２ａの径は２ｍｍであった。 In Table 2, "number of through holes" is the number (presence or absence) of through holes 730 formed in the electrode body 700 shown in FIG. In Examples 7 to 6, no through hole 730 was formed, and in Examples 7 and 8, one through hole 730 was formed in the electrode body 700. The "length of the electrode body" is the length from one end edge to the other edge of the electrode body 700 in the X-axis direction (winding axis direction), and is 300 mm in Reference Example 1, Comparative Examples 1 and 2, and Example In Examples 1 to 3, it was 500 mm, and in Examples 4 to 8, it was 600 mm. "Presence or absence of coat layer" refers to whether or not the separator 760 is provided with a coat layer. In Reference Example 1 and Comparative Example 1, the separator 760 is not provided with a coat layer, and in Comparative Example 2 and Example In Nos. 1 to 8, the separator 760 was provided with a coating layer. "Type of coating layer" is the type of coating layer provided on the separator 760, and includes aramid fiber in Comparative Example 2, aluminum silicate in Examples 1 and 4, barium sulfate in Examples 2, 5, and 7, and barium sulfate in Examples 2, 5, and 7. In Examples 3, 6, and 8, it was alumina (boehmite). In the "permeation area" column, the values of the permeation area corresponding to the types of coating layers shown in Table 1 are listed again. The "Liquid Penetration Time" column shows the experimental results of the time required for the electrolytic solution to penetrate into the entire electrode body 700 after dropping the electrolytic solution onto the target electrode body 700. In Table 2, in all cases of Reference Example 1, Comparative Examples 1 and 2, and Examples 1 to 8, the width of the electrode body 700 (length in the Z-axis direction) is 135.6 mm, and the width of the electrode body 700 is 135.6 mm. The thickness (length in the Y-axis direction) was 19.4 mm. In the through-hole 730, the diameter of the negative electrode through-hole 753a was 1 mm, the diameter of the positive electrode through-hole 743a was 3 mm, and the diameter of separator through-holes 761a and 762a was 2 mm.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　表２の参考例１に示すように、セパレータ７６０にコート層が設けられていない場合でも、電極体７００の長さが３００ｍｍであれば、比較的短時間（２時間以内）で電極体７００に電解液が浸透する。しかし、比較例１に示すように、セパレータ７６０にコート層が設けられていない場合に、電極体７００の長さが５００ｍｍになると、長時間（６時間）が経過しても電極体７００に電解液は浸透しない。比較例２に示すように、セパレータ７６０にコート層が設けられても、コート層が有機物質（有機繊維）であるアラミド繊維の場合には、電極体７００の長さが５００ｍｍでは、長時間（６時間）が経過しても電極体７００に電解液は浸透しない。 As shown in Reference Example 1 of Table 2, even if the separator 760 is not provided with a coating layer, if the length of the electrode body 700 is 300 mm, the electrode body 700 can be formed in a relatively short time (within 2 hours). The electrolyte penetrates. However, as shown in Comparative Example 1, when the separator 760 is not provided with a coating layer and the length of the electrode body 700 is 500 mm, the electrode body 700 is electrolyzed even after a long period of time (6 hours). Liquid does not penetrate. As shown in Comparative Example 2, even if the separator 760 is provided with a coating layer, if the coating layer is made of aramid fibers that are organic substances (organic fibers), if the length of the electrode body 700 is 500 mm, it will not work for a long time ( Even after 6 hours have passed, the electrolytic solution does not penetrate into the electrode body 700.
　これに対し、実施例１～３に示すように、セパレータ７６０に無機物質（無機粒子）を含む無機コート層７６０ｂ（ケイ酸アルミニウム、硫酸バリウム、または、アルミナ（べーマイト））を設けると、比較的短時間（２時間以内）で電極体７００に電解液が浸透する。このため、電極体７００の長さが５００ｍｍ以上であると、セパレータ７６０に無機コート層７６０ｂを設ける必要があることが分かる。無機コート層７６０ｂは、電解液が滴下されて３００秒目における電解液の浸透面積が８０ｍｍ２以上であるのが好ましい。比較例１、２及び実施例１～３において、電極体本体部７１０の長さ（Ｘ軸方向における一端縁から他端縁までの長さ）が５００ｍｍの場合でも同様の結果が得られる。 In contrast, when an inorganic coating layer 760b (aluminum silicate, barium sulfate, or alumina (boehmite)) containing an inorganic substance (inorganic particles) is provided on the separator 760, as shown in Examples 1 to 3, The electrolytic solution permeates into the electrode body 700 in a short period of time (within 2 hours). Therefore, it can be seen that when the length of the electrode body 700 is 500 mm or more, it is necessary to provide the inorganic coating layer 760b on the separator 760. It is preferable that the inorganic coat layer 760b has an electrolytic solution permeation area of 80 mm 2 or more at 300 seconds after the electrolytic solution is dropped. In Comparative Examples 1 and 2 and Examples 1 to 3, similar results are obtained even when the length of the electrode main body portion 710 (the length from one end edge to the other end edge in the X-axis direction) is 500 mm.
　実施例４に示すように、電極体７００の長さが６００ｍｍになると、無機コート層７６０ｂが無機粒子としてケイ酸アルミニウムを含む場合に、電極体７００への電解液の浸透時間が少し長く（４時間以内）なる。これに対し、実施例５、６に示すように、電極体７００の長さが６００ｍｍになっても、無機コート層７６０ｂが無機粒子として硫酸バリウムまたはアルミナ（べーマイト）を含む場合に、比較的短時間（２時間以内）で電極体７００に電解液が浸透する。このため、無機コート層７６０ｂは、無機粒子として、硫酸バリウム及びアルミナの少なくとも一方を含むのが好ましい。無機コート層７６０ｂは、電解液が滴下されて３００秒目における電解液の浸透面積が９０ｍｍ２以上（９５ｍｍ２）であるのが好ましい。実施例４～８において、電極体本体部７１０の長さ（Ｘ軸方向における一端縁から他端縁までの長さ）が６００ｍｍの場合でも同様の結果が得られる。 As shown in Example 4, when the length of the electrode body 700 is 600 mm, when the inorganic coat layer 760b contains aluminum silicate as inorganic particles, the time for the electrolyte to penetrate into the electrode body 700 is slightly longer (4 (within hours). On the other hand, as shown in Examples 5 and 6, even if the length of the electrode body 700 is 600 mm, when the inorganic coating layer 760b contains barium sulfate or alumina (boehmite) as inorganic particles, the The electrolytic solution permeates into the electrode body 700 in a short time (within 2 hours). Therefore, the inorganic coat layer 760b preferably contains at least one of barium sulfate and alumina as inorganic particles. The inorganic coat layer 760b preferably has an electrolytic solution permeation area of 90 mm 2 or more (95 mm 2 ) 300 seconds after the electrolytic solution is dropped. In Examples 4 to 8, similar results can be obtained even when the length of the electrode main body portion 710 (the length from one end edge to the other end edge in the X-axis direction) is 600 mm.
