JP2016110940A - Secondary battery, electric vehicle, power storage system and manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a secondary battery, etc. that can prevent thermal runaway of a battery to prevent firing and abnormal heating before happens under an abnormal condition such as occurrence of gas in a battery.SOLUTION: A secondary battery 50 has a battery element 20, an exterior package body 10 in which the battery element 20 is housed together with electrolyte, and electrode tabs 21, 25 of positive electrode and negative electrode which are connected to the battery element 20. The secondary battery 50 has a detachable seal portion 115 for partially welding confronting surfaces inside the exterior package body from a sealing portion to a protrusion portion or a separate position of the outer periphery of the exterior package body, and first contact members 111, 114, one of the first contact members being fixed to the electrode tab 21 while the other first contact member is brought into contact with the welded portion.SELECTED DRAWING: Figure 4

Description

  TECHNICAL FIELD The present invention relates to a battery safety mechanism and the like, and more particularly, a secondary battery and an electric vehicle that can safely stop a battery by preventing thermal runaway of the battery even in an abnormal situation where gas is generated in the battery. The present invention relates to a power storage system and a manufacturing method.

  In recent years, batteries used as power sources for electronic devices and automobiles have been strongly required to be smaller and lighter, and there are many batteries that use laminate films instead of conventional metal cans for battery outer bodies. It has become to. As the laminate film, a film using aluminum as a metal thin film, nylon (registered trademark) as a battery outer surface as a heat-fusible resin film, and polyethylene or polypropylene as an inner surface is generally used. A film-clad battery is one in which a battery element is housed together with an electrolyte in an exterior body (also referred to as a “film exterior body”) made of such a laminate film. Positive and negative electrode tabs are drawn from the battery element, and each electrode tab is configured to extend to the outside of the film outer package.

  By the way, as one of the safety measures in the film-clad battery, conventionally, it has been proposed to provide a pressure-release mechanism that releases the pressure when gas is generated in the film-clad body and the pressure exceeds a predetermined level. For example, in Patent Document 1, for the purpose of operating a gas venting mechanism with high reproducibility so that gas is not released at an unintended position, a protruding heat-bonding portion that is preferentially peeled off is provided on the film exterior body. It is disclosed to form.

  According to the configuration of the same document, when gas is generated and the film exterior body expands, stress concentration occurs in the protruding heat-welded portion, whereby the portion is preferentially peeled off. Therefore, the degassing mechanism can be operated with good reproducibility.

JP 2002-298895

  As in Patent Document 1, it is important as one aspect of the safety of the battery to release the gas in the battery and release the pressure as appropriate in the event of an abnormality. On the other hand, in a lithium ion battery or the like, a specific member inside the battery generates heat, and that heat may cause heat generation of other members. Development of a safety mechanism that can be stopped more safely is desired.

  The present invention has been made in view of the above problems, and its purpose is to prevent the occurrence of thermal runaway of the battery even in an abnormal situation where gas is generated in the battery, and to make the battery safe. An object of the present invention is to provide a secondary battery, an electric vehicle, a power storage system, and a manufacturing method that can be stopped.

In order to achieve the above object, a battery according to an embodiment of the present invention is as follows:
A battery element;
An exterior body that houses the battery element together with an electrolyte;
Positive and negative electrode tabs connected to the battery element;
A secondary battery comprising:
further,
A peelable seal part in which the surfaces facing each other inside the exterior body are partially welded at a position protruding from the outer periphery sealing part of the exterior body or spaced apart from each other;
A first contact member, one of which is fixed to the electrode tab and the other is in contact with the peelable seal portion;
A secondary battery.

(Explanation of terms)
The “secondary battery” includes not only those using a film outer package such as a laminate film (film outer battery) but also those using a hard container such as a metal can or a resin case as the outer package. Examples of the outer shape of the battery include a flat type (thin type), a square type, and a cylindrical type.
The “film outer package” means an outer package made of a flexible film and containing a battery element. The film element is hermetically sealed by arranging two films facing each other and welding them together. Alternatively, the battery element may be sealed by folding a single film and welding the opposed surfaces.
A “film-sheathed battery” refers to a battery in which battery elements are housed in a film-sheathed body together with an electrolyte (in one example, an electrolytic solution, including a gel-like one), and generally has a flat shape as a whole. doing. For example, a battery for an electric vehicle is required to have a large capacity, a low internal resistance, a high heat dissipation, and the like, and a film-covered battery is advantageous in these respects. One film-clad battery may be referred to as a “battery cell” or simply a “cell”.

With regard to the “exterior body”, the simple term “exterior body” includes both a non-flexible body (for example, a hard case) and a flexible body such as the film exterior body.
The “power supply unit” (assembled battery) can be used for a vehicle, a predetermined system, and the like, and includes a plurality of secondary batteries (cells). The plurality of cells may or may not be mounted as a sub-assembly every several cells. For example, a “battery pack” in which several cells are accommodated in a predetermined case is manufactured and one or more of them are mounted. It may be a configuration.

  According to the present invention, a secondary battery, an electric vehicle, a power storage system, a manufacturing method, and the like that can prevent ignition and abnormal heat generation by preventing thermal runaway of the battery even in an abnormal situation where gas is generated in the battery, etc. Can provide.

It is a perspective view of a film exterior battery. It is sectional drawing which shows a part of cross section of the battery of FIG. It is a top view which shows typically the structure of the electrode tab periphery of the battery which concerns on one form of this invention. It is a figure which shows an example of the short circuit mechanism of a film-clad battery to one form of this invention. It is a perspective view of the short circuit mechanism of FIG. It is a figure which shows another example of the short circuit mechanism of a film-clad battery. It is a figure which shows another example of the short circuit mechanism of a film-clad battery. It is a figure which shows another example of the short circuit mechanism of a film-clad battery. It is a figure which shows another example of the short circuit mechanism of a film-clad battery. It is a perspective view of the short circuit mechanism of FIG. It is a figure which shows an example of the electricity interruption | blocking mechanism of a film-clad battery. It is a figure which shows another example of the electricity interruption | blocking mechanism of a film-clad battery. It is a figure which shows an example of a structure which has a short circuit mechanism and an electricity supply interruption | blocking mechanism. It is a figure which shows an example of a manufacturing method. It is a schematic diagram of an electrical storage system. It is a schematic diagram of an electric vehicle.

1. Basic Configuration of Film-Exterior Battery A basic configuration of the film-exterior battery will be described with reference to FIGS. As will be described later, the battery according to the present invention is characterized in that a short-circuit mechanism or the like for short-circuiting the electrode tabs in the case of an abnormality is provided in the exterior body. However, for convenience of explanation, FIGS. Then, those illustrations are omitted.

  Hereinafter, a film-clad battery will be described as an example, but it should be noted that the present invention is not necessarily limited to a film-clad battery as long as it has a welded part that expands and peels off due to generation of gas. I want to be. The present invention itself can be applied not only to a stacked battery but also to a wound battery. One of the technical ideas of the present invention is that the battery can be safely stopped by using a short-circuit mechanism and / or a power-off mechanism (detailed below) that is triggered by the occurrence of a predetermined amount of gas as a trigger. is there. Therefore, as long as such a technique can be applied, the secondary battery may have any shape and structure. Examples of the battery include a cylindrical type, a wound type, a flat wound laminate type, and a laminated laminate type.

