JP2005222923A - Non-aqueous electrolyte secondary battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-aqueous electrolyte secondary battery for preventing the leakage of non-aqueous electrolyte in case of damage to a rapture board by intense falling, vibration and shock, and restricting the flow of a current in an abnormal case such as an external short circuit and over charge, and further including a PTC element acting as a gas passageway when gas escapes and disperses by the rapture board. <P>SOLUTION: The non-aqueous electrolyte secondary battery comprises an enclosure can 1 having an opening at its one end, a group of electrodes each consisting of a negative electrode 4, a separator 5 and a positive electrode 3, non-aqueous electrolyte stored in the enclosure can, a group of sealing covers 9 for airtightly sealing the opening of the enclosure can via an insulating member, wherein the group of sealing covers are in ring-shaped, and a PTC element 14 having disc-like polymer molecule resin layer arranged to adhere closely to an inner circumference surface of the ring in the space of the ring. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a non-aqueous electrolyte secondary battery, and more particularly to a non-aqueous electrolyte secondary battery having an improved structure of a PTC element incorporated as a safety mechanism.

  In recent years, with the downsizing and high performance of electronic devices such as mobile phones and VTRs, it is required to increase the capacity of secondary batteries that are power sources of these electronic devices. In addition, air pollution due to exhaust gas from automobiles has become a social problem, and it is expected to use a lightweight and high-performance secondary battery as a power source for electric vehicles.

  In particular, lithium ion secondary batteries have high battery voltage, high energy density, and can be made smaller and lighter, so they are put to practical use as power sources for portable devices, and achieve even higher energy densities. Research and development are underway.

  On the other hand, in a cylindrical lithium ion secondary battery, when an abnormality such as overcharge or short circuit occurs, an overcurrent flows inside the battery and the nonaqueous electrolyte is decomposed, and the battery temperature rises due to heat generated by the decomposition reaction of the electrolyte. There is a problem that the non-aqueous electrolyte leaks or ruptures in some cases. For this reason, a lithium ion secondary battery incorporates a PTC element as one of the battery constituent members that increases the resistance and restricts the flow of current when the battery temperature rises due to overcharging or the like. This PTC element has a structure in which an element body showing a sudden increase in resistance with a temperature rise caused by an overcurrent or the like is interposed between a pair of electrodes.

  Further, as disclosed in Patent Document 1, the conventional PTC element has a donut shape (ring shape) in order to ensure a sufficient gas flow path. That is, the rupture plate that is broken when the internal pressure is increased due to gas generation is separately incorporated in the outer can from the PTC element so as to be connected to the PTC element, and the internal pressure of the battery is increased due to heat generation at the time of abnormality. In this case, the rupture plate is broken to release the gas. At this time, by making the PTC element into a ring shape, a gas flow path is secured in the hollow portion, and the gas can be smoothly discharged to the outside and released.

However, when the rupture plate is damaged due to a violent drop or vibration shock of the secondary battery, the PTC element may leak a non-aqueous electrolyte from its shape. The leakage of the non-aqueous electrolyte causes a short circuit or the like of the protection circuit of the battery pack incorporating the secondary battery, and there is a high possibility of causing smoke or ignition.
JP-A-7-65856

  The present invention prevents leakage of the non-aqueous electrolyte when the rupture plate is damaged due to violent dropping or vibration shock, and restricts the current flow in the event of an abnormality such as an external short circuit or overcharge. It aims at providing the nonaqueous electrolyte secondary battery provided with the PTC element which works as a gas channel at the time of gas escape.

According to the present invention, an outer can opened at one end;
An electrode group housed in the outer can and comprising a negative electrode, a separator and a positive electrode;
A non-aqueous electrolyte contained in the outer can, and a sealing lid group that hermetically seals the opening of the outer can via an insulating member,
The sealing lid group comprises a non-water-containing PTC element having a ring shape and having a disk-shaped polymer resin layer disposed in close contact with the inner peripheral surface of the ring in a space within the ring. An electrolyte secondary battery is provided.

According to the present invention, an outer can whose one end is opened;
An electrode group housed in the outer can and comprising a negative electrode, a separator and a positive electrode;
A non-aqueous electrolyte contained in the outer can, and a sealing lid group that hermetically seals the opening of the outer can via an insulating member,
The sealing lid group includes a non-water-containing PTC element having a ring shape and having a disk-like electrolyte solution holding member disposed in close contact with the inner peripheral surface of the ring in a space in the ring. An electrolyte secondary battery is provided.

Furthermore, according to the present invention, an outer can that also serves as a unipolar terminal having one end opened;
An electrode group housed in the outer can and composed of a negative electrode, a separator and a positive electrode;
A non-aqueous electrolyte contained in the outer can;
A sealing lid group hermetically sealed via an insulator at the opening of the outer can,
The sealing lid group is disposed to face the electrode group, and is electrically connected to one of the positive and negative electrodes of the electrode group through an electrode connection tab to transmit and cut off current and increase internal pressure accompanying gas generation. A current interrupting mechanism having an open valve that is sometimes broken, a terminal member that becomes an other polarity terminal arranged on the outside, a ring-shaped PTC element interposed between the current interrupting mechanism and the terminal member, There is provided a nonaqueous electrolyte secondary battery comprising a disk-shaped polymer resin layer disposed in close contact with an inner surface of a ring in a space in a ring of a PTC element.

Furthermore, according to the present invention, an outer can that also serves as a unipolar terminal having one end opened;
An electrode group housed in the outer can and composed of a negative electrode, a separator and a positive electrode;
A non-aqueous electrolyte contained in the outer can;
A sealing lid group hermetically sealed via an insulator at the opening of the outer can,
The sealing lid group is disposed to face the electrode group, and is electrically connected to one of the positive and negative electrodes of the electrode group through an electrode connection tab to transmit and cut off current and increase internal pressure accompanying gas generation. A current interrupting mechanism having an open valve that is sometimes broken, a terminal member serving as an other polarity terminal disposed on the outside, a ring-shaped PTC element interposed between the current interrupting mechanism and the terminal member, There is provided a non-aqueous electrolyte secondary battery comprising a disk-like electrolyte solution holding member disposed in close contact with an inner surface of a ring in a ring of a PTC element.

  The present invention prevents non-aqueous electrolyte leakage when the rupture plate is damaged due to violent dropping, vibration shock, and short circuit of the protection circuit of the battery pack accompanying this, and at the time of abnormality such as overcharge or short circuit state It is possible to provide a safe non-aqueous electrolyte secondary battery including a PTC element that restricts the flow of current and functions as a gas flow path when gas escapes by the rupture plate.

  Hereinafter, a non-aqueous electrolyte secondary battery according to the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a partial sectional view showing a cylindrical nonaqueous electrolyte secondary battery according to the first embodiment, and FIG. 2 shows a main part of a sealing lid group incorporated in the cylindrical nonaqueous electrolyte secondary battery of FIG. It is a disassembled perspective view.