　実施例７、８に示すように、電極体７００に貫通孔７３０が形成されている場合には、さらに短時間（１時間以内）で電極体７００に電解液が浸透する。このため、電極体７００に貫通孔７３０が形成されるのがさらに好ましい。 As shown in Examples 7 and 8, when the through hole 730 is formed in the electrode body 700, the electrolytic solution permeates into the electrode body 700 in an even shorter time (within one hour). For this reason, it is more preferable that a through hole 730 be formed in the electrode body 700.
　電極体７００の長さ（電極体７００の巻回軸方向（Ｘ軸方向）における一端縁から他端縁までの長さ）が長いほど、電極体７００に電解液を浸透させるのが困難になるため、セパレータ７６０に無機コート層７６０ｂを形成することによる効果を享受できる。このため、電極体７００の長さは、５００ｍｍ以上であり、５００ｍｍよりも長いのが好ましく、５５０ｍｍ以上であるのがより好ましく、６００ｍｍ以上であるのがさらに好ましい。電極体本体部７１０の長さが、５００ｍｍ以上であり、５００ｍｍよりも長いのが好ましく、５５０ｍｍ以上であるのがより好ましく、６００ｍｍ以上であるのがさらに好ましい、としてもよい。 The longer the length of the electrode body 700 (the length from one end edge to the other edge of the electrode body 700 in the winding axis direction (X-axis direction)), the more difficult it becomes to infiltrate the electrolyte into the electrode body 700. Therefore, the effect of forming the inorganic coat layer 760b on the separator 760 can be enjoyed. Therefore, the length of the electrode body 700 is 500 mm or more, preferably longer than 500 mm, more preferably 550 mm or more, and even more preferably 600 mm or more. The length of the electrode main body portion 710 may be 500 mm or more, preferably longer than 500 mm, more preferably 550 mm or more, and even more preferably 600 mm or more.
　電解液の浸透を効果的に行う観点から、電極体７００に貫通孔７３０が形成されていない場合には、上記の電極体７００の長さ（または電極体本体部７１０の長さ）は、８００ｍｍ以下が好ましく、７００ｍｍ以下がさらに好ましい。電極体７００に貫通孔７３０が形成されている場合には、電極体７００の長さ（または電極体本体部７１０の長さ）は、１６００ｍｍ以下が好ましく、１４００ｍｍ以下がさらに好ましい。 From the viewpoint of effectively permeating the electrolyte, if the through hole 730 is not formed in the electrode body 700, the length of the electrode body 700 (or the length of the electrode body body part 710) is 800 mm. The length is preferably 700 mm or less, and more preferably 700 mm or less. When the through hole 730 is formed in the electrode body 700, the length of the electrode body 700 (or the length of the electrode body main body portion 710) is preferably 1600 mm or less, and more preferably 1400 mm or less.
　つまり、電極体７００に貫通孔７３０が形成されていない場合には、電極体７００の長さ（または電極体本体部７１０の長さ）は、５００ｍｍ以上８００ｍｍ以下であるのが好ましく、５００ｍｍよりも長く８００ｍｍ以下であるのがより好ましく、５５０ｍｍ以上７００ｍｍ以下であるのがさらに好ましく、６００ｍｍ以上７００ｍｍ以下であるのが特に好ましい。電極体７００に貫通孔７３０が形成されている場合には、電極体７００の長さ（または電極体本体部７１０の長さ）は、５００ｍｍ以上１６００ｍｍ以下であるのが好ましく、５００ｍｍよりも長く１６００ｍｍ以下であるのがより好ましく、５５０ｍｍ以上１４００ｍｍ以下であるのがさらに好ましく、６００ｍｍ以上１４００ｍｍ以下であるのが特に好ましい。 In other words, when the through hole 730 is not formed in the electrode body 700, the length of the electrode body 700 (or the length of the electrode body body part 710) is preferably 500 mm or more and 800 mm or less, and less than 500 mm. The length is more preferably 800 mm or less, further preferably 550 mm or more and 700 mm or less, and particularly preferably 600 mm or more and 700 mm or less. When the through hole 730 is formed in the electrode body 700, the length of the electrode body 700 (or the length of the electrode body part 710) is preferably 500 mm or more and 1600 mm or less, and is preferably longer than 500 mm and 1600 mm. It is more preferably the following, further preferably 550 mm or more and 1400 mm or less, particularly preferably 600 mm or more and 1400 mm or less.