  The film-clad battery 50 which concerns on one form of this invention is connected to the battery element 20, the film-clad body 10 which accommodates it with an electrolyte solution, and the battery element 20, as shown in FIGS. In addition, a positive electrode tab 21 and a negative electrode tab 25 (hereinafter also simply referred to as “electrode tabs”) drawn out of the film outer package 10 are provided.

  The battery element 20 is formed by alternately laminating a plurality of positive electrodes and a plurality of negative electrodes made of metal foils each coated with an electrode material on both sides of a separator. Although the overall external shape of the battery element 20 is not particularly limited, in this example, it is a flat and substantially rectangular parallelepiped.

  Although detailed illustration is omitted, each of the positive electrode and the negative electrode has an extended portion that partially protrudes from a part of the outer periphery. The extension part of the positive electrode and the extension part of the negative electrode are alternately arranged so as not to interfere with each other when the positive electrode and the negative electrode are stacked. All the negative electrode extensions are collected together and connected to the negative electrode tab. Similarly, for the positive electrode, all the positive electrode extensions are collected together and connected to the positive electrode tab. The portions gathered together in the stacking direction between the extension portions in this way are also called “current collecting portions” or the like. In FIG. 3, the current collectors of the positive electrode and the negative electrode are illustrated by reference numerals 18a and 18b. For connection between the current collectors 18a, 18b and the electrode tabs 21, 25, resistance welding, ultrasonic welding, laser welding, caulking, adhesion with a conductive adhesive, or the like can be employed.

  Various materials can be adopted as the electrode tabs 21 and 25. As an example, the positive electrode tab 21 is aluminum or an aluminum alloy, and the negative electrode tab 25 is copper or nickel. When the material of the negative electrode tab 25 is copper, the surface may be nickel-plated.

For each element of the battery element, specifically, the following may be adopted.
<Separator>
As separators, webs and sheets made of organic materials, for example, woven fabrics such as cellulose, non-woven fabrics, polyolefins such as polyethylene and polypropylene, polyimides, porous polymer membranes such as porous polyvinylidene fluoride membranes, or ion conductive polymers An electrolyte membrane or the like can be used. These can be used alone or in combination.

Moreover, the separator which consists of inorganic materials, such as a ceramic and glass, can also be used as a separator. As an inorganic separator, a nonwoven fabric separator made of ceramic short fibers such as alumina, alumina-silica, potassium titanate, or a base material made of a woven fabric, a nonwoven fabric, paper, or a porous film, a heat-resistant nitrogen-containing aromatic polymer, and A separator comprising a layer containing ceramic powder, or a heat resistant layer is provided on a part of the surface, and this heat resistant layer is a porous thin film layer containing ceramic powder, a porous thin film layer of a heat resistant resin, or Porous thin film layer separator made of a composite of ceramic powder and heat-resistant resin, or porous made by binding secondary particles formed by sintering or dissolving and recrystallizing a part of primary particles of a ceramic material by a binder A separator provided with a membrane layer or a base material layer made of a polyolefin porous membrane, and formed on one or both sides of the base material layer The heat-resistant insulating layer includes a separator containing oxidation-resistant ceramic particles and a heat-resistant resin, or a porous film formed by combining a ceramic substance and a binder, Silica (SiO ₂ ), alumina (Al ₂ O ₃ ), zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ), nitride of silicon (Si), hydroxide of aluminum (Al), zirconium (Zr ) Alkoxide, a separator using a titanium (Ti) ketone compound, or a polymer substrate, and Al ₂ O ₃ , MgO, TiO ₂ , Al (OH) ₃ , Mg ( Examples thereof include a separator including a ceramic-containing coating layer of OH) ₂ and Ti (OH) ₄ .

<Negative electrode>
The negative electrode has a negative electrode current collector formed of a metal foil, and a negative electrode active material coated on both surfaces of the negative electrode current collector. The negative electrode active material is bound so as to cover the negative electrode current collector with a negative electrode binder. The negative electrode current collector is formed to have an extension connected to the negative electrode terminal, and the negative electrode active material is not applied to the extension.

  The negative electrode active material in the present embodiment is not particularly limited. For example, the carbon material (a) that can occlude and release lithium ions, the metal (b) that can be alloyed with lithium, and the lithium ions are occluded and released. The metal oxide (c) etc. which can be mentioned.

  Examples of the carbon material (a) include carbon, amorphous carbon, diamond-like carbon, carbon nanotubes, and composites thereof. Here, carbon with high crystallinity has high electrical conductivity, and is excellent in adhesiveness and voltage flatness with a negative electrode current collector made of a metal such as copper. On the other hand, since amorphous carbon having low crystallinity has a relatively small volume expansion, it has a high effect of relaxing the volume expansion of the entire negative electrode, and deterioration due to non-uniformity such as crystal grain boundaries and defects hardly occurs.

  Examples of the metal (b) include Al, Si, Pb, Sn, In, Bi, Ag, Ba, Ca, Hg, Pd, Pt, Te, Zn, La, or alloys of two or more thereof. It is done. Moreover, you may use these metals or alloys in mixture of 2 or more types. These metals or alloys may contain one or more non-metallic elements.

  In the present embodiment, the negative electrode active material preferably includes tin or silicon, and more preferably includes silicon. The reason is that tin and silicon have a large capacity because they can store up to 4.4 Li atoms per atom, and the elements themselves have been used in many fields and are easy to handle. Furthermore, since silicon is an element lighter than tin, its capacity per unit weight is high.

  Examples of the metal oxide (c) include silicon oxide, aluminum oxide, tin oxide, indium oxide, zinc oxide, lithium oxide, and composites thereof. In this embodiment, it is preferable that tin oxide or silicon oxide is included as a negative electrode active material, and it is more preferable that silicon oxide is included. This is because silicon oxide is relatively stable and hardly causes a reaction with other compounds. Moreover, 0.1-5 mass% of 1 type, or 2 or more types of elements chosen from nitrogen, boron, and sulfur can also be added to a metal oxide (c). By carrying out like this, the electrical conductivity of a metal oxide (c) can be improved.

  All or part of the metal oxide (c) preferably has an amorphous structure. The metal oxide (c) having an amorphous structure can suppress volume expansion of the carbon material (a) and the metal (b) which are other negative electrode active materials. Although this mechanism is not clear, it is presumed that the formation of a film on the interface between the carbon material (a) and the electrolytic solution has some influence due to the amorphous structure of the metal oxide (c). The amorphous structure is considered to have relatively few elements due to non-uniformity such as crystal grain boundaries and defects. In addition, it can be confirmed by X-ray diffraction measurement (general XRD measurement) that all or part of the metal oxide (c) has an amorphous structure. Specifically, when the metal oxide (c) does not have an amorphous structure, a peak specific to the metal oxide (c) is observed, but all or part of the metal oxide (c) is amorphous. In the case of having a structure, the intrinsic peak of the metal oxide (c) is broad and observed.

  The metal (b) is preferably silicon, and the metal oxide (c) is preferably silicon oxide. That is, the negative electrode active material is preferably composed of a composite of silicon, silicon oxide, and a carbon material (hereinafter also referred to as Si / SiO / C composite). It is also possible to use a material in which the negative electrode active material is chemically and thermally doped with lithium in advance. For example, chemical dope can be obtained by a method in which lithium is forcibly doped into an active material using a solvent containing a lithium metal or a lithium compound and a reducing agent. In thermal doping, the negative electrode active material can be doped with lithium by bringing the negative electrode active material into contact with lithium metal and warming the whole.