  As shown in FIG. 1, the bottomed cylindrical outer can 1 is made of, for example, stainless steel, iron, or aluminum, and also serves as a unipolar terminal (for example, a negative electrode terminal), and an insulator (not shown) is disposed at the bottom. . The electrode group 2 is housed in the outer can 1. This electrode group 2 is produced by winding the positive electrode 3 and the negative electrode 4 in a spiral shape with a separator 5 interposed therebetween. Two semicircular holes 6 and an insulating pressing plate 8 having a small hole 7 opened near the center are arranged on the electrode group 2 in the outer can 1.

  The sealing lid group 9 is attached to the upper end opening of the outer can 1 via an insulating member, for example, an insulating gasket 10. As shown in FIGS. 1 and 2, the sealing lid group 9 includes a metal stripper 11, an insulating sheet 12, a metal rupture plate 13, an annular PTC element 14, and a gas from the electrode group 2 side. A terminal plate 16 serving as another polarity terminal (for example, a positive electrode terminal) having a punched hole 15 is disposed in this order by caulking and fixing the peripheral edges thereof with the insulating gasket 10. The insulating sheet 12 has a dish shape, and the center side is opened from the vicinity of the rising portion to form a gas flow path.

  As shown in FIG. 2, the stripper 11 has a dish shape. For example, three fan holes 17 serving as gas flow paths are opened at locations corresponding to the openings of the insulating sheet 12, and a small hole 18 is formed near the center. It is open. The connection plate 19 is bonded to the surface (bottom surface) of the stripper 11 facing the electrode group 2 so as to seal the small hole 18. A foldable lead wire 20 made of a metal such as aluminum is connected to the surface of the connection plate 19 facing the electrode group 2. The lead wire 20 is connected to one electrode (for example, the positive electrode 3) of the electrode group 2. The stripper 11 is made of stainless steel or aluminum, for example, and has a thickness of 0.1 to 1.0 mm. The connecting plate 19 is made of aluminum, for example, and has a thickness of 0.05 to 0.2 mm. The connecting plate can be omitted.

  As shown in FIG. 2, the rupture plate 13 has a dish shape and is overlapped on the stripper 11 with the insulating sheet 12 interposed therebetween. The rupture plate 13 has an inverted conical current transmission / cut-off portion 21 protruding toward the stripper 11 at the center. The tip of the current transmission / cut-off portion 21 is connected to the connection plate 19 through the opening of the insulating sheet 12 and the small hole 18 of the stripper 11. That is, the current transmission / cut-off unit 21 is connected to the folding lead wire 20 through the connection plate 19. Therefore, the current interrupting member is composed of the stripper 11, the insulating sheet 12, and the rupture plate 13. Further, the rupture plate 13 has a notch portion that is a breakable portion that can be broken by an increase in internal pressure accompanying gas generation on the surface on the PTC element 14 side, for example, a circular notch portion 22 surrounding the current transmission / cutoff portion 21 and For example, eight linear cut portions 23 extending radially from the circular cut portion 22 to the periphery are formed. The rupture plate 13 is made of aluminum, for example, and has a thickness of 0.1 to 0.5 mm.

  Note that the above-described current interrupting member is not limited to the above-described configuration as long as the required current interrupting can be performed in accordance with the increase in pressure in the battery, and any means / configuration may be used. For example, the member that transmits and interrupts the current may be a foldable lead wire that is deformed by compression due to an increase in the internal pressure of the battery, and the member that is broken when the internal pressure increases is a valve membrane.

  The PTC element 14 is interposed between the rupture plate 13 and the terminal plate 16, that is, is interposed in the current path of the positive electrode. When the overcurrent flows and the temperature rises, the PTC element 14 limits the current by increasing the resistance value. Prevents abnormal heat generation due to current. The PTC element 14 has a ring shape as shown in FIGS. 1 and 2, and a disk-shaped polymer resin layer 24 is disposed in the space in the ring so that the outer peripheral surface thereof is in close contact with the inner surface of the ring of the PTC element 14. (Embedded) structure.

  As shown in FIG. 1, the PTC element 14 includes a ring-shaped resin sheet such as polyethylene or polypropylene containing a conductive material such as carbon between two ring-shaped metal thin plates (for example, ring-shaped nickel thin plates) 25a and 25b. 26.

  The disk-shaped polymer resin layer 24 melts at about 150 to 200 ° C. in order to prevent the leakage of the non-aqueous electrolyte and to secure a gas flow path when a large amount of gas is generated when the temperature is abnormal. It is preferable to make it from a polymer resin. Examples of the polymer resin include polyvinylidene fluoride and polypropylene.

  The ring-shaped PTC element 14 having the disk-shaped polymer resin layer 24 is formed by, for example, a method in which a polymer resin is injected into the ring inner space of the PTC element 14 by an injection molding machine or the like, or is previously molded in the ring inner space. The disc-shaped polymer resin layer can be manufactured by press-fitting.

  The terminal plate 16 which becomes the other polarity terminal (for example, positive electrode terminal) with which the said gas vent hole 15 was opened is made from stainless steel, iron, or aluminum, for example, and has a thickness of 0.2-1.0 mm.

  Next, the positive electrode 3, the negative electrode 4, and the non-aqueous electrolyte will be specifically described.

a) Positive electrode 3
For example, the positive electrode 3 is made of a positive electrode material paste obtained by dispersing a positive electrode active material, a conductive agent, and a binder in an appropriate solvent, continuously or in a larger area than desired on one side or both sides of a current collector. It is produced by alternately applying a length to be applied and an uncoated portion, and cutting a dried thin sheet into a desired size.

A lithium composite metal oxide can be used as the positive electrode active material. Specifically such _{LiCoO 2, LiNiO 2, LiMnO 2} , LiMn 2 O 4 is used. Examples of the binder include polyvinylidene fluoride, a copolymer of vinylidene fluoride-6-propylene fluoride, a terpolymer of polyvinylidene fluoride-tetrafluoroethylene-6-propylene fluoride, and vinylidene fluoride-pentafluoropropylene. And a copolymer of vinylidene fluoride-chlorotrifluoroethylene, or a copolymer of other fluorine-based monomer and vinylidene fluoride. Examples of the copolymer of the other fluorine-based monomer and vinylidene fluoride include tetrafluoroethylene-vinylidene fluoride copolymer, tetrafluoroethylene-perfluoroalkyl vinyl ether (PFA) -vinylidene fluoride terpolymer. Polymer, Tetrafluoroethylene-hexafluoropropylene (FEP) -vinylidene fluoride terpolymer, Tetrafluoroethylene-ethylene-vinylidene fluoride copolymer, Chlorotrifluoroethylene-vinylidene fluoride copolymer And a terpolymer of chlorotrifluoroethylene-ethylene-vinylidene fluoride and a copolymer of vinyl fluoride-vinylidene fluoride. These binders may be used alone.

  As the organic solvent for dispersing the binder, N-methylpyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide, methyl ethyl ketone, tetrahydrofuran, acetone, ethyl acetate and the like are used.

  Examples of the conductive agent include acetylene black, ketjen black, and graphite.

