WO2024090080A1 - Battery - Google Patents

Battery Download PDF

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Publication number
WO2024090080A1
WO2024090080A1 PCT/JP2023/034053 JP2023034053W WO2024090080A1 WO 2024090080 A1 WO2024090080 A1 WO 2024090080A1 JP 2023034053 W JP2023034053 W JP 2023034053W WO 2024090080 A1 WO2024090080 A1 WO 2024090080A1
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WO
WIPO (PCT)
Prior art keywords
insulating
electrode
case
conductive cap
battery
Prior art date
Application number
PCT/JP2023/034053
Other languages
French (fr)
Japanese (ja)
Inventor
良太 沖本
Original Assignee
パナソニックエナジー株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by パナソニックエナジー株式会社 filed Critical パナソニックエナジー株式会社
Publication of WO2024090080A1 publication Critical patent/WO2024090080A1/en

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Classifications

    • 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
    • H01G11/04—Hybrid capacitors
    • H01G11/06—Hybrid capacitors with one of the electrodes allowing ions to be reversibly doped thereinto, e.g. lithium ion capacitors [LIC]
    • 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
    • H01G11/80—Gaskets; Sealings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/102—Primary casings; Jackets or wrappings characterised by their shape or physical structure
    • H01M50/107—Primary casings; Jackets or wrappings characterised by their shape or physical structure having curved cross-section, e.g. round or elliptic
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/147—Lids or covers
    • H01M50/148—Lids or covers characterised by their shape
    • H01M50/152—Lids or covers characterised by their shape for cells having curved cross-section, e.g. round or elliptic
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/147—Lids or covers
    • H01M50/166—Lids or covers characterised by the methods of assembling casings with lids
    • H01M50/167—Lids or covers characterised by the methods of assembling casings with lids by crimping
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/531—Electrode connections inside a battery casing
    • H01M50/533—Electrode connections inside a battery casing characterised by the shape of the leads or tabs
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/543—Terminals
    • H01M50/545—Terminals formed by the casing of the cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/543—Terminals
    • H01M50/552—Terminals characterised by their shape
    • H01M50/559—Terminals adapted for cells having curved cross-section, e.g. round, elliptic or button cells
    • H01M50/56—Cup shaped terminals
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/572—Means for preventing undesired use or discharge
    • H01M50/584—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries
    • H01M50/586—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries inside the batteries, e.g. incorrect connections of electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/50—Current conducting connections for cells or batteries
    • H01M50/572—Means for preventing undesired use or discharge
    • H01M50/584—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries
    • H01M50/59—Means for preventing undesired use or discharge for preventing incorrect connections inside or outside the batteries characterised by the protection means
    • H01M50/593—Spacers; Insulating plates