  In the Si / SiO / C composite, for example, all or part of silicon oxide has an amorphous structure, and all or part of silicon is dispersed in silicon oxide. Such a Si / SiO / C composite can be produced, for example, by a method disclosed in Japanese Patent Application Laid-Open No. 2004-47404. That is, the Si / SiO / C composite can be obtained, for example, by performing CVD treatment of silicon oxide in an atmosphere containing an organic gas such as methane gas. The Si / SiO / C composite obtained by such a method has a form in which the surface of particles made of silicon oxide containing silicon is coated with carbon. Silicon is nanoclustered in silicon oxide.

  In the Si / SiO / C composite, the ratio of the carbon material, silicon and silicon oxide is not particularly limited. The carbon material is preferably 2% by mass or more and 50% by mass or less, and more preferably 2% by mass or more and 30% by mass or less with respect to the Si / SiO / C composite. Silicon is preferably 5% by mass or more and 90% by mass or less, and more preferably 20% by mass or more and 50% by mass or less with respect to the Si / SiO / C composite. The silicon oxide is preferably 5% by mass or more and 90% by mass or less, and more preferably 40% by mass or more and 70% by mass or less with respect to the Si / SiO / C composite.

  The Si / SiO / C composite can be made of a mixture of carbon material, silicon and silicon oxide. For example, the Si / SiO / C composite can be obtained by mixing particles of carbon materials, silicon, and silicon oxide. For example, the average particle diameter of silicon can be configured to be smaller than the average particle diameter of the carbon material and the average particle diameter of silicon oxide. In this way, silicon with a large volume change during charge / discharge has a relatively small particle size, and carbon materials and silicon oxide with a small volume change have a relatively large particle size. Is more effectively suppressed. In addition, lithium is occluded and released in the order of large-diameter particles, small-diameter particles, and large-diameter particles during the charge / discharge process. This also suppresses the occurrence of residual stress and residual strain. Is done. The average particle diameter of silicon can be, for example, 20 μm or less, and is preferably 15 μm or less.

  The binder for the negative electrode is not particularly limited. For example, polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, styrene-butadiene copolymer. Rubber, polytetrafluoroethylene, polypropylene, polyethylene, polyimide, polyamideimide, polyacrylic acid, or the like can be used. Of these, polyimide or polyamideimide is preferred because of its high binding properties. The amount of the binder for the negative electrode to be used is preferably 5 to 25 parts by mass with respect to 100 parts by mass of the negative electrode active material from the viewpoints of “sufficient binding force” and “high energy” which are in a trade-off relationship. .

  As the negative electrode current collector, aluminum, nickel, stainless steel, chromium, copper, silver, and alloys thereof are preferable from the viewpoint of electrochemical stability. Examples of the shape include foil, flat plate, and mesh.

<Positive electrode>
The positive electrode has a positive electrode current collector formed of a metal foil, and a positive electrode active material coated on both surfaces of the positive electrode current collector. The positive electrode active material is bound so as to cover the positive electrode current collector with a positive electrode binder. The positive electrode current collector is formed to have an extension connected to the positive electrode terminal, and the positive electrode active material is not applied to the extension.

As the positive electrode active material, manganese having a layered structure such as LiMnO ₂ , LixMn ₂ O ₄ (0 <x <2), Li ₂ MnO ₃ , LixMn _1.5 Ni _0.5 O ₄ (0 <x <2), etc. Lithium oxalate or lithium manganate having a spinel structure, LiCoO ₂ , LiNiO _2, or a part of these transition metals replaced with another metal, LiNi _1/3 Co _1/3 Mn _1/3 O _2, etc. Examples include lithium transition metal oxides in which the number of transition metals does not exceed half, those in which these lithium transition metal oxides have an excess of Li over the stoichiometric composition, and those having an olivine structure such as LiFePO ₄ . Further, these metal oxides were partially substituted with Al, Fe, P, Ti, Si, Pb, Sn, In, Bi, Ag, Ba, Ca, Hg, Pd, Pt, Te, Zn, La, etc. Materials can also be used. In particular, Li _α Ni _β Co _γ Al _δ O ₂ (1 ≦ α ≦ 2, β + γ + δ = 1, β ≧ 0.7, γ ≦ 0.2) or Li _α Ni _β Co _γ Mn _δ O2 (1 ≦ α ≦ 1.2, β + γ + δ = 1, β ≧ 0.6, γ ≦ 0.2) are preferable. A positive electrode active material can be used individually by 1 type or in combination of 2 or more types.

  A radical material or the like can also be used as the positive electrode active material.

  As the positive electrode binder, the same binder as the negative electrode binder can be used. The amount of the binder for the positive electrode to be used is preferably 2 to 15 parts by mass with respect to 100 parts by mass of the positive electrode active material from the viewpoints of “sufficient binding force” and “high energy” in a trade-off relationship. .

  As the positive electrode current collector, the same as the negative electrode current collector can be used.

  A conductive auxiliary material may be added to the coating layer of the positive electrode active material for the purpose of reducing impedance. Examples of the conductive auxiliary material include carbonaceous fine particles such as graphite, carbon black, and acetylene black.

<Electrolyte>
As the electrolytic solution used in the present embodiment, a nonaqueous electrolytic solution containing a lithium salt (supporting salt) and a nonaqueous solvent that dissolves the supporting salt can be used.

  As the non-aqueous solvent, an aprotic organic solvent such as a carbonic acid ester (chain or cyclic carbonate), a carboxylic acid ester (chain or cyclic carboxylic acid ester), or a phosphoric acid ester can be used.

  Examples of carbonate solvents include cyclic carbonates such as propylene carbonate (PC), ethylene carbonate (EC), butylene carbonate (BC), and vinylene carbonate (VC); dimethyl carbonate (DMC), diethyl carbonate (DEC), and ethyl methyl carbonate. (EMC), chain carbonates such as dipropyl carbonate (DPC); and propylene carbonate derivatives.

  Examples of the carboxylic acid ester solvent include aliphatic carboxylic acid esters such as methyl formate, methyl acetate, and ethyl propionate; and lactones such as γ-butyrolactone.

  Among these, ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), vinylene carbonate (VC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (MEC), dipropyl carbonate Carbonic acid esters (cyclic or chain carbonates) such as (DPC) are preferred.

  Examples of the phosphate ester include trimethyl phosphate, triethyl phosphate, tripropyl phosphate, trioctyl phosphate, and triphenyl phosphate.

