JP5103822B2 - Nonaqueous electrolyte secondary battery - Google Patents

Description

  The present invention relates to a non-aqueous electrolyte secondary battery, and more particularly, to a non-aqueous electrolyte secondary battery using a laminate material for an exterior and having excellent resistance to physical external force.

  In recent years, many portable electronic devices such as a camera-integrated VTR (videotape recorder), a mobile phone, or a portable computer have appeared, and their size and weight have been reduced. Along with this, development of batteries, particularly secondary batteries, has been actively promoted as portable power sources for electronic devices. Among these, lithium ion secondary batteries are attracting attention as being capable of realizing a high energy density.

In such a lithium ion secondary battery, a metal battery can such as aluminum (Al) or iron (Fe) is used as an exterior member. Recently, by using a laminate film as an exterior member instead of a metal battery can, the battery has been further reduced in size, weight, and thickness (see, for example, Patent Documents 1 and 2).
JP 2003-217664 A JP-A-6-150900

  However, the laminate film has lower rigidity than a metal exterior member such as aluminum or iron, and has a low ability to protect the internal power generation element from physical external force such as dropping. In particular, the end faces of the positive electrode and the negative electrode constituting the power generation element are likely to be deformed by a physical external force, and an internal short circuit is likely to occur.

  This invention is made | formed in view of the subject which such a prior art has, The place made into the objective is providing the non-aqueous electrolyte secondary battery which has the outstanding tolerance with respect to a physical external force. is there.

  As a result of intensive studies to achieve the above object, the present inventors have found that the above object can be achieved by using a separator having a size larger than that of the battery element housing portion of the laminate exterior member, and the present invention has been completed. It came to do.

That is, the non-aqueous electrolyte secondary battery of the present invention includes a battery element formed by winding or laminating a positive electrode and a negative electrode with a separator interposed therebetween, a non-aqueous electrolyte composition, and an exterior member made of a laminate material that accommodates them. equipped with a,
The non-aqueous electrolyte composition is in a gel form, and the gel-like non-aqueous electrolyte composition is present between at least one of the positive electrode and the separator and between the negative electrode and the separator of the battery element. ,
The exterior member contains the battery element and has a rectangular accommodating portion that forms a rectangular recess,
Dimensions of the separator in the battery element, much larger than the internal dimension of the rectangular housing part in the outer member,
The separator has at least one surface covered with the gel-like nonaqueous electrolyte composition, and has a protruding portion protruding from the positive electrode and the negative electrode,
The protruding portion is curved or bent and is accommodated in the rectangular accommodating portion .

Further, a preferred embodiment of the nonaqueous electrolyte secondary battery of the present invention is characterized in that the battery element has a rectangular plate shape, and the vertical dimension of the separator is larger than the inner vertical dimension of the rectangular housing portion in the exterior member. To do.
Here, the “vertical dimension” means a length in a direction substantially parallel to the direction in which the positive electrode terminal or the negative electrode terminal protrudes in the rectangular plate-shaped battery element, and in this case, “substantially parallel”. Is intended not to be completely parallel in consideration of measurement errors and the like.

In another preferred embodiment of the non-aqueous electrolyte secondary battery of the present invention, the battery elements are stacked to form a rectangular plate shape, and the lateral dimension of the separator is larger than the inner lateral dimension of the rectangular housing portion in the exterior member. It is characterized by.
Here, the “lateral dimension” means a length in a direction substantially perpendicular to the direction in which the positive electrode terminal or the negative electrode terminal protrudes in the rectangular plate-shaped battery element. In this case, “substantially vertical” Is intended not to be completely vertical in consideration of measurement errors and the like.

Furthermore, another preferred embodiment of the nonaqueous electrolyte secondary battery of the present invention is characterized in that the gel-like nonaqueous electrolyte composition is formed by impregnating a polymer support with a nonaqueous electrolyte.
In this case, the polymer support is preferably adhered to the separator and at least one of the positive electrode and the negative electrode.

  According to the present invention, since a separator having a size larger than that of the battery element housing portion of the laminate exterior member is used, it is possible to provide a nonaqueous electrolyte secondary battery having excellent resistance to physical external force.

Next, the nonaqueous electrolyte secondary battery of the present invention will be described in detail.
FIG. 1 is an exploded perspective view showing an example of a wound battery using a laminate material as an embodiment of the nonaqueous electrolyte secondary battery of the present invention.
In this figure, this secondary battery is configured by enclosing a wound battery element 20 to which a positive electrode terminal 11 and a negative electrode terminal 12 are attached inside a film-like exterior member 30 (30A, 30B). The positive electrode terminal 11 and the negative electrode terminal 12 are led out, for example, in the same direction from the inside of the exterior member 30 to the outside. The positive electrode terminal 11 and the negative electrode terminal 12 are each made of a metal material such as aluminum (Al), copper (Cu), nickel (Ni), or stainless steel.

The exterior member 30 is configured by a rectangular laminate film in which, for example, a nylon film, an aluminum foil, and a polyethylene film are bonded together in this order. The exterior member 30 is arrange | positioned so that the polyethylene film side and the battery element 20 may oppose, for example, and each outer edge part is mutually joined by melt | fusion or the adhesive agent.
An adhesion film 31 is inserted between the exterior member 30 and the positive electrode terminal 11 and the negative electrode terminal 12 to prevent intrusion of outside air. The adhesion film 31 is made of a material having adhesion to the positive electrode terminal 11 and the negative electrode terminal 12. For example, when the positive electrode terminal 11 and the negative electrode terminal 12 are made of the metal materials described above, polyethylene, polypropylene, modified It is preferably composed of a polyolefin resin such as polyethylene or modified polypropylene.

In addition, the exterior member 30 may be configured by another structure, for example, a laminate film having no metal material, a polymer film such as polypropylene, or a metal film, instead of the above-described laminate film.
Here, the general structure of an exterior member can be represented by the laminated structure of an exterior layer / metal foil / sealant layer (however, the exterior layer and the sealant layer may be composed of a plurality of layers), and the above. In this example, the nylon film corresponds to the exterior layer, the aluminum foil corresponds to the metal foil, and the polyethylene film corresponds to the sealant layer.
In addition, as metal foil, it is sufficient if it functions as a moisture-permeable barrier film, and not only aluminum foil but also stainless steel foil, nickel foil and plated iron foil can be used, but it is thin and lightweight. Thus, an aluminum foil excellent in workability can be suitably used.