Definitions

  • This disclosure relates to batteries.
  • Patent Document 1 batteries that can be used repeatedly by charging and discharging are known (for example, Patent Document 1).
  • the battery in Patent Document 1 comprises a bottomed cylindrical case with an opening at one end, an electrode group housed in the case and having a first electrode and a second electrode, and a sealing unit that seals the opening of the case.
  • the sealing unit comprises a sealing body formed by layering, in order from the electrode group side, a filter, a lower valve body, an insulator, an upper valve body, and a cap, and a gasket provided between the case and the sealing body.
  • batteries can sometimes combust when an abnormality occurs. When combustion occurs, the heat can melt the gasket, causing contact between the sealing body components and the case, resulting in electrical conduction. Such electrical conduction or internal short circuiting is particularly problematic in battery packs that include multiple batteries. This is because a large current can flow from the other batteries into the battery in which combustion has occurred, reducing the output of the battery pack. In such situations, one of the objectives of this disclosure is to suppress internal short circuits during combustion.
  • the battery includes a bottomed cylindrical case having an opening at one end, an electrode group having a first electrode and a second electrode housed in the case, and a sealing unit that seals the opening.
  • the case has a crimping portion that fixes the sealing unit and is electrically connected to the first electrode.
  • the sealing unit includes a current collector plate that is electrically connected to the second electrode, a conductive cap that is arranged axially outward of the case from the current collector plate and is joined to the current collector plate at a first joint, an insulating gasket that is interposed between the crimping portion and the current collector plate and the conductive cap, and an insulating member that includes a first insulating portion that is arranged between the peripheral portion of the current collector plate and the peripheral portion of the conductive cap, and the first insulating portion is arranged closer to the outer periphery than the first joint.
  • FIG. 1 is a cross-sectional view illustrating a schematic example of a battery according to the present disclosure.
  • FIG. 2 is an enlarged cross-sectional view showing a main part of the battery of FIG. 1 .
  • 1 is a conceptual diagram for explaining a short circuit suppression function of a battery according to the present disclosure.
  • the battery according to the present disclosure may be a primary battery such as a lithium primary battery, or a secondary battery such as an alkaline storage battery (nickel-metal hydride battery, nickel-cadmium battery, etc.), a lithium-ion secondary battery, or a lithium metal secondary battery.
  • the category of secondary batteries also includes power storage devices (e.g., lithium-ion capacitors) in which at least one of the positive and negative electrodes is an electrode that develops capacity through a Faraday reaction.
  • the battery according to the present disclosure comprises a case, an electrode group, and a sealing unit.
  • the type of battery is not particularly limited, but the following description will mainly use a lithium ion secondary battery as an example.
  • the case is formed in a bottomed tubular shape with an opening at one end.
  • the case may be in the shape of a bottomed cylinder or a bottomed rectangular tube.
  • the case may be made of a conductor (e.g., a metal whose main component is iron or a metal whose main component is aluminum).
  • the electrode group is housed in a case and has a first electrode and a second electrode.
  • the electrode group may be a wound type electrode group formed by winding the first electrode and the second electrode with a separator interposed therebetween.
  • the outer shape of the electrode group may be, for example, cylindrical or prismatic.
  • One of the first electrode and the second electrode is a positive electrode, and the other of the first electrode and the second electrode is a negative electrode.
  • the first electrode may have a first current collector in the form of a long sheet and a first active material layer formed on the surface of the first current collector.
  • the first current collector may be made of copper foil or copper alloy foil.
  • the first active material layer may contain a negative electrode active material (carbonaceous material, silicon-containing material, etc.), a conductive agent, a binder, etc. Note that the first active material layer does not necessarily have to be provided.
  • the second electrode may have a long sheet-like second current collector and a second active material layer formed on the surface of the second current collector.
  • the second current collector may be made of aluminum foil or aluminum alloy foil.
  • the second active material layer may include a positive electrode active material (e.g., a lithium-containing transition metal oxide), a conductive agent, and a binder.
  • the separator may be made of a porous sheet that is ion-permeable and insulating.
  • porous sheets include thin films with micropores, woven fabrics, and nonwoven fabrics.
  • the case has a crimping portion that fixes the sealing unit.
  • the case is electrically connected to the first electrode of the electrode group.
  • the case functions as one of the external terminals of the battery.
  • the sealing unit seals the opening of the case.
  • the sealing unit has a current collector, a conductive cap, an insulating gasket, and an insulating member.
  • the current collector is electrically connected to the second electrode of the electrode group.
  • the conductive cap is disposed axially outward of the case from the current collector and is joined to the current collector at a first joint. Thus, the conductive cap functions as the other external terminal of the battery.
  • the gasket is interposed between the crimping portion and the current collector and between the current collector and the conductive cap.
  • the gasket may be made of, for example, polypropylene.
  • the insulating member includes a first insulating portion disposed between the peripheral edge of the current collector and the peripheral edge of the conductive cap. The first insulating portion is disposed closer to the outer periphery than the first joint.
  • the first insulating part is desirably made of a material that is more heat resistant than the gasket.
  • the first insulating part may contain as its main component a resin material that has a higher melting point or deflection temperature under load than the gasket, may contain as its main component ceramics, or may be made of a cured product of a thermosetting resin composition.
  • the deflection temperature under load may be measured by a deflection temperature under load measurement method conforming to ASTM-D648 of the American Society for Testing and Materials.
  • the main component may be a component that constitutes 50% or more by mass of the first insulating part, or may be a component that constitutes 70% or more by mass.
  • the insulating member including the first insulating part may be made of, for example, polyphenylene sulfide or a copolymer of tetrafluoroethylene and perfluoroalkoxyethylene, which have high sealing properties and heat resistance.
  • the sealing unit when the battery burns, the gasket melts and the conductive components of the sealing unit (particularly the current collector plate) come into contact with the crimped portion of the case, which may cause an internal short circuit.
  • the sealing unit according to the present disclosure has an insulating member including a first insulating portion located outside the gasket and in a position less susceptible to combustion. Such a first insulating portion is less likely to melt or burn even when the battery burns, and by being present between the peripheral portion of the current collector plate and the peripheral portion of the conductive cap, the conductive cap can be maintained insulated from the current collector plate and the case even if the current collector plate comes into contact with the crimped portion of the case. Note that the first joint between the current collector plate and the conductive cap can be released from its joint state due to the combustion heat and/or thermal expansion of the first insulating portion when the battery burns. Therefore, an internal short circuit during combustion can be suppressed.
  • the insulating member may further include a second insulating portion extending from the outer peripheral end of the first insulating portion in the axial direction of the case and positioned between the conductive cap and the gasket.
  • the second insulating portion is positioned radially outside the peripheral portion of the conductive cap, and a part of the gasket is present further radially outside the second insulating portion.
  • the second insulating portion may contain as its main component a resin material having a higher melting point or deflection temperature under load than the gasket, may contain as its main component ceramics, or may be composed of a cured product of a thermosetting resin composition.
  • the insulating member may further include a third insulating portion extending from an end of the second insulating portion toward the radial inside of the case and located between the conductive cap and the gasket.
  • the third insulating portion is located axially outside the peripheral portion of the conductive cap, and a part of the gasket is present further axially outside the third insulating portion.
  • the third insulating portion may contain as its main component a resin material having a higher melting point or deflection temperature under load than the gasket, may contain as its main component ceramics, or may be composed of a cured product of a thermosetting resin composition.
  • the insulating member may be made of a thermal expansion material having a linear expansion coefficient of 2.0 ⁇ 10 ⁇ 5 /K or more at 25° C.
  • the first insulating part expands significantly when the battery is burned, which easily releases the bonded state of the first bonding part. Therefore, even if the portion of the current collector plate corresponding to the first bonding part does not melt due to the heat of combustion, it is easy to electrically insulate the current collector plate from the conductive cap.
  • the radial distance from the outer circumferential edge of the conductive cap to the inner circumferential end of the first insulating part may be 0.25D or more, where D is the radial distance from the outer circumferential edge of the conductive cap to the first joint.
  • the radial distance from the outer circumferential edge of the conductive cap to the inner circumferential end of the first insulating part may be 0.4D or more, 0.5D or more, 0.6D or more, 0.7D or more, 0.8D or more, or 0.9D or more.
  • an insulating member in a position that is less susceptible to combustion than the gasket, it is possible to suppress internal short circuits during combustion.
  • the battery 10 of this embodiment is configured as a lithium ion secondary battery, but is not limited to this. As shown in Figures 1 and 2, the battery 10 includes a case 20, an electrode group 30, and a sealing unit 50.
  • the case 20 is formed in a bottomed cylindrical shape with an opening at one end (the upper end in FIG. 1), and has a cylindrical side wall portion 21 and a disk-shaped bottom portion 23.
  • a crimping portion 22 that fixes the sealing unit 50 is formed in the area near the opening of the side wall portion 21.
  • the case 20 in this embodiment is made of a metal whose main component is iron, but is not limited to this.
  • the electrode group 30 is housed in the case 20 and has a negative electrode and a positive electrode.
  • the electrode group 30 is a wound type electrode group formed by winding a negative electrode and a positive electrode with a separator interposed therebetween.
  • the electrode group 30 has a cylindrical outer shape.
  • the negative electrode is electrically connected to the bottom 23 of the case 20. Therefore, the case 20 functions as an external negative electrode terminal.
  • the positive electrode is electrically connected to a current collector 54 (described later) of the sealing unit 50 via a positive electrode lead 41.
  • the negative electrode is an example of a first electrode
  • the positive electrode is an example of a second electrode.
  • the sealing unit 50 seals the opening of the case 20.
  • the sealing unit 50 has a conductive cap 51, a current collector 54, and a gasket 55.
  • the conductive cap 51 is made of metal and is disposed axially outward of the case 20 from the current collector 54.
  • the conductive cap 51 is exposed to the outside of the case 20.
  • the current collector 54 is made of metal and is joined to the conductive cap 51 at the first joint J, for example, by welding. As described above, the current collector 54 is electrically connected to the positive electrode of the electrode group 30, and therefore the conductive cap 51 joined to the current collector 54 functions as an external positive electrode terminal.
  • the gasket 55 is made of insulating resin and is interposed between the conductive cap 51, the current collector 54, and the crimping portion 22.
  • the sealing unit 50 further includes an insulating member 56 having a melting point or deflection temperature under load higher than that of the gasket 55.
  • the insulating member 56 is made of a thermal expansion material having a linear expansion coefficient of 2.0 ⁇ 10 ⁇ 5 /K or more at 25° C., but is not limited thereto.
  • the insulating member 56 may contain ceramics as a main component.
  • the insulating member 56 is disposed closer to the outer periphery than the first joint J, and includes a first insulating portion 56a, a second insulating portion 56b, and a third insulating portion 56c.
  • the first insulating portion 56a is disposed between the peripheral portion of the current collector plate 54 and the peripheral portion of the conductive cap 51.
  • the second insulating portion 56b extends from the outer peripheral end of the first insulating portion 56a in the axial direction of the case 20 (upward in FIG. 1 ) and is located between the conductive cap 51 and the gasket 55.
  • the third insulating portion 56 c extends radially inward of the case 20 from an end (the upper end in FIG. 1 ) of the second insulating portion 56 b , and is positioned between the conductive cap 51 and the gasket 55 .
  • the radial distance from the outer peripheral edge of the conductive cap 51 to the first joint J is D, and the radial distance from the outer peripheral edge of the conductive cap 51 to the inner peripheral end of the first insulating portion 56a is 0.25D or more, preferably 0.5D or more, and more preferably 0.8D or more.
  • a first insulating plate 81 and a second insulating plate 82 are provided between the electrode group 30 and the sealing unit 50.
  • the first insulating plate 81 is disposed closer to the electrode group 30 (lower side in FIG. 1 ) than the second insulating plate 82.
  • the first insulating plate 81 is interposed between the electrode group 30 and the positive electrode lead 41 to prevent contact between the negative electrode of the electrode group 30 and the positive electrode lead 41.
  • the second insulating plate 82 is interposed between the case 20 and the positive electrode lead 41 to prevent contact between the case 20 and the positive electrode lead 41.
  • FIG. 3 shows the battery 10 of this embodiment before and after combustion occurs.
  • the gasket 55 melts and the peripheral portion of the current collector 54 may come into contact with the case 20.
  • an insulating member 56 with a high melting point or deflection temperature under load is interposed between the peripheral portion of the current collector 54 and the peripheral portion of the conductive cap 51, so that electrical conduction between the case 20 and the conductive cap 51 is suppressed. Note that the area near the inner circumference of the current collector 54 may melt during combustion, but may remain unmelted.
  • the sealing unit includes: a current collector plate electrically connected to the second electrode; a conductive cap disposed axially outboard of the case relative to the current collecting plate and joined to the current collecting plate at a first joint portion; an insulating gasket interposed between the crimping portion and the current collecting plate and between the crimping portion and the conductive cap; an insulating member including a first insulating portion disposed between a peripheral portion of the current collecting plate and a peripheral portion of the conductive cap; having The first insulating portion is disposed closer to an outer periphery than the first joint portion.
  • This disclosure can be used in batteries.
  • Electrode group 41 Positive electrode lead 50: Sealing unit 51: Conductive cap 54: Current collector plate 55: Gasket 56: Insulating member 56a: First insulating portion 56b: Second insulating portion 56c: Third insulating portion 81: First insulating plate 82: Second insulating plate J: First joint portion