　［４ 効果の説明］
　以上のように、本発明の実施の形態に係る蓄電素子１０は、巻回型の電極体７００を備え、容器１００のうちの電極体７００の巻回軸方向に延びる壁部（蓋体１２０）に電解液の注液部１３０が設けられている。このため、容器１００内への電解液の注液時に、電極体７００の外部から内部に電解液が浸透しにくく、電極体７００に電解液を浸透させるのが困難になる。特に、電極体７００が、巻回軸方向の長さが５００ｍｍ以上であるという、巻回軸方向の長さが比較的長い電極体であるため、電極体７００に電解液を浸透させるのがさらに困難になる。このため、セパレータ７６０を無機コート層７６０ｂでコートする。これにより、セパレータ７６０への電解液の浸透性（液濡れ性及び毛細管力）を向上させることができる。したがって、電極体７００への電解液の浸透時間を短くできるため、電極体７００に電解液を容易に浸透できる。電極体７００への電解液の浸透時間が長いと、負極板７５０の銅が溶出し、短絡が発生する懸念があるが、電極体７００への電解液の浸透時間を短くできることで、当該短絡の発生を抑制できる。 [4 Explanation of effects]
As described above, the power storage element 10 according to the embodiment of the present invention includes the wound electrode body 700, and the wall portion (lid body 120) extending in the direction of the winding axis of the electrode body 700 of the container 100. An electrolyte injection part 130 is provided at . Therefore, when pouring the electrolyte into the container 100, the electrolyte is difficult to penetrate from the outside to the inside of the electrode body 700, making it difficult to infiltrate the electrolyte into the electrode body 700. In particular, since the electrode body 700 has a relatively long length in the winding axis direction, that is, the length in the winding axis direction is 500 mm or more, it is more difficult to infiltrate the electrolyte into the electrode body 700. It becomes difficult. For this purpose, the separator 760 is coated with an inorganic coating layer 760b. Thereby, the permeability (liquid wettability and capillary force) of the electrolytic solution into the separator 760 can be improved. Therefore, the time for the electrolytic solution to penetrate into the electrode body 700 can be shortened, so that the electrolytic solution can easily penetrate into the electrode body 700. If the electrolytic solution penetrates into the electrode body 700 for a long time, there is a concern that the copper of the negative electrode plate 750 will be eluted and a short circuit will occur. The occurrence can be suppressed.
　セパレータ７６０にコートされる無機コート層７６０ｂは、電解液が滴下されて３００秒目における電解液の浸透面積が８０ｍｍ２以上という、電解液が比較的短時間で比較的広い面積に浸透可能な無機コート層７６０ｂである。このように、電解液が比較的短時間で比較的広い面積に浸透可能な無機コート層７６０ｂを用いることで、セパレータ７６０への電解液の浸透性を向上できる。電極体７００への電解液の浸透に６時間以上かかると、負極板７５０の銅が溶出し、短絡が発生する懸念があるが、当該無機コート層７６０ｂを用いた場合には、４時間以内で浸透できる実験結果を得られたため、当該短絡の発生を抑制できる。 The inorganic coating layer 760b coated on the separator 760 is an inorganic inorganic material that allows the electrolyte to penetrate a relatively wide area in a relatively short period of time. This is a coat layer 760b. In this way, by using the inorganic coating layer 760b that allows the electrolyte to permeate into a relatively wide area in a relatively short time, the permeability of the electrolyte into the separator 760 can be improved. If it takes more than 6 hours for the electrolyte to penetrate into the electrode body 700, there is a concern that the copper of the negative electrode plate 750 will be eluted and a short circuit will occur. Since we obtained experimental results that allow penetration, the occurrence of the short circuit can be suppressed.
　本願発明者は、硫酸バリウム及びアルミナの少なくとも一方を含む無機コート層７６０ｂに電解液を滴下した場合、電解液は、他の無機粒子（ケイ酸アルミニウム等）と比べて、比較的短時間で、無機コート層７６０ｂの比較的広い面積に浸透できることを見出した。当該無機コート層７６０ｂを用いた場合には、２時間以内で電極体７００に電解液を浸透できる実験結果を得られた。このため、セパレータ７６０にコートされる無機コート層７６０ｂに、硫酸バリウム及びアルミナの少なくとも一方を含ませることで、セパレータ７６０への電解液の浸透性を向上できる。 The inventor of the present application has discovered that when an electrolytic solution is dropped onto an inorganic coat layer 760b containing at least one of barium sulfate and alumina, the electrolytic solution is removed in a relatively short time compared to other inorganic particles (such as aluminum silicate). It has been found that it can penetrate into a relatively wide area of the inorganic coat layer 760b. When the inorganic coating layer 760b was used, an experimental result was obtained in which the electrolytic solution could penetrate into the electrode body 700 within 2 hours. Therefore, by including at least one of barium sulfate and alumina in the inorganic coating layer 760b coated on the separator 760, the permeability of the electrolyte into the separator 760 can be improved.
　巻回軸方向における長さが６００ｍｍ以上という長い電極体７００を用いた場合には、電極体７００に電解液を浸透させるのがさらに困難になる。これに対し、本願発明者は、当該電極体７００を用いた場合でも、セパレータ７６０を無機コート層７６０ｂでコートすることで、電極体７００に電解液を容易に浸透できることを見出した。このため、このような長い電極体７００を用いた場合に、本願の構成を採用することによる効果が高い。このように、電極体７００の長さが長い方が本願の構成を採用することによる効果が高いため、電極体７００の長さは、５００ｍｍ以上であり、５００ｍｍよりも長いのが好ましく、５５０ｍｍ以上であるのがより好ましく、６００ｍｍ以上であるのがさらに好ましい。 When using a long electrode body 700 with a length of 600 mm or more in the direction of the winding axis, it becomes more difficult to infiltrate the electrolyte into the electrode body 700. On the other hand, the inventor of the present invention has found that even when the electrode body 700 is used, the electrolytic solution can be easily penetrated into the electrode body 700 by coating the separator 760 with the inorganic coating layer 760b. Therefore, when such a long electrode body 700 is used, the effect of adopting the configuration of the present application is high. As described above, the longer the length of the electrode body 700, the higher the effect of adopting the configuration of the present application, so the length of the electrode body 700 is 500 mm or more, preferably longer than 500 mm, and 550 mm or more. More preferably, the length is 600 mm or more.