  The structures that can be used as the exterior member are listed in the form of (exterior layer / metal foil / sealant layer): Ny (nylon) / Al (aluminum) / CPP (unstretched polypropylene), PET (polyethylene terephthalate) / Al / CPP, PET / Al / PET / CPP, PET / Ny / Al / CPP, PET / Ny / Al / Ny / CPP, PET / Ny / Al / Ny / PE (polyethylene), Ny / PE / Al / LLDPE (direct) Chain low density polyethylene), PET / PE / Al / PET / LDPE (low density polyethylene), and PET / Ny / Al / LDPE / CPP.

  FIG. 2 is a schematic cross-sectional view taken along the line II-II of the battery element 20 shown in FIG. In the figure, a battery element 20 is wound with a positive electrode 21 and a negative electrode 22 facing each other with a polymer support layer (described later) 23 holding a non-aqueous electrolyte and a separator 24 interposed therebetween. The outermost peripheral part is protected by the protective tape 25.

As shown in FIG. 2, the positive electrode 21 has a structure in which a positive electrode active material layer 21B is coated on both surfaces or one surface of a positive electrode current collector 21A having a pair of opposed surfaces, for example. The positive electrode current collector 21 </ b> A has a portion exposed without being covered with the positive electrode active material layer 21 </ b> B at one end portion in the longitudinal direction, and the positive electrode terminal 11 is attached to the exposed portion.
The positive electrode current collector 21A is made of a metal foil such as an aluminum foil, a nickel foil, or a stainless steel foil.

The positive electrode active material layer 21B includes one or more positive electrode materials capable of occluding and releasing lithium ions as a positive electrode active material, and a conductive material and a binder as necessary. May be included.
Examples of the positive electrode material capable of inserting and extracting lithium include sulfur (S), iron disulfide (FeS ₂ ), titanium disulfide (TiS ₂ ), molybdenum disulfide (MoS ₂ ), and niobium diselenide. lithium (NbSe _2), vanadium oxide _{(V 2 O} 5), chalcogenides containing no lithium, such as titanium dioxide (TiO ₂₎ and manganese dioxide (MnO ₂₎ (especially layered compound and the spinel-type compound), containing lithium Examples thereof include conductive compounds such as polyaniline, polythiophene, polyacetylene, and polypyrrole.

  Among these, lithium-containing compounds are preferable because some compounds can obtain a high voltage and a high energy density. Examples of such a lithium-containing compound include a composite oxide containing lithium and a transition metal element, and a phosphate compound containing lithium and a transition metal element. From the viewpoint of obtaining a higher voltage, cobalt is particularly preferred. (Co), nickel (Ni), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), chromium (Cr), vanadium (V), titanium (Ti) or any mixture thereof. The inclusion is preferred.

Such lithium-containing compounds are typically represented by the following general formula (1) or (2)
Li _x M ^I O ₂ (1)
Li _y M ^II PO ₄ (2)
(In the formula, M ^I and M ^II represent one or more transition metal elements, and the values of x and y vary depending on the charge / discharge state of the battery, but usually 0.05 ≦ x ≦ 1.10, 0.05 ≦ y ≦ 1.10), and the compound of the formula (8) generally has a layered structure, and the compound of the formula (9) generally has an olivine structure.

Specific examples of the composite oxide containing lithium and a transition metal element include lithium cobalt composite oxide (Li _x CoO ₂ ), lithium nickel composite oxide (Li _x NiO ₂ ), lithium nickel cobalt composite oxide ( _Examples include Li _x Ni _1-z Co _z O ₂ (0 <z <1), lithium manganese composite oxide (LiMn ₂ O ₄ ) having a spinel structure.
Specific examples of the phosphate compound containing lithium and a transition metal element include, for example, a lithium iron phosphate compound having a olivine structure (LiFePO ₄ ) or a lithium iron manganese phosphate compound (LiFe _1-v Mn _v PO ₄ (v < 1)).
In these composite oxides, for the purpose of stabilizing the structure, a transition metal is partially substituted with Al, Mg or other transition metal elements or included in the crystal grain boundary, and a part of oxygen is fluorine. The thing substituted by etc. can also be mentioned. Further, at least a part of the surface of the positive electrode active material may be coated with another positive electrode active material. Moreover, you may use a positive electrode active material in mixture of multiple types.

On the other hand, similarly to the positive electrode 21, the negative electrode 22 has a structure in which a negative electrode active material layer 22B is provided on both surfaces or one surface of a negative electrode current collector 22A having a pair of opposed surfaces, for example. The negative electrode current collector 22A has an exposed portion without being provided with the negative electrode active material layer 22B at one end in the longitudinal direction, and the negative electrode terminal 12 is attached to the exposed portion.
The anode current collector 22A is made of a metal foil such as a copper foil, a nickel foil, or a stainless steel foil.

The negative electrode active material layer 22B includes one or more of a negative electrode material capable of inserting and extracting lithium ions and metallic lithium as a negative electrode active material, and a conductive material and a binder as necessary. An adhesive may be included.
Examples of the negative electrode material capable of inserting and extracting lithium include a carbon material, a metal oxide, and a polymer compound. Examples of the carbon material include non-graphitizable carbon materials, artificial graphite materials, and graphite-based materials. More specifically, pyrolytic carbons, cokes, graphites, glassy carbons, organic polymer compound firing Body, carbon fiber, activated carbon and carbon black.
Among these, coke includes pitch coke, needle coke and petroleum coke, and the organic polymer compound fired body is carbonized by firing a polymer material such as phenol resin or furan resin at an appropriate temperature. Say things. In addition, examples of the metal oxide include iron oxide, ruthenium oxide, and molybdenum oxide, and examples of the polymer compound include polyacetylene and polypyrrole.

Further, examples of the negative electrode material capable of inserting and extracting lithium include a material containing as a constituent element at least one of a metal element and a metalloid element capable of forming an alloy with lithium. The negative electrode material may be a single element, alloy or compound of a metal element or a metalloid element, or may have at least a part of one or more of these phases.
In the present invention, alloys include those containing one or more metal elements and one or more metalloid elements in addition to those composed of two or more metal elements. Moreover, the nonmetallic element may be included. Some of the structures include a solid solution, a eutectic (eutectic mixture), an intermetallic compound, or a mixture of two or more of these.

Examples of such metal elements or metalloid elements include tin (Sn), lead (Pb), aluminum, indium (In), silicon (Si), zinc (Zn), antimony (Sb), bismuth (Bi), Examples include gallium (Ga), germanium (Ge), arsenic (As), silver (Ag), hafnium (Hf), zirconium (Zr), and yttrium (Y).
Among them, a group 14 metal element or metalloid element in the long-period type periodic table is preferable, and silicon or tin is particularly preferable. This is because silicon and tin have a large ability to occlude and release lithium, and a high energy density can be obtained.