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Materials Engineering (AREA)
  • Sealing Battery Cases Or Jackets (AREA)

Abstract

Disclosed is a battery 10 which is provided with: a case 20; an electrode group which is contained in the case 20 and comprises a first electrode and a second electrode; and a sealing unit 50 which seals the opening of the case 20. The case 20 is electrically connected to the first electrode and has a crimped part 22 which fixes the sealing unit 50. The sealing unit 50 comprises: a collector plate 54 which is electrically connected to the second electrode; a conductive cap 51 which is disposed further toward the outer side of the collector plate 54 in the axial direction of the case 20, and is bonded to the collector plate 54 at a first bonding part J; an insulating gasket 55 which is interposed among the crimped part 22, the collector plate 54 and the conductive cap 51; and an insulating member 56 which comprises a first insulating part 56a that is disposed between the peripheral edge part of the collector plate 54 and the peripheral edge part of the conductive cap 51. The first insulating part 56a is disposed closer to the outer periphery than the first bonding part J. Consequently, the present invention is capable of suppressing internal short-circuiting upon combustion.

Description

電池battery
　本開示は、電池に関する。 This disclosure relates to batteries.
　従来、充放電により繰り返し使用できる電池が知られている（例えば、特許文献１）。特許文献１の電池は、一端に開口を有する有底筒状のケースと、ケースに収容され、第１電極および第２電極を有する電極群と、ケースの開口を封口する封口ユニットとを備える。封口ユニットは、電極群側から順に、フィルタ、下弁体、絶縁体、上弁体、およびキャップが積層されてなる封口体と、ケースと封口体との間に設けられたガスケットとを有する。 　Conventionally, batteries that can be used repeatedly by charging and discharging are known (for example, Patent Document 1). The battery in Patent Document 1 comprises a bottomed cylindrical case with an opening at one end, an electrode group housed in the case and having a first electrode and a second electrode, and a sealing unit that seals the opening of the case. The sealing unit comprises a sealing body formed by layering, in order from the electrode group side, a filter, a lower valve body, an insulator, an upper valve body, and a cap, and a gasket provided between the case and the sealing body.
特開２０１９－１５３３８８号公報JP 2019-153388 A
　ところで、電池は、異常発生時に燃焼することがある。燃焼が生じると、その熱によってガスケットが溶融し、封口体の構成要素とケースとが接触して電気的に導通し得る。そのような電気的導通ないし内部短絡は、複数の電池を備える組電池において特に問題となる。なぜなら、燃焼が生じた電池に対して、それ以外の電池から大電流が流れ込み、組電池としての出力が低下してしまうためである。このような状況において、本開示は、燃焼時の内部短絡を抑制することを目的の１つとする。 However, batteries can sometimes combust when an abnormality occurs. When combustion occurs, the heat can melt the gasket, causing contact between the sealing body components and the case, resulting in electrical conduction. Such electrical conduction or internal short circuiting is particularly problematic in battery packs that include multiple batteries. This is because a large current can flow from the other batteries into the battery in which combustion has occurred, reducing the output of the battery pack. In such situations, one of the objectives of this disclosure is to suppress internal short circuits during combustion.
　本開示に係る一局面は、電池に関する。当該電池は、一端に開口を有する有底筒状のケースと、前記ケースに収容され、第１電極および第２電極を有する電極群と、前記開口を封口する封口ユニットと、を備え、前記ケースは、前記封口ユニットを固定するかしめ部を有し、かつ前記第１電極と電気的に接続され、前記封口ユニットは、前記第２電極と電気的に接続される集電板と、前記集電板よりも前記ケースの軸方向外側に配置され、前記集電板に第１接合部で接合される導電性キャップと、前記かしめ部と前記集電板および前記導電性キャップとの間に介在する絶縁性のガスケットと、前記集電板の周縁部と前記導電性キャップの周縁部との間に配置された第１絶縁部を含む絶縁部材と、を有し、前記第１絶縁部は、前記第１接合部よりも外周寄りに配置されている。 One aspect of the present disclosure relates to a battery. The battery includes a bottomed cylindrical case having an opening at one end, an electrode group having a first electrode and a second electrode housed in the case, and a sealing unit that seals the opening. The case has a crimping portion that fixes the sealing unit and is electrically connected to the first electrode. The sealing unit includes a current collector plate that is electrically connected to the second electrode, a conductive cap that is arranged axially outward of the case from the current collector plate and is joined to the current collector plate at a first joint, an insulating gasket that is interposed between the crimping portion and the current collector plate and the conductive cap, and an insulating member that includes a first insulating portion that is arranged between the peripheral portion of the current collector plate and the peripheral portion of the conductive cap, and the first insulating portion is arranged closer to the outer periphery than the first joint.
　本開示によれば、燃焼時の内部短絡を抑制することができる。 According to this disclosure, it is possible to suppress internal short circuits during combustion.
　本発明の新規な特徴を添付の請求の範囲に記述するが、本発明は、構成および内容の両方に関し、本願の他の目的および特徴と併せ、図面を照合した以下の詳細な説明によりさらによく理解されるであろう。 The novel features of the present invention are set forth in the appended claims, but the present invention, both in terms of structure and content, together with other objects and features of the present application, will be better understood from the following detailed description taken in conjunction with the drawings.
本開示に係る電池の一例を模式的に示す断面図である。FIG. 1 is a cross-sectional view illustrating a schematic example of a battery according to the present disclosure. 図１の電池の要部を示す拡大断面図である。FIG. 2 is an enlarged cross-sectional view showing a main part of the battery of FIG. 1 . 本開示に係る電池の短絡抑制機能を説明するための概念図である。1 is a conceptual diagram for explaining a short circuit suppression function of a battery according to the present disclosure.
　本開示に係る電池の実施形態について例を挙げて以下に説明する。しかしながら、本開示は以下に説明する例に限定されない。以下の説明では、具体的な数値や材料を例示する場合があるが、本開示の効果が得られる限り、他の数値や材料を適用してもよい。 The following describes an embodiment of the battery according to the present disclosure by way of example. However, the present disclosure is not limited to the examples described below. In the following description, specific numerical values and materials may be given as examples, but other numerical values and materials may be applied as long as the effects of the present disclosure are obtained.
　本開示に係る電池は、リチウム一次電池などの一次電池であってもよいし、アルカリ蓄電池（ニッケル水素電池、ニッケルカドミウム電池など）、リチウムイオン二次電池、リチウム金属二次電池などの二次電池であってもよい。本開示では、二次電池の範疇に、正極と負極の少なくとも一方がファラデー反応により容量を発現する電極である蓄電デバイス（例えば、リチウムイオンキャパシタ）も含める。 The battery according to the present disclosure may be a primary battery such as a lithium primary battery, or a secondary battery such as an alkaline storage battery (nickel-metal hydride battery, nickel-cadmium battery, etc.), a lithium-ion secondary battery, or a lithium metal secondary battery. In the present disclosure, the category of secondary batteries also includes power storage devices (e.g., lithium-ion capacitors) in which at least one of the positive and negative electrodes is an electrode that develops capacity through a Faraday reaction.
