WO2015041201A1 - Overcharging prevention unit and secondary battery - Google Patents

Overcharging prevention unit and secondary battery Download PDF

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Publication number
WO2015041201A1
WO2015041201A1 PCT/JP2014/074360 JP2014074360W WO2015041201A1 WO 2015041201 A1 WO2015041201 A1 WO 2015041201A1 JP 2014074360 W JP2014074360 W JP 2014074360W WO 2015041201 A1 WO2015041201 A1 WO 2015041201A1
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WO
WIPO (PCT)
Prior art keywords
short
circuit lead
lead
negative electrode
positive electrode
Prior art date
Application number
PCT/JP2014/074360
Other languages
French (fr)
Japanese (ja)
Inventor
博清 間明田
信保 根岸
直樹 岩村
橋本　達也
Original Assignee
株式会社 東芝
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.)
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Publication date
Application filed by 株式会社 東芝 filed Critical 株式会社 東芝
Priority to CN201480047260.2A priority Critical patent/CN105518925A/en
Publication of WO2015041201A1 publication Critical patent/WO2015041201A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/48—Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte
    • 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
    • H01M50/574—Devices or arrangements for the interruption of current
    • H01M50/583—Devices or arrangements for the interruption of current in response to current, e.g. fuses
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
    • H02J7/0031—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits using battery or load disconnect circuits
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
    • H02J7/00302—Overcharge protection
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • Embodiments of the present invention relate to an overcharge prevention unit and a secondary battery.
  • the secondary battery includes a fuse that cuts off a charging current supplied from an external device when an overcharge state occurs. When the battery voltage exceeds a predetermined voltage, the fuse melts and interrupts the charging current supplied from the external device.
  • the overcharge prevention unit includes a current interrupting unit, a first short-circuit lead, a second short-circuit lead, a voltage detection unit, and a connection unit.
  • the current interrupting unit is electrically connected at one end to one electrode terminal of the secondary battery, and cuts off when a predetermined current passes.
  • the first short-circuit lead is electrically connected to the other end of the current interrupting part.
  • the second short-circuit lead is electrically connected to the other electrode terminal of the secondary battery.
  • the voltage detector measures a voltage between the first short-circuit lead and the second short-circuit lead.
  • the connection unit electrically connects the first short-circuit lead and the second short-circuit lead when the voltage measured by the voltage detection unit exceeds a predetermined threshold.
  • FIG. 1 is a block diagram illustrating a configuration example of the secondary battery system according to the first embodiment.
  • FIG. 2 is a diagram illustrating an example of current flow in the secondary battery system according to the first embodiment.
  • FIG. 3 is a diagram illustrating an example of a current flow of the secondary battery system according to the first embodiment.
  • FIG. 4 is a diagram illustrating an example of current flow in the secondary battery system according to the first embodiment.
  • FIG. 5 is a block diagram illustrating a configuration example of the secondary battery system according to the second embodiment.
  • FIG. 6 is a block diagram illustrating an example of a top view of the secondary battery according to the second embodiment.
  • FIG. 1 is a block diagram illustrating a configuration example of the secondary battery system according to the first embodiment.
  • the secondary battery system includes a secondary battery 1, a charging device 20, wirings 29a and b, and the like.
  • the secondary battery 1 includes an outer can 2, an electrode group 3 housed in the outer can 2, an internal positive electrode lead 4, an internal negative electrode lead 5, a positive electrode terminal 6, and a negative electrode terminal. 7, a cap plate 15, an insulating member 16, and an overcharge prevention unit 30.
  • An electrolyte (not shown) is held in the electrode group 3.
  • the outer can 2 has a box shape formed on a rectangle, and the upper surface of the outer can 2 is open.
  • the outer can 2 can be formed from, for example, aluminum or an aluminum alloy.
  • the aluminum alloy is an alloy containing elements such as magnesium, zinc, and silicon.
  • transition metals, such as iron, copper, nickel, and chromium are contained in the alloy, the amount is, for example, 100 ppm or less.
  • the plate thickness of the outer can can be 1 mm or less, and may be 0.5 mm or less.
  • the electrode group 3 has a positive electrode and a negative electrode wound in a flat shape with a separator between them.
  • the positive electrode is a positive current collector except for a strip-shaped positive current collector made of, for example, a metal foil, a positive current collector tab 10 having one end parallel to the long side of the positive current collector, and at least the positive current collector tab 10 portion.
  • the negative electrode is, for example, a strip-shaped negative electrode current collector made of a metal foil, a negative electrode current collector tab 11 having one end parallel to the long side of the negative electrode current collector, and at least the negative electrode current collector tab 11 portion.
  • a negative electrode material layer (negative electrode active material-containing layer) formed on the negative electrode current collector.
  • Such a positive electrode, separator and negative electrode have a positive electrode and a negative electrode so that the positive electrode current collecting tab 10 protrudes from the separator in the winding axis direction of the electrode group and the negative electrode current collecting tab 11 protrudes from the separator in the opposite direction. It has been wound around the position of. By such winding, as shown in FIG. 1, the electrode group 3 has the positive electrode current collecting tab 10 wound in a spiral shape from one end face and is wound in a spiral form from the other end face. The negative electrode current collection tab 11 protrudes.
  • the positive electrode current collector tab 10 and the negative electrode current collector tab 11 are selected from the group consisting of aluminum, Mg, Ti, Zn, Mn, Fe, Cu, and Si, even if formed from the same material as the positive and negative electrode current collectors. You may form from the aluminum alloy containing an at least 1 sort (s) of element.
  • the internal positive electrode lead 4 and the internal negative electrode lead 5 are each made of a strip-shaped conductive plate.
  • the internal positive electrode lead 4 is electrically connected to the positive electrode current collecting tab 10, and the internal negative electrode lead 5 is electrically connected to the negative electrode current collecting tab 11.
  • the positive electrode terminal 6 and the negative electrode terminal 7 are each fixed to the cap plate 15 via an insulating member 16.
  • the tip of the internal positive electrode lead 4 is electrically connected to the positive electrode terminal 6, and the tip of the internal negative electrode lead 5 is electrically connected to the negative electrode terminal 7.
  • the cap plate 15 is a plate that covers the upper surface of the outer can 2.
  • the cap plate 15 includes a hole through which the positive electrode terminal 6 passes and a hole through which the negative electrode terminal 7 passes.
  • the cap plate 15 fixes the positive terminal 6 and the negative terminal 7 through an insulating member 16 installed in the hole.
  • the cap plate 15 fixes the positive electrode short-circuit lead 8, the negative electrode short-circuit lead 9, the insulator 13, the voltage detection unit 14, and the like through an insulating material (not shown).
  • the cap plate 15 can be formed from, for example, aluminum or an aluminum alloy.
  • the positive electrode, negative electrode, separator, and electrolyte of the secondary battery 1 will be described.
  • the positive electrode, negative electrode, separator, and electrolyte of the secondary battery 1 will be described.
  • the positive electrode includes a positive electrode current collector and a positive electrode material layer that is supported on one or both surfaces of the current collector and includes a positive electrode active material.
  • the positive electrode active material examples include lithium-containing composite compounds, manganese dioxide (MnO2), iron oxide, copper oxide, nickel oxide, conductive polymer materials such as polyaniline and polypyrrole, disulfide polymer materials, sulfur (S), and fluoride.
  • lithium-containing composite compounds include carbon, iron sulfate (Fe2 (SO4) 3), and vanadium oxide (for example, V2O5).
  • lithium-containing composite compounds are preferable.
  • lithium-containing composite compound examples include LiaMnO 2 (0 ⁇ a ⁇ 1.2), lithium cobalt composite oxide (LiaCoMhO 2, where M is selected from the group consisting of Al, Cr, Mg, and Fe, or 2 or more elements, 0 ⁇ a ⁇ 1.2, 0 ⁇ h ⁇ 0.1), lithium manganese cobalt composite oxide (for example, LiMn1-g-hCogMhO2, where M is composed of Al, Cr, Mg, and Fe) At least one or more elements selected from the group, 0 ⁇ g ⁇ 0.5, 0 ⁇ h ⁇ 0.1), lithium manganese nickel composite oxide ⁇ for example, LiMnjNijM1-2jO2 (M is Co, Cr , Al, Mg and Fe, at least one or more elements selected from the group consisting of 1/3 ⁇ j ⁇ 1/2), LiMn1 / 3Ni / 3Co1 / 3O2, LiMn1 / 2Ni1 / 2O
  • the positive electrode material layer contains a binder
  • a binder for example, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), or fluorine-based rubber can be used as the binder.
  • the positive electrode material layer may contain a conductive agent.
  • the conductive agent include carbonaceous materials such as acetylene black, carbon black, and graphite.
  • the blending ratio of the positive electrode active material, the conductive agent and the binder may be 73 to 95% by weight of the positive electrode active material, 3 to 20% by weight of the conductive agent, and 2 to 7% by weight of the binder.
  • the positive electrode current collector may be formed from an aluminum foil or an aluminum alloy foil.
  • the thickness of the aluminum foil and the aluminum alloy foil can be 20 ⁇ m or less, and may be 15 ⁇ m or less.
  • the purity of the aluminum foil may be 99% by mass or more.
  • the aluminum alloy may be an alloy containing elements such as magnesium, zinc, and silicon.
  • the content of transition metals such as iron, copper, nickel, and chromium may be 1% by mass or less.
  • a conductive agent and a binder are added to the positive electrode active material, these are suspended in an appropriate solvent, and this suspension (slurry) is applied to a current collector, dried and pressed to form a strip electrode It is produced by making.
  • the negative electrode includes a negative electrode current collector and a negative electrode material layer that is supported on one or both surfaces of the negative electrode current collector and includes a negative electrode active material.
  • the negative electrode active material examples include metal lithium and a material capable of occluding and releasing lithium ions.
  • a substance capable of inserting and extracting lithium ions for example, lithium titanium composite oxide can be given.
  • the lithium-titanium composite oxide includes, for example, Li4 + xTi5O12 (x varies in the range of ⁇ 1 ⁇ x ⁇ 3 by charge / discharge reaction), ramsteride type Li2 + xTi3O7 (x is charge / discharge) And a metal composite oxide containing at least one element selected from the group consisting of Ti and P, V, Sn, Cu, Ni and Fe. It is done.
  • Examples of the metal composite oxide containing at least one element selected from the group consisting of Ti and P, V, Sn, Cu, Ni and Fe include TiO2-P2O5, TiO2-V2O5, TiO2-P2O5-SnO2 TiO2-P2O5-MeO (Me is at least one element selected from the group consisting of Cu, Ni and Fe). These metal composite oxides change to lithium titanium composite oxides when lithium is inserted by charging.
  • the lithium titanium composite oxide may be spinel type lithium titanate.
  • lithium ions include, for example, carbonaceous materials and metal compounds.
  • Examples of the carbonaceous material include natural graphite, artificial graphite, coke, vapor-grown carbon fiber, mesophase pitch-based carbon fiber, spherical carbon, and resin-fired carbon.
  • examples of the carbonaceous material include vapor grown carbon fiber, mesophase pitch carbon fiber, and spherical carbon.
  • the carbonaceous material may have a (002) plane spacing d002 of 0.34 nm or less by X-ray diffraction.
  • the metal compound can be a metal sulfide or metal nitride.
  • the metal sulfide titanium sulfide such as TiS2, for example, molybdenum sulfide such as MoS2, for example, iron sulfide such as FeS, FeS2, and LixFeS2 can be used.
  • the metal nitride for example, lithium cobalt nitride (for example, LisCotN, 0 ⁇ s ⁇ 4, 0 ⁇ t ⁇ 0.5) can be used.
  • a copper foil, an aluminum foil, or an aluminum alloy foil can be used as the current collector.
  • the thickness of the aluminum foil or aluminum alloy foil may be 20 ⁇ m or less, or 15 ⁇ m or less.
  • the aluminum foil may have a purity of 99% by mass or more.
  • the aluminum alloy may be an alloy containing elements such as magnesium, zinc, and silicon. 1 mass% or less may be sufficient as transition metals, such as iron, copper, nickel, and chromium contained as an alloy component.
  • the negative electrode material layer can contain a binder.