Examples of the tin alloy include silicon, magnesium (Mg), nickel, copper, iron, cobalt, manganese, zinc, indium, silver, titanium (Ti), germanium, bismuth, and antimony as second constituent elements other than tin. And at least one selected from the group consisting of chromium (Cr).
As an alloy of silicon, for example, as a second constituent element other than silicon, tin, magnesium, nickel, copper, iron, cobalt, manganese, zinc, indium, silver, titanium, germanium, bismuth, antimony, and chromium can be used. The thing containing at least 1 sort (s) of them is mentioned.

  Examples of the tin compound or the silicon compound include those containing oxygen (O) or carbon (C), and may contain the second constituent element described above in addition to tin or silicon.

Next, the polymer support layer 23 has ionic conductivity and can hold a non-aqueous electrolyte. In the embodiment shown in FIG. 2, the polymer support layer 23 adheres or adheres to the separator 24, but does not adhere to the separator and the electrode as in the separator 24 and the positive electrode 21 and the separator 24 and the negative electrode 22. It may be adhered, or may not be adhered or adhered to the separator, and may be adhered or adhered only to either one or both of the positive electrode 21 and the negative electrode 22.
Here, “adhesion” means that the polymer support layer 23 and the separator 24, the positive electrode 21, and the negative electrode 22 are in contact with each other to the extent that they do not move relative to each other unless a predetermined force is applied. .

  The polymer support layer 23 and the separator 24, or the polymer support layer 23 and the positive electrode or the negative electrode are in close contact or bonded to each other, so that the polymer support layer 23 holds the non-aqueous electrolyte and has a gel-like shape. In a state where the nonaqueous electrolyte layer is formed, the positive electrode 21 or the negative electrode 22 and the separator 24 are bonded via the nonaqueous electrolyte layer. The degree of adhesion is preferably such that, for example, the peel strength between the exposed portion of the positive electrode 21 and the negative electrode 22 where the active material layer is not provided and the current collector is exposed and the separator is 5 mN / mm or more. . The peel strength is measured between 6 seconds and 25 seconds after the current collector is placed on a support stand, pulled in a 180 ° direction at a speed of 10 cm / min, and the current collector is peeled off from the separator. , The average force required to peel.

  By such close contact or adhesion, in the nonaqueous electrolyte secondary battery of the present invention, it is possible to reduce excess nonaqueous electrolyte solution that is not substantially involved in the battery reaction, and the nonaqueous electrolyte solution is efficiently disposed around the electrode active material. Well supplied. Therefore, the non-aqueous electrolyte secondary battery of the present invention exhibits excellent cycle characteristics even when the amount of the non-aqueous electrolyte is smaller than that of the conventional one. Excellent liquidity.

The polymer support constituting the polymer support layer is not particularly limited as long as it retains the non-aqueous electrolyte and exhibits ionic conductivity, but the copolymerization amount of acrylonitrile is 50% or more. 80% or more of acrylonitrile polymer, aromatic polyamide, acrylonitrile / butadiene copolymer, acrylic polymer comprising acrylate or methacrylate homopolymer or copolymer, acrylamide polymer, vinylidene fluoride, etc. Examples thereof include a polymer, polysulfone, and polyallylsulfone. In particular, a polymer having an acrylonitrile copolymerization amount of 50% or more has a CN group in its side chain, so that a polymer gel electrolyte having a high dielectric constant and high ion conductivity can be produced.
In order to improve the support of non-aqueous electrolytes for these polymers and the ionic conductivity of polymer gel electrolytes from these polymers, acrylonitrile and vinyl carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, acrylamide, methacrylic Copolymerization of sulfonic acid, hydroxyalkylene glycol (meth) acrylate, alkoxyalkylene glycol (meth) acrylate, vinyl chloride, vinylidene chloride, vinyl acetate, various (meth) acrylates, preferably at a ratio of 50% or less, particularly 20% or less. It is also possible to use.
In addition, since the aromatic polyamide is a high heat-resistant polymer, it is a preferable high-molecular polymer when a polymer gel electrolyte that requires high heat resistance such as an automobile battery is required. Further, a polymer having a crosslinked structure obtained by copolymerizing butadiene or the like can also be used.
In particular, a polymer containing vinylidene fluoride as a constituent component, that is, a homopolymer, a copolymer, and a multi-component copolymer are preferable. Specifically, polyvinylidene fluoride (PVdF), polyvinylidene fluoride-hexafluoropropylene copolymer A combination (PVdF-HFP) and a polyvinylidene fluoride-hexafluoropropylene-chlorotrifluoroethylene copolymer (PVdF-HEP-CTFE) can be mentioned.

  The separator 24 has a high ion permeability and a predetermined mechanical strength, such as a porous film made of a polyolefin-based synthetic resin such as polypropylene or polyethylene, or a porous film made of an inorganic material such as a ceramic nonwoven fabric. It is good also as a structure which laminated | stacked these 2 or more types of porous films. In particular, those containing a polyolefin-based porous membrane are suitable because they have excellent separability between the positive electrode 21 and the negative electrode 22 and can further reduce internal short-circuiting and open circuit voltage reduction.

  In such a wound battery, since the separator 24 has a belt-like shape, the dimension adjustment with the rectangular housing portion (the recessed portion of 30A, see FIG. 1) of the exterior member 30 intended by the present invention is performed. Is the width of the strip separator, that is, the dimension in the short direction. This point will be described later.

The non-aqueous electrolyte solution means a liquid non-aqueous electrolyte composition, and may contain any electrolyte salt and non-aqueous solvent.
Here, as the electrolyte salt, any electrolyte salt may be used as long as it dissolves or disperses in a nonaqueous solvent described later, and lithium hexafluorophosphate (LiPF ₆ ) can be suitably used. Needless to say, it is not limited.
That is, lithium tetrafluoroborate (LiBF _4), lithium hexafluoroarsenate (LiAsF _6), lithium hexafluoro antimonate (LiSbF _6), lithium perchlorate (LiClO _4), four lithium aluminum chloride acid ( Inorganic lithium salts such as LiAlCl ₄ ), lithium trifluoromethanesulfonate (LiCF ₃ SO ₃ ), lithium bis (trifluoromethanesulfone) imide (LiN (CF ₃ SO ₂ ) ₂ ), lithium bis (pentafluoromethanesulfone) imide (LiN (C ₂ F ₅ SO ₂ ) ₂ ) and lithium salts of perfluoroalkanesulfonic acid derivatives such as lithium tris (trifluoromethanesulfone) methide (LiC (CF ₃ SO ₂ ) ₃ ) can also be used. These can be used alone or in combination of two or more. It is also possible to use it.