　本開示に係る電池は、ケースと、電極群と、封口ユニットとを備える。なお、電池の種類は、上述のとおり特に限定されないが、以下では主にリチウムイオン二次電池の場合を例にして説明する。 The battery according to the present disclosure comprises a case, an electrode group, and a sealing unit. As mentioned above, the type of battery is not particularly limited, but the following description will mainly use a lithium ion secondary battery as an example.
　ケースは、一端に開口を有する有底筒状に形成される。ケースは、有底円筒状または有底角筒状であってもよい。ケースは、導電体（例えば、鉄を主成分とする金属、またはアルミニウムを主成分とする金属）で構成されてもよい。 The case is formed in a bottomed tubular shape with an opening at one end. The case may be in the shape of a bottomed cylinder or a bottomed rectangular tube. The case may be made of a conductor (e.g., a metal whose main component is iron or a metal whose main component is aluminum).
　電極群は、ケースに収容され、第１電極および第２電極を有する。電極群は、第１電極および第２電極を、セパレータを介して巻回してなる巻回型の電極群であってもよい。電極群の外形は、例えば、円柱状または角柱状であってもよい。第１電極および第２電極の一方は正極であり、第１電極および第２電極の他方は負極である。 The electrode group is housed in a case and has a first electrode and a second electrode. The electrode group may be a wound type electrode group formed by winding the first electrode and the second electrode with a separator interposed therebetween. The outer shape of the electrode group may be, for example, cylindrical or prismatic. One of the first electrode and the second electrode is a positive electrode, and the other of the first electrode and the second electrode is a negative electrode.
　第１電極は、長尺シート状の第１集電体と、第１集電体の表面に形成された第１活物質層とを有してもよい。第１電極がリチウムイオン二次電池の負極である場合、第１集電体は、銅箔または銅合金箔で構成されてもよい。第１電極がリチウムイオン二次電池の負極である場合、第１活物質層は、負極活物質（炭素質材料、ケイ素含有材料など）、導電剤、および結着剤などを含んでもよい。なお、第１活物質層が設けられなくてもよい。 The first electrode may have a first current collector in the form of a long sheet and a first active material layer formed on the surface of the first current collector. When the first electrode is the negative electrode of a lithium ion secondary battery, the first current collector may be made of copper foil or copper alloy foil. When the first electrode is the negative electrode of a lithium ion secondary battery, the first active material layer may contain a negative electrode active material (carbonaceous material, silicon-containing material, etc.), a conductive agent, a binder, etc. Note that the first active material layer does not necessarily have to be provided.
　第２電極は、長尺シート状の第２集電体と、第２集電体の表面に形成された第２活物質層とを有してもよい。第２電極がリチウムイオン二次電池の正極である場合、第２集電体は、アルミニウム箔またはアルミニウム合金箔で構成されてもよい。第２電極がリチウムイオン二次電池の正極である場合、第２活物質層は、正極活物質（例えば、リチウム含有遷移金属酸化物）、導電剤、および結着剤などを含んでもよい。 The second electrode may have a long sheet-like second current collector and a second active material layer formed on the surface of the second current collector. When the second electrode is the positive electrode of a lithium-ion secondary battery, the second current collector may be made of aluminum foil or aluminum alloy foil. When the second electrode is the positive electrode of a lithium-ion secondary battery, the second active material layer may include a positive electrode active material (e.g., a lithium-containing transition metal oxide), a conductive agent, and a binder.
　セパレータは、イオン透過性および絶縁性を有する多孔性シートで構成されてもよい。多孔性シートとしては、例えば、微多孔を有する薄膜、織布、不織布などが挙げられる。 The separator may be made of a porous sheet that is ion-permeable and insulating. Examples of porous sheets include thin films with micropores, woven fabrics, and nonwoven fabrics.
　上記ケースは、封口ユニットを固定するかしめ部を有する。ケースは、電極群の第１電極と電気的に接続される。よって、ケースは、電池の一方の外部端子として機能する。 The case has a crimping portion that fixes the sealing unit. The case is electrically connected to the first electrode of the electrode group. Thus, the case functions as one of the external terminals of the battery.
　封口ユニットは、ケースの開口を封口する。封口ユニットは、集電板と、導電性キャップと、絶縁性のガスケットと、絶縁部材とを有する。集電板は、電極群の第２電極と電気的に接続される。導電性キャップは、集電板よりもケースの軸方向外側に配置され、集電板に第１接合部で接合される。よって、導電性キャップは、電池の他方の外部端子として機能する。ガスケットは、かしめ部と集電板および導電性キャップとの間に介在する。ガスケットは、例えば、ポリプロピレンで構成されてもよい。絶縁部材は、集電板の周縁部と導電性キャップの周縁部との間に配置された第１絶縁部を含む。第１絶縁部は、第１接合部よりも外周寄りに配置されている。 The sealing unit seals the opening of the case. The sealing unit has a current collector, a conductive cap, an insulating gasket, and an insulating member. The current collector is electrically connected to the second electrode of the electrode group. The conductive cap is disposed axially outward of the case from the current collector and is joined to the current collector at a first joint. Thus, the conductive cap functions as the other external terminal of the battery. The gasket is interposed between the crimping portion and the current collector and between the current collector and the conductive cap. The gasket may be made of, for example, polypropylene. The insulating member includes a first insulating portion disposed between the peripheral edge of the current collector and the peripheral edge of the conductive cap. The first insulating portion is disposed closer to the outer periphery than the first joint.
　第１絶縁部は、ガスケットよりも耐熱性が高い材料で構成されることが望ましい。例えば、第１絶縁部は、ガスケットよりも融点または荷重たわみ温度が高い樹脂材料を主成分として含んでもよく、セラミックスを主成分として含んでもよく、熱硬化性樹脂組成物の硬化物で構成されてもよい。荷重たわみ温度は、アメリカ材料試験協会の試験法ＡＳＴＭ－Ｄ６４８に準拠した荷重たわみ温度測定で測定すればよい。なお、主成分とは、第１絶縁部の５０質量％以上を構成する成分であってもよく、７０質量％以上を構成する成分であってもよい。第１絶縁部を含む絶縁部材は、密閉性と耐熱性が高い点で、例えば、ポリフェニレンサルファイド、または四フッ化エチレンとパーフルオロアルコキシエチレンの共重合体で構成されてもよい。 The first insulating part is desirably made of a material that is more heat resistant than the gasket. For example, the first insulating part may contain as its main component a resin material that has a higher melting point or deflection temperature under load than the gasket, may contain as its main component ceramics, or may be made of a cured product of a thermosetting resin composition. The deflection temperature under load may be measured by a deflection temperature under load measurement method conforming to ASTM-D648 of the American Society for Testing and Materials. The main component may be a component that constitutes 50% or more by mass of the first insulating part, or may be a component that constitutes 70% or more by mass. The insulating member including the first insulating part may be made of, for example, polyphenylene sulfide or a copolymer of tetrafluoroethylene and perfluoroalkoxyethylene, which have high sealing properties and heat resistance.
