JP2008130528A - Non-aqueous electrolyte composition and non-aqueous electrolyte secondary battery - Google Patents

Abstract

A non-aqueous electrolyte composition capable of suppressing battery swelling in a high-temperature environment and a non-aqueous electrolyte secondary battery using such a non-aqueous electrolyte composition are provided.
An electrolyte salt and a phosphoric acid monoester such as a methylphosphoric anhydride cyclic trimer, a phenylphosphoric anhydride cyclic trimer, and a phenylphosphonic anhydride cyclic trimer in a non-aqueous solvent. A cyclic acid anhydride or an arylphosphonic acid cyclic anhydride is added to obtain a non-aqueous electrolyte composition, and a non-aqueous electrolyte secondary battery is obtained using such a non-aqueous electrolyte composition.
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Description

  The present invention relates to a non-aqueous electrolyte composition and a non-aqueous electrolyte secondary battery, and more specifically, for example, phosphoric acid monoesters such as phenylphosphoric acid cyclic anhydrides and phenylphosphonic acid cyclic anhydrides and cyclic anhydrides of phosphonic acid. The present invention relates to a non-aqueous electrolyte composition containing a product and a lithium ion non-aqueous electrolyte secondary battery using such a non-aqueous electrolyte composition.

  In recent years, many portable electronic devices such as a camera-integrated VTR (video tape recorder), a digital still camera, a mobile phone, a portable information terminal, and a notebook computer have appeared, and the size and weight have been reduced. As a portable power source for these electronic devices, various research and development for improving the energy density of a battery, particularly a secondary battery, is being actively promoted.

  Among them, a lithium ion secondary battery using carbon as a negative electrode active material, a lithium-transition metal composite oxide as a positive electrode active material, and a carbonate ester mixture as an electrolytic solution is a lead battery that is a conventional aqueous electrolyte secondary battery, Since a large energy density is obtained as compared with a nickel cadmium battery, it is widely put into practical use (for example, see Patent Document 1).

In particular, a laminate battery using an aluminum laminate film for the exterior has a feature of high energy density because it is lightweight (see, for example, Patent Document 2).
In such a laminated battery, since the deformation of the battery can be suppressed by using a polymer swollen with an electrolytic solution, a laminated polymer battery is also widely used (for example, see Patent Document 3).

On the other hand, in a square battery such as a laminate battery, swelling is likely to occur due to high-temperature storage. Therefore, it has been proposed to suppress such swelling by adding 1-alkylphosphonic anhydride (patent). Reference 4).
JP-A-4-332479 Japanese Patent No. 3482591 JP 2005-166448 A JP 2001-202992 A

  However, in the proposal according to Patent Document 4 described above, only dimethyl carbonate is used as the low viscosity solvent in the electrolytic solution. Therefore, there is no problem in the metal can battery as in this proposal, but in the laminated battery having a higher energy density, the temperature is high. There was a problem of swelling during storage.

  The present invention has been made in view of such problems of the prior art, and the object of the present invention is to provide a non-aqueous electrolyte composition capable of suppressing swelling of a battery in a high temperature environment, and this An object of the present invention is to provide a non-aqueous electrolyte secondary battery using such a non-aqueous electrolyte composition.

  As a result of intensive studies to achieve the above object, the present inventor has added a cyclic acid anhydride of phosphoric acid monoester or arylphosphonic acid, or a cyclic acid anhydride of alkylphosphonic acid and dimethyl carbonate. The present inventors have found that the above problem can be solved by combining with a solvent having a relatively small content, and have completed the present invention.

  That is, the nonaqueous electrolyte composition of the present invention contains an electrolyte salt, a nonaqueous solvent, a cyclic acid anhydride of phosphoric monoester acid and / or a cyclic acid anhydride of arylphosphonic acid, or An electrolyte salt, a non-aqueous solvent, a cyclic acid anhydride of alkylphosphonic acid, and a polymer compound, wherein the non-aqueous solvent includes dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate in components other than the electrolyte salt. The content of at least one selected from the group consisting of 50 to 80% by mass, the content of ethyl methyl carbonate and / or diethyl carbonate is 10% by mass or more, and the content of dimethyl carbonate is 40% by mass or less. It is characterized by.