  • binder examples include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), fluorine rubber, and styrene butadiene rubber.
  • the negative electrode material layer can contain a conductive agent.
  • the conductive agent include carbonaceous materials such as acetylene black, carbon black, and graphite.
  • the mixing ratio of the negative electrode active material, the conductive agent and the binder may be in the range of 73 to 96% by weight of the negative electrode active material, 2 to 20% by weight of the conductive agent, and 2 to 7% by weight of the binder.
  • the negative electrode is prepared by adding a conductive agent and a binder to a powdered negative electrode active material, suspending them in a suitable solvent, applying the suspension (slurry) to a current collector, drying, and pressing. It is produced by forming a strip electrode.
  • the separator is not particularly limited as long as it has insulating properties, but a porous film or a nonwoven fabric made of a polymer such as polyolefin, cellulose, polyethylene terephthalate, and vinylon can be used.
  • a porous film or a nonwoven fabric made of a polymer such as polyolefin, cellulose, polyethylene terephthalate, and vinylon can be used.
  • One type of separator material may be used, or two or more types may be used in combination.
  • the nonaqueous electrolyte includes a nonaqueous solvent and an electrolyte salt dissolved in the nonaqueous solvent.
  • the non-aqueous solvent may contain a polymer.
  • the overcharge prevention unit 30 includes a positive electrode short-circuit lead 8, a negative electrode short-circuit lead 9, a current interruption unit 12, an insulator 13, and a voltage detection unit 14.
  • the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 are each made of a strip-shaped conductive plate.
  • the positive electrode short-circuit lead 8 is electrically connected to the current interrupting unit 12, and the negative electrode short-circuit lead 9 is electrically connected to the negative electrode terminal 7.
  • the electrical connection of each part is performed by welding, caulking fixation, etc., for example.
  • the internal positive and negative electrode leads, the positive and negative electrode short-circuit leads and the positive and negative electrode terminals are made of, for example, an aluminum alloy containing at least one element selected from the group consisting of aluminum, Mg, Ti, Zn, Mn, Fe, Cu and Si. Can be used. Cu and Cu alloys having a melting point higher than that of Al may be coated on the contacts between the components and the periphery thereof.
  • the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 are formed so as to generate stress in a direction in which they contact each other.
  • the positive electrode short-circuit lead 8 is formed such that the tip thereof generates stress upward in FIG.
  • the negative electrode short-circuit lead 9 is formed such that the tip thereof generates a downward stress in FIG.
  • either the positive electrode short-circuit lead 8 or the negative electrode short-circuit lead 9 may be formed so as to generate stress in a direction in contact with the other.
  • An insulator 13 is formed between the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9.
  • the insulator 13 prevents the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 from being energized.
  • the insulator 13 is formed so as to be pulled in the direction of being drawn from between the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9.
  • the insulator 13 is fixed to the cap plate 15 in a state where stress is applied. For this reason, the insulator 13 is structured to be pulled out from between the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 when a part thereof is cut.
  • the insulator 13 is made of a material that is cut by Joule heat generated from the electric power of the electrode group 3.
  • the insulator 13 may be applied with stress via another member. In this case, when the member is cut, the insulator 13 is pulled out from between the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9.
  • the current interrupting unit 12 interrupts a passing current when a current exceeding a predetermined threshold flows.
  • One of the current interrupting units 12 is connected to the positive electrode terminal 6, and the other is connected to the positive electrode short-circuit lead 8. That is, the current interrupting unit 12 interrupts the current flowing between the positive electrode terminal 6 and the positive electrode short-circuit lead 8.
  • the current interrupting unit 12 melts when the current flowing through the current interrupting unit 12 exceeds a predetermined threshold, and interrupts the current flowing through the positive electrode short-circuit lead 8.
  • the current interrupting unit 12 is a fuse or the like.
  • the current interrupting unit 12 may have a structure in which an area of a part of a cross section is smaller than that of another part. The current interrupting unit 12 may be replaceable.
  • the current interruption unit 12 is set with a current generated when the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 are electrically connected as a threshold value. That is, the current interrupting unit 12 interrupts the current that passes when the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 are electrically connected.
  • the voltage detection unit 14 measures a voltage generated between the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9. When the measured voltage exceeds a predetermined threshold, the voltage detector 14 applies a voltage generated between the positive terminal 6 and the negative terminal 7 to a cutting unit (not shown).
  • the voltage detection unit 14 may include a transistor or the like, and may apply a voltage to the cutting unit using the transistor.
  • the voltage detection unit 14 is set with a voltage generated between the positive electrode short-circuited lead 8 and the negative electrode short-circuited lead 9 as a threshold when an overcharge state occurs.
  • the threshold set in the voltage detector 14 is determined according to the type of the secondary battery 1 and the like. For example, the voltage detection unit 14 is set to 3.5 V as the threshold value.
  • the cutting means cuts the insulator 13 when a voltage is applied.
  • the cutting means is formed from, for example, nichrome wire.
  • the cutting means is disposed at a position where the insulator 13 can be heated.
  • the cutting means may be formed to wrap around the insulator 13.
  • the cutting means When the voltage is applied, the cutting means generates heat and melts a part of the insulator 13. As a result, the insulator 13 is cut and pulled out from between the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9.
  • the cutting means may cut a member applying a stress to the insulator 13.
  • the charging device 20 charges the secondary battery 1 with electric power.
  • the charging device 20 is electrically connected to the secondary battery 1 via the wirings 21a and b.
  • the charging device 20 applies a predetermined voltage between the positive electrode short-circuited lead 8 and the negative electrode short-circuited lead 9 via the wirings 21 a and b.
  • FIG. 2 is a circuit diagram showing an example of current flowing through the secondary battery system in a normal charge state (that is, not in an overcharge state).
  • the current flowing through the current interrupting unit 12 is smaller than the current at which the current interrupting unit 12 melts. For this reason, the current interrupting unit 12 electrically connects the positive electrode terminal 6 and the positive electrode short-circuit lead 8 without melting.
  • the current flowing through the secondary battery system when an overcharge state occurs will be described.
  • the secondary battery 1 When the secondary battery 1 is overcharged, the secondary battery 1 generates a voltage higher than normal (that is, a voltage higher than a threshold set in the voltage detection unit 14).
  • the voltage detection unit 14 detects a voltage higher than the threshold value.
  • the voltage detection unit 14 causes the cutting unit to apply a voltage generated between the positive terminal 6 and the negative terminal 7.
  • the cutting means When the voltage detector 14 applies a voltage to the cutting means, the cutting means generates Joule heat. When Joule heat is generated, the cutting means heats and melts a part of the insulator 13.
  • the insulator 13 When the cutting means melts a part of the insulator 13, the insulator 13 is cut and pulled out from between the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9. When the insulator 13 is pulled out from between the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9, the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 come into contact with each other and are electrically connected.
  • FIG. 3 is a circuit diagram showing a current flow immediately after the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 are electrically connected.
  • the current flows from the positive electrode side of the electrode group 3.
  • the current passes through the positive electrode current collecting tab 10, the internal positive electrode lead 4 and the positive electrode terminal 6.
  • the current flows to the current interrupting unit 12.
  • the current flows through the positive electrode short-circuit lead 8, the negative electrode short-circuit lead 9, the negative electrode terminal 7, the internal negative electrode lead 5, and the negative electrode current collecting tab 11.
  • the current flows to the negative electrode side of the electrode group 3.
  • the current flowing through the current interrupting unit 12 exceeds the threshold value of the current that the current interrupting unit 12 cuts. Therefore, after the state shown in FIG. 3 occurs, the current interrupting unit 12 cuts off and disconnects the electrical connection between the positive electrode terminal 6 and the positive electrode short-circuit lead 8.
  • FIG. 4 is a circuit diagram showing a current flow after the current interrupting unit 12 is disconnected.
  • the current from the charging device 20 is not supplied to the inside of the secondary battery 1. Therefore, the secondary battery 1 is not further charged with electric power from the charging device 20, and the overcharged state of the secondary battery 1 converges.
  • the secondary battery 1 may include a current interrupting unit 12 between the negative electrode terminal 7 and the negative electrode short-circuit lead 9.
  • the secondary battery configured as described above can include a voltage detection unit outside. Therefore, the voltage detection unit can operate without being affected by the temperature and pressure in the outer can. Therefore, the secondary battery can reliably melt the current interrupting part when an overcharged state occurs.
  • the secondary battery can be provided with a current interrupting unit outside. This facilitates replacement of the current interrupting unit. Furthermore, the energy density of the secondary battery is improved.
  • the current interruption unit 12 is between the positive terminal 6 and the internal positive electrode lead 4, and the overcharge prevention unit 30 includes a driver, a fastening mechanism, a heating unit, and the like. It differs from the secondary battery 1 in 1st Embodiment by the point provided. Therefore, the other parts are denoted by the same reference numerals, and detailed description thereof is omitted.
  • FIG. 5 is a block diagram illustrating a configuration example of the secondary battery system according to the embodiment.
  • FIG. 6 is a top view of the secondary battery according to the embodiment.
  • the secondary battery 1 includes a current interrupting unit 12 between the internal positive electrode lead 4 and the positive electrode terminal 6.
  • the current interrupting unit 12 interrupts the current flowing between the internal positive electrode lead 4 and the positive electrode terminal 6 when a current exceeding a predetermined threshold value passes.
  • the current interrupting unit 12 may be formed as a part of the internal positive electrode lead 54. In this case, the current interrupting part 12 may be formed thinner than the other part of the internal positive electrode lead 4.
  • the overcharge prevention unit 30 includes a positive electrode short-circuit lead 8, a negative electrode short-circuit lead 9, a driving body 22, a fastening mechanism 23, a heating unit 24, and the like.
  • the positive electrode short-circuit lead 8 is electrically connected to the positive electrode terminal 6. Further, unlike the first embodiment, the positive electrode short-circuit lead 8 does not generate stress in any direction.
  • the negative electrode short-circuit lead 9 extends to the front of the positive electrode short-circuit lead 8 and is bent downward therefrom.
  • the negative electrode short-circuit lead 9 extends below the thickness of the positive electrode short-circuit lead 8.
  • the negative electrode short-circuit lead 9 extends a predetermined length from there to the positive electrode short-circuit lead 8.
  • the negative electrode short-circuit lead 9 is formed such that the tip of the negative electrode short-circuit lead 9 lies under the positive electrode short-circuit lead 8.
  • the negative electrode short-circuit lead 9 is provided with a hole for passing the fastening mechanism 23 on the negative electrode terminal 7 side rather than a portion bent downward.
  • the driving body 22 is an elastic body that generates stress according to pressure from the outside. When the driving body 22 is compressed, a stress is generated in a direction opposite to the direction in which the driving body 22 is compressed.
  • the drive body 22 is, for example, a plate spring, a thin plate spring, a torsion coil spring, or a coil spring.
  • the driving body 22 is installed between the negative electrode short-circuit lead 9 and the upper surface of the outer can 2 in a compressed state. Therefore, the driver 22 continues to apply upward stress to the negative electrode short-circuit lead 9. That is, the driving body 22 continues to apply stress to the negative electrode short-circuit lead 9 in a direction in which the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 are brought into contact with each other.
  • the fastening mechanism 23 prevents the negative electrode short-circuit lead 9 from moving upward against the stress applied by the driver 22.
  • the fastening mechanism 23 is fixed to the upper surface of the outer can 2.
  • the fastening mechanism 23 is formed so as to penetrate the negative electrode short-circuit lead 9 and have a tip protruding from the negative electrode short-circuit lead 9.
  • the front end of the fastening mechanism 23 is formed larger than the hole of the negative electrode short-circuit lead 9 and prevents the negative electrode short-circuit lead 9 from moving upward.
  • the fastening mechanism 23 is an insulator having a hardness necessary for fixing the negative electrode short-circuit lead 9.
  • the fastening mechanism 23 is formed of a material that is melted by the heat of the heating unit 24 that is heated by the voltage generated by the secondary battery 1 and that is cut without extending due to melting.
  • the material constituting the fastening mechanism 23 is determined by the voltage of the secondary battery 1, the stress of the driving body 22, the configuration of the negative electrode short-circuit lead 9, and the like, and is not limited to a specific material.