　ここで、電池の燃焼が生じると、ガスケットが溶融し、封口ユニットが有する導電性の構成要素（特に、集電板）がケースのかしめ部に接触し、それにより内部短絡が生じるおそれがある。しかし、本開示に係る封口ユニットは、ガスケットよりも外側で、より燃焼されにくい位置に、第１絶縁部を含む絶縁部材を有する。そのような第１絶縁部は、電池の燃焼時にも溶融もしくは燃焼しにくく、これが集電板の周縁部と導電性キャップの周縁部との間に存在することで、集電板がケースのかしめ部に接触しても導電性キャップは集電板およびケースから絶縁された状態に維持され得る。なお、集電板と導電性キャップとの間の第１接合部は、電池の燃焼時に、燃焼熱により、および／または第１絶縁部の熱膨張により、その接合状態が解除され得る。したがって、燃焼時の内部短絡を抑制することができる。 Here, when the battery burns, the gasket melts and the conductive components of the sealing unit (particularly the current collector plate) come into contact with the crimped portion of the case, which may cause an internal short circuit. However, the sealing unit according to the present disclosure has an insulating member including a first insulating portion located outside the gasket and in a position less susceptible to combustion. Such a first insulating portion is less likely to melt or burn even when the battery burns, and by being present between the peripheral portion of the current collector plate and the peripheral portion of the conductive cap, the conductive cap can be maintained insulated from the current collector plate and the case even if the current collector plate comes into contact with the crimped portion of the case. Note that the first joint between the current collector plate and the conductive cap can be released from its joint state due to the combustion heat and/or thermal expansion of the first insulating portion when the battery burns. Therefore, an internal short circuit during combustion can be suppressed.
　絶縁部材は、第１絶縁部の外周端部からケースの軸方向に延び、かつ導電性キャップとガスケットとの間に位置する第２絶縁部をさらに含んでもよい。つまり、第２絶縁部は、導電性キャップの周縁部の径方向外側に位置し、第２絶縁部のさらに径方向外側にガスケットの一部が存在する。第２絶縁部は、ガスケットよりも融点または荷重たわみ温度が高い樹脂材料を主成分として含んでもよく、セラミックスを主成分として含んでもよく、熱硬化性樹脂組成物の硬化物で構成されてもよい。この構成によると、導電性キャップの周縁部の径方向外側のガスケットが燃焼時に溶融しても、第２絶縁部によって導電性キャップの周縁部がケースのかしめ部に接触することが抑制され得る。 The insulating member may further include a second insulating portion extending from the outer peripheral end of the first insulating portion in the axial direction of the case and positioned between the conductive cap and the gasket. In other words, the second insulating portion is positioned radially outside the peripheral portion of the conductive cap, and a part of the gasket is present further radially outside the second insulating portion. The second insulating portion may contain as its main component a resin material having a higher melting point or deflection temperature under load than the gasket, may contain as its main component ceramics, or may be composed of a cured product of a thermosetting resin composition. With this configuration, even if the gasket radially outside the peripheral portion of the conductive cap melts during combustion, the second insulating portion can prevent the peripheral portion of the conductive cap from contacting the crimped portion of the case.
　絶縁部材は、第２絶縁部の端部からケースの径方向内側に延び、かつ導電性キャップとガスケットとの間に位置する第３絶縁部をさらに含んでもよい。つまり、第３絶縁部は、導電性キャップの周縁部の軸方向外側に位置し、第３絶縁部のさらに軸方向外側にガスケットの一部が存在する。第３絶縁部は、ガスケットよりも融点または荷重たわみ温度が高い樹脂材料を主成分として含んでもよく、セラミックスを主成分として含んでもよく、熱硬化性樹脂組成物の硬化物で構成されてもよい。この構成によると、導電性キャップの周縁部の軸方向外側のガスケットが燃焼時に溶融しても、第３絶縁部によって導電性キャップの周縁部がケースのかしめ部に接触することが抑制され得る。 The insulating member may further include a third insulating portion extending from an end of the second insulating portion toward the radial inside of the case and located between the conductive cap and the gasket. In other words, the third insulating portion is located axially outside the peripheral portion of the conductive cap, and a part of the gasket is present further axially outside the third insulating portion. The third insulating portion may contain as its main component a resin material having a higher melting point or deflection temperature under load than the gasket, may contain as its main component ceramics, or may be composed of a cured product of a thermosetting resin composition. With this configuration, even if the gasket axially outside the peripheral portion of the conductive cap melts during combustion, the third insulating portion can prevent the peripheral portion of the conductive cap from contacting the crimped portion of the case.
　絶縁部材は、２５℃における線膨張係数が２．０×１０-5／Ｋ以上の熱膨張材料で構成されてもよい。この場合、電池の燃焼時に第１絶縁部が大きく膨張し、それにより第１接合部の接合状態が解除されやすい。したがって、燃焼熱で集電板のうち第１接合部に対応する部位が溶融しなかったとしても、集電板と導電性キャップとを電気的に絶縁しやすい。 The insulating member may be made of a thermal expansion material having a linear expansion coefficient of 2.0×10 −5 /K or more at 25° C. In this case, the first insulating part expands significantly when the battery is burned, which easily releases the bonded state of the first bonding part. Therefore, even if the portion of the current collector plate corresponding to the first bonding part does not melt due to the heat of combustion, it is easy to electrically insulate the current collector plate from the conductive cap.
　導電性キャップの外周縁から第１接合部までの径方向距離をＤとして、導電性キャップの外周縁から第１絶縁部の内周端部までの径方向距離は、０．２５Ｄ以上であってもよい。この構成によると、第１絶縁部の内周端部が、第１接合部の比較的近くに位置する。したがって、電池の燃焼時の第１絶縁部の膨張によって、第１接合部において集電板と導電性キャップとが互いに引き離されやすく、第１接合部の接合状態が解除されやすい。なお、導電性キャップの外周縁から第１絶縁部の内周端部までの径方向距離は、０．４Ｄ以上、０．５Ｄ以上、０．６Ｄ以上、０．７Ｄ以上、０．８Ｄ以上、または０．９Ｄ以上であってもよい。 The radial distance from the outer circumferential edge of the conductive cap to the inner circumferential end of the first insulating part may be 0.25D or more, where D is the radial distance from the outer circumferential edge of the conductive cap to the first joint. With this configuration, the inner circumferential end of the first insulating part is located relatively close to the first joint. Therefore, due to the expansion of the first insulating part when the battery burns, the current collector plate and the conductive cap are likely to be pulled away from each other at the first joint, and the joint state of the first joint is likely to be released. The radial distance from the outer circumferential edge of the conductive cap to the inner circumferential end of the first insulating part may be 0.4D or more, 0.5D or more, 0.6D or more, 0.7D or more, 0.8D or more, or 0.9D or more.
　以上のように、本開示によれば、ガスケットよりも燃焼しにくい位置に絶縁部材を設けることで、燃焼時の内部短絡を抑制することができる。 As described above, according to the present disclosure, by providing an insulating member in a position that is less susceptible to combustion than the gasket, it is possible to suppress internal short circuits during combustion.