  The nonaqueous electrolyte secondary battery of the present invention accommodates a positive electrode and a negative electrode using a material capable of inserting and extracting lithium ions as a positive electrode active material or a negative electrode active material, a nonaqueous electrolyte composition, a separator, and these. A nonaqueous electrolyte secondary battery comprising an exterior member, wherein the nonaqueous electrolyte composition comprises an electrolyte salt, a nonaqueous solvent, a cyclic acid anhydride of phosphoric monoester and / or a cyclic acid anhydride of arylphosphonic acid. Or the non-aqueous electrolyte composition contains an electrolyte salt, a non-aqueous solvent, a cyclic acid anhydride of alkylphosphonic acid, and a polymer compound, and the non-aqueous solvent contains an electrolyte. The content of at least one selected from the group consisting of dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate in the components other than the salt is 50 to 80% by mass, Boneto and / or the content of diethyl carbonate 10 wt% or more, and the content of dimethyl carbonate is equal to or less than 40 wt%.

  According to the present invention, a cyclic acid anhydride of phosphoric acid monoester and / or a cyclic acid anhydride of arylphosphonic acid is added, or a cyclic acid anhydride of alkylphosphonic acid and a polymer compound are contained. , Dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate are contained in a predetermined ratio, so that a non-aqueous electrolyte composition that can suppress swelling deformation of the battery during high-temperature storage, and non-aqueous using the same An electrolyte secondary battery can be provided.

  Hereinafter, the nonaqueous electrolyte composition of the present invention will be described in detail. In the present specification, “%” represents mass percentage unless otherwise specified.

  As described above, the non-aqueous electrolyte composition of the present invention includes a cyclic acid anhydride of phosphoric acid monoester, a cyclic acid anhydride of arylphosphonic acid, or a cyclic acid anhydride of alkylphosphonic acid in addition to an electrolyte salt and a non-aqueous solvent. Of these, the cyclic acid anhydride of the phosphoric acid monoester includes the cyclic acid anhydride of the alkyl phosphoric acid monoester represented by the following chemical formula (1), and the chemical formula (2 A cyclic acid anhydride of aryl phosphoric acid monoester shown in FIG.

[R1 to R6 in Formulas (1) and (2) represent C _m H _{2m + 1} (0 ≦ m ≦ 4), and n satisfies 2 ≦ n ≦ 4. ]

  Here, specific examples of the cyclic acid anhydride of the alkyl phosphate monoester represented by the formula (1) include a methyl phosphate anhydride cyclic trimer represented by the chemical formula (3), (2 ) Specific examples of the cyclic acid anhydride of the aryl phosphate monoester represented by the formula include a phenyl phosphate anhydride cyclic trimer represented by the chemical formula (4).

  The cyclic acid anhydride of arylphosphonic acid is represented by the following chemical formula (5)

[R1 to R6 in Formula (5) represent C _m H _{2m + 1} (0 ≦ m ≦ 4), and n satisfies 2 ≦ n ≦ 4. Specific examples thereof include phenylphosphonic anhydride cyclic trimers represented by chemical formula (6).

  Furthermore, the cyclic acid anhydride of alkylphosphonic acid is represented by the following chemical formula (7)

[R1 to R6 in Formula (7) represent C _m H _{2m + 1} (0 ≦ m ≦ 4), and n satisfies 2 ≦ n ≦ 4. Specific examples include 1-propylphosphonic acid anhydride cyclic trimer represented by chemical formula (8).

  In addition, it goes without saying that the various cyclic trimers represented by the chemical formulas (3), (4), (6) and (8) are merely examples, and are not limited to these compounds. Further, not only the same kind of compounds but also different kinds of compounds can be mixed and used.