  • the substance constituting the fastening mechanism 23 is, for example, polyphenyl sulfide (PPS).
  • the heating unit 24 converts the electric power generated by the secondary battery 1 into Joule heat.
  • the heating unit 24 applies the generated Joule heat to the fastening mechanism 23.
  • the heating unit 24 applies Joule heat to the region 23 a of the fastening mechanism 23 between the upper surface of the outer can 2 and the negative electrode short-circuit lead 9.
  • the heating unit 24 is a nichrome wire or the like.
  • the heating unit 24 is wound around the region 23 a of the fastening mechanism 23.
  • the voltage detection unit 14 applies a voltage generated between the positive electrode terminal 6 and the negative electrode terminal 7 to the heating unit 24 when the voltage between the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 exceeds a predetermined threshold.
  • the voltage detection unit 14 includes a transistor and the like. In this case, one end of the heating unit 24 is electrically connected to the negative electrode terminal 7 and the other end is electrically connected to the transistor.
  • the transistor of the voltage detector 14 is electrically connected to the positive terminal 6.
  • the transistor of the voltage detection unit 14 electrically connects the negative electrode terminal 7 and the heating unit 24. Connect to. By this operation, the heating unit 24 is applied with a voltage between the positive terminal 6 and the negative terminal 7.
  • the voltage detection unit 14 When the secondary battery 1 is overcharged, the voltage between the positive short-circuit lead 8 connected to the positive terminal 6 and the negative short-circuit lead 9 connected to the negative terminal 7 increases. When the voltage between the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 exceeds a predetermined threshold value, the voltage detection unit 14 indicates that the voltage between the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 exceeds a predetermined threshold value. Is detected. When detecting that the voltage has exceeded a predetermined threshold, the voltage detection unit 14 causes the heating unit 24 to apply a voltage generated between the positive electrode terminal 6 and the negative electrode terminal 7. When the voltage detection unit 14 applies a voltage to the heating unit 24, the heating unit 24 generates Joule heat by the applied voltage. When Joule heat is generated, the heating unit 24 heats and melts the region 23 a of the fastening mechanism 23.
  • the heating unit 24 melts the region 23a of the fastening mechanism 23
  • the fastening mechanism 23 is cut in the region 23a.
  • the driving body 22 pushes the negative electrode short-circuit lead 9 upward by its own stress.
  • the drive body 22 pushes up the negative electrode short-circuit lead 9
  • the negative electrode short-circuit lead 9 comes into contact with the positive electrode short-circuit lead 8 and is electrically connected to the positive electrode short-circuit lead 8.
  • the positive electrode short-circuit lead 8 When the negative electrode short-circuit lead 9 and the positive electrode short-circuit lead 8 are electrically connected, the positive electrode short-circuit lead 8, the positive electrode terminal 6, the internal positive electrode lead 4, the positive electrode current collecting tab 10, the electrode group 3, the negative electrode current collecting tab 11, the internal A closed circuit including the negative electrode lead 5, the negative electrode terminal 7, and the negative electrode short-circuit lead 9 is formed. If the said closed circuit is formed, the electric current which flows into the electric current interruption part 12 will exceed the threshold value of the electric current which the electric current interruption part 12 cut
  • the driver 22, the fastening mechanism 23, and the heating unit 24 may be installed on the positive electrode short-circuit lead 8 side.
  • the secondary battery 1 according to the second embodiment may include the characteristics of the secondary battery 1 according to the first embodiment.
  • the secondary battery configured as described above can reliably connect the positive electrode short-circuited lead and the negative electrode short-circuited lead when an overcharged state occurs. Therefore, the secondary battery can reliably melt the current interrupting part when an overcharged state occurs.

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Abstract

According to the embodiments, this overcharging prevention unit is provided with a current cutoff unit, a first short circuit lead, a second short circuit lead, a voltage detection unit, and a connection section. One end of the current cutoff unit is electrically connected to one electrode terminal of a secondary battery, and breaks when a predetermined current passes through. The first short circuit lead is electrically connected to the other end of the current cutoff unit. The second short circuit lead is electrically connected to the other electrode terminal of the secondary battery. The voltage detection unit measures the voltage between the first short circuit lead and the second short circuit lead. The connection section electrically connects the first short circuit lead and the second short circuit lead when the voltage measured by the voltage detection unit exceeds a predetermined threshold.

Description

過充電防止ユニット及び二次電池Overcharge prevention unit and secondary battery
　本発明の実施形態は、過充電防止ユニット及び二次電池に関する。 Embodiments of the present invention relate to an overcharge prevention unit and a secondary battery.
　二次電池は、過充電状態が生じた場合に、電池電圧の上昇及び電池内部のガス圧の上昇などを生じる。そのため、二次電池は、過充電状態が生じた場合に、外部装置から供給される充電電流を遮断するヒューズを備える。電池電圧が所定の電圧を超過すると、ヒューズは、融解し、外部装置から供給される充電電流を遮断する。 二 Secondary batteries cause an increase in battery voltage and an increase in gas pressure inside the battery when an overcharged state occurs. Therefore, the secondary battery includes a fuse that cuts off a charging current supplied from an external device when an overcharge state occurs. When the battery voltage exceeds a predetermined voltage, the fuse melts and interrupts the charging current supplied from the external device.
特開２００６－１８５７０８号公報JP 2006-185708 A
　信頼性の高い電流遮断機構を備える過充電防止ユニット及び二次電池を提供する。 Provide an overcharge prevention unit and a secondary battery equipped with a highly reliable current interruption mechanism.
　実施形態によれば、過充電防止ユニットは、電流遮断部と、第１短絡リードと、第２短絡リードと、電圧検知部と、接続部と、を備える。電流遮断部は、前記二次電池の一方の電極端子と電気的に一端を接続され、所定の電流が通過すると切断する。第１短絡リードは、前記電流遮断部の他端と電気的に接続される。第２短絡リードは、前記二次電池の他方の電極端子と電気的に接続される。電圧検知部は、前記第１短絡リードと前記第２短絡リードとの間の電圧を測定する。接続部は、前記電圧検知部が測定した電圧が所定の閾値を超えると、前記第１短絡リードと前記第２短絡リードとを電気的に接続させる。 According to the embodiment, the overcharge prevention unit includes a current interrupting unit, a first short-circuit lead, a second short-circuit lead, a voltage detection unit, and a connection unit. The current interrupting unit is electrically connected at one end to one electrode terminal of the secondary battery, and cuts off when a predetermined current passes. The first short-circuit lead is electrically connected to the other end of the current interrupting part. The second short-circuit lead is electrically connected to the other electrode terminal of the secondary battery. The voltage detector measures a voltage between the first short-circuit lead and the second short-circuit lead. The connection unit electrically connects the first short-circuit lead and the second short-circuit lead when the voltage measured by the voltage detection unit exceeds a predetermined threshold.
図１は、第１実施形態に係る二次電池システムの構成例を示すブロック図である。FIG. 1 is a block diagram illustrating a configuration example of the secondary battery system according to the first embodiment. 図２は、第１実施形態に係る二次電池システムの電流の流れの例を示す図である。FIG. 2 is a diagram illustrating an example of current flow in the secondary battery system according to the first embodiment. 図３は、第１実施形態に係る二次電池システムの電流の流れの例を示す図である。FIG. 3 is a diagram illustrating an example of a current flow of the secondary battery system according to the first embodiment. 図４は、第１実施形態に係る二次電池システムの電流の流れの例を示す図である。FIG. 4 is a diagram illustrating an example of current flow in the secondary battery system according to the first embodiment. 図５は、第２実施形態に係る二次電池システムの構成例を示すブロック図である。FIG. 5 is a block diagram illustrating a configuration example of the secondary battery system according to the second embodiment. 図６は、第２実施形態に係る二次電池の上面図の例を示すブロック図である。FIG. 6 is a block diagram illustrating an example of a top view of the secondary battery according to the second embodiment.
（第１実施形態）
　以下、実施の形態について、図面を参照して説明する。　
　図１は、第１実施形態に係る二次電池システムの構成例を示すブロック図である。図１に示すように、二次電池システムは、二次電池１、充電装置２０及び配線２９ａ並びにｂなどを備える。 (First embodiment)
Hereinafter, embodiments will be described with reference to the drawings.
FIG. 1 is a block diagram illustrating a configuration example of the secondary battery system according to the first embodiment. As shown in FIG. 1, the secondary battery system includes a secondary battery 1, a charging device 20, wirings 29a and b, and the like.
　図１が示すように、二次電池１は、外装缶２と、外装缶２内に収納される電極群３と、内部正極リード４と、内部負極リード５と、正極端子６と、負極端子７と、キャッププレート１５と、絶縁部材１６と、過充電防止ユニット３０と、を備える。電解質（図示しない）は電極群３に保持されている。外装缶２は、矩形上に形成される箱状であって、外装缶２の上面は、開口している。外装缶２は、例えば、アルミニウム又はアルミニウム合金等から形成することができる。たとえば、アルミニウム合金は、マグネシウム、亜鉛、ケイ素等の元素を含む合金などである。合金中に鉄、銅、ニッケル、クロム等の遷移金属が含む場合、その量は、たとえば、１００ｐｐｍ以下である。外装缶の板厚は、１ｍｍ以下にすることができ、０．５ｍｍ以下であってもよい。 As shown in FIG. 1, the secondary battery 1 includes an outer can 2, an electrode group 3 housed in the outer can 2, an internal positive electrode lead 4, an internal negative electrode lead 5, a positive electrode terminal 6, and a negative electrode terminal. 7, a cap plate 15, an insulating member 16, and an overcharge prevention unit 30. An electrolyte (not shown) is held in the electrode group 3. The outer can 2 has a box shape formed on a rectangle, and the upper surface of the outer can 2 is open. The outer can 2 can be formed from, for example, aluminum or an aluminum alloy. For example, the aluminum alloy is an alloy containing elements such as magnesium, zinc, and silicon. When transition metals, such as iron, copper, nickel, and chromium, are contained in the alloy, the amount is, for example, 100 ppm or less. The plate thickness of the outer can can be 1 mm or less, and may be 0.5 mm or less.
　電極群３は、正極と負極がその間にセパレータを介して偏平形状に捲回されたものである。正極は、例えば金属箔からなる帯状の正極集電体と、正極集電体の長辺に平行な一端部からなる正極集電タブ１０と、少なくとも正極集電タブ１０の部分を除いて正極集電体に形成された正極材料層（正極活物質含有層）とを含む。一方、負極は、例えば金属箔からなる帯状の負極集電体と、負極集電体の長辺に平行な一端部からなる負極集電タブ１１と、少なくとも負極集電タブ１１の部分を除いて負極集電体に形成された負極材料層（負極活物質含有層）とを含む。このような正極、セパレータ及び負極は、正極集電タブ１０が電極群の捲回軸方向にセパレータから突出し、かつ負極集電タブ１１がこれとは反対方向にセパレータから突出するよう、正極及び負極の位置をずらして捲回されている。このような捲回により、電極群３は、図１に示すように、一方の端面から渦巻状に捲回された正極集電タブ１０が突出し、かつ他方の端面から渦巻状に捲回された負極集電タブ１１が突出している。正極集電タブ１０及び負極集電タブ１１は、正負極の集電体と同じ材料から形成しても、アルミニウム、Ｍｇ、Ｔｉ、Ｚｎ、Ｍｎ、Ｆｅ、Ｃｕ及びＳｉよりなる群から選択される少なくとも１種類の元素を含むアルミニウム合金から形成しても良い。 The electrode group 3 has a positive electrode and a negative electrode wound in a flat shape with a separator between them. The positive electrode is a positive current collector except for a strip-shaped positive current collector made of, for example, a metal foil, a positive current collector tab 10 having one end parallel to the long side of the positive current collector, and at least the positive current collector tab 10 portion. A positive electrode material layer (positive electrode active material-containing layer) formed on the electric body. On the other hand, the negative electrode is, for example, a strip-shaped negative electrode current collector made of a metal foil, a negative electrode current collector tab 11 having one end parallel to the long side of the negative electrode current collector, and at least the negative electrode current collector tab 11 portion. A negative electrode material layer (negative electrode active material-containing layer) formed on the negative electrode current collector. Such a positive electrode, separator and negative electrode have a positive electrode and a negative electrode so that the positive electrode current collecting tab 10 protrudes from the separator in the winding axis direction of the electrode group and the negative electrode current collecting tab 11 protrudes from the separator in the opposite direction. It has been wound around the position of. By such winding, as shown in FIG. 1, the electrode group 3 has the positive electrode current collecting tab 10 wound in a spiral shape from one end face and is wound in a spiral form from the other end face. The negative electrode current collection tab 11 protrudes. The positive electrode current collector tab 10 and the negative electrode current collector tab 11 are selected from the group consisting of aluminum, Mg, Ti, Zn, Mn, Fe, Cu, and Si, even if formed from the same material as the positive and negative electrode current collectors. You may form from the aluminum alloy containing an at least 1 sort (s) of element.