  The amount of the binder is 2% to 8% by weight based on 100 parts by weight of the active material and the binder (100 parts by weight of the conductive agent when the conductive agent is included). % Is preferable.

  The blending amount of the conductive agent is preferably in the range of 1% by weight to 15% by weight with respect to 100 parts by weight of the active material.

  The organic solvent is blended in an amount of 65% to 150% by weight based on 100 parts by weight of the active material and the binder (100 parts by weight of the conductive agent when the conductive agent is included). It is preferable to be in the range.

  As a means for dispersing the positive electrode active material, the conductive agent and the binder in an appropriate solvent, a dispersing device such as a ball mill, a bead mill, a dissolver, a sand grinder, or a roll mill is used.

  Examples of the current collector include aluminum foil, stainless steel foil, and titanium foil having a thickness of 10 to 40 μm.

b) Negative electrode 4
The anode 4 is made of, for example, a carbonaceous material that occludes / releases lithium ions or a chalcogen compound, a light metal, or the like. Among these, a negative electrode containing a carbonaceous material or a chalcogen compound that occludes / releases lithium ions is preferable because battery characteristics such as cycle life of the secondary battery are improved.

  Examples of the carbonaceous material that occludes / releases lithium ions include coke, carbon fiber, pyrolytic vapor phase carbon material, graphite, resin fired body, mesophase pitch-based carbon fiber, or mesophase spherical carbon fired body. . Among them, it is preferable to use mesophase pitch carbon fiber graphitized at 2500 ° C. or higher because the electrode capacity is increased.

Examples of the chalcogen compound that absorbs and releases lithium ions include titanium disulfide (TiS ₂ ), molybdenum disulfide (MoS ₂ ), and niobium selenide (NbSe ₂ ). When such a chalcogen compound is used for the negative electrode, although the voltage of the secondary battery drops, the capacity of the negative electrode increases, so that the capacity of the secondary battery is improved. Furthermore, since the negative electrode has a high diffusion rate of lithium ions, the rapid charge / discharge performance of the secondary battery is improved.

  Examples of the light metal include aluminum, aluminum alloy, magnesium alloy, lithium metal, and lithium alloy.

  Examples of the binder include polyvinylidene fluoride, a copolymer of vinylidene fluoride-6-propylene fluoride, a terpolymer of polyvinylidene fluoride-tetrafluoroethylene-6-propylene fluoride, and vinylidene fluoride-pentafluoropropylene. And a copolymer of vinylidene fluoride-chlorotrifluoroethylene, or a copolymer of other fluorine-based monomer and vinylidene fluoride. Examples of such a copolymer of another fluorine-based monomer and vinylidene fluoride include a copolymer of tetrafluoroethylene-vinylidene fluoride and a terpolymer of tetrafluoroethylene-perfluoroalkyl vinyl ether (PFA) -vinylidene fluoride. Polymer, Tetrafluoroethylene-hexafluoropropylene (FEP) -vinylidene fluoride terpolymer, Tetrafluoroethylene-ethylene-vinylidene fluoride copolymer, Chlorotrifluoroethylene-vinylidene fluoride copolymer , Chlorotrifluoroethylene-ethylene-vinylidene fluoride terpolymer, vinyl fluoride-vinylidene fluoride copolymer, styrene butadiene copolymer, nitrile butadiene copolymer, acrylic copolymer, polyacrylic Acid, carboxymethylcellulose, Mention may be made of Le cellulose.

  As an organic solvent for dispersing the binder, N-methylpyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide, methyl ethyl ketone, tetrahydrofuran, acetone, ethyl acetate, water and the like are used.

  The negative electrode (for example, a negative electrode made of a carbon material) is specifically desired on one side or both sides of a negative electrode material paste obtained by dispersing the carbon material, a conductive agent, and a binder in an appropriate solvent. A continuous or desired length and an unapplied portion are alternately applied to an area larger than the size to be formed, and dried and cut into a desired plate size.

The mixing ratio of the negative electrode material and the binder is preferably in the range of 80 to 98% by weight of the negative electrode material and 2 to 20% by weight of the binder. In particular, the carbon material is preferably in the range of 50 to 200 g / m ² as the coating amount per side in the state in which the negative electrode 6 is produced.

  As the current collector, for example, a copper foil, a nickel foil, or the like can be used, but a copper foil is most preferable in view of electrochemical stability and flexibility during winding. In this case, the thickness of the foil is preferably 8 μm or more and 20 μm or less.

c) Nonaqueous electrolyte This nonaqueous electrolyte has a composition in which an electrolyte is dissolved in a nonaqueous solvent.

  Examples of the non-aqueous solvent include cyclic carbonates such as propylene carbonate (PC) and ethylene carbonate (EC), chain carbonates such as dimethyl carbonate (DMC), methyl ethyl carbonate (MEC), and diethyl carbonate (DEC). , 2-dimethoxyethane (DME), chain ethers such as diethoxyethane (DEE), cyclic ethers such as tetrahydrofuran (THF) and 2-methyltetrahydrofuran (2-MeTHF), crown ethers, γ-butyrolactone (γ-BL) ), Nitrogen compounds such as acetonitrile (AN), sulfur compounds such as sulfolane (SL) and dimethyl sulfoxide (DMSO), and the like.

  Among these, at least one selected from EC, PC, and γ-BL, at least one selected from EC, PC, and γ-BL and DMC, MEC, DEC, DME, DEE, THF, 2-MeTHF, It is preferable to use a mixed solvent composed of at least one selected from AN. Moreover, when using what contains the carbonaceous material which occludes and discharge | releases the said lithium ion for a negative electrode, from a viewpoint of improving the cycle life of the secondary battery provided with the said negative electrode, EC and PC, (gamma) -BL, EC and PC It is preferable to use a mixed solvent consisting of EC and MEC, EC and PC and DEC, EC and PC and DEE, EC and AN, EC and MEC, PC and DMC, PC and DEC, or EC and DEC.

Examples of the electrolyte include lithium perchlorate (LiClO ₄ ), lithium hexafluorophosphate (LiPF ₆ ), lithium borofluoride (LiBF ₄ ), lithium arsenic hexafluoride (LiAsF ₆ ), and lithium trifluorometasulfonate. Examples thereof include lithium salts such as (LiCF ₃ SO ₃ ), lithium aluminum tetrachloride (LiAlCl ₄ ), and bistrifluoromethylsulfonylimide lithium [LiN (CF ₃ SO ₂ ) ₂ ]. Of these, LiPF ₆ , LiBF ₄ , and LiN (CF ₃ SO ₂ ) ₂ are preferable because conductivity and safety are improved.

  The amount of the electrolyte dissolved in the non-aqueous solvent is preferably in the range of 0.5 mol / L to 2.0 mol / L.

  In the nonaqueous electrolyte secondary battery according to the first embodiment shown in FIG. 1 and FIG. 2 described above, the operation at the time of 1) abnormality (at the time of external short circuit) and 2) at the time of abnormality (at the time of overcharge) will be described.