  Other solvents that can be contained in the non-aqueous electrolyte include, for example, ethylene sulfite (ES), propane sultone (PS), butane sultone (BS), dioxathilane-2,2-dioxide (DD), and sulfolene. 3-methylsulfolene, sulfolane (SL), succinic anhydride (SUCAH), propionic anhydride, acetic anhydride, maleic anhydride, diallyl carbonate (DAC), dimethyl 2,5-dioxahexanoate, 2,5 Dimethyl hexane hexanoate, furan, 2,5-dimethylfuran, diphenyl disulfide (DPS), dimethoxyethane (DME), dimethoxymethane (DMM), diethoxyethane (DEE), ethoxymethoxyethane, chloroethylene carbonate , Dimethyl ether, methyl ether Ether, methyl propyl ether, ethyl propyl ether, dipropyl ether, methyl butyl ether, diethyl ether, phenyl methyl ether, tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeTHF), tetrahydropyran (THP), 1,4-dioxane (DIOX), 1,3-dioxolane (DOL), methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, methyl difluoroacetate, methyl propionate, ethyl propionate, propyl propionate, methyl formate , Ethyl formate, ethyl butyrate, isopropyl butyrate, methyl isobutyrate, methyl cyanoacetate, vinyl acetate, diphenyl Disulfide, dimethyl sulfide, diethyl sulfide, adiponitrile, valeronitrile, glutaronitrile, malononitrile, succinonitrile, pimonitrile, suberonitrile, isobutyronitrile, biphenyl, thiophene, methyl ethyl ketone, fluorobenzene, hexafluorobenzene, carbonate electrolyte, glyme , Ether, acetonitrile, propiononitrile, γ-butyrolactone, γ-valerolactone, dimethyl sulfoxide (DMSO) ionic liquid, phosphazene, methyl formate, methyl acetate, ethyl propionate and other aliphatic carboxylic acid esters, or these compounds In which a part of the hydrogen atoms are substituted with fluorine atoms.

As the supporting salt in the present embodiment, LiPF ₆ , LiAsF ₆ , LiAlCl ₄ , LiClO ₄ , LiBF ₄ , LiSbF ₆ , LiCF ₃ SO ₃ , LiC ₄ F ₉ SO ₃ , LiC (CF ₃ SO ₂ ) ₃ , LiN ( CF ₃ SO _{2) 2} normal lithium salt which can be used in lithium ion batteries or the like can be used. The supporting salt can be used alone or in combination of two or more.

  A non-aqueous solvent can be used individually by 1 type or in combination of 2 or more types.

<Exterior body>
The exterior body can be appropriately selected as long as it is stable to the electrolytic solution and has a sufficient water vapor barrier property. For example, in the case of a laminated laminate type secondary battery, it is preferable to use a laminate film of aluminum and resin as the outer package. An exterior body may be comprised with a single member and may be comprised combining several members.

  In the present embodiment, as shown in FIG. 1, the film outer package 10 may be composed of a first film 11 and a second film 12 disposed to face the first film 11. The outline shape of the film outer package 10 is not particularly limited, but may be a quadrangle, which is a rectangle in this example. Both the films 11 and 12 are heat-welded to each other around the battery element 20 and joined. Thereby, the peripheral part of the film exterior body 10 becomes the heat welding part 15.

  A positive electrode tab 21 and a negative electrode tab 25 are drawn from one side of the short side of the heat-welded portion 15. In one embodiment, the positive electrode tab 21 and the negative electrode tab 25 are preferably parallel, but the present invention is not limited to this. In addition, as shown in FIG. 3, it is good also as a structure by which a cup part is formed in one film 11, and a cup part is not formed in the other film 12, and a cup part is formed in both films 11 and 12. It is good also as a structure (not shown).

2-1. Electrode Tab Short-Circuit Mechanism A film-clad battery according to an embodiment of the present invention is such that when a film-clad body expands beyond a predetermined level, a preset welded part (this is referred to as a “peelable seal part”) peels off Switching the electrical connection state of the battery is triggered by the peeling. The electrical connection state switching mechanism can be roughly classified as follows: (i) a “short-circuit mechanism” that systematically shorts the electrode tabs in the event of an abnormality, and (ii) There is an “energization cut-off mechanism” that disables the function. Several examples will be described below with reference to the drawings.

  In the following description, when a plurality of the same members are depicted in the drawings, for example, a description such as “Members A1 and A2 are made of metal and formed in a rectangle” may be used. However, those skilled in the art will understand that both members do not have to be formed in exactly the same material and shape without departing from the spirit of the present invention.

(First embodiment)
4 and 5 show examples of the film-clad battery of the first embodiment. In this example, a peelable seal portion 115 is formed inside the film exterior body 10 by partially welding the mutually facing surfaces inside the film exterior body 10. The peelable seal portion 115, and a first contact member 111 and a second contact member 113, which will be described later, constitute a short-circuit mechanism 110A of the present embodiment (see FIGS. 4A and 5).

  The peelable seal portion 115 has priority over other welded portions (here, the heat welded portion 15 at the periphery of the film) when gas is generated in the film outer package 10 and the film outer package 10 expands beyond a predetermined level. It is a welded part that peels off. The peelable seal portion 115 may have any shape as long as preferential peeling is performed as described above, but in this embodiment, the peelable seal portion 115 is provided as a seal portion having a relatively small seal area. ing.

  The outline shape of the peelable seal portion 115 is not limited, but may be a circle, an ellipse, a polygon, a rectangle, a triangle, a line, or a combination of at least two of them. The peelable seal portion 115 is formed in a region between the electrode tabs 21 and 25. In the example of FIG. 4, specifically, the peelable seal portion 115 is located near the middle between the electrode tabs 21 and 25.

  Any principle may be used for the peelable seal portion 115 to peel off preferentially. For example, when stress concentrates on the peelable seal portion 115, the portion is peeled off preferentially. It may be that which is peeled off preferentially by partially lowering the strength of heat welding or a combination thereof.

  The set pressure at which the peelable seal portion 115 completely peels depends on the size of the film outer package 10 and the flexibility of the film, but is an example, and the increase from atmospheric pressure is 0.05 MPa to 1.00 MPa. More preferably, it may be 0.1 MPa to 0.2 MPa. If this pressure is too low, a short-circuit mechanism, which will be described later, will operate even when a large current flows temporarily or when the temperature becomes temporarily high, resulting in a problem that the battery does not operate. On the other hand, if the opening pressure is too high, the film outer package 10 may open at other parts that are not intended.

  The peelable seal portion 115 may be formed at the same time as the thermal welding portion 15 in the process of forming the peripheral thermal welding portion 15, or may be formed in a different process.

(Peelable seal part with cross-linked structure)
In one embodiment of the present invention, a cross-linked seal portion (thermal welding portion) as disclosed in Japanese Patent No. 4232038 can also be used. One feature of this structure is that a crosslinked structure portion made of a crosslinked resin is formed on a part of the heat-welded portion of the film. According to such a configuration, when a peeling stress is applied to the heat-welded portion, the region where the crosslinked structure portion is formed peels with a smaller force than the other regions. Therefore, when a peeling stress acts on the heat-welded portion due to an increase in the internal pressure of the battery, peeling proceeds preferentially at the interface of the facing exterior film in the region where the crosslinked structure portion is formed. As a result, the separation position and the pressure release position are specified, and this makes it easy to set the release pressure.

  What is necessary is just to form a crosslinked structure part in any one resin layer among the films which oppose. The cross-linking structure portion only needs to be formed in a region including at least a region desired to be peeled off preferentially. Such a crosslinked structure portion is formed in the resin layer of one film, and the crosslinked structure portion is welded to the resin layer of the counterpart film facing it.