　内部正極リード４及び内部負極リード５は、それぞれ、帯状の導電板からなる。内部正極リード４が正極集電タブ１０に電気的に接続され、また、内部負極リード５が負極集電タブ１１に電気的に接続されている。正極端子６及び負極端子７は、それぞれ、絶縁部材１６を介してキャッププレート１５に固定されている。内部正極リード４の先端は、正極端子６に電気的に接続され、内部負極リード５の先端は負極端子７に電気的に接続されている。 The internal positive electrode lead 4 and the internal negative electrode lead 5 are each made of a strip-shaped conductive plate. The internal positive electrode lead 4 is electrically connected to the positive electrode current collecting tab 10, and the internal negative electrode lead 5 is electrically connected to the negative electrode current collecting tab 11. The positive electrode terminal 6 and the negative electrode terminal 7 are each fixed to the cap plate 15 via an insulating member 16. The tip of the internal positive electrode lead 4 is electrically connected to the positive electrode terminal 6, and the tip of the internal negative electrode lead 5 is electrically connected to the negative electrode terminal 7.
　キャッププレート１５は、外装缶２の上面を覆うプレートである。キャッププレート１５は、正極端子６を通過させる穴と、負極端子７を通過させる穴と、を備える。キャッププレート１５は、穴に設置される絶縁部材１６を介して正極端子６及び負極端子７を固定する。また、キャッププレート１５は、図示されない絶縁物質などを介して正極短絡リード８、負極短絡リード９、絶縁体１３、及び、電圧検知部１４などを固定する。キャッププレート１５は、例えば、アルミニウム又はアルミニウム合金等から形成することができる。 The cap plate 15 is a plate that covers the upper surface of the outer can 2. The cap plate 15 includes a hole through which the positive electrode terminal 6 passes and a hole through which the negative electrode terminal 7 passes. The cap plate 15 fixes the positive terminal 6 and the negative terminal 7 through an insulating member 16 installed in the hole. The cap plate 15 fixes the positive electrode short-circuit lead 8, the negative electrode short-circuit lead 9, the insulator 13, the voltage detection unit 14, and the like through an insulating material (not shown). The cap plate 15 can be formed from, for example, aluminum or an aluminum alloy.
　二次電池１の正極、負極、セパレータ及び電解質について説明する。　
（１）正極
　正極は、正極集電体と、集電体の片面もしくは両面に担持され、正極活物質を含む正極材料層とを含む。 The positive electrode, negative electrode, separator, and electrolyte of the secondary battery 1 will be described.
(1) Positive Electrode The positive electrode includes a positive electrode current collector and a positive electrode material layer that is supported on one or both surfaces of the current collector and includes a positive electrode active material.
　正極活物質には、例えば、リチウム含有複合化合物、二酸化マンガン（ＭｎＯ２）、酸化鉄、酸化銅、酸化ニッケル、ポリアニリンやポリピロールなどの導電性ポリマー材料、ジスルフィド系ポリマー材料、イオウ（Ｓ）、フッ化カーボン、硫酸鉄（Ｆｅ２（ＳＯ４）３）、バナジウム酸化物（例えばＶ２Ｏ５）を挙げることができる。中でも、リチウム含有複合化合物が好ましい。リチウム含有複合化合物には、例えば、ＬｉａＭｎＯ２（０＜ａ≦１．２）、リチウムコバルト複合酸化物（ＬｉａＣｏＭｈＯ２、ここでＭはＡｌ，Ｃｒ，ＭｇおよびＦｅよりなる群から選択される少なくとも１つまたは２つ以上の元素、０＜ａ≦１．２、０≦ｈ≦０．１）、リチウムマンガンコバルト複合酸化物（例えばＬｉＭｎ１－ｇ－ｈＣｏｇＭｈＯ２、ここでＭはＡｌ，Ｃｒ，ＭｇおよびＦｅよりなる群から選択される少なくとも１つまたは２つ以上の元素、０≦ｇ≦０．５、０≦ｈ≦０．１）、リチウムマンガンニッケル複合酸化物｛例えば、ＬｉＭｎｊＮｉｊＭ１－２ｊＯ２（ＭはＣｏ，Ｃｒ，Ａｌ，ＭｇおよびＦｅよりなる群より選択される少なくとも１つまたは２つ以上の元素、１／３≦ｊ≦１／２）、ＬｉＭｎ１／３Ｎｉ１／３Ｃｏ１／３Ｏ２、ＬｉＭｎ１／２Ｎｉ１／２Ｏ２｝、スピネル型リチウムマンガン複合酸化物（例えばＬｉａＭｎ２－ｂＭｂＯ４、ここでＭはＡｌ，Ｃｒ，ＮｉおよびＦｅよりなる群から選択される少なくとも１つまたは２つ以上の元素、０＜ａ≦１．２、０≦ｂ≦１）、スピネル型リチウムマンガンニッケル複合酸化物（例えばＬｉａＭｎ２－ｂＮｉｂＯ４、０＜ａ≦１．２、０≦ｂ≦１）、オリビン構造を有するリチウムリン酸化物｛例えば、ＬｉａＦｅＰＯ４（０＜ａ≦１．２）、ＬｉａＦｅ１－ｂＭｎｂＰＯ４（０＜ａ≦１．２、０≦ｂ≦１）、ＬｉａＣｏＰＯ４（０＜ａ≦１．２）など｝を挙げることができる。 Examples of the positive electrode active material include lithium-containing composite compounds, manganese dioxide (MnO2), iron oxide, copper oxide, nickel oxide, conductive polymer materials such as polyaniline and polypyrrole, disulfide polymer materials, sulfur (S), and fluoride. Examples thereof include carbon, iron sulfate (Fe2 (SO4) 3), and vanadium oxide (for example, V2O5). Among these, lithium-containing composite compounds are preferable. Examples of the lithium-containing composite compound include LiaMnO 2 (0 <a ≦ 1.2), lithium cobalt composite oxide (LiaCoMhO 2, where M is selected from the group consisting of Al, Cr, Mg, and Fe, or 2 or more elements, 0 <a ≦ 1.2, 0 ≦ h ≦ 0.1), lithium manganese cobalt composite oxide (for example, LiMn1-g-hCogMhO2, where M is composed of Al, Cr, Mg, and Fe) At least one or more elements selected from the group, 0 ≦ g ≦ 0.5, 0 ≦ h ≦ 0.1), lithium manganese nickel composite oxide {for example, LiMnjNijM1-2jO2 (M is Co, Cr , Al, Mg and Fe, at least one or more elements selected from the group consisting of 1/3 ≦ j ≦ 1/2), LiMn1 / 3Ni / 3Co1 / 3O2, LiMn1 / 2Ni1 / 2O2}, spinel-type lithium manganese composite oxide (for example, LiaMn2-bMbO4, where M is at least one or more selected from the group consisting of Al, Cr, Ni and Fe) Element, 0 <a ≦ 1.2, 0 ≦ b ≦ 1), spinel type lithium manganese nickel composite oxide (for example, LiaMn2-bNibO4, 0 <a ≦ 1.2, 0 ≦ b ≦ 1), olivine structure Lithium phosphorus oxide having {for example, LiaFePO4 (0 <a ≦ 1.2), LiaFe1-bMnbPO4 (0 <a ≦ 1.2, 0 ≦ b ≦ 1), LiaCoPO4 (0 <a ≦ 1.2), etc.} Can be mentioned.
　正極材料層に結着剤を含有させる場合、結着剤は、例えばポリテトラフルオロエチレン(ＰＴＦＥ）、ポリフッ化ビニリデン(ＰＶｄＦ）、フッ素系ゴムを用いることができる。 When the positive electrode material layer contains a binder, for example, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), or fluorine-based rubber can be used as the binder.
　また、正極材料層は、導電剤を含有させても良い。導電剤は、例えば、アセチレンブラック、カーボンブラック、黒鉛等の炭素質物を挙げることができる。 Moreover, the positive electrode material layer may contain a conductive agent. Examples of the conductive agent include carbonaceous materials such as acetylene black, carbon black, and graphite.
　正極活物質、導電剤および結着剤の配合割合は、正極活物質７３～９５重量％、導電剤３～２０重量％、結着剤２～７重量％であってもよい。 The blending ratio of the positive electrode active material, the conductive agent and the binder may be 73 to 95% by weight of the positive electrode active material, 3 to 20% by weight of the conductive agent, and 2 to 7% by weight of the binder.
　正極集電体は、アルミニウム箔若しくはアルミニウム合金箔から形成されてもよい。アルミニウム箔及びアルミニウム合金箔の厚さは、２０μｍ以下にすることができ、１５μｍ以下であってもよい。アルミニウム箔の純度は９９質量％以上であってもよい。アルミニウム合金としては、マグネシウム、亜鉛、ケイ素、などの元素を含む合金であってもよい。一方、鉄、銅、ニッケル、クロムなどの遷移金属の含有量は１質量％以下にしてもよい。 The positive electrode current collector may be formed from an aluminum foil or an aluminum alloy foil. The thickness of the aluminum foil and the aluminum alloy foil can be 20 μm or less, and may be 15 μm or less. The purity of the aluminum foil may be 99% by mass or more. The aluminum alloy may be an alloy containing elements such as magnesium, zinc, and silicon. On the other hand, the content of transition metals such as iron, copper, nickel, and chromium may be 1% by mass or less.
　正極は、例えば、正極活物質に導電剤および結着剤を添加し、これらを適当な溶媒に懸濁させ、この懸濁物（スラリー）を集電体に塗布、乾燥、プレスして帯状電極にすることにより作製される。 For the positive electrode, for example, a conductive agent and a binder are added to the positive electrode active material, these are suspended in an appropriate solvent, and this suspension (slurry) is applied to a current collector, dried and pressed to form a strip electrode It is produced by making.
（２）負極
　負極は、負極集電体と、負極集電体の片面もしくは両面に担持され、負極活物質を含む負極材料層とを含む。 (2) Negative Electrode The negative electrode includes a negative electrode current collector and a negative electrode material layer that is supported on one or both surfaces of the negative electrode current collector and includes a negative electrode active material.
　負極活物質には、例えば、金属リチウム、リチウムイオンを吸蔵及び放出し得る物質を挙げることができる。リチウムイオンを吸蔵及び放出し得る物質として、例えば、リチウムチタン複合酸化物が挙げられる。リチウムチタン複合酸化物は、例えば、Ｌｉ４+ｘＴｉ５Ｏ１２（ｘは充放電反応により－１≦ｘ≦３の範囲で変化する）で表されるスピネル型チタン酸リチウム、ラムステライド型Ｌｉ２＋ｘＴｉ３Ｏ７（ｘは充放電反応により－１≦ｘ≦３の範囲で変化する）、ＴｉとＰ、Ｖ、Ｓｎ、Ｃｕ、ＮｉおよびＦｅよりなる群から選択される少なくとも１種類の元素を含有する金属複合酸化物などが挙げられる。ＴｉとＰ、Ｖ、Ｓｎ、Ｃｕ、ＮｉおよびＦｅよりなる群から選択される少なくとも１種類の元素を含有する金属複合酸化物としては、例えば、ＴｉＯ２－Ｐ２Ｏ５、ＴｉＯ２－Ｖ２Ｏ５、ＴｉＯ２－Ｐ２Ｏ５－ＳｎＯ２、ＴｉＯ２－Ｐ２Ｏ５－ＭｅＯ（ＭｅはＣｕ、ＮｉおよびＦｅよりなる群から選択される少なくとも１つの元素）を挙げることができる。これらの金属複合酸化物は、充電によりリチウムが挿入されることでリチウムチタン複合酸化物に変化する。リチウムチタン複合酸化物は、スピネル型チタン酸リチウムであってもよい。 Examples of the negative electrode active material include metal lithium and a material capable of occluding and releasing lithium ions. As a substance capable of inserting and extracting lithium ions, for example, lithium titanium composite oxide can be given. The lithium-titanium composite oxide includes, for example, Li4 + xTi5O12 (x varies in the range of −1 ≦ x ≦ 3 by charge / discharge reaction), ramsteride type Li2 + xTi3O7 (x is charge / discharge) And a metal composite oxide containing at least one element selected from the group consisting of Ti and P, V, Sn, Cu, Ni and Fe. It is done. Examples of the metal composite oxide containing at least one element selected from the group consisting of Ti and P, V, Sn, Cu, Ni and Fe include TiO2-P2O5, TiO2-V2O5, TiO2-P2O5-SnO2 TiO2-P2O5-MeO (Me is at least one element selected from the group consisting of Cu, Ni and Fe). These metal composite oxides change to lithium titanium composite oxides when lithium is inserted by charging. The lithium titanium composite oxide may be spinel type lithium titanate.