  The concentration of such electrolyte salt is preferably in the range of 0.1 mol to 3.0 mol, more preferably in the range of 0.5 mol to 2.0 mol, with respect to 1 liter (l) of the solvent. This is because higher ion conductivity can be obtained within this range.

Examples of the non-aqueous solvent include various high dielectric constant solvents and low viscosity solvents.
As the high dielectric constant solvent, ethylene carbonate, propylene carbonate, and the like can be suitably used, but are not limited thereto, butylene carbonate, vinylene carbonate, 4-fluoro-1,3-dioxolan-2-one Cyclic carbonates such as (fluoroethylene carbonate), 4-chloro-1,3-dioxolan-2-one (chloroethylene carbonate), and trifluoromethylethylene carbonate can be used.

  Further, as a high dielectric constant solvent, instead of or in combination with a cyclic carbonate, a lactone such as γ-butyrolactone and γ-valerolactone, a lactam such as N-methylpyrrolidone, and a cyclic carbamate such as N-methyloxazolidinone A sulfone compound such as tetramethylene sulfone can also be used.

  On the other hand, diethyl carbonate can be preferably used as the low-viscosity solvent, but besides this, chain carbonates such as dimethyl carbonate, ethyl methyl carbonate and methyl propyl carbonate, methyl acetate, ethyl acetate, methyl propionate Chain carboxylic acid esters such as ethyl propionate, methyl butyrate, methyl isobutyrate, methyl trimethylacetate and ethyl trimethylacetate, chain amides such as N, N-dimethylacetamide, methyl N, N-diethylcarbamate and N, Chain carbamates such as ethyl N-diethylcarbamate and ethers such as 1,2-dimethoxyethane, tetrahydrofuran, tetrahydropyran and 1,3-dioxolane can be used.

In addition, as a non-aqueous electrolyte used for the non-aqueous electrolyte secondary battery of the present invention, the above-mentioned high dielectric constant solvent and low-viscosity solvent may be used alone or in combination of two or more. However, those containing 20 to 50% cyclic carbonate and 50 to 80% low viscosity solvent (low viscosity non-aqueous solvent) are preferred, and those having a boiling point of 130 ° C. or less as the low viscosity solvent are particularly preferred Is desirable.
If the ratio between the cyclic carbonate and the low-viscosity solvent deviates from the above range, the ionic conductivity is lowered, and the battery performance may be lowered.
Examples of the chain carbonate having a boiling point of 130 ° C. or lower include dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate.

Next, an example of a method for manufacturing the secondary battery described above will be described.
The laminate type secondary battery can be manufactured as follows.
First, the positive electrode 21 is produced. For example, when a particulate positive electrode active material is used, a positive electrode mixture is prepared by mixing a positive electrode active material and, if necessary, a conductive material and a binder, and a dispersion medium such as N-methyl-2-pyrrolidone. To produce a positive electrode mixture slurry.
Next, the positive electrode mixture slurry is applied to the positive electrode current collector 21A, dried, and compression molded to form the positive electrode active material layer 21B.

  Moreover, the negative electrode 22 is produced. For example, when a particulate negative electrode active material is used, a negative electrode mixture is prepared by mixing a negative electrode active material and, if necessary, a conductive material and a binder, and a dispersion medium such as N-methyl-2-pyrrolidone. To prepare a negative electrode mixture slurry. Thereafter, the negative electrode mixture slurry is applied to the negative electrode current collector 22A, dried, and compression molded to form the negative electrode active material layer 22B.

Then, the polymer support layer 23 is formed on the separator 24. As a method of forming the polymer support layer 23 on the separator 24, a method of applying a solution containing the polymer support to the surface of the separator 24 and removing the solvent, and a separately formed polymer support layer are used. A technique of closely fixing to the surface of the separator 24 is exemplified.
As a method of applying a solution containing a polymer support to the surface of the separator 24, a method of immersing the separator in a solution containing a polymer support, a method of supplying and applying by a T-die extrusion method, a spray method, a roll coater, a knife A technique of applying the solution to the surface of the substrate with a coater or the like can be mentioned.
Examples of the solvent removal treatment method for removing the solvent include a method for drying and removing, a method for extracting and removing the solvent by immersing it in a poor solvent for the polymer support, and a method for drying and removing the poor solvent, or a combination thereof. Can be used.
As a method of closely fixing the separately formed polymer support layer to the surface of the separator 24, it is possible to adhere using an adhesive, but in this case, the type of electrolyte used (acid, alkali, organic solvent, etc.) ), It is necessary to select an adhesive appropriately and to prevent clogging.
Moreover, as a method of closely attaching the polymer support layer formed on the separator, heat fusion at a temperature equal to or higher than the gel transition point can be mentioned. In particular, heat fusion while applying pressure such as hot roll compression is preferable.

  Next, the positive electrode terminal 11 is attached to the positive electrode 21 and the negative electrode terminal 12 is attached to the negative electrode 22, and then the separator 24 with the polymer support layer 23, the positive electrode 21, the same separator 24, and the negative electrode 22 are sequentially laminated and wound. Rotate and adhere the protective tape 25 to the outermost periphery to form a wound electrode body. Further, the wound electrode body is sandwiched between the exterior members 30 (30A and 30B), and the outer peripheral edge except one side is heat-sealed to form a bag shape.

Thereafter, an electrolyte salt such as lithium hexafluorophosphate and a non-aqueous electrolyte solution containing a non-aqueous solvent such as ethylene carbonate are prepared, and injected into the wound electrode body from the opening of the exterior member 30, The opening of the exterior member 30 is heat-sealed and sealed. Thereby, the non-aqueous electrolyte is held on the polymer support layer 23, and the secondary battery shown in FIGS. 1 and 2 is completed.
In this way, after the polymer support layer is formed and stored, the electrolyte is swollen to form an electrolyte. In this method, the precursor and solvent that are the raw materials for forming the polymer support are removed in advance, and the electrolyte is almost completely removed from the electrolyte. It is possible not to leave it, and the polymer support forming step can be well controlled. Therefore, the separator, the positive electrode, the negative electrode, and the polymer support layer can be adhered to each other.

  In the secondary battery described above, when charged, lithium ions are released from the positive electrode active material layer 21 </ b> B and occluded in the negative electrode active material layer 22 </ b> B through the non-aqueous electrolyte held in the polymer support layer 23. Is done. When discharging is performed, lithium ions are released from the negative electrode active material layer 22B, and are inserted in the positive electrode active material layer 21B through the polymer support layer 23 and the nonaqueous electrolytic solution.