　電極体７００の極板に貫通孔７３０を形成することで、無機コート層７６０ｂによって電解液の浸透性が向上されたセパレータ７６０から、貫通孔７３０を介して電極体７００に電解液を浸透できる。貫通孔７３０を電極体７００の下部に形成することで、貫通孔７３０を、容器１００の底壁部１１３に近い位置に配置できるため、容器１００の下部に溜まった電解液を電極体７００に浸透させやすい。特に、容器１００内の電解液の量が少ない場合（寿命末期の場合等）でも、容器１００の下部に溜まった電解液を電極体７００に浸透させることができる。 By forming the through-hole 730 in the electrode plate of the electrode body 700, the electrolyte can permeate into the electrode body 700 through the through-hole 730 from the separator 760 whose permeability for the electrolyte has been improved by the inorganic coating layer 760b. By forming the through hole 730 at the bottom of the electrode body 700, the through hole 730 can be placed close to the bottom wall 113 of the container 100, so that the electrolytic solution collected at the bottom of the container 100 can permeate into the electrode body 700. Easy to do. In particular, even when the amount of electrolytic solution in container 100 is small (such as when the container is at the end of its life), the electrolytic solution accumulated in the lower part of container 100 can be permeated into electrode body 700.
　貫通孔７３０を電極体７００（の下部）に形成することで、貫通孔７３０に電解液を溜めておくこともできるため、充放電時の電解液の還元（ＳＥＩ被膜形成）によって電解液が消費されて電解液が不足するのを抑制できる。ガス排出弁１４０から蓄電素子１０外部にガスが排出される際に、貫通孔７３０を介して電極体７００内のガスを容易に排出できる。貫通孔７３０を電極体７００の電極体本体部７１０の平坦部７１２に形成することで、貫通孔７３０を形成しやすい。 By forming the through hole 730 in (the lower part of) the electrode body 700, the electrolytic solution can be stored in the through hole 730, so that the electrolytic solution is not consumed due to reduction of the electrolytic solution (SEI film formation) during charging and discharging. This can prevent the electrolyte from running out. When the gas is discharged from the gas discharge valve 140 to the outside of the power storage element 10 , the gas inside the electrode body 700 can be easily discharged through the through hole 730 . By forming the through hole 730 in the flat portion 712 of the electrode body main body portion 710 of the electrode body 700, the through hole 730 can be easily formed.
　［５ 変形例の説明］
　以上、本発明の実施の形態に係る蓄電素子１０について説明したが、本発明は、上記実施の形態には限定されない。今回開示された実施の形態は、全ての点で例示であり、本発明の範囲には、特許請求の範囲と均等の意味及び範囲内での全ての変更が含まれる。 [5 Description of modification]
Although the power storage element 10 according to the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. The embodiments disclosed this time are illustrative in all respects, and the scope of the present invention includes all changes within the meaning and range equivalent to the scope of the claims.
　（変形例１）
　上記実施の形態において、電極体７００の貫通孔７３０の正極貫通孔７４３ａの周囲の正極活物質層７４２に、樹脂を塗布したり、樹脂をしみこませたりしてもよい。図６は、本実施の形態の変形例１に係る電極体７００の貫通孔７３０の構成を示す正面図及び断面図である。図６は、図５に対応する図である。 (Modification 1)
In the embodiment described above, resin may be applied to or impregnated into the positive electrode active material layer 742 around the positive electrode through hole 743a of the through hole 730 of the electrode body 700. FIG. 6 is a front view and a cross-sectional view showing the configuration of a through hole 730 of an electrode body 700 according to Modification 1 of the present embodiment. FIG. 6 is a diagram corresponding to FIG. 5.
　図６に示すように、本変形例では、正極貫通孔７４３ａは、Ｙ軸方向から見て、負極貫通孔７５３ａと同じサイズに形成されており、正極貫通孔７４３ａの周囲の正極活物質層７４２に絶縁部７４４が設けられている。つまり、正極貫通孔７４３ａの周囲に配置され、外周７４４ａのサイズが負極貫通孔７５３ａよりも大きい絶縁部７４４を、正極板７４０は有している。本変形例のその他の構成については、上記実施の形態と同様であるため、詳細な説明は省略する。 As shown in FIG. 6, in this modification, the positive electrode through hole 743a is formed to have the same size as the negative electrode through hole 753a when viewed from the Y-axis direction, and the positive electrode active material layer 742 around the positive electrode through hole 743a An insulating section 744 is provided in the. That is, the positive electrode plate 740 has an insulating part 744 that is arranged around the positive electrode through hole 743a and has an outer periphery 744a larger in size than the negative electrode through hole 753a. The other configurations of this modification are the same as those of the above embodiment, so detailed explanations will be omitted.
　絶縁部７４４は、正極貫通孔７４３ａの周囲の正極活物質層７４２に、樹脂等の絶縁部材を溶かし込むことによりマスキングされた部位である。つまり、絶縁部７４４は、正極活物質層７４２における他の部位よりも樹脂等の絶縁材料の含有率が大きい部位である。絶縁部７４４は、紫外線を照射することにより硬化するＵＶ硬化性のエポキシ樹脂を正極活物質層７４２に溶かし込んだり、加熱により溶融したＰＥ、ＰＰ等のポリオレフィン樹脂を溶かし込んだりして、形成できる。絶縁部７４４は、樹脂成型金型を押し当て、樹脂を流し込むことで容易に形成できる。絶縁部７４４は、あらかじめ正極貫通孔７４３ａの周囲を覆う形状に成形した結着性変性ポリオレフィンシート（ポリオレフィンに極性基を導入し、異種材料との接着性を付与したシート部材）を、正極貫通孔７４３ａの周囲の正極活物質層７４２に配置し、加熱し、溶融してしみこませてもよい。正極活物質層７４２に当該樹脂等の絶縁材料がしみこむことで、正極活物質層７４２が失活する（放電容量が小さくなる）。 The insulating portion 744 is a portion masked by melting an insulating member such as resin into the positive electrode active material layer 742 around the positive electrode through hole 743a. In other words, the insulating portion 744 is a portion having a higher content of an insulating material such as resin than other portions of the positive electrode active material layer 742. The insulating portion 744 can be formed by dissolving a UV-curable epoxy resin that is cured by irradiation with ultraviolet rays into the positive electrode active material layer 742, or by dissolving a polyolefin resin such as PE or PP melted by heating. . The insulating portion 744 can be easily formed by pressing a resin molding die and pouring the resin. The insulating part 744 is made of a binder-modified polyolefin sheet (a sheet member in which polar groups are introduced into polyolefin to give it adhesive properties with different materials) that has been previously formed into a shape that covers the periphery of the positive electrode through hole 743a. It may be placed in the positive electrode active material layer 742 around the electrode 743a, heated, melted, and impregnated. When the insulating material such as the resin permeates into the positive electrode active material layer 742, the positive electrode active material layer 742 is deactivated (discharge capacity becomes smaller).