　その他のリチウムイオンを吸蔵及び放出し得る物質には、例えば、炭素質物、金属化合物が挙げられる。 Other materials that can occlude and release lithium ions include, for example, carbonaceous materials and metal compounds.
　炭素質物は、例えば、天然黒鉛、人造黒鉛、コークス、気相成長炭素繊維、メソフェーズピッチ系炭素繊維、球状炭素、樹脂焼成炭素を挙げることができる。たとえば、炭素質物は、気相成長炭素繊維、メソフェーズピッチ系炭素繊維、球状炭素が挙げられる。炭素質物は、Ｘ線回折による（００２）面の面間隔ｄ００２が０．３４ｎｍ以下であってもよい。 Examples of the carbonaceous material include natural graphite, artificial graphite, coke, vapor-grown carbon fiber, mesophase pitch-based carbon fiber, spherical carbon, and resin-fired carbon. For example, examples of the carbonaceous material include vapor grown carbon fiber, mesophase pitch carbon fiber, and spherical carbon. The carbonaceous material may have a (002) plane spacing d002 of 0.34 nm or less by X-ray diffraction.
　金属化合物は、金属硫化物、金属窒化物を用いることができる。金属硫化物は、例えばＴｉＳ２のような硫化チタン、例えばＭｏＳ２のような硫化モリブデン、例えばＦｅＳ、ＦｅＳ２、ＬｉｘＦｅＳ２のような硫化鉄を用いることができる。金属窒化物は、例えばリチウムコバルト窒化物（例えばＬｉｓＣｏｔＮ、０＜ｓ＜４，０＜ｔ＜０．５）を用いることができる。 The metal compound can be a metal sulfide or metal nitride. As the metal sulfide, titanium sulfide such as TiS2, for example, molybdenum sulfide such as MoS2, for example, iron sulfide such as FeS, FeS2, and LixFeS2 can be used. As the metal nitride, for example, lithium cobalt nitride (for example, LisCotN, 0 <s <4, 0 <t <0.5) can be used.
　集電体は、例えば、銅箔、アルミニウム箔またはアルミニウム合金箔を用いることができる。アルミニウム箔またはアルミニウム合金箔の厚さは、２０μｍ以下であってもよく、１５μｍ以下であってもよい。アルミニウム箔は９９質量％以上の純度を有してもよい。アルミニウム合金は、マグネシウム、亜鉛、ケイ素などの元素を含む合金であってもよい。合金成分として含まれる鉄、銅、ニッケル、クロムなどの遷移金属は１質量％以下であってもよい。 As the current collector, for example, a copper foil, an aluminum foil, or an aluminum alloy foil can be used. The thickness of the aluminum foil or aluminum alloy foil may be 20 μm or less, or 15 μm or less. The aluminum foil may have a purity of 99% by mass or more. The aluminum alloy may be an alloy containing elements such as magnesium, zinc, and silicon. 1 mass% or less may be sufficient as transition metals, such as iron, copper, nickel, and chromium contained as an alloy component.
　負極材料層には、結着剤を含有させることができる。結着剤は、例えばポリテトラフルオロエチレン(ＰＴＦＥ）、ポリフッ化ビニリデン(ＰＶｄＦ）、フッ素系ゴム、スチレンブタジエンゴムなどが挙げられる。 The negative electrode material layer can contain a binder. Examples of the binder include polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVdF), fluorine rubber, and styrene butadiene rubber.
　負極材料層には、導電剤を含有させることができる。導電剤は、例えば、アセチレンブラック、カーボンブラック、黒鉛等の炭素質物を挙げることができる。 The negative electrode material layer can contain a conductive agent. Examples of the conductive agent include carbonaceous materials such as acetylene black, carbon black, and graphite.
　負極活物質、導電剤および結着剤の配合割合は、負極活物質７３～９６重量％、導電剤２～２０重量％、結着剤２～７重量％の範囲であってもよい。 The mixing ratio of the negative electrode active material, the conductive agent and the binder may be in the range of 73 to 96% by weight of the negative electrode active material, 2 to 20% by weight of the conductive agent, and 2 to 7% by weight of the binder.
　負極は、例えば、粉末状の負極活物質に導電剤および結着剤を添加し、これらを適当な溶媒に懸濁させ、この懸濁物（スラリー）を集電体に塗布、乾燥、プレスして帯状電極にすることにより作製される。 For example, the negative electrode is prepared by adding a conductive agent and a binder to a powdered negative electrode active material, suspending them in a suitable solvent, applying the suspension (slurry) to a current collector, drying, and pressing. It is produced by forming a strip electrode.
（３）セパレータ
　セパレータは、絶縁性を有するものであれば特に限定されないが、ポリオレフィン、セルロース、ポリエチレンテレフタレート、及びビニロンのようなポリマーで作られた多孔質フィルム又は不織布を用いることができる。セパレータの材料は１種類であってもよく、或いは、２種類以上を組合せて用いてもよい。 (3) Separator The separator is not particularly limited as long as it has insulating properties, but a porous film or a nonwoven fabric made of a polymer such as polyolefin, cellulose, polyethylene terephthalate, and vinylon can be used. One type of separator material may be used, or two or more types may be used in combination.
（４）非水電解質
　非水電解質は、非水溶媒と、この非水溶媒に溶解される電解質塩を含む。非水溶媒中にはポリマーを含んでもよい。 (4) Nonaqueous electrolyte The nonaqueous electrolyte includes a nonaqueous solvent and an electrolyte salt dissolved in the nonaqueous solvent. The non-aqueous solvent may contain a polymer.
　次に、過充電防止ユニット３０について説明する。　
　図１が示すように、過充電防止ユニット３０は、正極短絡リード８と、負極短絡リード９と、電流遮断部１２と、絶縁体１３と、電圧検知部１４と、を含む。 Next, the overcharge prevention unit 30 will be described.
As shown in FIG. 1, the overcharge prevention unit 30 includes a positive electrode short-circuit lead 8, a negative electrode short-circuit lead 9, a current interruption unit 12, an insulator 13, and a voltage detection unit 14.
　正極短絡リード８及び負極短絡リード９は、それぞれ、帯状の導電板からなる。正極短絡リード８は、電流遮断部１２に電気的に接続され、また、負極短絡リード９は、負極端子７に電気的に接続されている。なお、各部の電気的接続は、例えば、溶接、かしめ固定等によって行われる。内部正負極リード、正負極短絡リード及び正負極端子には、例えば、アルミニウム、Ｍｇ、Ｔｉ、Ｚｎ、Ｍｎ、Ｆｅ、Ｃｕ及びＳｉよりなる群から選択される少なくとも１種類の元素を含むアルミニウム合金を使用することができる。部品同士の接点及びその周辺は、Ａｌよりも融点の高いＣｕ、Ｃｕ合金がコーティングされてもよい。 The positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 are each made of a strip-shaped conductive plate. The positive electrode short-circuit lead 8 is electrically connected to the current interrupting unit 12, and the negative electrode short-circuit lead 9 is electrically connected to the negative electrode terminal 7. In addition, the electrical connection of each part is performed by welding, caulking fixation, etc., for example. The internal positive and negative electrode leads, the positive and negative electrode short-circuit leads and the positive and negative electrode terminals are made of, for example, an aluminum alloy containing at least one element selected from the group consisting of aluminum, Mg, Ti, Zn, Mn, Fe, Cu and Si. Can be used. Cu and Cu alloys having a melting point higher than that of Al may be coated on the contacts between the components and the periphery thereof.
　正極短絡リード８及び負極短絡リード９は、互いに接触する方向に応力を生じるように形成される。図１に示す例において、正極短絡リード８は、その先端が図１において上方向に応力を生じるように形成される。また、負極短絡リード９は、その先端が図１において下方向に応力を生じるように形成される。なお、正極短絡リード８又は負極短絡リード９のいずれかが、他方に接触する方向に応力を生じるように形成されてもよい。 The positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 are formed so as to generate stress in a direction in which they contact each other. In the example shown in FIG. 1, the positive electrode short-circuit lead 8 is formed such that the tip thereof generates stress upward in FIG. Further, the negative electrode short-circuit lead 9 is formed such that the tip thereof generates a downward stress in FIG. In addition, either the positive electrode short-circuit lead 8 or the negative electrode short-circuit lead 9 may be formed so as to generate stress in a direction in contact with the other.
　正極短絡リード８と負極短絡リード９との間に、絶縁体１３が形成される。絶縁体１３は、正極短絡リード８と負極短絡リード９とが通電することを阻止している。また、絶縁体１３は、正極短絡リード８と負極短絡リード９との間から引き出される方向に引っ張られるように形成される。たとえば、絶縁体１３は、応力を印加された状態でキャッププレート１５に固定される。このため、絶縁体１３は、その一部が切断すると、正極短絡リード８と負極短絡リード９との間から引き抜かれる構造になっている。また、絶縁体１３は、電極群３の電力から生じるジュール熱によって切断される物質から構成される。なお、絶縁体１３は、他の部材を介して応力を印加されてもよい。この場合、当該部材が切断されると、絶縁体１３は、正極短絡リード８と負極短絡リード９との間から引き抜かれる。 An insulator 13 is formed between the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9. The insulator 13 prevents the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 from being energized. The insulator 13 is formed so as to be pulled in the direction of being drawn from between the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9. For example, the insulator 13 is fixed to the cap plate 15 in a state where stress is applied. For this reason, the insulator 13 is structured to be pulled out from between the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 when a part thereof is cut. The insulator 13 is made of a material that is cut by Joule heat generated from the electric power of the electrode group 3. The insulator 13 may be applied with stress via another member. In this case, when the member is cut, the insulator 13 is pulled out from between the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9.
　電流遮断部１２は、所定の閾値以上の電流が流れると通過する電流を遮断する。電流遮断部１２は、一方を正極端子６に接続し、他方を正極短絡リード８に接続する。即ち、電流遮断部１２は、正極端子６と正極短絡リード８との間に流れる電流を遮断する。たとえば、電流遮断部１２は、電流遮断部１２を流れる電流が所定の閾値を超過した場合に融解し、正極短絡リード８を流れる電流を遮断する。たとえば、電流遮断部１２は、ヒューズなどである。また、電流遮断部１２は、一部の横断面の面積が他の部分に比して小さい構造であってもよい。電流遮断部１２は、交換可能であってもよい。 The current interrupting unit 12 interrupts a passing current when a current exceeding a predetermined threshold flows. One of the current interrupting units 12 is connected to the positive electrode terminal 6, and the other is connected to the positive electrode short-circuit lead 8. That is, the current interrupting unit 12 interrupts the current flowing between the positive electrode terminal 6 and the positive electrode short-circuit lead 8. For example, the current interrupting unit 12 melts when the current flowing through the current interrupting unit 12 exceeds a predetermined threshold, and interrupts the current flowing through the positive electrode short-circuit lead 8. For example, the current interrupting unit 12 is a fuse or the like. Further, the current interrupting unit 12 may have a structure in which an area of a part of a cross section is smaller than that of another part. The current interrupting unit 12 may be replaceable.