  In the above, for a wound battery using a laminate material, after the polymer support is housed in a laminate package (exterior member), it is swollen with a non-aqueous electrolyte and the gel electrolyte layer (polymer support layer) 23) is taken as an example. However, a wound type battery in which a gel electrolyte layer formed on a separator is wound together with a positive electrode and a negative electrode and then housed in a laminate package, and a separator After the positive electrode and the negative electrode are wound and accommodated in a laminate package, a battery in which the package is filled with a gel electrolyte, a battery using a liquid nonaqueous electrolyte composition (nonaqueous electrolyte) without using a gel, Since a strip-shaped separator is used, the present invention can also be applied to these.

  Regarding the structure of a battery using a non-aqueous electrolyte (liquid non-aqueous electrolyte composition) and not provided with a polymer support layer, the polymer support layer 23 is schematically omitted in FIG. It becomes a structure filled with electrolyte.

Next, as another embodiment of the nonaqueous electrolyte secondary battery of the present invention, a laminated battery using a laminate material will be described.
FIG. 3 is a partially cutaway perspective view showing another embodiment of the nonaqueous electrolyte secondary battery of the present invention and showing an example of a laminated battery using a laminate material.
In this figure, this laminated battery has a configuration in which a laminated battery element 50 to which a positive electrode terminal 41 and a negative electrode terminal 42 are attached is housed in a film-like exterior member 61.

The positive electrode terminal 41 and the negative electrode terminal 42 are for taking out the electromotive force generated in the stacked battery element 50 to the outside. Each of the positive electrode terminal 41 and the negative electrode terminal 42 has a strip shape. Are derived respectively. The positive terminal 41 and the negative terminal 42 have the same configuration as the positive terminal 11 and the negative terminal 12 of the wound battery shown in FIG.
An adhesion film 62 is inserted between the exterior member 61 and the positive electrode terminal 41 and the negative electrode terminal 42 to prevent intrusion of outside air. The exterior member 61 and the adhesion film 62 have the same configuration as the exterior member 30 and the adhesion film 31 of the wound battery.

  4 is a top view showing an appearance of the battery element 50 shown in FIG. 3, and FIG. 5 is a cross-sectional view showing a cross-sectional structure taken along the line V-V in FIG. FIG. 6 is a plan view of the single positive electrode 51 viewed from the stacking direction.

As shown in FIG. 5, the stacked battery element 50 is formed by alternately stacking positive electrodes 51 and negative electrodes 52 with separators 54 interposed therebetween.
As shown in FIGS. 5 and 6, the positive electrode 51 has a rectangular covering region 51D in which an active material layer 51B is provided on both surfaces of a current collector 51A. An exposed region 51C serving as a strip-shaped terminal mounting portion protrudes from one corner of the covering region 51D. In the exposed region 51C, the current collector 51A is exposed without providing the active material layer 51B, and the positive electrode terminal 41 (see FIG. 3) is joined. 4 and 5 show a state before the positive electrode terminal 41 is joined.

On the other hand, FIG. 7 shows the configuration of a single negative electrode 52 as viewed from the stacking direction.
In the negative electrode 52, similarly to the positive electrode 51, an exposed region 52 </ b> C serving as a strip-shaped terminal mounting portion protrudes from one corner of a rectangular covering region 52 </ b> D in which the active material layer 52 </ b> B is provided on both surfaces of the current collector 52 </ b> A. It has a configuration (see FIGS. 5 and 7). The exposed region 52C is in a state where the current collector 52A is exposed without providing the active material layer 52B, and the negative electrode terminal 42 (see FIG. 3) is joined. 4 and 5 show a state before the negative electrode terminal 42 is joined.

  As shown in FIGS. 3 and 4, the exposed region 51 </ b> C and the exposed region 52 </ b> C are provided at positions that do not overlap each other in the stacking direction A (direction orthogonal to the paper surface of FIG. 4) of the battery elements 50. The negative electrode 52 is formed with a size larger than that of the positive electrode 51, and the relative positions of the positive electrode 51 and the negative electrode 52 are adjusted so that the covering region 51D is within the covering region 52D when viewed from the stacking direction A. .

When the covering region 51D does not fit inside the covering region 52D, a portion that does not face the covering region 51D (a portion that protrudes from the covering region 51D) occurs at the end of the covering region 52D. Therefore, the area of the negative electrode 52 that should receive the lithium ions released from the positive electrode 51 during charging is insufficient (that is, the current density at the end of the negative electrode 52 increases), and dendritic (dendritic) metallic lithium can be deposited. There is sex.
When such dendritic metallic lithium is deposited, there is a risk of causing capacity loss or causing an internal short circuit due to damage of the separator 54. To prevent this, the present embodiment has the above-described configuration. . The lithium storage capacity per unit area of the active material layer 52B is set so as not to exceed the lithium release capacity per unit area of the active material layer 51B.

In the present embodiment, the separator 54 is bonded to the active material layers 51B and 52B occupying the coating regions 51D and 52D via the polymer support layer 53 (see FIG. 5).
Further, the separator 54 is bonded to the current collectors 51A and 52A via the polymer support layer 53 at the overlapping portion 51E with the exposed region 51C and the overlapping portion 52E with the exposed region 52C (FIGS. 4 and 4). 5). That is, the overlapping portions 51E and 52E are adhesion regions. Thereby, even if some external force is applied from the outside of the exterior member 61, the relative positions of the positive electrode 51 and the negative electrode 52 and the separator 54 can be maintained.
However, the arrangement of the adhesion region is not an essential requirement of the present invention and can be omitted.

Further, the separator 54 has a larger area than the areas where the active material layers 52A and 52B are formed in the positive electrode 51 and the negative electrode 52, that is, the covering areas 51D and 52D, and the outer edge portions 54B of the separator 54 cover the covering areas 51D and 52D. It is bonded via a polymer electrolyte 53 so as to surround it. Therefore, the separator 54 has a bag shape so as to enclose each of the positive electrode 51 and the negative electrode 52. Thereby, even in a high temperature environment, the thermal contraction of the separator 54 can be suppressed, and heat generation due to a short-circuit current generated when the current collector 51A and the current collector 52A are in contact can be suppressed. It has become.
However, disposing the separator in a bag shape as described above is not an essential requirement of the present invention and can be omitted.