　以上のように、本変形例に係る蓄電素子１０によれば、上記実施の形態と同様の効果を奏することができる。特に、正極板７４０及び負極板７５０に正極貫通孔７４３ａ及び負極貫通孔７５３ａが形成される場合、正極貫通孔７４３ａ及び負極貫通孔７５３ａの大きさに拘らず、負極活物質層７５２が正極活物質層７４２を覆う構成となるのが好ましい。このため、正極板７４０における正極貫通孔７４３ａの周囲に、外周７４４ａのサイズが負極貫通孔７５３ａよりも大きい絶縁部７４４を配置する。これにより、正極貫通孔７４３ａが負極貫通孔７５３ａと同じ大きさまたは負極貫通孔７５３ａよりも小さい（本変形例では、同じ大きさ）場合でも、負極活物質層７５２で正極活物質層７４２を覆うことができる。つまり、正極貫通孔７４３ａの周囲の正極活物質層７４２を失活させることで、活性な正極活物質層７４２を負極活物質層７５２で覆うことができ、負極板７５０へのリチウム電析を抑制できる。 As described above, the power storage element 10 according to this modification can achieve the same effects as the above embodiment. In particular, when the positive electrode through hole 743a and the negative electrode through hole 753a are formed in the positive electrode plate 740 and the negative electrode plate 750, the negative electrode active material layer 752 is made of positive electrode active material regardless of the size of the positive electrode through hole 743a and the negative electrode through hole 753a. Preferably, the structure covers layer 742. For this reason, an insulating part 744 having an outer periphery 744a larger in size than the negative electrode through hole 753a is arranged around the positive electrode through hole 743a in the positive electrode plate 740. With this, even if the positive electrode through hole 743a is the same size as the negative electrode through hole 753a or smaller than the negative electrode through hole 753a (in this modification, the same size), the negative electrode active material layer 752 covers the positive electrode active material layer 742. be able to. In other words, by deactivating the positive electrode active material layer 742 around the positive electrode through hole 743a, the active positive electrode active material layer 742 can be covered with the negative electrode active material layer 752, and lithium electrodeposition onto the negative electrode plate 750 is suppressed. can.
　本変形例において、正極貫通孔７４３ａは、Ｙ軸方向から見て、負極貫通孔７５３ａよりも小さくてもよいし大きくてもよく、絶縁部７４４の外周７４４ａのサイズが負極貫通孔７５３ａよりも大きければよい。セパレータ貫通孔７６１ａ及び７６２ａは、負極貫通孔７５３ａ及び正極貫通孔７４３ａと同じサイズ、または、負極貫通孔７５３ａ及び正極貫通孔７４３ａよりも小さなサイズでもよい。 In this modification, the positive electrode through hole 743a may be smaller or larger than the negative electrode through hole 753a when viewed from the Y-axis direction, and the size of the outer periphery 744a of the insulating portion 744 may be larger than the negative electrode through hole 753a. Bye. The separator through holes 761a and 762a may have the same size as the negative electrode through hole 753a and the positive electrode through hole 743a, or may have a smaller size than the negative electrode through hole 753a and the positive electrode through hole 743a.
　（その他の変形例）
　上記実施の形態では、注液部１３０は、容器１００の蓋体１２０に配置されていることとしたが、容器本体１１０に配置されていてもよい。注液部１３０は、容器本体１１０の長側壁部１１１に配置されていてもよいし、底壁部１１３に配置されていてもよい。つまり、注液部１３０は、電極体７００の巻回軸方向に延びる壁部に配置されていればよい。ガス排出弁１４０は、蓋体１２０に配置されていることとしたが、容器本体１１０のいずれかの壁部に配置されていてもよい。 (Other variations)
In the embodiment described above, the liquid injection part 130 is arranged on the lid 120 of the container 100, but it may be arranged on the container main body 110. The liquid injection part 130 may be arranged on the long side wall part 111 of the container main body 110, or may be arranged on the bottom wall part 113. In other words, the liquid injection part 130 may be disposed on a wall extending in the direction of the winding axis of the electrode body 700. Although the gas exhaust valve 140 is arranged on the lid 120, it may be arranged on any wall of the container body 110.
　上記実施の形態では、セパレータ７６０の無機コート層７６０ｂに含まれる無機粒子として、ケイ酸アルミニウム、硫酸バリウム、及び、アルミナ（べーマイト）を例示したが、これには限定されない。電極体７００への電解液の浸透時間を短くできるのであれば、無機コート層７６０ｂは、どのような無機粒子を含んでいてもよい。 In the above embodiment, aluminum silicate, barium sulfate, and alumina (boehmite) are exemplified as inorganic particles contained in the inorganic coat layer 760b of the separator 760, but the inorganic particles are not limited thereto. The inorganic coat layer 760b may contain any inorganic particles as long as the time for the electrolyte to penetrate into the electrode body 700 can be shortened.
　上記実施の形態では、セパレータ７６０の無機コート層７６０ｂは、電解液が滴下されて３００秒目における電解液の浸透面積が８０ｍｍ２以上であることとしたが、これには限定されない。電極体７００への電解液の浸透時間を短くできるのであれば、当該浸透面積は８０ｍｍ２よりも小さくてもよい。 In the above embodiment, the inorganic coat layer 760b of the separator 760 has an electrolyte permeation area of 80 mm 2 or more at 300 seconds after the electrolyte is dropped, but the invention is not limited to this. The permeation area may be smaller than 80 mm 2 as long as the time for permeation of the electrolyte into the electrode body 700 can be shortened.