  As a method for forming the crosslinked structure portion, various conventionally known methods can be used. For example, the resin layer can be formed by irradiating an electron beam. As a method for crosslinking the heat-welding resin, there is a method in which a crosslinking agent is added to the resin. However, by using an electron beam, a mask for shielding the electron beam can be used easily and selectively at a specific position. A crosslinked structure part can be formed. As such a resin layer, one having a composition that can be thermally welded and can form a crosslinked structure by irradiation with an electron beam is used. In the case of such a resin composition, an electron beam reactive compound is added even if it is a single resin, a mixture of a plurality of types of resins, or an electron beam decomposition type resin (including mixing, coating, etc.). )) May be used.

(About contact members)
Both the first and second contact members 111 and 113 are basically an elastically deformable conductive material (for example, a metal material). In this example, the contact members 111 and 113 are connected to the electrode tabs 21 and 25 at their base ends. Specifically, each of the contact members 111 and 113 is configured to be held in a cantilever shape by the corresponding electrode tabs 21 and 25, and is configured so that the distal end side is elastically bent. The contact members 111 and 113 may be straight members in a state where no force is applied.

  For the connection between the contact members 111 and 113 and the electrode tabs 21 and 25, resistance welding, ultrasonic welding, laser welding, caulking, adhesion with a conductive adhesive, or the like can be employed. Alternatively, a fixture that mechanically connects the contact member and the electrode tab may be used. Of course, a combination of a method by welding or adhesion and a method of mechanical connection may be used. Examples of such a fixture include mechanical fasteners (mechanical fasteners) such as screws / bolts, rivets, and eyelets. The material may be either resin or metal. The above description regarding the connection between the members is applicable to the connection between the contact member and the electrode tab in other embodiments in the present specification, and in addition to that, it applies to the connection between arbitrary members. Those skilled in the art will readily understand that this is possible.

  As shown in FIG. 4A, the contact members 111 and 113 are assembled in an elastically bent state. Specifically, one of the contact members 111 is curved with a part of the tip side pressed against a part of the outer peripheral portion of the peelable seal part 115, and the other contact member 113 is curved in the opposite direction. In addition, a part on the tip side is pressed against a part on the opposite side of the peelable seal portion 115. In other words, the contact members 111 and 113 are assembled in a state where the distal end sides thereof are biased in the direction of approaching each other. Since the peelable seal portion 115 exists between the contact members 111 and 113, electrical connection is not performed in this state.

  The contact members 111 and 113 are also preferably configured to bend and deform in a plane orthogonal to the thickness direction of the film-clad battery (a plane parallel to the plane on which the electrode tabs extend). This is because when the contact members 111 and 113 are bent in the thickness direction of the battery, a certain amount of space is required to secure the movable range of the contact members 111 and 113, which adversely affects the thinning of the battery. This is because, according to the configuration of this embodiment, there is no adverse effect of thinning the battery.

  As will be described later, the contact members 111 and 113 are members that are not electrically connected in the normal state but are electrically connected to each other in order to release the electric energy of the cell in the abnormal state. Therefore, a resistance member (not shown) is provided between at least a part of the contact members 111 and 113 or between the contact members 111 and 113 so that the electric energy of the cell can be efficiently released as heat energy. It is preferable. It is also preferable that at least one of the contact members 111 and 113 is made of a resistance material instead of or in addition to such a configuration, so that these members themselves function as a resistance. In this case, there is no need to provide a resistance member separately from the contact members 111 and 113, which can be advantageous in terms of reducing the number of parts and simplifying the configuration.

(Operation)
The short-circuit mechanism 110A of the present embodiment configured as described above operates as follows. First, when gas is generated in the film outer package 10 due to an abnormality such as use under high temperature or overcharge, and the outer package 10 starts to expand, the opposing films are separated from each other even in the vicinity of the peelable seal portion 115. Begin to deform in the direction. And if the exterior body 10 expand | swells more than predetermined, the peelable seal | sticker part 115 will peel. As a result, the member interposed between the contact members 111 and 113 disappears, so that each contact member 111 and 113 returns to its original shape due to its elastic force, and some of them contact each other. As a result, the electrode tabs 21 and 25 are short-circuited, and the cell energy is released. In particular, when a resistance member (not shown) is provided as the short-circuit mechanism 110A, electric energy can be efficiently released as heat energy.

  According to the configuration of the present embodiment as described above, when gas is generated in the battery at the time of abnormality and the exterior body 10 expands to a predetermined level, the electrode tab 21 is triggered by the peeling of the peelable seal portion 115, A systematic short circuit between 25 can be caused. As a result, the energy of the cell can be released and the battery can be safely stopped.

  The basic technical idea in the configuration of the above embodiment is that the peelable seal part peels off when a predetermined amount of gas is generated in the battery, and as a result, the member whose deformation or movement is restricted by the peelable seal part (For example, reference numerals 111 and 113. Two members are not essential.) Can be deformed or moved, and the electrode tabs are electrically connected to each other by deformation or movement of the members. Various specific configurations for realizing this are assumed. Hereinafter, some examples will be described.

(Second Embodiment)
Although the above embodiment uses a pair of contact members 111 and 113, only one contact member is used in another embodiment of the present invention. An example of this is shown in FIG.

  In the short-circuit mechanism 110B of FIG. 6, only one contact member 111-2 is used instead of the pair of contact members 111 and 113. As in the above-described embodiment, a part of the base end side of the contact member 111-2 is fixed to one electrode tab 21, and is held in a cantilever shape. The contact member 111-2 may be a straight member as in the first embodiment, but in this example, the tip side is slightly bent and bent. The bent portion is configured to be caught by the peelable seal portion 115. The tip 111-2a of the contact member 111-2 is generally bent toward the current collecting portion 18b of the other electrode tab 25.

  In the short-circuit mechanism 110B of the present embodiment configured as described above, the peelable seal portion 115 first peels when the film exterior body 10 expands beyond a predetermined level. Thereby, since there is no member that prevents the deformation of the contact member 111-2, the contact member 111-2 is deformed by its elastic force, and the tip 111-2a of the contact member 111-2 is a part of the current collector 18b. (See FIG. 6B).

  Since the current collector 18b has the same potential as the electrode tab 25 connected thereto, this state means that the electrode tabs 21 and 25 are short-circuited. Therefore, as in the above-described embodiment, the battery can be safely stopped by losing cell energy due to a short circuit between the electrode tabs 21 and 25.

  Even in such a configuration, a part of the contact member 111-2 or between the contact member 111-2 and the current collector 18b can be used so that the electric energy of the cell can be efficiently released as heat energy. A resistance member (not shown) is preferably provided. As described above, the contact member 111-2 may be made of a resistance material so as to function as a resistor.

  Of course, the shape of the contact member 111-2 can be changed as appropriate, and for example, a straight contact member may be used.

(Third embodiment)
In the second embodiment, the configuration in which the bent contact member abuts on the current collector electrically connected to the other electrode tab has been described. However, as shown in FIG. 6 is biased in the direction opposite to that of FIG. 6, and when the peelable seal portion 115 is peeled off, the tip thereof is configured to come into contact with the contact member 113-3 connected to the other electrode tab 25. Also good.

  The contact member 113-3 is not necessarily a long member (a member that can be easily bent in other words) like the contact member 113-3. The contact member 113-3 may be formed to be shorter and have a rigidity sufficient to receive the contact member 113-3 when it is pressed.