  In such a stacked battery, since the separator 54 has a rectangular plate shape (see FIG. 4), the rectangular housing portion of the exterior member 61 intended by the present invention (the recessed portion of 61, see FIG. 3). ) With respect to the dimension adjustment, at least one of the short side and the long side of the separator 54 is a target, which will be described later.

The secondary battery 2 can be manufactured, for example, as follows.
First, for example, a positive electrode active material, a conductive agent, and a binder are mixed to prepare a positive electrode mixture, which is dispersed in a solvent such as N-methyl-2-pyrrolidone to obtain a positive electrode mixture slurry.
Next, as shown in FIG. 8A, the positive electrode mixture slurry is applied to both sides of a strip-shaped metal foil 51AZ such as an aluminum foil, dried, and compression molded to form an active material film 51BZ. At this time, the active material film 51BZ is formed only on the covering portion 51DZ, which will later become the covering region 51D, and not on the exposed portion 51CZ, which will later become the exposed region 51C. Further, the formation position of the covering portion 51DZ is made substantially the same on both surfaces of the metal foil 51AZ.

Subsequently, by cutting the metal foil 51AZ on which the active material film 51BZ is formed along the broken lines X1 and X2 and the broken lines Y1 to Y3 shown in FIG. 8A, four electrode plates 51Z having a rectangular shape are formed. Is made. Note that the number of electrode plates 51Z produced at a time is not limited to four, and can be selected as appropriate.
Further, by cutting along the broken line 51L shown in FIG. 8B, four positive electrodes 51 having a predetermined shape are completed as shown in FIG. 8C.

  One negative electrode 52 may be formed in the same manner as the positive electrode 21. Specifically, a negative electrode active material and a binder are first mixed to prepare a negative electrode mixture, which is dispersed in a solvent such as N-methyl-2-pyrrolidone to obtain a negative electrode mixture slurry, which is then copper The active material film 52BZ is formed by applying it on both surfaces of a strip-shaped metal foil 52AZ such as a foil, drying, and compression molding. At this time, similarly to the positive electrode 51, the active material film 52BZ is formed only on the covering portion 52DZ that becomes the covering region 52D in the metal foil 52AZ, and is not formed on the exposed portion 52CZ that becomes the exposed region 52C. Further, the formation position of the covering portion 52DZ is made substantially the same on both surfaces of the metal foil 52AZ. That is, the coating end of the covering portion 52DZ is made to be substantially on the same line on both surfaces.

  Subsequently, the metal foil 52AZ on which the active material film 52BZ is formed is cut along the broken lines X1 and X2 and the broken lines Y1 to Y3 shown in FIG. 8A, and further, the broken line 52L shown in FIG. 8B. As shown in FIG. 8C, four negative electrodes 52 having a predetermined shape are completed.

  When forming the active material layer 51B and the active material layer 52B, the lithium storage capacity per weight of the negative electrode mixture and the lithium release capacity per weight of the positive electrode mixture are measured in advance, and the active material layer The lithium storage capacity per unit area of 52B is prevented from exceeding the lithium release capacity per unit area of the active material layer 51B.

After producing the positive electrode 51 and the negative electrode 52, the separator 54 cut into a rectangular shape so as to have an area larger than the covering regions 51D and 52D in the positive electrode 51 and the negative electrode 52 is prepared.
Then, for example, using three positive electrodes 51, four negative electrodes 52, and six separators 54, as shown in FIG. 5, the negative electrode 52, the separator 54, the positive electrode 51, the separator 54, and the negative electrode 52 are used. The stacked battery element 50 is formed by stacking the separator 54, the positive electrode 51, the separator 54, the negative electrode 52, the separator 54, the positive electrode 51, the separator 54, and the negative electrode 52 in this order.

At this time, by adjusting the relative positions of the positive electrode 51 and the negative electrode 52, the exposed region 51 </ b> C and the exposed region 52 </ b> C are mutually aligned while the covered region 51 </ b> D is accommodated inside the covered region 52 </ b> D when viewed from the stacking direction A. Avoid overlapping.
In addition, the polymer support layer 53 is previously applied to the separator 54 by applying a polymer solution in which the above-described polymer is dissolved in a solvent such as N-methyl-2-pyrrolidone and drying to remove the solvent. You may form.
When a gel-like nonaqueous electrolyte composition is used without providing a polymer support layer, a predetermined polymer compound solution is applied in advance to the positive electrode 51 or the negative electrode 52 without being applied to the separator 54. You may keep it.

  In this manner, a stacked battery element 50 having the active material layer 51B, the separator 54, and the active material layer 52B as a basic stack unit is manufactured, and the active material layers 52B are disposed at both ends in the stacking direction A.

  After the battery element 50 is fabricated, the exposed regions 51C of the three positive electrodes 51 are collectively joined to the positive terminal 41 (see FIG. 3). Similarly, the exposed regions 52 </ b> C of the four negative electrodes 52 are joined together with the negative terminal 42. These joining is performed by ultrasonic welding, for example.

After the positive electrode terminal 41 and the negative electrode terminal 42 are joined, the laminated battery element 50 is impregnated with the electrolytic solution, the laminated battery element 50 is sandwiched between the exterior members 61, and the outer edges of the exterior member 61 are thermally melted together. Enclose it tightly by wearing.
At this time, the adhesion film 62 is inserted between the positive electrode terminal 41, the negative electrode terminal 42, and the exterior member 61. Then, it heats as needed and makes the polymer support body 53 hold | maintain electrolyte solution. Thereby, the stacked secondary battery shown in FIG. 3 is completed.

  In the above, for a laminated battery using a laminate material, the polymer support is housed in a laminate package (exterior member) and then swollen with a nonaqueous electrolytic solution to form a gel electrolyte layer (polymer support layer 53). ) Is taken as an example, and a laminated battery in which a gel electrolyte layer formed on a separator is laminated together with a positive electrode and a negative electrode and then stored in a laminate package, or a separator, a positive electrode, and a negative electrode After stacking and storing in a laminate package, a battery in which the package is filled with a gel electrolyte, a battery using a liquid non-aqueous electrolyte composition (non-aqueous electrolyte) without using a gel, also use a separator. Therefore, the present invention can also be applied to these.

  Regarding the structure of a battery using a non-aqueous electrolyte (liquid non-aqueous electrolyte composition) and not provided with a polymer support layer, the polymer support layer 53 is schematically omitted in FIG. It becomes a structure filled with electrolyte.

Next, the relationship between the dimension of the battery element accommodating part of the exterior member and the dimension of the separator of the battery element in the nonaqueous electrolyte secondary battery of the present invention will be described.
In the non-aqueous electrolyte secondary battery described above, the exterior member is denoted by reference numeral 30 or 61, the battery element is denoted by reference numeral 20 or 50, and the separator is denoted by reference numeral 24 or 54. Reference numeral 30 represents a battery element, reference numeral 20 represents a battery element, and reference numeral 24 represents a separator.