　上記実施の形態において、セパレータ７６１及び７６２は、同じ材質で形成されてもよいし、異なる材質で形成されてもよい。つまり、セパレータ７６１のセパレータ基材７６０ａとセパレータ７６２のセパレータ基材７６０ａとは、同じ材質で形成されてもよいし、異なる材質で形成されてもよい。セパレータ７６１の無機コート層７６０ｂとセパレータ７６２の無機コート層７６０ｂとは、同じ無機粒子を含んでもよいし、異なる無機粒子を含んでもよい。 In the embodiments described above, separators 761 and 762 may be made of the same material or may be made of different materials. That is, the separator base material 760a of the separator 761 and the separator base material 760a of the separator 762 may be formed of the same material or may be formed of different materials. The inorganic coat layer 760b of the separator 761 and the inorganic coat layer 760b of the separator 762 may contain the same inorganic particles or may contain different inorganic particles.
　上記実施の形態では、電極体７００の貫通孔７３０は、電極体本体部７１０のＹ軸マイナス方向の平坦部７１２におけるＸ軸方向中央部かつＺ軸マイナス方向端部に形成されることとしたが、電極体７００のどの位置に形成されてもよい。貫通孔７３０は、当該平坦部７１２におけるＸ軸方向端部に形成されてもよいし、Ｚ軸方向中央部またはＺ軸プラス方向端部に形成されてもよい。貫通孔７３０は、電極体本体部７１０のＹ軸プラス方向の平坦部７１２に形成されてもよいし、電極体本体部７１０の湾曲部７１１に形成されてもよい。貫通孔７３０を湾曲部７１１に形成すると、貫通孔７３０が容器１００によって塞がれにくいため、電極体７００に電解液を浸透させやすくなる。 In the embodiment described above, the through hole 730 of the electrode body 700 is formed at the center in the X-axis direction and at the end in the negative Z-axis direction of the flat portion 712 in the Y-axis minus direction of the electrode body body 710. , may be formed at any position on the electrode body 700. The through hole 730 may be formed at the end of the flat portion 712 in the X-axis direction, the center in the Z-axis direction, or the end in the positive Z-axis direction. The through hole 730 may be formed in the flat portion 712 of the electrode body portion 710 in the positive Y-axis direction, or may be formed in the curved portion 711 of the electrode body portion 710. When the through hole 730 is formed in the curved portion 711, the through hole 730 is less likely to be blocked by the container 100, making it easier for the electrolyte to penetrate into the electrode body 700.
　上記実施の形態では、電極体７００には１つの貫通孔７３０が形成されていることとしたが、２つ以上の貫通孔７３０が形成されてもよい。貫通孔７３０の配置位置は特に限定されないが、電極体７００のＸ軸方向の長さがさらに長くなった場合には、電極体７００のＸ軸方向における異なる位置に複数の貫通孔７３０を形成するのが好ましい。電極体７００のＺ軸方向の長さが長くなった場合には、電極体７００のＺ軸方向における異なる位置に複数の貫通孔７３０を形成するのが好ましい。これらにより、電極体７００に電解液を容易に浸透できる。 In the above embodiment, one through hole 730 is formed in the electrode body 700, but two or more through holes 730 may be formed. The arrangement position of the through-hole 730 is not particularly limited, but if the length of the electrode body 700 in the X-axis direction becomes longer, a plurality of through-holes 730 are formed at different positions in the X-axis direction of the electrode body 700. is preferable. When the length of the electrode body 700 in the Z-axis direction becomes long, it is preferable to form a plurality of through holes 730 at different positions in the Z-axis direction of the electrode body 700. These allow the electrolytic solution to easily penetrate into the electrode body 700.
　電極体７００に貫通孔７３０を形成することで、電極体７００の有効電極面積が減少し、蓄電素子１０の容量が低下する（容量ロスが生じる）。電極体７００の有効電極面積とは、極板における活物質層が配置される領域（具体的には、正極板７４０における正極活物質層７４２が配置される領域）の面積である。この有効電極面積が減少する割合を、開口面積割合と称す。開口面積割合は、極板における活物質層が配置される領域の面積に対する、領域内に位置する１以上の貫通孔７３０の開口面積の合計の割合である。具体的には、開口面積割合は、正極板７４０における正極活物質層７４２が配置される領域の面積に対する、当該領域内に位置する正極貫通孔７４３ａの開口面積の合計の割合である。詳細には、開口面積割合は、電極体７００の巻回状態を展開して正極板７４０を広げ、正極板７４０を平面視した場合に、正極活物質層７４２が配置される領域の面積に対する、当該領域内に位置する正極貫通孔７４３ａの開口面積の合計の割合である。 By forming the through holes 730 in the electrode body 700, the effective electrode area of the electrode body 700 is reduced, and the capacity of the energy storage element 10 is reduced (capacity loss occurs). The effective electrode area of the electrode body 700 is the area of the region in the electrode plate where the active material layer is arranged (specifically, the region in the positive electrode plate 740 where the positive electrode active material layer 742 is arranged). The rate at which this effective electrode area is reduced is referred to as the opening area ratio. The opening area ratio is the ratio of the total opening area of one or more through holes 730 located within the region to the area of the region in the electrode plate where the active material layer is arranged. Specifically, the opening area ratio is the ratio of the total opening area of the positive electrode through holes 743a located within the region to the area of the region in the positive electrode plate 740 where the positive electrode active material layer 742 is arranged. In detail, the opening area ratio is the ratio of the total opening area of the positive electrode through holes 743a located in the region where the positive electrode active material layer 742 is disposed to the area of the region when the wound state of the electrode body 700 is unfolded to spread the positive electrode plate 740 and the positive electrode plate 740 is viewed in a plan view.