　以下では、本開示に係る電池の一例について、図面を参照して具体的に説明する。以下で説明する一例の電池の構成要素には、上述した構成要素を適用できる。以下で説明する一例の電池の構成要素は、上述した記載に基づいて変更できる。また、以下で説明する事項を、上記の実施形態に適用してもよい。以下で説明する一例の電池の構成要素のうち、本開示に係る電池に必須ではない構成要素は省略してもよい。なお、以下で示す図は模式的なものであり、実際の部材の形状や数を正確に反映するものではない。 Below, an example of a battery according to the present disclosure will be described in detail with reference to the drawings. The components described above can be applied to the components of the example battery described below. The components of the example battery described below can be modified based on the above description. The matters described below may also be applied to the above embodiment. Among the components of the example battery described below, components that are not essential to the battery according to the present disclosure may be omitted. Note that the diagrams shown below are schematic and do not accurately reflect the shape or number of actual components.
　本実施形態の電池１０は、リチウムイオン二次電池として構成されるが、これに限られるものではない。電池１０は、図１および図２に示すように、ケース２０と、電極群３０と、封口ユニット５０とを備える。 The battery 10 of this embodiment is configured as a lithium ion secondary battery, but is not limited to this. As shown in Figures 1 and 2, the battery 10 includes a case 20, an electrode group 30, and a sealing unit 50.
　ケース２０は、一端（図１における上端）に開口を有する有底筒状に形成され、円筒状に形成された側壁部２１と、円板状の底部２３とを有する。側壁部２１における開口近傍の領域には、封口ユニット５０を固定するかしめ部２２が形成される。本実施形態のケース２０は、鉄を主成分とする金属で構成されるが、これに限られるものではない。 The case 20 is formed in a bottomed cylindrical shape with an opening at one end (the upper end in FIG. 1), and has a cylindrical side wall portion 21 and a disk-shaped bottom portion 23. A crimping portion 22 that fixes the sealing unit 50 is formed in the area near the opening of the side wall portion 21. The case 20 in this embodiment is made of a metal whose main component is iron, but is not limited to this.
　電極群３０は、ケース２０に収容され、負極および正極を有する。電極群３０は、負極および正極を、セパレータを介して巻回してなる巻回型の電極群である。電極群３０の外形は、円柱状である。負極は、ケース２０の底部２３に電気的に接続される。このため、ケース２０は、外部負極端子として機能する。正極は、正極リード４１を介して封口ユニット５０の集電板５４（後述）に電気的に接続される。負極は、第１電極の一例であり、正極は、第２電極の一例である。 The electrode group 30 is housed in the case 20 and has a negative electrode and a positive electrode. The electrode group 30 is a wound type electrode group formed by winding a negative electrode and a positive electrode with a separator interposed therebetween. The electrode group 30 has a cylindrical outer shape. The negative electrode is electrically connected to the bottom 23 of the case 20. Therefore, the case 20 functions as an external negative electrode terminal. The positive electrode is electrically connected to a current collector 54 (described later) of the sealing unit 50 via a positive electrode lead 41. The negative electrode is an example of a first electrode, and the positive electrode is an example of a second electrode.
　封口ユニット５０は、ケース２０の開口を封口する。封口ユニット５０は、導電性キャップ５１と、集電板５４と、ガスケット５５とを有する。導電性キャップ５１は、金属で構成され、集電板５４よりもケース２０の軸方向外側に配置される。導電性キャップ５１は、ケース２０の外部に露出する。集電板５４は、金属で構成され、導電性キャップ５１と第１接合部Ｊで例えば溶接により接合される。上述のとおり、集電板５４は電極群３０の正極と電気的に接続されているため、集電板５４に接合された導電性キャップ５１は、外部正極端子として機能する。ガスケット５５は、絶縁性樹脂で構成され、導電性キャップ５１および集電板５４とかしめ部２２との間に介在する。 The sealing unit 50 seals the opening of the case 20. The sealing unit 50 has a conductive cap 51, a current collector 54, and a gasket 55. The conductive cap 51 is made of metal and is disposed axially outward of the case 20 from the current collector 54. The conductive cap 51 is exposed to the outside of the case 20. The current collector 54 is made of metal and is joined to the conductive cap 51 at the first joint J, for example, by welding. As described above, the current collector 54 is electrically connected to the positive electrode of the electrode group 30, and therefore the conductive cap 51 joined to the current collector 54 functions as an external positive electrode terminal. The gasket 55 is made of insulating resin and is interposed between the conductive cap 51, the current collector 54, and the crimping portion 22.
　封口ユニット５０は、ガスケット５５よりも融点または荷重たわみ温度が高い絶縁部材５６をさらに有する。絶縁部材５６は、２５℃における線膨張係数が２．０×１０-5／Ｋ以上の熱膨張材料で構成されるが、これに限定されるものではない。例えば、絶縁部材５６は、セラミックスを主成分として含んでもよい。絶縁部材５６は、上記第１接合部Ｊよりも外周寄りに配置され、第１絶縁部５６ａ、第２絶縁部５６ｂ、および第３絶縁部５６ｃを含む。第１絶縁部５６ａは、集電板５４の周縁部と導電性キャップ５１の周縁部との間に配置される。第２絶縁部５６ｂは、第１絶縁部５６ａの外周端部からケース２０の軸方向（図１における上方）に延び、かつ導電性キャップ５１とガスケット５５との間に位置する。第３絶縁部５６ｃは、第２絶縁部５６ｂの端部（図１における上端部）からケース２０の径方向内側に延び、かつ導電性キャップ５１とガスケット５５との間に位置する。 The sealing unit 50 further includes an insulating member 56 having a melting point or deflection temperature under load higher than that of the gasket 55. The insulating member 56 is made of a thermal expansion material having a linear expansion coefficient of 2.0×10 −5 /K or more at 25° C., but is not limited thereto. For example, the insulating member 56 may contain ceramics as a main component. The insulating member 56 is disposed closer to the outer periphery than the first joint J, and includes a first insulating portion 56a, a second insulating portion 56b, and a third insulating portion 56c. The first insulating portion 56a is disposed between the peripheral portion of the current collector plate 54 and the peripheral portion of the conductive cap 51. The second insulating portion 56b extends from the outer peripheral end of the first insulating portion 56a in the axial direction of the case 20 (upward in FIG. 1 ) and is located between the conductive cap 51 and the gasket 55. The third insulating portion 56 c extends radially inward of the case 20 from an end (the upper end in FIG. 1 ) of the second insulating portion 56 b , and is positioned between the conductive cap 51 and the gasket 55 .
　導電性キャップ５１の外周縁から第１接合部Ｊまでの径方向距離をＤとして、導電性キャップ５１の外周縁から第１絶縁部５６ａの内周端部までの径方向距離は、０．２５Ｄ以上であり、好ましくは０．５Ｄ以上であり、より好ましくは０．８Ｄ以上である。 The radial distance from the outer peripheral edge of the conductive cap 51 to the first joint J is D, and the radial distance from the outer peripheral edge of the conductive cap 51 to the inner peripheral end of the first insulating portion 56a is 0.25D or more, preferably 0.5D or more, and more preferably 0.8D or more.
　電極群３０と封口ユニット５０との間には、第１絶縁板８１および第２絶縁板８２が設けられる。第１絶縁板８１は、第２絶縁板８２よりも電極群３０側（図１における下側）に配置される。第１絶縁板８１は、電極群３０と正極リード４１との間に介在して、電極群３０の負極と正極リード４１との接触を阻止する。第２絶縁板８２は、ケース２０と正極リード４１との間に介在して、ケース２０と正極リード４１との接触を阻止する。 A first insulating plate 81 and a second insulating plate 82 are provided between the electrode group 30 and the sealing unit 50. The first insulating plate 81 is disposed closer to the electrode group 30 (lower side in FIG. 1 ) than the second insulating plate 82. The first insulating plate 81 is interposed between the electrode group 30 and the positive electrode lead 41 to prevent contact between the negative electrode of the electrode group 30 and the positive electrode lead 41. The second insulating plate 82 is interposed between the case 20 and the positive electrode lead 41 to prevent contact between the case 20 and the positive electrode lead 41.