FIG. 9 is a schematic plan view showing an exterior member and a battery element in an embodiment of the nonaqueous electrolyte secondary battery of the present invention. FIG. 4A schematically shows a plane of the exterior member 30. The exterior member 30 has a rectangular accommodating portion 30R for accommodating the battery element 20, and this rectangular accommodating portion 30R is usually Molded by drawing to form a bathtub shape, forming a substantially rectangular space (see FIGS. 1 and 3).
On the other hand, FIG. 9B schematically shows a plane of the battery element 20 and shows only the separator 24 of the wound battery element or the stacked battery element.

As described above, in the nonaqueous electrolyte secondary battery of the present invention, the dimension of the separator 24 is larger than the inner dimension of the rectangular accommodating part 30R.
Specifically, in FIG. 9, the C dimension indicating the vertical dimension of the separator 24 in FIG. 9 is larger than the A dimension indicating the vertical dimension among the inner dimensions of the rectangular accommodating portion 30R (A dimension <C dimension). The D dimension indicating the lateral dimension of 24 is larger than the B dimension indicating the inner lateral dimension of the rectangular accommodating portion 30R (B dimension <D dimension), or a combination thereof (A dimension <C dimension and B dimension <D Dimension).

In the non-aqueous electrolyte secondary battery that satisfies the above relationship, the separator protrudes from the positive electrode and the negative electrode, which are power generation elements, and the protruding portion is compressed, curved or bent, and accommodated and sealed in the rectangular accommodating portion. Thus, the separator which was compressed and became high density exhibits the function which raises the mechanical strength with respect to external forces, such as dropping, and protects an electric power generation element.
If the polymer support layer is further adhered or adhered to the separator, the mechanical strength against external force is further improved.
In addition, since the surface of the separator is covered with the polymer support layer, the separator is not easily damaged even when the separator is bent or bent, and the separators are in contact with each other, and the mechanical strength against the external force is ensured. It is possible to improve and protect.

As described above, some of the non-aqueous electrolyte secondary batteries of the present invention use a wound battery element and a stacked battery element. In the wound battery element, on the short side of the strip-shaped separator. Since only the end face of the electrode (positive electrode or negative electrode) is present, the mechanical strength against the external force of the battery can be improved by adjusting the A and C dimensions shown in FIG. 9 as described above.
On the other hand, in the laminated battery element, since the end face of the electrode exists on both the short side and the long side of the separator having a rectangular sheet shape (strip shape), A dimension and C dimension, B dimension and D dimension shown in FIG. Alternatively, by adjusting both of them as described above, the mechanical strength against the external force of the battery can be improved.

In the non-aqueous electrolyte secondary battery of the present invention, the effect of improving the mechanical strength is that the battery is a wound type or a laminated type, and whether the non-aqueous electrolyte composition used is liquid or gel-like. However, a battery using a gel-like non-aqueous electrolyte or a polymer support in combination with a non-aqueous electrolyte is more effective than a battery using only a non-aqueous electrolyte.
In particular, the polymer support has an excellent effect of improving mechanical strength due to its cushioning properties. Further, when the polymer support is bonded to the separator and the positive electrode and / or the negative electrode, the effect is further increased.

  Hereinafter, the present invention will be described in more detail by way of examples and comparative examples with reference to the drawings. However, the present invention is not limited to these examples.

Example 1
A belt-like positive electrode and a negative electrode are wound through a belt-like separator having a width of 54.5 mm with a PVdF polymer support layer formed on both sides. In the dimensions shown in FIG. 9, the C dimension is 54.5 mm, and the D dimension. A winding element of 33.8 mm was produced. This was sealed together with the electrolyte in a laminated film exterior member molded into a bathtub shape having an A dimension of 54.4 mm and a B dimension of 34.0 mm. The thickness was 3.8 mm, the width was 35.0 mm, and the height was 62.0 mm. The battery of this example was assembled. Table 1 shows the specifications of the battery of this example.

(Example 2)
A belt-like positive electrode and a negative electrode are wound through a belt-like separator having a width of 56.4 mm on which a polymer support layer of PVdF is formed on both sides. In the dimensions shown in FIG. 9, the C dimension is 56.4 mm, the D dimension. A winding element of 33.8 mm was produced. This was sealed together with the electrolyte in a laminated film exterior member molded into a bathtub shape having an A dimension of 54.4 mm and a B dimension of 34.0 mm. The thickness was 3.8 mm, the width was 35.0 mm, and the height was 62.0 mm. The battery of this example was assembled. Table 1 shows the specifications of the battery of this example.

(Example 3)
A belt-like positive electrode and a negative electrode are wound through a belt-like separator having a width of 57.4 mm in which a PVdF polymer support layer is formed on both sides. In the dimensions shown in FIG. 9, the C dimension is 57.4 mm, and the D dimension. A winding element of 33.8 mm was produced. This was sealed together with the electrolyte in a laminated film exterior member molded into a bathtub shape having an A dimension of 54.4 mm and a B dimension of 34.0 mm. The thickness was 3.8 mm, the width was 35.0 mm, and the height was 62.0 mm. The battery of this example was assembled. Table 1 shows the specifications of the battery of this example.

Example 4
A strip-shaped positive electrode and a negative electrode are laminated via a strip-shaped separator having a height of 54.5 mm and a width of 34.1 mm formed by forming a polymer support layer of PVdF on both sides. A laminated element having a thickness of 0.5 mm and a D dimension of 34.1 mm was produced. This was sealed together with the electrolyte in a laminated film exterior member molded into a bathtub shape having an A dimension of 54.4 mm and a B dimension of 34.0 mm. The thickness was 3.8 mm, the width was 35.0 mm, and the height was 62.0 mm. The battery of this example was assembled. Table 1 shows the specifications of the battery of this example.

(Comparative Example 1)
A belt-like positive electrode and a negative electrode are wound through a strip-shaped separator having a width of 54.4 mm, on which a porous layer of PVdF is formed on both sides, and in the same manner as above, winding with a C dimension of 54.4 mm and a D dimension of 33.8 mm An element was produced. This was sealed together with the electrolyte in a laminated film exterior member molded into a bathtub shape having an A dimension of 54.4 mm and a B dimension of 34.0 mm. The thickness was 3.8 mm, the width was 35.0 mm, and the height was 62.0 mm. The battery of this example was assembled. Table 1 shows the specifications of the battery of this example.