　電極体７００に２つ以上の貫通孔７３０が形成される場合、開口面積割合は、蓄電素子１０の容量の低下を抑制する観点から、３％以下であるのが好ましく、０．１％よりも小さいのがより好ましく、０．０５％よりも小さいのがさらに好ましい。上述の通り、開口面積割合は、貫通孔７３０による蓄電素子１０の容量低下量（容量ロス）の割合であるとも言える。このため、蓄電素子１０の容量低下量（容量ロス）の割合も、３％以下であるのが好ましく、０．１％よりも小さいのがより好ましく、０．０５％よりも小さいのがさらに好ましい。 When two or more through holes 730 are formed in the electrode body 700, the opening area ratio is preferably 3% or less, and more than 0.1%, from the viewpoint of suppressing a decrease in the capacity of the power storage element 10. It is more preferably small, and even more preferably smaller than 0.05%. As described above, the opening area ratio can also be said to be the ratio of the amount of capacity reduction (capacity loss) of the power storage element 10 due to the through hole 730. Therefore, the rate of capacity reduction (capacity loss) of the electricity storage element 10 is also preferably 3% or less, more preferably less than 0.1%, and even more preferably less than 0.05%. .
　上記実施の形態では、積層された複数の正極活物質部７４３及び複数の負極活物質部７５３の全てに、貫通孔７３０（正極貫通孔７４３ａ及び負極貫通孔７５３ａ）が形成されることとしたが、これには限定されない。いずれかの正極活物質部７４３またはいずれかの負極活物質部７５３には、貫通孔７３０が形成されていなくてもよい。セパレータ７６１、７６２についても同様に、電極体７００における最外層のセパレータ７６１、７６２から最内層のセパレータ７６１、７６２までの間に、貫通孔７３０（セパレータ貫通孔７６１ａ、７６２ａ）が形成されていない箇所があってもよい。 In the embodiment described above, the through holes 730 (the positive electrode through holes 743a and the negative electrode through holes 753a) are formed in all of the plurality of stacked positive electrode active material parts 743 and the plurality of negative electrode active material parts 753. , but not limited to. The through hole 730 may not be formed in any of the positive electrode active material portions 743 or any of the negative electrode active material portions 753. Similarly, regarding the separators 761 and 762, the portions where the through holes 730 (separator through holes 761a and 762a) are not formed between the outermost layer separators 761 and 762 and the innermost layer separators 761 and 762 in the electrode body 700 There may be.
　上記実施の形態では、正極活物質部７４３及び負極活物質部７５３の双方に、貫通孔７３０（正極貫通孔７４３ａ及び負極貫通孔７５３ａ）が形成されることとしたが、これには限定されない。正極活物質部７４３及び負極活物質部７５３のいずれか一方にしか、貫通孔７３０が形成されていなくてもよい。セパレータ７６１、７６２についても同様に、セパレータ７６１及び７６２のいずれか一方にしか貫通孔７３０（セパレータ貫通孔７６１ａ、７６２ａ）が形成されなくてもよいし、セパレータ７６１及び７６２の双方に貫通孔７３０が形成されなくてもよい。電極体７００に貫通孔７３０が形成されない構成でもよい。 In the above embodiment, the through holes 730 (the positive electrode through holes 743a and the negative electrode through holes 753a) are formed in both the positive electrode active material portion 743 and the negative electrode active material portion 753, but the present invention is not limited thereto. The through hole 730 may be formed only in either one of the positive electrode active material portion 743 and the negative electrode active material portion 753. Similarly, for the separators 761 and 762, the through hole 730 (separator through holes 761a, 762a) may be formed only in either one of the separators 761 and 762, or the through hole 730 may be formed in both the separators 761 and 762. It does not have to be formed. A structure in which the through hole 730 is not formed in the electrode body 700 may also be used.
　上記実施の形態では、負極貫通孔７５３ａは、Ｙ軸方向から見て、正極貫通孔７４３ａよりも小さな形状を有しており、正極貫通孔７４３ａの内方に配置されることとしたが、これには限定されない。負極貫通孔７５３ａは、正極貫通孔７４３ａの内方に配置されず、少しずれた位置に配置されてもよいし、正極貫通孔７４３ａとは重ならない位置に配置されてもよく、正極貫通孔７４３ａ及び負極貫通孔７５３ａの形状、大小関係及び配置位置は、特に限定されない。ただし、この場合でも、正極活物質層７４２（活性な正極活物質層７４２）に、負極活物質層７５２と対向しない部分が存在しないのが好ましい。つまり、正極活物質層７４２（活性な正極活物質層７４２）の全てが、負極活物質層７５２と対向することが好ましい。セパレータ貫通孔７６１ａ及び７６２ａについても同様に、正極貫通孔７４３ａ及び負極貫通孔７５３ａから少しずれた位置に配置されてもよいし、正極貫通孔７４３ａ及び負極貫通孔７５３ａとは重ならない位置に配置されてもよい。つまり、セパレータ貫通孔７６１ａ及び７６２ａと正極貫通孔７４３ａ及び負極貫通孔７５３ａとの形状、大小関係及び配置位置は、特に限定されない。ただし、この場合でも、正極活物質層７４２（活性な正極活物質層７４２）の全てが、セパレータ７６１及び７６２と対向することが好ましい。 In the above embodiment, the negative electrode through hole 753a has a smaller shape than the positive electrode through hole 743a when viewed from the Y-axis direction, and is arranged inside the positive electrode through hole 743a. is not limited to. The negative electrode through hole 753a may not be placed inside the positive electrode through hole 743a, but may be placed at a position slightly shifted from the positive electrode through hole 743a, or may be placed at a position that does not overlap with the positive electrode through hole 743a. The shape, size relationship, and arrangement position of the negative electrode through hole 753a are not particularly limited. However, even in this case, it is preferable that there is no portion of the positive electrode active material layer 742 (active positive electrode active material layer 742) that does not face the negative electrode active material layer 752. That is, it is preferable that all of the positive electrode active material layer 742 (active positive electrode active material layer 742) face the negative electrode active material layer 752. Similarly, separator through holes 761a and 762a may be arranged at positions slightly shifted from positive electrode through holes 743a and negative electrode through holes 753a, or may be arranged at positions that do not overlap with positive electrode through holes 743a and negative electrode through holes 753a. You can. That is, the shape, size relationship, and arrangement position of the separator through holes 761a and 762a, the positive electrode through hole 743a, and the negative electrode through hole 753a are not particularly limited. However, even in this case, it is preferable that all of the positive electrode active material layer 742 (active positive electrode active material layer 742) face the separators 761 and 762.