1) At the time of an external short circuit When a large current flows due to an external short circuit, the PTC element 14 located between the rupture plate 13 and the terminal plate 16 operates due to heat generated by its own resistance, and its resistance value increases rapidly. For this reason, it is possible to avoid heat generation and an increase in internal pressure due to a large current continuing by suppressing the current flow.

3) At the time of overcharge When the temperature in the outer can 1 rises due to overcharge, and gas is generated due to the reaction between the electrode group 2 and the nonaqueous electrolyte and the decomposition of the nonaqueous electrolyte, and the internal pressure rises, The gas reaches the rupture plate 13 through the holes 6 and 7 of the insulating retainer plate 8, the three fan-shaped holes 17 opened in the stripper 11 and the opening of the insulating sheet 12, and pushes up the rupture plate 13 toward the terminal plate 16. When the rupture plate 13 is pushed up, the stripper 11 and the connection plate 19 are not deformed. Therefore, the reverse cone-shaped current transmission / cut-off portion 21 of the rupture plate 13 is separated from the connection plate 19 and the positive electrode transmission path is electrically connected. Blocked. As a result, it is possible to avoid further heat generation and an increase in internal pressure due to the continuous flow of current.

  If an increase in internal pressure occurs even after the current transmission path of the positive electrode is interrupted, a higher gas pressure is applied to the rupture plate 13 at a higher temperature through the gas path. At this time, the rupture plate 13 is formed with the cut portions 23 and 24 as shown in FIG. 2, so that the rupture plate 13 is broken from the cut portions 23 and 24 as a starting point due to the pressure of the gas. . As the rupture plate 13 is broken, the gas further flows toward the ring-shaped PTC element 14. In this PTC element 14, a disk-shaped polymer resin layer 24 is disposed in the space in the ring, and when the high-temperature gas is blown, the disk-shaped polymer resin layer 24 is melted by the heat and gas is discharged. In order to form the flow path, the gas generated in the outer can 1 is smoothly opened to the outside through the gas flow path. As a result, battery rupture due to an excessive increase in internal pressure can be prevented in advance.

  Furthermore, in the non-aqueous electrolyte secondary battery having the configuration shown in FIGS. 1 and 2, when the rupture plate 13 is damaged due to severe drop or vibration shock, the non-aqueous electrolyte in the outer can 1 is opened to the stripper 11. The PTC element 14 is reached through the fan-shaped hole 17, the opening of the insulating ring 12 and the damaged portion of the rupture plate 13. Since the disk-shaped polymer resin layer 24 is disposed in close contact with the inner surface of the ring in the space in the ring as described above, the PTC element 14 has the ring like the conventional ring-shaped PTC element. It is possible to prevent the nonaqueous electrolyte from leaking from the inner space.

  Therefore, according to the first embodiment of the present invention, it is possible to prevent heat generation (temperature increase) and increase in internal pressure at the time of abnormality such as external short circuit and overcharge, and even if gas generation due to temperature increase and internal pressure increase occur, the PTC element Therefore, it is possible to provide a non-aqueous electrolyte secondary battery excellent in battery characteristics and safety because it can ensure gas flow path and quickly escape gas to prevent rupture and the like.

  In addition, when the rupture plate is damaged due to violent dropping or vibration shock, the non-aqueous electrolyte is prevented from leaking, and the battery pack protection circuit is prevented from being short-circuited due to the leakage of the non-aqueous electrolyte. Can be prevented.

  In the first embodiment described above, the disc-shaped polymer resin layer 24 is directly fixed in the space in the ring of the PTC element 14, but the present invention is not limited to this. For example, as shown in FIG. 3, a ring-shaped nickel thin plate 25b of the PTC element 14 located on the rupture plate 13 side is extended into a space in the ring of the PTC element 14 to form a ring-shaped flange 27, and this PTC The disc-shaped polymer resin layer 24 may be disposed in a space in the ring of the element 14 so that the outer peripheral surface thereof is in close contact with the inner surface of the ring of the PTC element 14 and supported by the flange portion 27. Further, as shown in FIG. 4, a metal mesh 28 is integrally attached to the ring-shaped nickel thin plate 25b of the PTC element 14 positioned on the rupture plate 13 side so as to be positioned in the space in the ring of the PTC element 14, and this PTC element The disc-shaped polymer resin layer 24 may be disposed in the space in the ring 14 so that the outer peripheral surface thereof is in close contact with the inner surface of the ring of the PTC element 14 and supported by the metal mesh 28.

  According to such a configuration shown in FIG. 3 or FIG. 4, the disk-shaped polymer resin layer 24 can be fixed more satisfactorily in the space in the ring of the PTC element 14.

In addition, in the cylindrical nonaqueous electrolyte secondary battery according to the first embodiment of the present invention shown in FIGS. 1 and 2 described above, the conductive support plate shown in FIGS. Further, it is allowed to have a configuration provided.
As shown in FIG. 5, the conductive support plate 41 is disposed so as to cover the entire top surface of the PTC element 14 including the disk-shaped polymer resin layer 24. The conductive support plate 41 includes a conductive disc 42 that is caulked and fixed to the insulating gasket 10, and a cut portion that is formed on the conductive disc 42 and is an easily breakable portion that can be broken by an increase in internal pressure due to gas generation. It is comprised from the notch part, for example, the circular notch part 43, and the eight linear notch parts 44 extended radially outward from this notch part 43. As shown in FIG.
In the conductive support plate 41 having the configuration shown in FIG. 5, the internal pressure of the outer can increases due to gas generation, the rupture plate 13 is broken, and the disc-shaped polymer resin located in the space in the ring of the PTC element 14 When the gas pressure is applied to the support plate 41 by melting at a high temperature gas pressure in the layer 24 and the gas pressure is applied to the support plate 41, the gas is released by breaking at the notches 43 and 44.
As shown in FIG. 6, a conductive ring plate 45 that is a conductive support plate is caulked and fixed to the insulating gasket 10 so as to cover the entire upper surface of the PTC element 14 including the disk-shaped polymer resin layer 24.

As shown in FIG. 7, the conductive support plate 46 is disposed so as to cover the entire top surface of the PTC element 14 including the disc-shaped polymer resin layer 24. The conductive support plate 46 covers the hollow portion on at least one surface (for example, the upper surface) of the ring plate 47 excluding the fixing portion by the insulating gasket 10 by caulking and fixing to the insulating gasket 10. A circular thin plate 48 fixed in this manner, and a cut portion which is an easily breakable portion which can be broken by an increase in internal pressure due to gas generation formed in the thin plate 48, for example, a circular cut portion 49 and the cut portion 49 It is comprised from the eight linear notch parts 50 extended radially outside. The circular thin plate is preferably made of, for example, nickel, and has a thickness that is easily broken due to an increase in internal pressure accompanying gas generation, for example, a thickness of 0.05 to 0.3 mm.
In the conductive support plate 46 having the configuration shown in FIG. 7, the inner pressure of the outer can increases due to gas generation, the rupture plate 13 is broken, and the disc-shaped polymer resin is located in the space in the ring of the PTC element 14. The gas flow path is formed by melting the layer 24 with a high temperature gas pressure, and when the gas pressure is applied to the support plate 46, the gas is broken by starting from the notches 49 and 50 formed in the thin plate 48. Escape.
As shown in FIG. 8, the conductive support plate 51 is disposed so as to cover the entire top surface of the PTC element 14 including the disk-shaped polymer resin layer 24. The conductive support plate 51 includes a ring plate 52 that is caulked and fixed to the insulating gasket 10, and a disk-shaped polymer resin layer 53 that is disposed in close contact with the inner surface of the hollow portion of the ring plate 52. Yes. The disk-shaped polymer resin layer 53 is preferably melted at about 100 to 200 ° C., and is made of, for example, polyethylene, polyvinylidene fluoride, polypropylene or the like.