(Comparative Example 2)
A strip-shaped positive electrode and a negative electrode are laminated via a strip-shaped separator having a height of 54.4 mm and a width of 34.0 mm formed by forming a porous layer of PVdF on both sides, and the C dimension is 54.4 mm as described above. A laminated element having a D dimension of 34.0 mm was produced. This was sealed together with the electrolyte in a laminated film exterior member molded into a bathtub shape having an A dimension of 54.4 mm and a B dimension of 34.0 mm. The thickness was 3.8 mm, the width was 35.0 mm, and the height was 62.0 mm. The battery of this example was assembled. Table 1 shows the specifications of the battery of this example.

[Performance evaluation]
The batteries of Examples and Comparative Examples were dropped from the height of 1.9 m to the concrete floor surface, twice for each surface of the battery, a total of 12 times, and the number of occurrences of internal short circuits was measured. The obtained results are also shown in Table 1.
No internal short circuit occurred in the batteries of the examples belonging to the scope of the present invention.

As mentioned above, although this invention was demonstrated with some embodiment and an Example, this invention is not limited to these, A various deformation | transformation is possible within the range of the summary of this invention.
For example, in the above-described embodiment, the case where the battery element 20 in which the positive electrode 21 and the negative electrode 22 are stacked and wound is described, but the case of including a flat battery element in which a pair of positive electrode and negative electrode is stacked is also provided. The present invention can be applied. Moreover, it is applicable not only to a secondary battery but also to a primary battery.

Further, it is sufficient that the polymer support or the gel-like nonaqueous electrolyte composition is present at least between the positive electrode and the separator and between the negative electrode and the separator.
Further, for convenience of description of the dimensions, the terms “short side”, “long side”, and “rectangle” are used, but a configuration in which the short side and the long side are replaced is also included in the scope of the present invention. It may be a square, and accordingly, the case where the short side length and the long side length are the same is also included in the scope of the present invention.

Moreover, it is also possible to mix and use other electrolytes as a non-aqueous electrolyte composition. For example, other electrolytes include ion conductive inorganic compounds such as organic solid electrolytes, ion conductive ceramics, ion conductive glasses, and ionic crystals in which electrolyte salts are dissolved or dispersed in polymer compounds having ion conductivity. An inorganic solid electrolyte can be mixed.
In the case where the positive electrode 21 and the negative electrode 22 are wound, a case where a plurality of the positive electrodes 51 and the negative electrodes 52 are stacked has been described. However, the positive electrode and the negative electrode may be folded.

  Furthermore, as described above, the present invention relates to a battery using lithium as an electrode reactant, but the technical idea of the present invention is that other alkali metals such as sodium (Na) or potassium (K), magnesium The present invention can also be applied to the case of using an alkaline earth metal such as (Mg) or calcium (Ca), or another light metal such as aluminum.

It is one Embodiment of the nonaqueous electrolyte secondary battery of this invention, Comprising: It is a disassembled perspective view which shows an example of a laminate type battery. It is sectional drawing along the II line of the battery element shown in FIG. It is other embodiment of the nonaqueous electrolyte secondary battery of this invention, Comprising: It is a partially notched perspective view which shows the other example of a laminate type battery. It is a top view showing the external appearance of the battery element shown in FIG. FIG. 5 is a cross-sectional view illustrating a cross-sectional structure along line VI-VI in FIG. 4. It is the top view which looked at the positive electrode from the lamination direction. It is a top view of the negative electrode seen from the lamination direction. It is explanatory drawing which shows 1 process for demonstrating the manufacturing method of a battery. It is a schematic top view which shows the exterior member and battery element in one Embodiment of the nonaqueous electrolyte secondary battery of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Positive electrode terminal, 12 ... Negative electrode terminal, 20 ... Winding battery element, 21 ... Positive electrode, 21A ... Positive electrode collector, 21B ... Positive electrode active material layer, 22 ... Negative electrode, 22A ... Negative electrode collector, 22B ... Negative electrode active Material layer, 23 ... polymer support layer, 24 ... separator, 25 ... protective tape, 30 ... exterior member, 31 ... adhesion film, 41 ... positive electrode terminal, 42 ... negative electrode terminal, 50 ... battery element, 51 ... positive electrode, 51A , 52A ... current collector, 51B, 52B ... active material layer, 51C, 52C ... exposed region, 51D, 52D ... coated region, 52 ... negative electrode, 53 ... polymer electrolyte, 54 ... separator, 61 ... exterior member, 62 ... Adhesive film.

Claims (7)

A battery element formed by winding or laminating a positive electrode and a negative electrode via a separator, a non-aqueous electrolyte composition, and an exterior member made of a laminate material that accommodates these ,
The non-aqueous electrolyte composition is in a gel form, and the gel-like non-aqueous electrolyte composition is present between at least one of the positive electrode and the separator and between the negative electrode and the separator of the battery element. ,
The exterior member contains the battery element and has a rectangular accommodating portion that forms a rectangular recess,
Dimensions of the separator in the battery element, much larger than the internal dimension of the rectangular housing part in the outer member,
The separator has at least one surface covered with the gel-like nonaqueous electrolyte composition, and has a protruding portion protruding from the positive electrode and the negative electrode,
The non-aqueous electrolyte secondary battery in which the protruding portion is curved or bent and is accommodated in the rectangular accommodating portion . The non-aqueous electrolyte secondary battery according to claim 1, wherein the protruding portion is compressed to a high density. The battery element is a rectangular plate shape, a non-aqueous electrolyte secondary battery as claimed in any size have claims 21 to than the inner longitudinal dimension of the rectangular housing part in the longitudinal dimension above the exterior member of the separator. A rectangular plate-like the battery element is laminated, non-aqueous electrolyte secondary according to any size have the claim 21 to than the inner transverse dimension of the rectangular housing part transverse dimension of the separator in the outer member battery. The battery elements are stacked to form a rectangular plate shape, the vertical dimension of the separator is larger than the inner vertical dimension of the rectangular accommodating part in the exterior member, and the lateral dimension of the separator is the inner side of the rectangular accommodating part in the exterior member. the non-aqueous electrolyte secondary battery according to any one of claims 21 to have greater than the transverse dimension. The gelled non-aqueous electrolyte composition, the non-aqueous electrolyte secondary battery according to any one of claims 1 to 5 Ru formed by impregnating a nonaqueous electrolyte in a polymer support. The polymer support is the separator and the positive electrode and the nonaqueous electrolyte secondary battery according to claim 6 that has adhered to the adhesive to at least one of the negative electrode.

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