  Regarding the connection between such a short contact member and the electrode tab, resistance welding, ultrasonic welding, laser welding, caulking, adhesion with a conductive adhesive, or the like can be employed. In addition, the short contact member may be made of a resistance material so that the electric energy of the cell can be efficiently released as heat energy so that the cell itself functions as a resistor.

(Fourth embodiment)
FIG. 8 basically shows a configuration having a short-circuit mechanism 110D in which the principle of short-circuiting is the same as the configuration of FIG. 7, but in this example, the shape of the peelable seal portion 116 has been described so far. Is different.

  This peelable seal portion 116 is a protruding heat welded portion extending inward from the heat welded portion 15 at the periphery of the film exterior body. In the case of such a peelable seal portion 116, when the film outer package 10 expands, stress concentration occurs in this portion, and as a result, the peelable seal portion 116 gradually peels from the tip side. It becomes.

  The specific shape of the peelable seal portion 116 can be variously changed. For example, in addition to a shape in which the tip is formed in an arc shape as shown in the figure, a shape (semicircle, Semi-elliptical, trapezoidal, triangular, etc.).

  In the initial state, the contact member 111-4 is pressed near the tip of the peelable seal portion 116 with a predetermined urging force in a state of being elastically deformed. Although not limited, in the present embodiment, the tip side of the contact member 111-4 is also curved in an arc shape in accordance with the tip shape of the peelable seal portion 116.

  When gas is generated in the film outer package at the time of abnormality and the outer package begins to expand, stress concentrates on the peelable seal portion 116 and gradually peels from the tip side. Then, when the peelable seal portion 116 is peeled to a predetermined position, the contact member 111-4 and the contact member 113-4 come into contact with each other, and the electrode tabs are short-circuited.

  In this embodiment, a gas discharge hole 116 h is formed in a part of the peelable seal portion 116. The gas discharge hole 116h is formed as a hole penetrating the film. When the peeling of the seal portion 116 reaches the gas discharge hole 116h, the inside and the outside of the exterior body communicate with each other through the discharge hole 116h. As a result, the internal gas is released to the outside through this hole.

  Note that such a gas discharge hole 116h is not necessarily required, and may be omitted in one embodiment of the present invention. Further, in this embodiment, it is provided on the protruding seal portion 116, but it may be provided on a peelable seal portion 115 or the like separated from the peripheral heat welding portion as shown in FIG.

(Fifth embodiment)
In the embodiments described so far, the short-circuit mechanism using the elastic contact member (113 or the like) held in a cantilever shape has been described. However, the elastic contact member 114 as shown in FIGS. 9 and 10 should be used. You can also.

  In the short-circuit mechanism 110E of FIGS. 9 and 10, a spring-like elastic contact member 114 is provided. The contact member 114 is attached to the main body 114a that can be expanded and contracted in the length direction, an attachment member 114b provided at the base end (the right end in the drawing in FIG. 10), and the distal end of the main body 114a. A contact member 114c. In this embodiment, one of the features is that an expandable / contractible contact member is used, and the contact member and the attachment member are not essential components.

  As shown in FIG. 10, the base end side of the main body 114 a is fixed on the electrode tab 21 by connecting the attachment member 114 b to the electrode tab 21. In this state, the main body 114a extends toward the opposite electrode tab 25. The elastic contact member 114 is disposed in a slightly compressed state, and its tip (contact member 114 c) is in contact with the peelable seal portion 117 being urged.

  A contact member 113-5 disposed on the electrode tab 25 is formed at the tip of the stretchable contact member 114. As an example, the contact member 113-5 may have a shape having a flat portion bonded to the surface of the electrode tab 25 and a contact portion rising from an edge of the flat portion.

  The shape of the peelable seal portion 117 may be a simple linear shape, but may be a substantially U shape as in the present embodiment. By doing so, the contact member 114c at the tip of the elastic contact member 114 can be satisfactorily received.

  Regarding the connection between the mounting member 114b / contact member 113-5 and the electrode tab, resistance welding, ultrasonic welding, laser welding, caulking, adhesion with a conductive adhesive, or the like can be employed. It is also preferable that a part of the contact member 114, the contact member 113-5, or a resistance member be provided between them so that the electric energy of the cell can be efficiently released as heat energy.

  When the film exterior body expands beyond a predetermined level due to abnormalities such as use under high temperature or overcharge, the peelable seal portion 117 is first peeled off. As a result, since there is no member holding the tip of the stretchable contact member 114, the stretchable contact member 114 expands and the contact member 114c at the tip contacts the contact member 113-5. As a result, the electrode tabs are short-circuited.

2-2. Energization cutoff mechanism (sixth embodiment)
In any of the above-described embodiments, the film outer package is provided with a short-circuit mechanism for short-circuiting the electrode tabs when the peelable seal part is peeled off. When a body expand | swells and a peelable seal part peels, you may provide the electricity supply interruption | blocking mechanism which makes an electrode tab a non-energized state.

  In the energization cutoff mechanism 210A of FIG. 11, the electrode tab 25 is cut off in the middle of the film outer package 10, and the electrical connection state of the electrode tab 25 is determined using a pair of electrical connection members 211-1, 213-1. Maintained.

  As the electrical connection member 211-1, for example, as shown in FIG. 11B, a flat portion 211-1a joined to the upper surface of the electrode tab 25, and the electrode tab 25 extends in a direction along the flat portion 211-1a. It may have an extension part 211-1b. The other electrical connection member 213-1 may also have a flat part 213-1a and an extension part 213-1b as the same configuration as this. Although not limited, the extension part 213-1b of one electrical connection member 213-1 may be formed thinner than the other extension part 211-1b, and may be configured to be more flexible.

  As shown in FIG. 11A, a peelable seal portion 215a is formed on the back side of the extension portion 211-1b of the electrical connection member 211-1, and the extension portion 213-1a of the electrical connection member 213-1 is formed. Another peelable seal portion 215b is formed on the back side. And the position of each peelable seal | sticker part 215a, 215b is set to the position which makes the extension part 213-1b elastically deform in an initial state, and an extension part contacts mutually (FIG. 11 (a)). reference).

  According to the above configuration, the energized state is maintained before the peelable seal portions 215a and 215b are peeled off. However, when the exterior body expands to a predetermined level or more, the peelable seal portions 215a and 215b are peeled off, so that the extension portions 211-1b and 213-1b of the electrical connection members 211-1 and 213-1 are brought into contact with each other. Since there is no member to keep, the extensions are separated from each other (see FIG. 11B), and as a result, the energization of the electrode tab 25 is interrupted.

(Seventh embodiment)
As the energization cutoff mechanism, a mechanism as shown in FIG. 12A may be used. In this energization cutoff mechanism 210B, the pair of electrical connection members 211-2 and 213-2 are basically the same as those in FIG. 11, but the means for bringing them into contact with each other is different. That is, the spring-like elastic body 214 is disposed between the extension portion of the electrical connection members 211-2 and 213-2 and the peelable seal portion 215c in a state where the spring-like elastic body 214 is slightly compressed.

  The spring-like elastic body 214 urges the extension part of one electrical connection member 213-2 toward the extension part of the other electrical connection member 211-2, so that the extension parts come into contact with each other. The energized state of the electrode tab 25 is maintained. On the other hand, when the exterior body expands to a predetermined level or more, the peelable seal portion 215c is peeled off. As a result, there is no member for pressing the end of the compressed elastic body 214. The urging action on the extension portion of the member disappears, the extension portions are separated from each other, and as a result, the energization of the electrode tab 25 is interrupted.