In the conductive support plate 51 having the configuration shown in FIG. 8, the internal pressure of the outer can increases due to gas generation, the rupture plate 13 is broken, and the disc-shaped polymer resin is located in the space in the ring of the PTC element 14. When the gas pressure is applied to the support plate 51, the disc-shaped polymer resin layer 53 is melted to form a gas flow path. , Let the gas escape through here.
The conductive disk and the conductive ring plate constituting the conductive support plate are used for stably caulking and fixing the PTC element 14 and the rupture plate 13 to the insulating gasket 10. For this reason, if the thickness of the conductive disk and conductive ring plate is reduced, the function is not sufficiently exhibited.On the other hand, if the thickness is too large, the thickness of the sealing lid group increases and the capacity of the electrode group is increased. There is a risk that it will be effectively reduced. Therefore, it is desirable that the conductive disk and the conductive ring plate have a thickness of 0.1 to 0.5 mm, more preferably 0.2 to 0.35 mm.
The conductive disk and conductive ring plate constituting the conductive support plate have a relatively large Young's modulus (the Young's modulus at 25 ° C. is 1 × 10 ¹¹ Pa-3 in order to effectively express the function). It is preferably made from a conductive material (.27 × 10 ¹¹ Pa). For example, it can be manufactured from iron, nickel, copper, cobalt, chromium, or an alloy thereof, molybdenum, tantalum, or the like.
According to the configuration shown in FIGS. 5 to 8, since the caulking fixing property to the insulating gasket 10 at the periphery of the rupture plate 13 and the PTC element 14 is improved by the conductive support plate, the periphery of these members is gas. It is possible to prevent the outer can from being deformed by an increase in the internal pressure of the outer can. As a result, it is possible to suppress variations in operating pressure at which the rupture plate 13 is broken and operating pressure at which the disc-shaped polymer resin layer 24 of the PTC element 14 is melted, thereby providing a stable rupture function.
In particular, the conductive support plate 41 having the cut portions 43 and 44 shown in FIG. 5, the conductive support plate 46 having the circular thin plate 48 with the cut portions 49 and 50 shown in FIG. 7, and FIG. Since the conductive support plate 51 having the circular polymer resin layer 53 has a rupture function as described above, a triple rupture function member may be provided together with the rupture plate 13 and the disk-like polymer resin layer 24 of the PTC element 14. It is possible to prevent the inflow of moisture from the outside and the leakage of the non-aqueous electrolyte even more reliably even under impact such as dropping.

The conductive support plate shown in FIGS. 5 to 8 is not limited to the case where the conductive support plate is disposed on the upper surface of the PTC element 14 including the disc-shaped polymer resin layer 24, but between the rupture plate 13 and the PTC element 14, that is, the PTC. You may arrange | position on the element 14 lower surface.
(Second Embodiment)
The cylindrical nonaqueous electrolyte secondary battery of the second embodiment has the structure shown in FIG. 1 described above, and the PTC element 14 interposed between the rupture plate and the terminal plate is as shown in FIG. In addition, a disk-shaped electrolyte solution holding member, for example, a disk-shaped porous body 31 having continuous air holes is disposed in the space in the ring. Specifically, the ring-shaped nickel thin plate 25b of the PTC element 14 located on the rupture plate 13 side is extended into the space in the ring of the PTC element 14 to form the ring-shaped flange portion 27, and the disk-shaped porous The material 31 is arranged in the space in the ring of the PTC element 14 so that the outer peripheral surface thereof is in close contact with the inner surface of the ring of the PTC element 14 and supported by the flange portion 27.

  The porous body 31 can be made of any inorganic or organic material. Examples of the inorganic porous material include a silica porous material having continuous pores and an alumina porous material. In addition, when using an inorganic type porous body, it is preferable to mutually adhere | attach between the outer peripheral surface of the porous body, and the ring inner surface of a PTC element through an adhesive bond layer. Examples of the organic porous material include polymer resin foams such as polyurethane foam and polyethylene foam having continuous pores.

  In the cylindrical nonaqueous electrolyte secondary battery in which the PTC element 14 shown in FIG. 9 is incorporated, when a large current flows due to an external short circuit, the temperature in the outer can rises due to overcharging, and the electrode group When the gas resulting from the reaction of the non-aqueous electrolyte and the decomposition of the non-aqueous electrolyte is generated and the internal pressure rises, the current flows by the ring-shaped PTC elements 14 as described in the first embodiment. Suppresses and electrically interrupts the positive electrode transmission path.

  On the other hand, if the internal pressure rises with heat generation even after the current transmission path of the positive electrode is interrupted, the rupture plate is broken, and the gas further moves toward the ring-shaped PTC element 14 as the rupture plate is broken. Flowing. At this time, since the PTC element 14 is provided with a disk-shaped electrolyte solution holding member (for example, a disk-shaped silica porous body having continuous pores) 31 in the space in the ring, the gas is the disk-shaped silica. It is smoothly opened to the outside through the continuous pores (gas flow path) of the porous body 31. As a result, battery rupture due to an excessive increase in internal pressure can be prevented in advance.

  Further, in the non-aqueous electrolyte secondary battery incorporating the PTC element shown in FIG. 9, when the rupture plate is damaged due to severe drop or vibration shock, as described in the first embodiment, the non-aqueous electrolyte in the outer can The electrolytic solution reaches the PTC element 14 through the damaged portion of the rupture plate. Since the disk-shaped electrolyte solution holding member (for example, a silica porous body having continuous pores) 31 is disposed in the space in the ring of the PTC element 14 as described above, the non-aqueous electrolyte solution is used as the non-aqueous electrolyte solution. The disc-like silica porous body 31 can be held in the pores to prevent leakage.

  Therefore, according to the second embodiment of the present invention, it is possible to prevent heat generation (temperature rise) and increase in internal pressure at the time of abnormality such as external short circuit and overcharge, and even if gas generation due to temperature rise and internal pressure increase occur, the PTC element Therefore, it is possible to provide a non-aqueous electrolyte secondary battery excellent in battery characteristics and safety because it can ensure gas flow path and quickly escape gas to prevent rupture and the like.

  In addition, when the rupture plate is damaged due to a violent drop or vibration shock, the non-aqueous electrolyte is prevented from leaking, and the protection circuit of the battery pack is prevented from being short-circuited due to the leakage of the non-aqueous electrolyte. Accidents that lead to smoke or fire can be prevented.