As described above, the nonaqueous electrolyte composition of the present invention includes an electrolyte salt, a nonaqueous solvent, a cyclic acid anhydride of phosphoric monoester and / or a cyclic acid anhydride of arylphosphonic acid, or an electrolyte. It contains a salt, a non-aqueous solvent, a cyclic acid anhydride of an alkylphosphonic acid, and a polymer compound, and is combined with a non-aqueous solvent having a predetermined composition and a relatively low content of dimethyl carbonate. A battery that is suitably used as an electrolytic solution for a water electrolyte secondary battery and hardly swells even under a high temperature environment can be obtained.
The cyclic acid anhydride of phosphoric acid monoester or phosphonic acid forms a protective film on the electrode surface by ring-opening polymerization in the battery and suppresses the reaction between the solvent and the battery active material. It is considered that swelling during high temperature storage is prevented.

In addition, as content of the cyclic acid anhydride of phosphoric acid monoester and phosphonic acid in the non-aqueous electrolyte composition of the present invention, a range of about 0.05 to 2%, and further a range of 0.1 to 1% It is preferable to do.
That is, if the content of such a compound is less than 0.05%, the effect of the addition cannot be sufficiently obtained, and conversely if it exceeds 2%, the discharge capacity tends to deteriorate.

In the non-aqueous electrolyte composition of the present invention, from the viewpoint of improving the discharge capacity maintenance rate during repeated charge and discharge, for example, a carbonate having a carbon-carbon double bond such as vinylene carbonate or vinylene ethylene carbonate is contained. You can also.
The content of the carbonic acid ester having such a carbon-carbon double bond is preferably 0.05 to 5%. That is, if it is less than 0.05%, the effect of addition cannot be sufficiently obtained, and if it exceeds 5%, the capacity during large current discharge may be reduced.

Furthermore, in the non-aqueous electrolyte composition of the present invention, a predetermined polymer compound is added, and the polymer compound is swollen with the non-aqueous electrolyte composition of the present invention. It can be impregnated or retained.
The swelling, gelation or non-fluidization of the polymer compound can effectively suppress the occurrence of leakage of the nonaqueous electrolyte composition in the obtained battery.

Examples of such a polymer compound include polyvinyl formal (9), polyacrylate (10), polyvinylidene fluoride (11) represented by the following chemical formulas (9) to (11), and the like. Of these, among these, it is desirable to use polyvinylidene fluoride in view of the swelling prevention effect.
In each formula, N represents the degree of polymerization, and preferably N = 100 to 10,000. If N is less than 100, gelation is difficult, and if it exceeds 10,000, fluidity tends to decrease.

However, R in Formula (10) represents C _n H _2n-1 O _m (n is an integer of 1 to 8, and m is an integer of 0 to 4).

  In addition, it is preferable that content of the above-mentioned polymer compound shall be 0.1 to 5%. If it is less than 0.1%, gelation becomes difficult, and if it exceeds 5%, fluidity may be reduced.

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

  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 carbamic acid such as N-methyloxazolidinone Sulfone compounds such as esters and tetramethylene sulfone can also be used.

  On the other hand, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate and the like can be suitably used as the low viscosity solvent, but from the viewpoint of further improving the swelling suppression effect of the battery, ethyl methyl carbonate and diethyl are preferable to dimethyl carbonate. Containing mainly carbonate, that is, the content of at least one selected from the group consisting of dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate is 50 to 80% by mass, and the content of ethyl methyl carbonate and / or diethyl carbonate is 10 It is desirable that the content of dimethyl carbonate is 40% by mass or less. Among these low-viscosity solvents, dimethyl carbonate may cause swelling, so it may not be added. In addition, the value of content of the said solvent is not the ratio with respect to the whole nonaqueous electrolyte composition, but the percentage with respect to the mass remove | excluding electrolyte salt from the said composition.