　上記実施の形態では、一対の端子３００は、ともに、容器１００からＺ軸プラス方向に突出して配置されていることとしたが、端子３００の突出方向は、特に限定されない。一対の端子３００は、容器１００からＸ軸方向のいずれか一方に突出していてもよいし、Ｘ軸方向の双方に突出していてもよい。 In the above embodiment, both of the pair of terminals 300 are arranged to protrude from the container 100 in the positive Z-axis direction, but the direction in which the terminals 300 protrude is not particularly limited. The pair of terminals 300 may protrude from the container 100 in either one of the X-axis directions, or may protrude in both X-axis directions.
　上記実施の形態では、電極体７００は、湾曲部７１１と平坦部７１２とを有する長円柱形状（扁平形状）であるとしたが、円柱形状または楕円柱形状等でもよく、巻回型の電極体であればその形状は特に限定されない。電極体７００において、端部７２０は、電極体本体部７１０の一部から突出するタブ部（極板の複数のタブが積層された部位）であってもよい。電極体７００は、Ｘ軸方向に長尺な形状でなくてもよい。 In the above embodiment, the electrode body 700 has an elongated cylindrical shape (flat shape) having a curved part 711 and a flat part 712, but it may also have a cylindrical shape, an elliptical cylindrical shape, etc., or a wound type electrode body. If so, its shape is not particularly limited. In the electrode body 700, the end portion 720 may be a tab portion (a portion where a plurality of tabs of the electrode plate are stacked) projecting from a part of the electrode body main body portion 710. The electrode body 700 does not have to have a long shape in the X-axis direction.
　上記実施の形態及びその変形例に含まれる構成要素を任意に組み合わせて構築される形態も、本発明の範囲内に含まれる。 　Any combination of the components included in the above embodiment and its variations is also included within the scope of the present invention.
　本発明は、リチウムイオン二次電池などの蓄電素子に適用できる。 The present invention can be applied to power storage elements such as lithium ion secondary batteries.
　１０ 蓄電素子
　１００ 容器
　１１０ 容器本体
　１２０ 蓋体
　１３０ 注液部
　１３１ 注液口
　１３２ 注液栓
　１４０ ガス排出弁
　３００ 端子
　６００ 集電体
　７００ 電極体
　７１０ 電極体本体部
　７１１ 湾曲部
　７１２ 平坦部
　７２０ 端部
　７３０ 貫通孔
　７４０ 正極板
　７４１ 正極集電箔
　７４２ 正極活物質層
　７４３ 正極活物質部
　７４３ａ 正極貫通孔
　７４４ 絶縁部
　７４４ａ 外周
　７５０ 負極板
　７５１ 負極集電箔
　７５２ 負極活物質層
　７５３ 負極活物質部
　７５３ａ 負極貫通孔
　７６０、７６１、７６２ セパレータ
　７６０ａ セパレータ基材
　７６０ｂ 無機コート層
　７６１ａ、７６２ａ セパレータ貫通孔 10 Energy storage element 100 Container 110 Container body 120 Lid 130 Liquid injection part 131 Liquid injection port 132 Liquid injection plug 140 Gas discharge valve 300 Terminal 600 Current collector 700 Electrode body 710 Electrode body main body part 711 Curved part 712 Flat part 720 End part 730 Through hole 740 Positive electrode plate 741 Positive electrode current collector foil 742 Positive electrode active material layer 743 Positive electrode active material portion 743a Positive electrode through hole 744 Insulating portion 744a Outer periphery 750 Negative electrode plate 751 Negative electrode current collector foil 752 Negative electrode active material layer 753 Negative electrode active material portion 753a Negative electrode Through holes 760, 761, 762 Separator 760a Separator base material 760b Inorganic coat layer 761a, 762a Separator through holes

Claims (5)

  1. 　極板及びセパレータが巻回された電極体と、電解液と、前記電極体及び前記電解液が収容される容器と、を備え、
    前記容器は、前記電極体の巻回軸方向に延びる壁部に、前記電解液の注液部を有し、前記電極体は、前記巻回軸方向における長さが５００ｍｍ以上であり、
    前記セパレータは、基材と、前記基材にコートされた無機粒子を含む無機コート層と、を有している
    蓄電素子。     An electrode body having an electrode plate and a separator wound thereon, an electrolyte, and a container in which the electrode body and the electrolyte are housed,
    The container has an injection part for the electrolytic solution on a wall extending in the direction of the winding axis of the electrode body, and the length of the electrode body in the direction of the winding axis is 500 mm or more,
    The separator is a power storage element including a base material and an inorganic coat layer containing inorganic particles coated on the base material.
  2. 　前記無機コート層は、前記電解液が滴下されて３００秒目における前記電解液の浸透面積が８０ｍｍ２以上である
    　請求項１に記載の蓄電素子。     The energy storage element according to claim 1, wherein the inorganic coat layer has a permeation area of 80 mm 2 or more for the electrolyte at 300 seconds after the electrolyte is dropped.
  3. 　前記無機コート層は、前記無機粒子として、硫酸バリウム及びアルミナの少なくとも一方を含む
    　請求項１または２に記載の蓄電素子。     The electricity storage element according to claim 1 or 2, wherein the inorganic coat layer contains at least one of barium sulfate and alumina as the inorganic particles.
  4. 　前記電極体は、前記巻回軸方向における長さが６００ｍｍ以上である
    　請求項１または２に記載の蓄電素子。     The electricity storage element according to claim 1 or 2, wherein the electrode body has a length of 600 mm or more in the direction of the winding axis.
  5. 　前記極板には、貫通孔が形成されている
    　請求項１または２に記載の蓄電素子。     The electricity storage element according to claim 1 or 2, wherein the electrode plate has a through hole formed therein.
PCT/JP2023/027085 2022-09-16 2023-07-25 Power storage element WO2024057726A1 (en)

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