　図３は、本実施形態の電池１０において燃焼が生じる前と後の状態をそれぞれ示す。同図に示すように、電池１０において燃焼が生じると、ガスケット５５が溶融して、集電板５４の周縁部がケース２０に接触し得る。しかし、本実施形態の電池１０では、集電板５４の周縁部と導電性キャップ５１の周縁部との間に、融点または荷重たわみ温度の高い絶縁部材５６が介在しているので、ケース２０と導電性キャップ５１とが電気的に導通することが抑制される。なお、集電板５４における内周寄りの領域は燃焼時に溶融することもあるが、溶け残ることもある。後者の場合、第１接合部Ｊを介してケース２０と導電性キャップ５１とが電気的に導通するおそれがあるが、本実施形態の絶縁部材５６は燃焼時の熱で大きく膨張するので、当該膨張によって第１接合部Ｊにおける接合が解除される。以上のように、本実施形態の電池１０では、燃焼時の内部短絡が抑制され得る。 3 shows the battery 10 of this embodiment before and after combustion occurs. As shown in the figure, when combustion occurs in the battery 10, the gasket 55 melts and the peripheral portion of the current collector 54 may come into contact with the case 20. However, in the battery 10 of this embodiment, an insulating member 56 with a high melting point or deflection temperature under load is interposed between the peripheral portion of the current collector 54 and the peripheral portion of the conductive cap 51, so that electrical conduction between the case 20 and the conductive cap 51 is suppressed. Note that the area near the inner circumference of the current collector 54 may melt during combustion, but may remain unmelted. In the latter case, there is a risk of electrical conduction between the case 20 and the conductive cap 51 through the first joint J, but the insulating member 56 of this embodiment expands significantly due to the heat during combustion, and the expansion causes the joint at the first joint J to be released. As described above, in the battery 10 of this embodiment, an internal short circuit during combustion can be suppressed.
　《付記》
　以上の実施形態の記載により、下記の技術が開示される。
　（技術１）
　一端に開口を有する有底筒状のケースと、
　前記ケースに収容され、第１電極および第２電極を有する電極群と、
　前記開口を封口する封口ユニットと、
を備え、
　前記ケースは、前記封口ユニットを固定するかしめ部を有し、かつ前記第１電極と電気的に接続され、
　前記封口ユニットは、
　前記第２電極と電気的に接続される集電板と、
　前記集電板よりも前記ケースの軸方向外側に配置され、前記集電板に第１接合部で接合される導電性キャップと、
　前記かしめ部と前記集電板および前記導電性キャップとの間に介在する絶縁性のガスケットと、
　前記集電板の周縁部と前記導電性キャップの周縁部との間に配置された第１絶縁部を含む絶縁部材と、
を有し、
　前記第１絶縁部は、前記第１接合部よりも外周寄りに配置されている、電池。
　（技術２）
　前記絶縁部材は、前記第１絶縁部の外周端部から前記ケースの軸方向に延び、かつ前記導電性キャップと前記ガスケットとの間に位置する第２絶縁部をさらに含む、技術１に記載の電池。
　（技術３）
　前記絶縁部材は、前記第２絶縁部の端部から前記ケースの径方向内側に延び、かつ前記導電性キャップと前記ガスケットとの間に位置する第３絶縁部をさらに含む、技術２に記載の電池。
　（技術４）
　前記絶縁部材は、２５℃における線膨張係数が２．０×１０-5／Ｋ以上の熱膨張材料で構成される、技術１～３のいずれか１つに記載の電池。
　（技術５）
　前記導電性キャップの外周縁から前記第１接合部までの径方向距離をＤとして、前記導電性キャップの外周縁から前記第１絶縁部の内周端部までの径方向距離は、０．２５Ｄ以上である、技術４に記載の電池。
　（技術６）
　前記第１絶縁部は、前記ガスケットよりも融点または荷重たわみ温度が高い、技術１～５のいずれか１つに記載の電池。
　（技術７）
　前記第１絶縁部は、セラミックスを含む、技術１～６のいずれか１つに記載の電池。 Additional Notes
The above description of the embodiments discloses the following techniques.
(Technique 1)
A cylindrical case having an opening at one end and a bottom;
an electrode group housed in the case and having a first electrode and a second electrode;
a sealing unit that seals the opening;
Equipped with
the case has a crimping portion that fixes the sealing unit and is electrically connected to the first electrode,
The sealing unit includes:
a current collector plate electrically connected to the second electrode;
a conductive cap disposed axially outboard of the case relative to the current collecting plate and joined to the current collecting plate at a first joint portion;
an insulating gasket interposed between the crimping portion and the current collecting plate and between the crimping portion and the conductive cap;
an insulating member including a first insulating portion disposed between a peripheral portion of the current collecting plate and a peripheral portion of the conductive cap;
having
The first insulating portion is disposed closer to an outer periphery than the first joint portion.
(Technique 2)
The battery described in Technology 1, wherein the insulating member further includes a second insulating portion extending in the axial direction of the case from the outer peripheral end of the first insulating portion and positioned between the conductive cap and the gasket.
(Technique 3)
The battery according to claim 2, wherein the insulating member further includes a third insulating portion extending radially inward from an end of the second insulating portion and positioned between the conductive cap and the gasket.
(Technique 4)
The battery according to any one of Techniques 1 to 3, wherein the insulating member is made of a thermal expansion material having a linear expansion coefficient at 25° C. of 2.0×10 −5 /K or more.
(Technique 5)
The battery according to Technology 4, wherein the radial distance from the outer peripheral edge of the conductive cap to the first joint portion is D, and the radial distance from the outer peripheral edge of the conductive cap to the inner peripheral end of the first insulating portion is 0.25D or more.
(Technique 6)
The battery according to any one of claims 1 to 5, wherein the first insulating portion has a melting point or a deflection temperature under load higher than that of the gasket.
(Technique 7)
The battery according to any one of claims 1 to 6, wherein the first insulating portion includes ceramics.
　本発明を現時点での好ましい実施態様に関して説明したが、そのような開示を限定的に解釈してはならない。種々の変形および改変は、上記開示を読むことによって本発明に属する技術分野における当業者には間違いなく明らかになるであろう。したがって、添付の請求の範囲は、本発明の真の精神および範囲から逸脱することなく、すべての変形および改変を包含する、と解釈されるべきものである。 Although the present invention has been described with respect to the presently preferred embodiments, such disclosure is not to be interpreted as limiting. Various modifications and alterations will no doubt become apparent to those skilled in the art to which the present invention pertains upon reading the above disclosure. Accordingly, the appended claims should be construed to embrace all such modifications and alterations without departing from the true spirit and scope of the invention.
　本開示は、電池に利用できる。 This disclosure can be used in batteries.
１０：電池
　２０：ケース
　　２１：側壁部
　　　２２：かしめ部
　　２３：底部
　３０：電極群
　４１：正極リード
　５０：封口ユニット
　　５１：導電性キャップ
　　５４：集電板
　　５５：ガスケット
　　５６：絶縁部材
　　　５６ａ：第１絶縁部
　　　５６ｂ：第２絶縁部
　　　５６ｃ：第３絶縁部
　８１：第１絶縁板
　８２：第２絶縁板
Ｊ：第１接合部
  10: Battery 20: Case 21: Side wall portion 22: Crimping portion 23: Bottom portion 30: Electrode group 41: Positive electrode lead 50: Sealing unit 51: Conductive cap 54: Current collector plate 55: Gasket 56: Insulating member 56a: First insulating portion 56b: Second insulating portion 56c: Third insulating portion 81: First insulating plate 82: Second insulating plate J: First joint portion