　電流遮断部１２は、正極短絡リード８と負極短絡リード９とが電気的に接続された場合に生じる電流を閾値として設定される。即ち、電流遮断部１２は、正極短絡リード８と負極短絡リード９とが電気的に接続された場合に通過する電流を遮断する。 The current interruption unit 12 is set with a current generated when the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 are electrically connected as a threshold value. That is, the current interrupting unit 12 interrupts the current that passes when the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 are electrically connected.
　電圧検知部１４は、正極短絡リード８と負極短絡リード９との間に生じる電圧を測定する。電圧検知部１４は、測定された電圧が所定の閾値を超過すると、図示されない切断手段に正極端子６と負極端子７との間に生じる電圧を印加させる。電圧検知部１４は、トランジスタなどを備え、当該トランジスタを用いて電圧を切断手段に印加してもよい。 The voltage detection unit 14 measures a voltage generated between the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9. When the measured voltage exceeds a predetermined threshold, the voltage detector 14 applies a voltage generated between the positive terminal 6 and the negative terminal 7 to a cutting unit (not shown). The voltage detection unit 14 may include a transistor or the like, and may apply a voltage to the cutting unit using the transistor.
　電圧検知部１４は、過充電状態が生じた場合に正極短絡リード８と負極短絡リード９との間に生じる電圧を閾値として設定される。電圧検知部１４に設定される閾値は、二次電池１の種類などに応じて決定される。たとえば、電圧検知部１４は、閾値として３．５Ｖを設定される。 The voltage detection unit 14 is set with a voltage generated between the positive electrode short-circuited lead 8 and the negative electrode short-circuited lead 9 as a threshold when an overcharge state occurs. The threshold set in the voltage detector 14 is determined according to the type of the secondary battery 1 and the like. For example, the voltage detection unit 14 is set to 3.5 V as the threshold value.
　切断手段は、電圧が印加されると絶縁体１３を切断する。切断手段は、たとえば、ニクロム線などから形成される。この場合、切断手段は、絶縁体１３を加熱することができる位置に配置される。たとえば、切断手段は、絶縁体１３に巻きつくように形成されてもよい。切断手段は、電圧を印加されると、発熱し、絶縁体１３の一部を融解させる。その結果、絶縁体１３は、切断され、正極短絡リード８と負極短絡リード９との間から引き抜かれる。なお、切断手段は、絶縁体１３に応力を印加している部材を切断してもよい。 The cutting means cuts the insulator 13 when a voltage is applied. The cutting means is formed from, for example, nichrome wire. In this case, the cutting means is disposed at a position where the insulator 13 can be heated. For example, the cutting means may be formed to wrap around the insulator 13. When the voltage is applied, the cutting means generates heat and melts a part of the insulator 13. As a result, the insulator 13 is cut and pulled out from between the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9. Note that the cutting means may cut a member applying a stress to the insulator 13.
　充電装置２０は、二次電池１へ電力を充電する。充電装置２０は、配線２１ａ及びｂを介して、電気的に二次電池１へ接続する。充電装置２０は、配線２１ａ及びｂを介して、所定の電圧を正極短絡リード８と負極短絡リード９との間に印加する。 The charging device 20 charges the secondary battery 1 with electric power. The charging device 20 is electrically connected to the secondary battery 1 via the wirings 21a and b. The charging device 20 applies a predetermined voltage between the positive electrode short-circuited lead 8 and the negative electrode short-circuited lead 9 via the wirings 21 a and b.
　次に、二次電池システムを流れる電流について説明する。　
　図２は、通常の充電状態（即ち、過充電状態でない）において二次電池システムを流れる電流の例を示す回路図である。 Next, the current flowing through the secondary battery system will be described.
FIG. 2 is a circuit diagram showing an example of current flowing through the secondary battery system in a normal charge state (that is, not in an overcharge state).
　電流は、充電装置２０の正極端子から配線２１ａを通じて正極短絡リード８に流れる。正極短絡リード８へ流れると、電流は、電流遮断部１２、正極端子６、内部正極リード４及び正極集電タブ１０に流れる。正極集電タブ１０へ流れると、電流は、電極群３を通過し、電極群３を充電する。電極群３を通過すると、電流は、負極集電タブ１１、内部負極リード５及び負極端子７に流れる。負極端子７に流れると、電流は、配線２１ｂを通じて充電装置２０の負極端子へ流れる。 Current flows from the positive terminal of the charging device 20 to the positive short-circuit lead 8 through the wiring 21a. When flowing to the positive electrode short-circuit lead 8, the current flows to the current interrupter 12, the positive electrode terminal 6, the internal positive electrode lead 4, and the positive electrode current collecting tab 10. When flowing to the positive electrode current collecting tab 10, the current passes through the electrode group 3 and charges the electrode group 3. When passing through the electrode group 3, the current flows through the negative electrode current collecting tab 11, the internal negative electrode lead 5, and the negative electrode terminal 7. When flowing to the negative electrode terminal 7, the current flows to the negative electrode terminal of the charging device 20 through the wiring 21b.
　ここでは、電流遮断部１２に流れる電流は、電流遮断部１２が融解する電流よりも小さい。そのため、電流遮断部１２は、融解することなく、正極端子６と正極短絡リード８とを電気的に接続する。 Here, the current flowing through the current interrupting unit 12 is smaller than the current at which the current interrupting unit 12 melts. For this reason, the current interrupting unit 12 electrically connects the positive electrode terminal 6 and the positive electrode short-circuit lead 8 without melting.
　次に、過充電状態が生じた場合において二次電池システムを流れる電流について説明する。　
　二次電池１が過充電状態になると、二次電池１は、通常よりも高い電圧（即ち、電圧検知部１４に設定される閾値よりも高い電圧）を生じる。二次電池１が高い電圧を生じると、電圧検知部１４は、閾値よりも高い電圧を検知する。閾値よりも高い電圧を検知すると、電圧検知部１４は、切断手段に正極端子６と負極端子７との間に生じる電圧を印加させる。電圧検知部１４が切断手段に電圧を印加させると、切断手段は、ジュール熱を発生させる。ジュール熱を発生させると、切断手段は、絶縁体１３の一部を加熱し、融解させる。切断手段が絶縁体１３の一部を融解させると、絶縁体１３は、切断され、正極短絡リード８と負極短絡リード９との間から引き抜かれる。絶縁体１３が正極短絡リード８と負極短絡リード９との間から引き抜かれると、正極短絡リード８と負極短絡リード９とは、接触し、電気的に接続される。 Next, the current flowing through the secondary battery system when an overcharge state occurs will be described.
When the secondary battery 1 is overcharged, the secondary battery 1 generates a voltage higher than normal (that is, a voltage higher than a threshold set in the voltage detection unit 14). When the secondary battery 1 generates a high voltage, the voltage detection unit 14 detects a voltage higher than the threshold value. When a voltage higher than the threshold is detected, the voltage detection unit 14 causes the cutting unit to apply a voltage generated between the positive terminal 6 and the negative terminal 7. When the voltage detector 14 applies a voltage to the cutting means, the cutting means generates Joule heat. When Joule heat is generated, the cutting means heats and melts a part of the insulator 13. When the cutting means melts a part of the insulator 13, the insulator 13 is cut and pulled out from between the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9. When the insulator 13 is pulled out from between the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9, the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 come into contact with each other and are electrically connected.
　図３は、正極短絡リード８と負極短絡リード９とが電気的に接続された直後の電流の流れを示す回路図である。　
　図３が示すように、電流は、電極群３の正極側から流れる。電極群３の正極側から流れると、電流は、正極集電タブ１０、内部正極リード４及び正極端子６を通過する。正極端子６を通過すると、電流は、電流遮断部１２に流れる。電流遮断部１２を流れると、電流は、正極短絡リード８、負極短絡リード９、負極端子７、内部負極リード５及び負極集電タブ１１を流れる。負極集電タブ１１を流れると、電流は、電極群３の負極側へ流れる。 FIG. 3 is a circuit diagram showing a current flow immediately after the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 are electrically connected.
As shown in FIG. 3, the current flows from the positive electrode side of the electrode group 3. When flowing from the positive electrode side of the electrode group 3, the current passes through the positive electrode current collecting tab 10, the internal positive electrode lead 4 and the positive electrode terminal 6. When passing through the positive terminal 6, the current flows to the current interrupting unit 12. When flowing through the current interrupting unit 12, the current flows through the positive electrode short-circuit lead 8, the negative electrode short-circuit lead 9, the negative electrode terminal 7, the internal negative electrode lead 5, and the negative electrode current collecting tab 11. When flowing through the negative electrode current collecting tab 11, the current flows to the negative electrode side of the electrode group 3.
　ここでは、電流遮断部１２に流れる電流は、電流遮断部１２が切断する電流の閾値を超過する。したがって、図３が示す状態が生じた後に、電流遮断部１２は、切断し、正極端子６と正極短絡リード８との電気的な接続を遮断する。 Here, the current flowing through the current interrupting unit 12 exceeds the threshold value of the current that the current interrupting unit 12 cuts. Therefore, after the state shown in FIG. 3 occurs, the current interrupting unit 12 cuts off and disconnects the electrical connection between the positive electrode terminal 6 and the positive electrode short-circuit lead 8.
　次に、電流遮断部１２が切断した後の電流の流れについて説明する。　
　図４は、電流遮断部１２が切断した後の電流の流れを示す回路図である。 Next, the current flow after the current interrupting unit 12 is disconnected will be described.
FIG. 4 is a circuit diagram showing a current flow after the current interrupting unit 12 is disconnected.
　図４が示すように、電流は、充電装置２０の正極端子から配線２０ａへ流れる。配線２０ａへ流れると、電流は、正極短絡リード８、負極短絡リード９及び配線２０ｂを通過し、充電装置２０の負極端子へ流れる。 As shown in FIG. 4, current flows from the positive terminal of the charging device 20 to the wiring 20a. When flowing to the wiring 20 a, the current passes through the positive electrode short-circuit lead 8, the negative electrode short-circuit lead 9, and the wiring 20 b and flows to the negative electrode terminal of the charging device 20.
　図４が示す状態では、充電装置２０からの電流は、二次電池１の内部へは供給されない。そのため、二次電池１は、充電装置２０からさらに電力を充電されることなく、二次電池１の過充電状態は、収束する。 4, the current from the charging device 20 is not supplied to the inside of the secondary battery 1. Therefore, the secondary battery 1 is not further charged with electric power from the charging device 20, and the overcharged state of the secondary battery 1 converges.
　なお、二次電池１は、負極端子７と負極短絡リード９との間に電流遮断部１２を備えてもよい。 Note that the secondary battery 1 may include a current interrupting unit 12 between the negative electrode terminal 7 and the negative electrode short-circuit lead 9.
　以上のように構成される二次電池は、電圧検知部を外部に備えることができる。そのため、電圧検知部は、外装缶内の温度及び圧力の影響を受けずに、動作することができる。したがって、二次電池は、過充電状態が生じた場合に、確実に電流遮断部を融解させることができる。 The secondary battery configured as described above can include a voltage detection unit outside. Therefore, the voltage detection unit can operate without being affected by the temperature and pressure in the outer can. Therefore, the secondary battery can reliably melt the current interrupting part when an overcharged state occurs.
　また、二次電池は、電流遮断部を外部に備えることができる。そのため、電流遮断部の交換が容易になる。さらに、二次電池のエネルギー密度が向上する。 Also, the secondary battery can be provided with a current interrupting unit outside. This facilitates replacement of the current interrupting unit. Furthermore, the energy density of the secondary battery is improved.
（第２実施形態）
　次に、第２実施形態について説明する。　
　第２実施形態に係る二次電池１は、電流遮断部１２が正極端子６と内部正極リード４との間にある点、及び、過充電防止ユニット３０が駆動体、締結機構及び加熱部などを備える点などで第１実施形態における二次電池１と異なる。したがって、他の部分は、同一の符号を付して詳細な説明を省略する。 (Second Embodiment)
Next, a second embodiment will be described.