  In the second embodiment described above, the disc-shaped electrolyte solution holding member 31 is supported in the space in the ring of the PTC element 14 by the ring-shaped flange portion 27 of the ring-shaped nickel thin plate 25b. However, the present invention is not limited to this. For example, as shown in FIG. 10, a metal mesh 28 is integrally attached to a ring-shaped nickel thin plate 25b of the PTC element 14 positioned on the current interrupting mechanism side so as to be positioned in a space in the ring of the PTC element 14, and this PTC element The disc-shaped electrolyte holding member 31 may be disposed in a space in the ring of the 14 ring so that the outer peripheral surface thereof is in close contact with the inner surface of the ring of the PTC element 14 and supported by the metal mesh 28.

  In the second embodiment described above, a porous body is used as the disc-shaped electrolyte solution holding member 31, but a disk-shaped nonwoven fabric layer made of inorganic fibers or organic fibers may be used instead of the porous body. Good. For example, as shown in FIG. 11, a ring-shaped nickel thin plate 25b of the PTC element 14 positioned on the current interrupting mechanism side is extended into a space in the ring of the PTC element 14 to form a ring-shaped flange portion 27. A disc-shaped nonwoven fabric layer 32 is disposed in a space in the ring of the element 14 so that the outer peripheral surface thereof is in close contact with the inner surface of the ring of the PTC element 14 and supported by the flange portion 27. Further, as shown in FIG. 12, a metal mesh 28 is integrally attached to the ring-shaped nickel thin plate 25b of the PTC element 14 positioned on the current interrupting mechanism side so as to be positioned in the space in the ring of the PTC element 14, and this PTC element The disc-shaped nonwoven fabric layer 32 is disposed in the space in the ring 14 so that the outer peripheral surface thereof is in close contact with the inner surface of the ring of the PTC element 14 and supported by the metal mesh 28.

  Each of the fibers preferably has an affinity for a non-aqueous electrolyte. Examples of inorganic fibers include glass fibers, and examples of organic fibers include polymethyl methacrylate fibers, polyvinyl alcohol fibers, and polyethylene terephthalate fibers. Can do.

Furthermore, in the cylindrical nonaqueous electrolyte secondary battery according to the second embodiment of the present invention, the sealing lid group is allowed to have a configuration further including the conductive support plate shown in FIGS.
Embodiments of the present invention will be described below with reference to the drawings described above.

(Example 1)
100 parts by weight of LiCoO ₂ powder, ₂ parts by weight of acetylene black having an average particle diameter of 50 nm and 3 parts by weight of flake graphite (artificial graphite) having an average particle diameter of 1 μm are mixed with a mixer, and the resulting mixture is mixed with a binder. After adding 5 parts by weight of certain polyvinylidene fluoride, it was dispersed in N-methylpyrrolidone to prepare a positive electrode paste. Subsequently, this paste was applied to both sides of an aluminum foil as a current collector, dried, and then rolled to produce a positive electrode. Thereafter, a lead tab was connected to the non-coated portion of the positive electrode.

In addition, mesophase pitch carbon fibers were produced by graphitizing mesophase pitch carbon fibers made from mesophase pitch. Subsequently, a mixture comprising 90 parts by weight of this mesophase pitch-based carbon fiber, 10 parts by weight of natural graphite and 7 parts by weight of polyvinylidene fluoride was dispersed in N-methylpyrrolidone to prepare a negative electrode paste. This paste was applied to both sides of a copper foil as a current collector and dried, followed by roll pressing to produce a negative electrode having a filling density of 1.4 g / cm ³ . Thereafter, a lead tab was connected to the non-coated portion of the negative electrode.

Furthermore, 1M / L of lithium hexafluorophosphate (LiPF ₆ ) is dissolved in a mixed solvent of ethylene carbonate (EC) and methyl ethyl carbonate (MEC) (mixing volume ratio 1: 2) to obtain a non-aqueous electrolyte. Prepared.

  Next, the positive electrode, a separator made of a polyethylene porous film (shutdown temperature of 135 ° C.) and the negative electrode are laminated in this order, and then wound in a spiral shape so that the negative electrode is located on the outer side to produce an electrode group. did. This electrode group is housed in a stainless steel bottomed cylindrical outer can, and the non-aqueous electrolyte is injected into the outer can, and the sealing lid group is insulated from the upper end opening of the outer can via an insulating gasket. The cylindrical lithium-ion secondary battery (18650 size) having the structure shown in FIGS. 1 and 2 and having a design rated capacity of 1600 mAh was assembled by sealing in a sealed manner.

  The PTC element incorporated in the sealing lid group is press-fitted with a disk-like polymer resin layer 24 made of polyvinylidene fluoride in the inner space of the ring as shown in FIGS. Has a structure.

(Example 2)
As shown in FIG. 3, the ring-shaped nickel thin plate 25b of the PTC element 14 located on the rupture plate side is extended into a space in the ring of the PTC element 14 to form a ring-shaped flange portion 27. A disk-shaped polymer resin layer 24 made of polyvinylidene fluoride is arranged in a space inside the ring so that its outer peripheral surface is in close contact with the inner surface of the ring of the PTC element 14 and supported by the flange 27. A cylindrical nonaqueous electrolyte secondary battery having the same configuration as in Example 1 was assembled except that was incorporated into the sealing lid group.

(Example 3)
As shown in FIG. 4, a nickel mesh 29 is integrally attached to the ring-shaped nickel thin plate 25b of the PTC element 14 located on the rupture plate side so as to be located in the space in the ring of the PTC element 14, and the PTC element 14 A structure in which a disk-shaped polymer resin layer 24 made of polyvinylidene fluoride is disposed in a space in the ring so that its outer peripheral surface is in close contact with the inner surface of the ring of the PTC element 14 and supported by the nickel mesh 29. A cylindrical non-aqueous electrolyte secondary battery having the same configuration as in Example 1 was assembled except that it was incorporated in the sealing lid group.

Example 4
As shown in FIG. 9, the ring-shaped nickel thin plate 25b of the PTC element 14 located on the rupture plate side is extended into a space in the ring of the PTC element 14 to form a ring-shaped flange portion 27, and this PTC element 14 The sealing lid group has a structure in which the porous silica 31 is disposed in the space inside the ring so that its outer peripheral surface is in close contact with the inner surface of the ring of the PTC element 14 and is supported by the flange 27. A cylindrical non-aqueous electrolyte secondary battery having the same configuration as in Example 1 was assembled except that it was incorporated.

(Example 5)
As shown in FIG. 10, a nickel mesh 29 is integrally attached to the ring-shaped nickel thin plate 25b of the PTC element 14 located on the rupture plate side so as to be located in the space in the ring of the PTC element 14, and the PTC element 14 A structure having a structure in which a disk-like silica porous body 31 is arranged in a space in the ring so that its outer peripheral surface is in close contact with the inner surface of the ring of the PTC element 14 and supported by the nickel mesh 29 is incorporated in a sealing lid group. A cylindrical nonaqueous electrolyte secondary battery having the same configuration as in Example 1 was assembled.