Claims (7)

  1. 　一端に開口を有する有底筒状のケースと、
    　前記ケースに収容され、第１電極および第２電極を有する電極群と、
    　前記開口を封口する封口ユニットと、
    を備え、
    　前記ケースは、前記封口ユニットを固定するかしめ部を有し、かつ前記第１電極と電気的に接続され、
    　前記封口ユニットは、
    　前記第２電極と電気的に接続される集電板と、
    　前記集電板よりも前記ケースの軸方向外側に配置され、前記集電板に第１接合部で接合される導電性キャップと、
    　前記かしめ部と前記集電板および前記導電性キャップとの間に介在する絶縁性のガスケットと、
    　前記集電板の周縁部と前記導電性キャップの周縁部との間に配置された第１絶縁部を含む絶縁部材と、
    を有し、
    　前記第１絶縁部は、前記第１接合部よりも外周寄りに配置されている、電池。     A cylindrical case having an opening at one end and a bottom;
    an electrode group housed in the case and having a first electrode and a second electrode;
    a sealing unit that seals the opening;
    Equipped with
    the case has a crimping portion that fixes the sealing unit and is electrically connected to the first electrode,
    The sealing unit includes:
    a current collector plate electrically connected to the second electrode;
    a conductive cap disposed axially outboard of the case relative to the current collecting plate and joined to the current collecting plate at a first joint portion;
    an insulating gasket interposed between the crimping portion and the current collecting plate and between the crimping portion and the conductive cap;
    an insulating member including a first insulating portion disposed between a peripheral portion of the current collecting plate and a peripheral portion of the conductive cap;
    having
    The first insulating portion is disposed closer to an outer periphery than the first joint portion.
  2. 　前記絶縁部材は、前記第１絶縁部の外周端部から前記ケースの軸方向に延び、かつ前記導電性キャップと前記ガスケットとの間に位置する第２絶縁部をさらに含む、請求項１に記載の電池。 The battery of claim 1, wherein the insulating member further includes a second insulating portion extending from the outer peripheral end of the first insulating portion in the axial direction of the case and positioned between the conductive cap and the gasket.
  3. 　前記絶縁部材は、前記第２絶縁部の端部から前記ケースの径方向内側に延び、かつ前記導電性キャップと前記ガスケットとの間に位置する第３絶縁部をさらに含む、請求項２に記載の電池。 The battery of claim 2, wherein the insulating member further includes a third insulating portion extending radially inward from an end of the second insulating portion and positioned between the conductive cap and the gasket.
  4. 　前記絶縁部材は、２５℃における線膨張係数が２．０×１０-5／Ｋ以上の熱膨張材料で構成される、請求項１～３のいずれか１項に記載の電池。 4. The battery according to claim 1, wherein the insulating member is made of a thermal expansion material having a linear expansion coefficient at 25° C. of 2.0×10 −5 /K or more.
  5. 　前記導電性キャップの外周縁から前記第１接合部までの径方向距離をＤとして、前記導電性キャップの外周縁から前記第１絶縁部の内周端部までの径方向距離は、０．２５Ｄ以上である、請求項４に記載の電池。 The battery of claim 4, wherein the radial distance from the outer periphery of the conductive cap to the first joint is D, and the radial distance from the outer periphery of the conductive cap to the inner end of the first insulating portion is 0.25D or more.
  6. 　前記第１絶縁部は、前記ガスケットよりも融点または荷重たわみ温度が高い、請求項１～３のいずれか１項に記載の電池。 The battery according to any one of claims 1 to 3, wherein the first insulating part has a melting point or a deflection temperature under load higher than that of the gasket.
  7. 　前記第１絶縁部は、セラミックスを含む、請求項１～３のいずれか１項に記載の電池。
          The battery according to claim 1 , wherein the first insulating portion includes ceramics.
PCT/JP2023/034053 2022-10-27 2023-09-20 Battery WO2024090080A1 (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10247483A (en) * 1997-03-04 1998-09-14 Mitsubishi Cable Ind Ltd Safety structure of sealed battery
JPH10270003A (en) * 1997-03-27 1998-10-09 Toray Ind Inc Sealed battery
WO2010125755A1 (en) * 2009-04-27 2010-11-04 パナソニック株式会社 Assembled sealing body and battery using same
KR20120052586A (en) * 2010-11-16 2012-05-24 주식회사 엘지화학 Cap assembly and secondary battery using the same

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH10247483A (en) * 1997-03-04 1998-09-14 Mitsubishi Cable Ind Ltd Safety structure of sealed battery
JPH10270003A (en) * 1997-03-27 1998-10-09 Toray Ind Inc Sealed battery
WO2010125755A1 (en) * 2009-04-27 2010-11-04 パナソニック株式会社 Assembled sealing body and battery using same
KR20120052586A (en) * 2010-11-16 2012-05-24 주식회사 엘지화학 Cap assembly and secondary battery using the same

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