  In addition, it is good also as a structure provided with both an electricity supply interruption | blocking mechanism and a short circuit mechanism. In the configuration illustrated in FIG. 12B, a short-circuit mechanism 110 </ b> B that short-circuits between the electrode tabs 21 and 25 at the time of abnormality is provided, and a breaker term 210 </ b> B that shuts off the energization of the electrode tab 25 is provided. Such a configuration can stop the function of the battery more reliably, and is preferable as one embodiment.

(About manufacturing method)
(1) Method of manufacturing a film-clad battery having a short-circuit mechanism This method includes a step of preparing a battery element; when a gas is generated in the exterior body and the exterior body expands more than a predetermined amount, a positive electrode tab and a negative electrode Providing a short-circuit mechanism for electrically short-circuiting the electrode tab. In the step of providing the short-circuit mechanism, specifically, the following steps are performed:
a1: forming a peelable seal portion that peels preferentially when the exterior body expands;
a2: It is fixed to one electrode tab and elastically abuts on the peelable seal portion until the peelable seal portion peels, and when the peelable seal portion peels, it deforms and the other electrode tab or electric Forming a first contact member that abuts the connected member.

(2) Method for producing film-clad battery with current-carrying-off mechanism This method includes the step of preparing a battery element; and when the gas is generated in the exterior body and the exterior body expands beyond a predetermined level, the electrode tab is deenergized. And a step of providing an energization shut-off mechanism for setting the state. And as a step of providing an energization interruption mechanism, specifically, the following processes are performed:
a1: forming a peelable seal portion that peels preferentially when the exterior body expands;
a2: A step of forming a pair of electrical connection members in which a part of each other is in contact until the peelable seal is peeled off, and the parts that are deformed and separated from each other are separated from each other when peeled off.

(3) Manufacturing Method of Short-Circuit Mechanism / Electricity-cutoff Mechanism The short-circuit mechanism described as one embodiment of the present invention (for example, the short-circuit mechanism 110B in FIG. 6) can be manufactured by the following method. This will be described with reference to FIG. 13. Since the configuration shown in FIG. 13 is slightly changed from FIG. 6, this point will be described first.

  FIG. 13 shows a plurality of positive electrodes, negative electrodes, separators (not shown), and positive and negative electrode extensions 18a ′ and 18b ′ constituting the battery element. Reference numeral 141 denotes a thin plate-like conductive material connected to the positive electrode extension 18a ', and a contact member 111-2 is provided in advance on a part of the upper surface thereof. On the other hand, reference numeral 145 is a thin plate-like conductive material connected to the negative electrode extension 18b ', and a contact portion 145a with which the tip of the contact member 111-2 contacts is provided in advance on a part of the upper surface. ing.

  In the step of collecting the positive electrode and negative electrode extension portions 18a ′ and 18b ′ using, for example, ultrasonic bonding, the conductive materials 141 and 145 are respectively connected to the positive electrode extension portion 18a ′ and the positive electrode tab 21. In the meantime, it is sandwiched between the negative electrode extension 18 b ′ and the negative electrode tab 25.

  Then, for example, by performing ultrasonic bonding, the plurality of extensions 18a ′ of the positive electrode, the conductive material 141, and the positive electrode tab 21 are bonded, and the plurality of extensions 18b ′ of the negative electrode, the conductive material 145, and the positive electrode tab are joined. 25 is joined.

  According to such a manufacturing method, the manufacturing process of the short-circuit mechanism can be performed in the joining process of the electrode extension (current collector) and the electrode tab, which is conventionally performed in the manufacture of batteries. , Work efficiency is good. In addition, although the case of manufacture of a short circuit mechanism was illustrated here, such a manufacturing method is applicable also to manufacture of an electricity interruption | blocking mechanism.

<About other inventions>
FIG. 14 is a schematic diagram of a power storage system using a secondary battery according to one embodiment of the present invention. The power storage system 1 is not limited in size, but includes a power supply unit 1A having at least one secondary battery (for example, a film-clad battery 50) and control for monitoring / controlling charging / discharging thereof. And a device 1B. Such a power storage system 1 may be, for example, a backup power source, and may be various types such as for large facilities, offices, and homes.

  FIG. 15 is a schematic view of an electric vehicle using a secondary battery according to an embodiment of the present invention. The electric vehicle 2 includes a power supply unit 2A having at least one secondary battery (for example, a film-clad battery 50) and a control device 2B that performs monitoring / control of charging / discharging thereof.

  The secondary battery according to one embodiment of the present invention can be used in, for example, all industrial fields that require a power source. For example, it can be used as a power source for mobile devices such as mobile phones and laptop computers; it can be used as a power source for electric vehicles such as electric cars, hybrid cars, electric bikes, and electric assist bicycles; It can be used as a power source for mediums; it can be used as a power storage system for storing electric power.

(Appendix)
This application discloses the following inventions:
1. A battery element (20);
An exterior body (10) that houses the battery element (20) together with an electrolyte;
Positive and negative electrode tabs (21, 25) connected to the battery element (20);
A secondary battery (50) comprising:
In the protruding portion (the protruding portion protruding from the sealing portion, 116 or the like) or the separated position (115 or the like) from the sealing portion on the outer periphery of the outer package, a part of the mutually facing surfaces inside the outer package is Peelable seals (115, 116) welded directly or joined together via other members;
A first contact member (111, 114), one of which is fixed to the electrode tab (21) and the other is in contact with the peelable seal portion;
A secondary battery (50) comprising:
“Directly welded or joined to each other via another member” means that the peelable seal portion is formed by, for example, welding the inner surfaces (resin layers) of the film outer package. It may be a thing, and it may be what was joined by fusing | bonding or adhere | attaching with the other member interposed. Even if this is any form, if the “peelable seal part” is preferentially peeled over other seal parts (seal part for sealing), the effect of the present invention is achieved. This is because the effect can be obtained similarly.

2. The secondary battery according to the above, wherein the first contact member (111, 114) is a member (111) held in a cantilever shape on the electrode tab.

3. The secondary battery as described above, wherein the first contact member (111, 114) is an elastic member (114) that is stretchable.

4). The first contact members (111, 114) are
Until the peelable seal portion peels, it elastically contacts the peelable seal portion and deforms when the peelable seal portion peels, and the other electrode tab (25) or a member electrically connected thereto Configured to contact (113, 18b),
The secondary battery as described above.

5. The secondary according to the above, having the second contact member (113, 113-3-5) attached to the electrode tab as the member (113, 18b) electrically connected to the other electrode tab. battery.

6). The secondary according to the above 4, wherein the member (113, 18b) electrically connected to the other electrode tab is a current collector (18b) of the battery element to which the other electrode tab is connected. battery.

7). The rechargeable battery according to the above, wherein the peelable seal portion (115, 116) is configured to peel preferentially when the exterior body expands.

8). In the peelable seal portion (116),
Furthermore, the secondary battery according to the above description, wherein a gas discharge hole (116h) that opens when the peelable seal portion peels and communicates the inside and the outside of the exterior body is formed.

9. The peelable seal (115, 116);
The first contact member (111, 114);
The secondary battery according to the above, wherein a short-circuit mechanism (110A) having the following is provided.