(Example 6)
As shown in FIG. 11, a ring-shaped nickel thin plate 25b of the PTC element 14 located on the rupture plate side is extended into a space in the ring of the PTC element 14 to form a ring-shaped flange portion 27, and this PTC element 14 A sealing lid group is formed of a disk-shaped glass fiber nonwoven fabric layer 32 in a space inside the ring so that its outer peripheral surface is in close contact with the inner surface of the ring of the PTC element 14 and supported by the flange 27. A cylindrical non-aqueous electrolyte secondary battery having the same configuration as in Example 1 was assembled except that it was incorporated.

(Example 7)
As shown in FIG. 12, a support member 29 made of nickel mesh is integrally attached to the ring-shaped nickel thin plate 25b of the PTC element 14 positioned on the rupture plate side so as to be positioned in the space in the ring of the PTC element 14. Seal the disc-shaped glass fiber nonwoven fabric layer 32 in the space in the ring of the PTC element 14 so that the outer peripheral surface thereof is in close contact with the inner surface of the ring of the PTC element 14 and supported by the support member 29 A cylindrical non-aqueous electrolyte secondary battery having the same configuration as in Example 1 was assembled except that it was incorporated in the lid group.

(Comparative Example 1)
A cylindrical nonaqueous electrolyte secondary battery having the same configuration as in Example 1 was assembled except that the ring-shaped PTC element was incorporated in the sealing lid group.

(Comparative Example 2)
A cylindrical non-aqueous electrolyte secondary battery having the same configuration as in Example 1 was assembled except that a non-holed disk-shaped PTC element was incorporated in the sealing lid group.

  The cylindrical nonaqueous electrolyte secondary batteries of Examples 1 to 7 and Comparative Examples 1 and 2 thus obtained were subjected to the following two evaluation tests.

2) Evaluation test 1
Each secondary battery was charged at 20 ° C. with a charging current of 1600 mA (1C) and a constant voltage of 4.2 V for a total of 3 hours. Thereafter, a drop test was performed on each secondary battery with respect to the concrete plate from 3.0 m above. The battery drop direction is three directions, that is, the top, bottom, and side. The drop in these directions is repeated 10 times, and the leakage rate (percentage) of 100 batteries for the first time and the 10th time is shown in Table 1 below. Shown in

3) Evaluation test 2
Each secondary battery was charged at 20 ° C. with a charging current of 1600 mA (1C) and a constant voltage of 4.4 V for a total of 5 hours. Then, each secondary battery was hold | maintained on the hotplate of 250 degreeC, and it was tested whether it reached explosion. The number of secondary batteries used in the test is 100, and the ratio (percentage) of rupture is shown in Table 1 below.

  As can be seen from Table 1, the secondary batteries of Examples 1 to 7 and Comparative Example 2 have no reliability in the evaluation test 1 (drop test), and have high reliability. .

  On the other hand, in the secondary battery of Comparative Example 1 incorporating the ring-shaped PTC element, non-aqueous electrolyte leakage occurred in 70% of the batteries when the drop test was repeated 10 times.

  Furthermore, it can be seen that the secondary batteries of Examples 1 to 7 and Comparative Example 1 have no safety in the evaluation test 2 (forced heating test) and have high safety.

  On the other hand, the secondary battery of Comparative Example 2 in which the disk-like PTC element was incorporated was ruptured in 80% of the batteries.

  In the above-described embodiment, an example in which the present invention is applied to a 1600 mAh cylindrical non-aqueous electrolyte secondary battery has been described. However, the present invention can be sufficiently applied to a large battery having a higher capacity and a higher output.

  According to the present invention, it is possible to provide a nonaqueous electrolyte secondary battery having extremely high reliability and safety.

1 is a partial cross-sectional view showing a nonaqueous electrolyte secondary battery (cylindrical nonaqueous electrolyte secondary battery) according to a first embodiment of the present invention. The principal part disassembled perspective view of the cylindrical nonaqueous electrolyte secondary battery of FIG. Sectional drawing which shows the other form of the PTC element integrated in the nonaqueous electrolyte secondary battery which concerns on 1st Embodiment of this invention. Sectional drawing which shows the other form of the PTC element integrated in the nonaqueous electrolyte secondary battery which concerns on 1st Embodiment of this invention. The principal part disassembled perspective view which shows the other form of the sealing lid group integrated in the cylindrical nonaqueous electrolyte secondary battery which concerns on this invention. The principal part disassembled perspective view which shows the other form of the sealing lid group integrated in the cylindrical nonaqueous electrolyte secondary battery which concerns on this invention. The principal part disassembled perspective view which shows the other form of the sealing lid group integrated in the cylindrical nonaqueous electrolyte secondary battery which concerns on this invention. The principal part disassembled perspective view which shows the other form of the sealing lid group integrated in the cylindrical nonaqueous electrolyte secondary battery which concerns on this invention. Sectional drawing which shows the PTC element integrated in the nonaqueous electrolyte secondary battery which concerns on 2nd Embodiment of this invention. Sectional drawing which shows the other form of the PTC element integrated in the nonaqueous electrolyte secondary battery which concerns on 2nd Embodiment of this invention. Sectional drawing which shows the other form of the PTC element integrated in the nonaqueous electrolyte secondary battery which concerns on 2nd Embodiment of this invention. Sectional drawing which shows the other form of the PTC element integrated in the nonaqueous electrolyte secondary battery which concerns on 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Exterior can, 2 ... Electrode group, 3 ... Positive electrode, 4 ... Negative electrode, 5 ... Separator, 9 ... Sealing lid group, 10 ... Insulating gasket, 11 ... Stripper, 13 ... Rupture plate, 14 ... PTC element, 16 ... Terminal plate, 21 ... current transmission / interruption part, 24 ... disk-shaped polymer resin layer, 25a, 25b ... ring-shaped nickel thin plate, 26 ... ring-shaped resin sheet, 27 ... ring-shaped collar part, 28 ... metal mesh, 31 ... disk-shaped porous body (disk-shaped electrolyte solution holding member), 32 ... disk-shaped nonwoven fabric layer (disk-shaped electrolyte solution holding member), 41, 46, 51 ... conductive support plate.