In the secondary battery 1 according to the second embodiment, the current interruption unit 12 is between the positive terminal 6 and the internal positive electrode lead 4, and the overcharge prevention unit 30 includes a driver, a fastening mechanism, a heating unit, and the like. It differs from the secondary battery 1 in 1st Embodiment by the point provided. Therefore, the other parts are denoted by the same reference numerals, and detailed description thereof is omitted.
　図５は、実施形態に係る二次電池システムの構成例を示すブロック図である。　
　図６は、実施形態に係る二次電池の上面図である。　
　図５及び６が示すように、二次電池１は、内部正極リード４と正極端子６との間に電流遮断部１２を備える。電流遮断部１２は、所定の閾値以上の電流が通過すると、内部正極リード４と正極端子６との間に流れる電流を遮断する。なお、電流遮断部１２は、内部正極リード５４一部として形成されてもよい。この場合、電流遮断部１２は、内部正極リード４の他の部分よりも細く形成されてもよい。 FIG. 5 is a block diagram illustrating a configuration example of the secondary battery system according to the embodiment.
FIG. 6 is a top view of the secondary battery according to the embodiment.
As shown in FIGS. 5 and 6, the secondary battery 1 includes a current interrupting unit 12 between the internal positive electrode lead 4 and the positive electrode terminal 6. The current interrupting unit 12 interrupts the current flowing between the internal positive electrode lead 4 and the positive electrode terminal 6 when a current exceeding a predetermined threshold value passes. Note that the current interrupting unit 12 may be formed as a part of the internal positive electrode lead 54. In this case, the current interrupting part 12 may be formed thinner than the other part of the internal positive electrode lead 4.
　図５及び６が示すように、過充電防止ユニット３０は、正極短絡リード８、負極短絡リード９、駆動体２２、締結機構２３及び加熱部２４などを備える。 5 and 6, the overcharge prevention unit 30 includes a positive electrode short-circuit lead 8, a negative electrode short-circuit lead 9, a driving body 22, a fastening mechanism 23, a heating unit 24, and the like.
　正極短絡リード８は、正極端子６に電気的に接続する。また、正極短絡リード８は、第１実施形態と異なり、いずれの方向にも応力を生じていない。 The positive electrode short-circuit lead 8 is electrically connected to the positive electrode terminal 6. Further, unlike the first embodiment, the positive electrode short-circuit lead 8 does not generate stress in any direction.
　負極短絡リード９は、正極短絡リード８の手前まで延び、そこから下方向に折れ曲がっている。負極短絡リード９は、正極短絡リード８の厚み分よりも下方向に延びる。負極短絡リード９は、そこから正極短絡リード８へ所定の長さ延びている。即ち、負極短絡リード９は、その先端が正極短絡リード８の下に潜り込むように形成される。また、負極短絡リード９は、下方向に折れ曲がっている箇所よりも負極端子７側に締結機構２３を通すための穴を備える。 The negative electrode short-circuit lead 9 extends to the front of the positive electrode short-circuit lead 8 and is bent downward therefrom. The negative electrode short-circuit lead 9 extends below the thickness of the positive electrode short-circuit lead 8. The negative electrode short-circuit lead 9 extends a predetermined length from there to the positive electrode short-circuit lead 8. In other words, the negative electrode short-circuit lead 9 is formed such that the tip of the negative electrode short-circuit lead 9 lies under the positive electrode short-circuit lead 8. Further, the negative electrode short-circuit lead 9 is provided with a hole for passing the fastening mechanism 23 on the negative electrode terminal 7 side rather than a portion bent downward.
　駆動体２２は、外部からの圧力に応じて応力を生じる弾性体である。駆動体２２は、圧縮されると、駆動体２２が圧縮された方向と逆方向に応力を生じる。駆動体２２は、たとえば、板バネ、薄板バネ、ねじりコイルバネ、又は、コイルバネなどである。 The driving body 22 is an elastic body that generates stress according to pressure from the outside. When the driving body 22 is compressed, a stress is generated in a direction opposite to the direction in which the driving body 22 is compressed. The drive body 22 is, for example, a plate spring, a thin plate spring, a torsion coil spring, or a coil spring.
　駆動体２２は、圧縮された状態で負極短絡リード９と外装缶２の上面との間に設置される。そのため、駆動体２２は、負極短絡リード９に上方向の応力を印加し続けている。即ち、駆動体２２は、負極短絡リード９に対して、正極短絡リード８と負極短絡リード９とを接触させる方向に応力を印加し続けている。 The driving body 22 is installed between the negative electrode short-circuit lead 9 and the upper surface of the outer can 2 in a compressed state. Therefore, the driver 22 continues to apply upward stress to the negative electrode short-circuit lead 9. That is, the driving body 22 continues to apply stress to the negative electrode short-circuit lead 9 in a direction in which the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 are brought into contact with each other.
　締結機構２３は、駆動体２２が印加する応力に抗って負極短絡リード９を上方向に移動することを防止している。たとえば、締結機構２３は、外装缶２の上面に固定される。締結機構２３は、負極短絡リード９を貫通し、その先端が負極短絡リード９から突き出すように形成される。締結機構２３の先端は、負極短絡リード９が有する穴よりも大きく形成され、負極短絡リード９が上方向に移動することを阻止する。締結機構２３により、正極短絡リード８と負極短絡リード９とは、所定の間隔を維持することができる。 The fastening mechanism 23 prevents the negative electrode short-circuit lead 9 from moving upward against the stress applied by the driver 22. For example, the fastening mechanism 23 is fixed to the upper surface of the outer can 2. The fastening mechanism 23 is formed so as to penetrate the negative electrode short-circuit lead 9 and have a tip protruding from the negative electrode short-circuit lead 9. The front end of the fastening mechanism 23 is formed larger than the hole of the negative electrode short-circuit lead 9 and prevents the negative electrode short-circuit lead 9 from moving upward. By the fastening mechanism 23, the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 can maintain a predetermined interval.
　締結機構２３は、負極短絡リード９を固定するために必要な硬度を有する絶縁体である。また、締結機構２３は、二次電池１が生じる電圧によって加熱される加熱部２４の熱で融解し、かつ、融解によって延びることなく切断される物質で形成される。締結機構２３を構成する物質は、二次電池１の電圧、駆動体２２の応力、及び、負極短絡リード９の構成などによって決定され、特定の物質に限定されるものではない。締結機構２３を構成する物質は、たとえば、ポリフェニルサルファイド（ＰＰＳ）などである。 The fastening mechanism 23 is an insulator having a hardness necessary for fixing the negative electrode short-circuit lead 9. The fastening mechanism 23 is formed of a material that is melted by the heat of the heating unit 24 that is heated by the voltage generated by the secondary battery 1 and that is cut without extending due to melting. The material constituting the fastening mechanism 23 is determined by the voltage of the secondary battery 1, the stress of the driving body 22, the configuration of the negative electrode short-circuit lead 9, and the like, and is not limited to a specific material. The substance constituting the fastening mechanism 23 is, for example, polyphenyl sulfide (PPS).
　加熱部２４は、二次電池１が生じる電力をジュール熱に変換する。加熱部２４は、発生されたジュール熱を締結機構２３に加える。実施形態において、加熱部２４は、外装缶２の上面と負極短絡リード９との間にある締結機構２３の領域２３ａにジュール熱を加える。たとえば、加熱部２４は、ニクロム線などである。たとえば、加熱部２４は、締結機構２３の領域２３ａに巻き付けられる。 The heating unit 24 converts the electric power generated by the secondary battery 1 into Joule heat. The heating unit 24 applies the generated Joule heat to the fastening mechanism 23. In the embodiment, the heating unit 24 applies Joule heat to the region 23 a of the fastening mechanism 23 between the upper surface of the outer can 2 and the negative electrode short-circuit lead 9. For example, the heating unit 24 is a nichrome wire or the like. For example, the heating unit 24 is wound around the region 23 a of the fastening mechanism 23.
　電圧検知部１４は、正極短絡リード８と負極短絡リード９との間の電圧が所定の閾値を超えた場合に、正極端子６と負極端子７との間に生じる電圧を加熱部２４に印加する。たとえば、電圧検知部１４は、トランジスタなどを備える。この場合、加熱部２４の一端は、負極端子７と電気的に接続し、他端はトランジスタに電気的に接続する。電圧検知部１４のトランジスタは、正極端子６と電気的に接続する。電圧検知部１４が正極短絡リード８と負極短絡リード９との間の電圧が所定の閾値を超えたと判断した場合に、電圧検知部１４のトランジスタは、負極端子７と加熱部２４とを電気的に接続させる。この動作によって、加熱部２４は、正極端子６と負極端子７との間の電圧を印加される。 The voltage detection unit 14 applies a voltage generated between the positive electrode terminal 6 and the negative electrode terminal 7 to the heating unit 24 when the voltage between the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 exceeds a predetermined threshold. . For example, the voltage detection unit 14 includes a transistor and the like. In this case, one end of the heating unit 24 is electrically connected to the negative electrode terminal 7 and the other end is electrically connected to the transistor. The transistor of the voltage detector 14 is electrically connected to the positive terminal 6. When the voltage detection unit 14 determines that the voltage between the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 exceeds a predetermined threshold, the transistor of the voltage detection unit 14 electrically connects the negative electrode terminal 7 and the heating unit 24. Connect to. By this operation, the heating unit 24 is applied with a voltage between the positive terminal 6 and the negative terminal 7.
　次に、過充電状態が生じた場合の二次電池１の動作例について説明する。　
　二次電池１が過充電状態となると、正極端子６に接続される正極短絡リード８と負極端子７に接続される負極短絡リード９との間の電圧が上昇する。正極短絡リード８と負極短絡リード９との間の電圧が所定の閾値を超えると、電圧検知部１４は、正極短絡リード８と負極短絡リード９との間の電圧が所定の閾値を超えたことを検知する。電圧が所定の閾値を超えたことを検知すると、電圧検知部１４は、加熱部２４に正極端子６と負極端子７との間に生じる電圧を印加させる。電圧検知部１４が加熱部２４に電圧を印加させると、加熱部２４は、印加された電圧によってジュール熱を発生させる。ジュール熱を発生させると、加熱部２４は、締結機構２３の領域２３ａを加熱し、融解させる。 Next, an operation example of the secondary battery 1 when an overcharge state occurs will be described.
When the secondary battery 1 is overcharged, the voltage between the positive short-circuit lead 8 connected to the positive terminal 6 and the negative short-circuit lead 9 connected to the negative terminal 7 increases. When the voltage between the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 exceeds a predetermined threshold value, the voltage detection unit 14 indicates that the voltage between the positive electrode short-circuit lead 8 and the negative electrode short-circuit lead 9 exceeds a predetermined threshold value. Is detected. When detecting that the voltage has exceeded a predetermined threshold, the voltage detection unit 14 causes the heating unit 24 to apply a voltage generated between the positive electrode terminal 6 and the negative electrode terminal 7. When the voltage detection unit 14 applies a voltage to the heating unit 24, the heating unit 24 generates Joule heat by the applied voltage. When Joule heat is generated, the heating unit 24 heats and melts the region 23 a of the fastening mechanism 23.