10. The secondary battery as described above, wherein the short-circuit mechanism (110A) includes a resistance member disposed between the electrode tabs in terms of electrical connection.
Note that “disposed between the electrode tabs in terms of electrical connection” does not mean that the physical positional relationship is “between the electrode tabs”; "Means that a resistance member is provided.

11. A battery element (20);
An exterior body (10) that houses the battery element (20) together with an electrolyte;
Positive and negative electrode tabs (21, 25) connected to the battery element (20);
A film-clad battery (50) comprising:
further,
At least one of the electrode tabs is cut;
A peelable seal portion (115, 116) in which the surfaces facing each other inside the exterior body are partially welded at a position protruding from or spaced from the outer peripheral sealing portion of the exterior body,
A first member (211-1) provided on one of the separated electrode tabs, and a second member (partly in contact with the first member provided on the other of the separated electrode tabs) 213-1),
A secondary battery.

12 A battery element (20);
An exterior body (10) that houses the battery element (20) together with an electrolyte;
Positive and negative electrode tabs (21, 25) connected to the battery element (20);
A secondary battery (50) comprising:
further,
In a position protruding from or spaced from the outer peripheral sealing portion of the exterior body, a part of the mutually facing surfaces inside the exterior body is directly welded or joined to each other via another member. A first peelable seal (115, 116) made;
A first contact member (111, 114), one of which is fixed to the electrode tab (21) and the other is in contact with the welded portion;
And having
At least one of the electrode tabs is cut;
In a position protruding from or spaced from the outer peripheral sealing portion of the exterior body, a part of the mutually facing surfaces inside the exterior body is directly welded or joined to each other via another member. A second peelable seal portion (115, 116) separate from the first peelable seal portion,
A first member (211-1) provided on one of the separated electrode tabs, and a second member (partly in contact with the first member provided on the other of the separated electrode tabs) 213-1).

13. An electric vehicle comprising a power supply unit having a plurality of the secondary batteries described above.

14 An electrical storage system provided with the power supply part which has two or more said secondary batteries.

15. Providing a battery element;
A peelable seal portion (115, 116) is formed in which a part of mutually facing surfaces inside the exterior body are directly or indirectly joined to each other at a position protruding from the outer peripheral sealing portion of the exterior body or spaced apart. And steps to
And a step of providing a first contact member (111, 114), one of which is fixed to the electrode tab (21) and the other is in contact with the welded portion.
This method includes a step of providing a short-circuit mechanism that electrically short-circuits the positive electrode tab and the negative electrode tab when gas is generated in the outer package and the outer package expands beyond a predetermined level. The step of providing the short-circuit mechanism includes
(A1) forming a peelable seal portion that peels preferentially during expansion of the exterior body;
(A2) It is fixed to one of the electrode tabs and elastically abuts on the peelable seal part until the peelable seal part peels off, and deforms when the peelable seal part peels off, and the other electrode tab Or forming a first contact member that abuts against a member electrically connected thereto.

1 Power storage system (power storage equipment)
2 Electric vehicle 10 Film exterior body 11, 12 Laminate film 15 Thermal welded portion 18 a, 18 b Current collector 18 a ′, 18 b ′ Electrode extension 20 Battery element 21, 25 Electrode tabs 110 </ b> A to 110 </ b> E Short-circuit mechanism 111, 111-2, 111-3, 111-4 Contact member 113, 113-3, 113-4, 113-5 Contact member 114 Stretchable contact member 115, 116, 117 Peelable seal part 116h Gas discharge hole 141, 145 Conductive material 145a Contact part 210A, 210B Energization interruption mechanism 211-1, 211-2 Electrical connection member 213-1, 211-2 Electrical connection member 214 Elastic body 215a-215c Peelable seal part

Claims (15)

A battery element;
An exterior body that houses the battery element together with an electrolyte;
Positive and negative electrode tabs connected to the battery element;
A secondary battery comprising:
In a position protruding from or spaced from the outer peripheral sealing portion of the exterior body, a part of the mutually facing surfaces inside the exterior body is directly welded or joined to each other via another member. A peelable seal portion,
A first contact member, one of which is fixed to the electrode tab and the other is in contact with the peelable seal portion;
A secondary battery.   The secondary battery according to claim 1, wherein the first contact member is a member held in a cantilever shape on the electrode tab.   The secondary battery according to claim 1, wherein the first contact member is a stretchable elastic member. The first contact member is
Until the peelable seal portion peels, it elastically contacts the peelable seal portion, deforms when the peelable seal portion peels, and contacts the other electrode tab or a member electrically connected thereto. Configured as
The secondary battery as described in any one of Claims 1-3.   The secondary battery according to claim 4, wherein the member electrically connected to the other electrode tab includes a second contact member attached to the electrode tab.   The secondary battery according to claim 4, wherein the member electrically connected to the other electrode tab is a current collector of the battery element to which the other electrode tab is connected.   The secondary battery according to any one of claims 1 to 6, wherein the peelable seal portion is configured to peel preferentially when the exterior body expands. In the peelable seal part,
The secondary battery according to any one of claims 1 to 7, wherein when the peelable seal portion is peeled off, a gas discharge hole that opens and communicates the inside and the outside of the exterior body is formed.   The secondary battery as described in any one of Claims 1-8 provided with the short circuit mechanism which has the said peelable seal part and a said 1st contact member.   The secondary battery according to claim 9, wherein the short-circuit mechanism includes a resistance member disposed between the electrode tabs in terms of electrical connection. A battery element;
An exterior body that houses the battery element together with an electrolyte;
Positive and negative electrode tabs connected to the battery element;
A film-clad battery comprising:
At least one of the electrode tabs is cut;
A peelable seal part in which the surfaces facing each other inside the exterior body are partially welded at a position protruding from the outer periphery sealing part of the exterior body or spaced apart from each other;
A first member provided on one of the cut electrode tabs, and a second member provided on the other of the cut electrode tabs and partially in contact with the first member;
A secondary battery. A battery element;
An exterior body that houses the battery element together with an electrolyte;
Positive and negative electrode tabs connected to the battery element;
A secondary battery comprising:
In a position protruding from or spaced from the outer peripheral sealing portion of the exterior body, a part of the mutually facing surfaces inside the exterior body is directly welded or joined to each other via another member. A first peelable seal portion,
A first contact member, one of which is fixed to the electrode tab and the other is in contact with the welded portion;
And having
At least one of the electrode tabs is cut;
In a position protruding from or spaced from the outer peripheral sealing portion of the exterior body, a part of the mutually facing surfaces inside the exterior body is directly welded or joined to each other via another member. A second peelable seal portion different from the first peelable seal portion,
A first member provided on one of the cut electrode tabs, and a second member provided on the other of the cut electrode tabs and partially in contact with the first member;
A secondary battery.   An electric vehicle comprising a power supply unit including a plurality of the secondary batteries according to any one of claims 1 to 12.   An electrical storage system provided with the power supply part which has two or more secondary batteries as described in any one of Claims 1-12. Providing a battery element;
Forming a peelable seal part in which a part of mutually facing surfaces inside the exterior body are joined directly or indirectly at a position protruding from the outer peripheral sealing part of the exterior body or spaced apart; and
Providing a first contact member, one of which is fixed to the electrode tab and the other is in contact with the welded portion.

Images