Claims (26)

An outer can opened at one end;
An electrode group housed in the outer can and comprising a negative electrode, a separator and a positive electrode;
A non-aqueous electrolyte contained in the outer can, and a sealing lid group that hermetically seals the opening of the outer can via an insulating member,
The sealing lid group comprises a non-water-containing PTC element having a ring shape and having a disk-shaped polymer resin layer disposed in close contact with the inner peripheral surface of the ring in a space within the ring. Electrolyte secondary battery.   The PTC element is formed of a ring-shaped resin sheet containing a conductive material between two ring-shaped metal thin plates, and the ring-shaped metal thin plate on the electrode group side has an inner periphery extending into a space in the ring. In addition, the disc-shaped polymer resin layer is closely attached to the inner surface of the ring in the space of the ring of the PTC element and is supported by the collar portion. The nonaqueous electrolyte secondary battery according to claim 1.   The PTC element is composed of a ring-shaped resin sheet containing a conductive material between two ring-shaped metal thin plates, and the metal mesh is integrated with the ring-shaped metal thin plate on the electrode group side so as to be positioned in the space inside the ring. The disk-shaped polymer resin layer is further attached to the inner surface of the ring of the PTC element and supported by the metal mesh. The nonaqueous electrolyte secondary battery according to 1.   The said sealing lid group is further equipped with the rupture board which has an easily broken part which an outer edge part is fixed to the said insulating member, and can be fractured | ruptured by the internal pressure rise accompanying gas generation | occurrence | production. Non-aqueous electrolyte secondary battery.   The non-aqueous electrolyte secondary battery according to claim 4, wherein the easily breakable portion is a cut portion formed in at least one surface of the rupture plate.   The non-aqueous electrolyte secondary battery according to claim 1, wherein the sealing lid group further includes a current blocking member.   The said sealing lid group is further equipped with the electroconductive support plate which is located in the one surface side of the said PTC element, and an outer edge part is fixed to the said insulating member, The non-constitution of any one of Claims 1-6 characterized by the above-mentioned. Water electrolyte secondary battery.   8. The non-aqueous electrolyte secondary battery according to claim 7, wherein the support plate has no holes and has an easily breakable portion that can be broken by an increase in internal pressure accompanying gas generation.   The non-aqueous electrolyte secondary battery according to claim 7, wherein the support plate has a ring shape.   The support plate includes a conductive ring plate fixed by the insulating member, a thin plate fixed so as to cover the hollow portion on at least one surface of the ring plate excluding the fixing portion by the insulating member, and 8. The non-aqueous electrolyte secondary battery according to claim 7, wherein the non-aqueous electrolyte secondary battery is composed of an easily breakable portion that can be broken by an increase in internal pressure accompanying gas generation formed on a thin plate.   The non-aqueous electrolyte secondary according to claim 7, wherein the support plate includes a ring plate and a disc-shaped polymer resin layer disposed in close contact with the inner surface of the hollow portion of the ring plate. battery. An outer can opened at one end;
An electrode group housed in the outer can and comprising a negative electrode, a separator and a positive electrode;
A non-aqueous electrolyte contained in the outer can, and a sealing lid group that hermetically seals the opening of the outer can via an insulating member,
The sealing lid group includes a non-water-containing PTC element having a ring shape and having a disk-like electrolyte solution holding member disposed in close contact with the inner peripheral surface of the ring in a space in the ring. Electrolyte secondary battery.   13. The nonaqueous electrolyte secondary battery according to claim 12, wherein the disk-shaped electrolyte solution holding member is a disk-shaped porous body having continuous air holes.   The non-aqueous electrolyte secondary battery according to claim 12, wherein the disk-shaped electrolyte solution holding member is a disk-shaped nonwoven fabric layer.   The PTC element is formed of a ring-shaped resin sheet containing a conductive material between two ring-shaped metal thin plates, and the ring-shaped metal thin plate on the electrode group side has an inner periphery extending into a space in the ring. In addition, the disc-shaped polymer resin layer is closely attached to the inner surface of the ring in the space of the ring of the PTC element and is supported by the collar portion. The nonaqueous electrolyte secondary battery according to any one of claims 12 to 14.   The PTC element is composed of a ring-shaped resin sheet containing a conductive material between two ring-shaped metal thin plates, and the metal mesh is integrated with the ring-shaped metal thin plate on the electrode group side so as to be positioned in the space inside the ring. The disk-shaped polymer resin layer is further attached to the inner surface of the ring of the PTC element and supported by the metal mesh. The nonaqueous electrolyte secondary battery according to any one of 12 to 14.   The said sealing lid group is further equipped with the rupture board which an outer edge part is being fixed to the said insulation member, and has an easily fracture part which can be fractured | ruptured by the internal pressure rise accompanying gas generation, It is characterized by the above-mentioned. Non-aqueous electrolyte secondary battery.   The non-aqueous electrolyte secondary battery according to claim 17, wherein the easily breakable portion is a cut portion formed in at least one surface of the rupture plate.   The non-aqueous electrolyte secondary battery according to claim 12, wherein the sealing lid group further includes a current blocking member.   The said sealing lid group is further equipped with the electroconductive support plate which is located in the one surface side of the said PTC element, and an outer edge part is fixed to the said insulating member. Water electrolyte secondary battery.   21. The nonaqueous electrolyte secondary battery according to claim 20, wherein the support plate has no holes and has an easily breakable portion that can be broken by an increase in internal pressure accompanying gas generation.   The non-aqueous electrolyte secondary battery according to claim 20, wherein the support plate has a ring shape.   The support plate includes a conductive ring plate fixed by the insulating member, a thin plate fixed so as to cover the hollow portion on at least one surface of the ring plate excluding the fixing portion by the insulating member, and 21. The non-aqueous electrolyte secondary battery according to claim 20, wherein the non-aqueous electrolyte secondary battery is formed of an easily breakable portion that can be broken by an increase in internal pressure accompanying gas generation formed on a thin plate.   21. The non-aqueous electrolyte secondary according to claim 20, wherein the support plate includes a ring plate and a disk-shaped polymer resin layer disposed in close contact with the inner surface of the hollow portion of the ring plate. battery. An outer can also serving as a unipolar terminal with one end open;
An electrode group housed in the outer can and composed of a negative electrode, a separator and a positive electrode;
A non-aqueous electrolyte contained in the outer can;
A sealing lid group hermetically sealed via an insulator at the opening of the outer can,
The sealing lid group is disposed to face the electrode group, and is electrically connected to one of the positive and negative electrodes of the electrode group through an electrode connection tab to transmit and cut off current and increase internal pressure accompanying gas generation. A current interrupting mechanism having an open valve that is sometimes broken, a terminal member that becomes an other polarity terminal arranged on the outside, a ring-shaped PTC element interposed between the current interrupting mechanism and the terminal member, A nonaqueous electrolyte secondary battery comprising: a disk-shaped polymer resin layer disposed in close contact with an inner surface of a ring in a space in a ring of a PTC element. An outer can also serving as a unipolar terminal with one end open;
An electrode group housed in the outer can and composed of a negative electrode, a separator and a positive electrode;
A non-aqueous electrolyte contained in the outer can;
A sealing lid group hermetically sealed via an insulator at the opening of the outer can,
The sealing lid group is disposed to face the electrode group, and is electrically connected to one of the positive and negative electrodes of the electrode group through an electrode connection tab to transmit and cut off current and increase internal pressure accompanying gas generation. A current interrupting mechanism having an open valve that is sometimes broken, a terminal member serving as an other polarity terminal disposed on the outside, a ring-shaped PTC element interposed between the current interrupting mechanism and the terminal member, A nonaqueous electrolyte secondary battery comprising: a disk-shaped electrolyte solution holding member disposed in close contact with an inner surface of a ring in a space in a ring of a PTC element.

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