　加熱部２４が締結機構２３の領域２３ａを融解させると、締結機構２３は、領域２３ａにおいて切断される。締結機構２３が切断されると、駆動体２２は、自身の応力によって、負極短絡リード９を上方向に押し上げる。駆動体２２が負極短絡リード９を押し上げると、負極短絡リード９は、正極短絡リード８と接触し、電気的に正極短絡リード８と接続される。負極短絡リード９と正極短絡リード８とが電気的に接続されると、正極短絡リード８、正極端子６、内部正極リード４、正極集電タブ１０、電極群３、負極集電タブ１１、内部負極リード５、負極端子７及び負極短絡リード９からなる閉回路が形成される。当該閉回路が形成されると、電流遮断部１２に流れる電流は、電流遮断部１２が切断する電流の閾値を超過する。そのため、電流遮断部１２は、正極集電タブ１０と正極端子６との間の電気的な接続を遮断する。　
　以上の動作によって、二次電池１は、充電装置２０からさらに電力を充電されることなく、二次電池１の過充電状態は、収束する。 When the heating unit 24 melts the region 23a of the fastening mechanism 23, the fastening mechanism 23 is cut in the region 23a. When the fastening mechanism 23 is cut, the driving body 22 pushes the negative electrode short-circuit lead 9 upward by its own stress. When the drive body 22 pushes up the negative electrode short-circuit lead 9, the negative electrode short-circuit lead 9 comes into contact with the positive electrode short-circuit lead 8 and is electrically connected to the positive electrode short-circuit lead 8. When the negative electrode short-circuit lead 9 and the positive electrode short-circuit lead 8 are electrically connected, the positive electrode short-circuit lead 8, the positive electrode terminal 6, the internal positive electrode lead 4, the positive electrode current collecting tab 10, the electrode group 3, the negative electrode current collecting tab 11, the internal A closed circuit including the negative electrode lead 5, the negative electrode terminal 7, and the negative electrode short-circuit lead 9 is formed. If the said closed circuit is formed, the electric current which flows into the electric current interruption part 12 will exceed the threshold value of the electric current which the electric current interruption part 12 cut | disconnects. Therefore, the current interrupting part 12 interrupts the electrical connection between the positive electrode current collecting tab 10 and the positive electrode terminal 6.
With the above operation, the secondary battery 1 is not charged with power from the charging device 20 and the overcharged state of the secondary battery 1 converges.
　なお、駆動体２２、締結機構２３、及び、加熱部２４は、正極短絡リード８側に設置されてもよい。　
　また、第２実施形態に係る二次電池１は、第１実施形態に係る二次電池１の特徴を備えてもよい。 The driver 22, the fastening mechanism 23, and the heating unit 24 may be installed on the positive electrode short-circuit lead 8 side.
In addition, the secondary battery 1 according to the second embodiment may include the characteristics of the secondary battery 1 according to the first embodiment.
　以上のように構成される二次電池は、過充電状態が生じた場合に、確実に正極短絡リードと負極短絡リードとを電気的に接続させることができる。そのため、二次電池は、過充電状態が生じた場合に、確実に電流遮断部を融解させることができる。 The secondary battery configured as described above can reliably connect the positive electrode short-circuited lead and the negative electrode short-circuited lead when an overcharged state occurs. Therefore, the secondary battery can reliably melt the current interrupting part when an overcharged state occurs.
　本発明のいくつかの実施形態を説明したが、これらの実施形態は、例として提示したものであり、発明の範囲を限定することは意図していない。これら新規な実施形態は、その他の様々な形態で実施されることが可能であり、発明の要旨を逸脱しない範囲で、種々の省略、置き換え、変更を行うことができる。これら実施形態やその変形は、発明の範囲や要旨に含まれるとともに、特許請求の範囲に記載された発明とその均等の範囲に含まれる。 Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.
　１…二次電池、２…外装缶、３…電極群、４…内部正極リード、５…内部負極リード、６…正極端子、７…負極端子、８…正極短絡リード、９…負極短絡リード、１０…正極集電タブ、１１…負極集電タブ、１２…電流遮断部、１３…絶縁体、１４…電圧検知部、１５…キャッププレート、２２…駆動体、２３…締結機構、２４…加熱部、３０…過充電防止ユニット。 DESCRIPTION OF SYMBOLS 1 ... Secondary battery, 2 ... Exterior can, 3 ... Electrode group, 4 ... Internal positive electrode lead, 5 ... Internal negative electrode lead, 6 ... Positive electrode terminal, 7 ... Negative electrode terminal, 8 ... Positive electrode short circuit lead, 9 ... Negative electrode short circuit lead, DESCRIPTION OF SYMBOLS 10 ... Positive electrode current collection tab, 11 ... Negative electrode current collection tab, 12 ... Current interruption part, 13 ... Insulator, 14 ... Voltage detection part, 15 ... Cap plate, 22 ... Driver, 23 ... Fastening mechanism, 24 ... Heating part 30 ... Overcharge prevention unit.

Claims (9)

  1. 　二次電池に設置する過充電防止ユニットであって、
    　前記二次電池の一方の電極端子と電気的に一端を接続され、所定の電流が通過すると切断する電流遮断部と、
    　前記電流遮断部の他端と電気的に接続される第１短絡リードと、
    　前記二次電池の他方の電極端子と電気的に接続される第２短絡リードと、
    　前記第１短絡リードと前記第２短絡リードとの間の電圧を測定する電圧検知部と、
    　前記電圧検知部が測定した電圧が所定の閾値を超えると、前記第１短絡リードと前記第２短絡リードとを電気的に接続させる接続部と、
    を備える過充電防止ユニット。     An overcharge prevention unit installed in a secondary battery,
    One end of the secondary battery is electrically connected to one of the electrode terminals, and a current interrupting unit that is disconnected when a predetermined current passes through,
    A first short-circuit lead electrically connected to the other end of the current interrupting unit;
    A second short-circuit lead electrically connected to the other electrode terminal of the secondary battery;
    A voltage detector for measuring a voltage between the first short-circuit lead and the second short-circuit lead;
    When the voltage measured by the voltage detection unit exceeds a predetermined threshold, a connection unit that electrically connects the first short-circuit lead and the second short-circuit lead;
    An overcharge prevention unit.
  2. 　前記電流遮断部は、前記二次電池の電力によって融解することで切断する、
    前記請求項１に記載の過充電防止ユニット。     The current interrupting part is cut by melting by the power of the secondary battery,
    The overcharge prevention unit according to claim 1.
  3. 　前記第１短絡リード又は前記第２短絡リードのいずれかの短絡リードの少なくとも一部は、他の短絡リードと重なるように形成され、
    　前記接続部は、
    　前記第１短絡リード又は前記第２短絡リードのいずれかの短絡リードを、他の短絡リードと接触する方向に応力を印加する駆動部と、
    　前記短絡リードを、他の前記短絡リードとの間隔を維持するように固定する固定部と、
    　前記電圧検知部が測定した電圧が所定の前記閾値を超えると、前記固定部を加熱し、前記固定部に前記短絡リードを固定できなくさせる加熱部と、
    を備える、
    前記請求項１又２に記載の過充電防止ユニット。     At least a part of the short-circuit lead of either the first short-circuit lead or the second short-circuit lead is formed to overlap with another short-circuit lead,
    The connecting portion is
    A driving unit that applies stress in a direction in which the short-circuit lead of either the first short-circuit lead or the second short-circuit lead is in contact with another short-circuit lead;
    A fixing portion for fixing the short-circuit lead so as to maintain a distance from the other short-circuit lead;
    When the voltage measured by the voltage detection unit exceeds a predetermined threshold, the heating unit heats the fixing unit and makes the fixing unit unable to fix the short-circuit lead,
    Comprising
    The overcharge prevention unit according to claim 1 or 2.
  4. 　前記加熱部は、二次電池の電力によって前記固定部を加熱する、
    前記請求項３に記載の過充電防止ユニット。     The heating unit heats the fixed unit by the power of the secondary battery.
    The overcharge prevention unit according to claim 3.
  5. 　上面が開口している外装容器と、
    　前記外装容器内に含まれ、電解質を含む電極群と、
    　前記電極群の正極に電気的に接続される正極リードと、
    　前記電極群の負極に電気的に接続される負極リードと、
    　前記正極リードの電気的に接続され前記外装容器の外部に設置される正極端子と、
    　前記負極リードの電気的に接続され前記外装容器の外部に設置される負極端子と、
    　前記請求項１乃至４の何れか１項に記載の過充電防止ユニットと、
    を備え、
    　前記電流遮断部は、前記第１短絡リードと前記第２短絡リードとが電気的に接続された場合に電流を遮断する、
    二次電池。     An exterior container having an open top surface;
    An electrode group contained in the outer container and containing an electrolyte; and
    A positive electrode lead electrically connected to a positive electrode of the electrode group;
    A negative electrode lead electrically connected to the negative electrode of the electrode group;
    A positive electrode terminal electrically connected to the positive electrode lead and installed outside the outer container;
    A negative electrode terminal electrically connected to the negative electrode lead and installed outside the outer container;
    The overcharge prevention unit according to any one of claims 1 to 4,
    With
    The current interrupting unit interrupts current when the first short-circuit lead and the second short-circuit lead are electrically connected.
    Secondary battery.
  6. 　二次電池に設置する過充電防止ユニットであって、
    　前記二次電池の一方の電極端子と電気的に接続される第１短絡リードと、
    　前記二次電池の他方の電極端子と電気的に接続され、少なくとも一部が前記第１短絡リードと重なるように形成される第２短絡リードと、
    　前記第１短絡リードと前記第２短絡リードとの間の電圧を測定する電圧検知部と、
    　前記第１短絡リード又は前記第２短絡リードのいずれかの短絡リードを、他の短絡リードと接触する方向に応力を印加する駆動部と、
    　前記短絡リードを、他の前記短絡リードとの間隔を維持するように固定する固定部と、
    　前記電圧検知部が測定した電圧が所定の前記閾値を超えると、前記固定部を加熱し、前記固定部に前記短絡リードを固定できなくさせる加熱部と、
    を備える過充電防止ユニット。     An overcharge prevention unit installed in a secondary battery,
    A first short-circuit lead electrically connected to one electrode terminal of the secondary battery;
    A second short-circuit lead that is electrically connected to the other electrode terminal of the secondary battery and is formed so that at least a portion thereof overlaps the first short-circuit lead;
    A voltage detector for measuring a voltage between the first short-circuit lead and the second short-circuit lead;
    A driving unit that applies stress in a direction in which the short-circuit lead of either the first short-circuit lead or the second short-circuit lead is in contact with another short-circuit lead;
    A fixing portion for fixing the short-circuit lead so as to maintain a distance from the other short-circuit lead;
    When the voltage measured by the voltage detection unit exceeds a predetermined threshold, the heating unit heats the fixing unit and makes the fixing unit unable to fix the short-circuit lead,
    An overcharge prevention unit.
  7. 　前記加熱部は、二次電池の電力によって前記固定部を加熱する、
    前記請求項６に記載の過充電防止ユニット。     The heating unit heats the fixed unit by the power of the secondary battery.
    The overcharge prevention unit according to claim 6.
  8. 　前記短絡リードは、前記固定部を通過させる穴を備え、
    　前記固定部は、前記二次電池のキャッププレートに一端を固定され、前記穴に他端を固定される、
    前記請求項６乃至７の何れか１項に記載の過充電防止ユニット。     The short-circuit lead includes a hole through which the fixing portion passes,
    The fixing part has one end fixed to the cap plate of the secondary battery and the other end fixed to the hole.
    The overcharge prevention unit according to any one of claims 6 to 7.
  9. 　上面が開口している外装容器と、
    　前記外装容器内に含まれ、電解質を含む電極群と、
    　前記電極群の正極に電気的に接続される正極リードと、
    　前記電極群の負極に電気的に接続される負極リードと、
    　前記正極リードの電気的に接続され前記外装容器の外部に設置される正極端子と、
    　前記負極リードの電気的に接続され前記外装容器の外部に設置される負極端子と、
    　前記正極リードと前記負極リードとが電気的に接続された場合に、前記正極リードと前記電極群の前記正極との間に流れる電流、又は、前記負極リードと前記電極群の前記負極との間に流れる電流を遮断する電流遮断部と、
    　請求項６乃至１０の何れか１項に記載の過充電防止ユニットと、
    を備える二次電池。     An exterior container having an open top surface;
    An electrode group contained in the outer container and containing an electrolyte; and
    A positive electrode lead electrically connected to a positive electrode of the electrode group;
    A negative electrode lead electrically connected to the negative electrode of the electrode group;
    A positive electrode terminal electrically connected to the positive electrode lead and installed outside the outer container;
    A negative electrode terminal electrically connected to the negative electrode lead and installed outside the outer container;
    When the positive electrode lead and the negative electrode lead are electrically connected, the current flowing between the positive electrode lead and the positive electrode of the electrode group, or between the negative electrode lead and the negative electrode of the electrode group A current interrupting unit that interrupts the current flowing through
    The overcharge prevention unit according to any one of claims 6 to 10,
    A secondary battery comprising:
PCT/JP2014/074360 2013-09-17 2014-09-16 Overcharging prevention unit and secondary battery WO2015041201A1 (en)

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