  As other low-viscosity solvents, chain carbonates such as methylpropyl carbonate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, methyl butyrate, methyl isobutyrate, methyl trimethyl acetate, ethyl trimethyl acetate, etc. Chain carboxylic acid esters, chain amides such as N, N-dimethylacetamide, chain carbamic acid esters such as methyl N, N-diethylcarbamate, ethyl N, N-diethylcarbamate, 1,2-dimethoxyethane , Ethers such as tetrahydrofuran, tetrahydropyran, and 1,3-dioxolane can be used.

In the non-aqueous electrolyte composition of the present invention, the high dielectric constant solvent and the low viscosity solvent described above can be used alone or in combination of two or more.
Moreover, it is preferable that content of the above-mentioned non-aqueous solvent shall be 70 to 90%. If it is less than 70%, the viscosity increases, and if it exceeds 90%, sufficient electrical conductivity may not be obtained.

The electrolyte salt used in the non-aqueous electrolyte composition of the present invention may be any salt that dissolves or disperses in the non-aqueous solvent to generate ions, and preferably uses lithium hexafluorophosphate (LiPF ₆ ). Needless to say, the present invention is not limited to this.
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) methide Lithium salts of perfluoroalkanesulfonic acid derivatives such as (LiN (C ₂ F ₅ SO ₂ ) ₂ ) and lithium tris (trifluoromethanesulfone) methide (LiC (CF ₃ SO ₂ ) ₃ ) can also be used. Alone or in combination of two or more It is also possible to use it.

  In addition, it is preferable that content of such electrolyte salt shall be 10 to 30%. If it is less than 10%, sufficient conductivity may not be obtained, and if it exceeds 30%, the viscosity may increase excessively.

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 laminated battery as an embodiment of the nonaqueous electrolyte secondary battery of the present invention.
In the figure, the secondary battery is configured by enclosing a battery element 20 to which a positive electrode terminal 11 and a negative electrode terminal 12 are attached in a film-like exterior member 30. 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.

Note that the exterior member 30 may be configured by another structure, for example, a laminate film not including a 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 cross-sectional view taken along the line 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 non-aqueous electrolyte composition layer 23 made of the non-aqueous electrolyte composition of the present invention and a separator 24 therebetween. The outermost peripheral part is protected by the protective tape 25.

Here, the positive electrode 21 has, for example, 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. 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. (NbSe ₂ ), vanadium oxide (V ₂ O ₅ ), titanium dioxide (TiO ₂ ), chalcogenides containing no lithium such as manganese dioxide (MnO ₂ ) (particularly layered compounds and spinel compounds), lithium 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 (12) or (13):
LiM ^I O ₂ (12)
Li _y M ^II PO ₄ (13)
(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 (12) generally has a layered structure, and the compound of the formula (13) 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, part of the transition metal is replaced with Al, Mg or other transition metal elements or included in the grain boundaries, and part of oxygen is contained. The thing substituted with fluorine 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 carbon materials 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, carbon black.
Among these, coke includes pitch coke, needle coke, petroleum coke and the like, 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, molybdenum oxide, and the like, and examples of the polymer compound include polyacetylene and polypyrrole.

Furthermore, examples of the negative electrode material capable of inserting and extracting lithium include a material containing at least one of a metal element and a metalloid element capable of forming an alloy with lithium as a constituent element. 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.

As an alloy of tin, for example, as a second constituent element other than tin, silicon, magnesium (Mg), nickel, copper, iron, cobalt, manganese, zinc, indium, silver, titanium (Ti), germanium, bismuth, antimony 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.

  Furthermore, the negative electrode material as described above may be an element that forms a complex oxide with lithium, such as titanium. Of course, metallic lithium may be precipitated and dissolved, and magnesium and aluminum other than lithium may be precipitated and dissolved.

  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.

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.

  Next, after attaching the positive electrode terminal 11 to the positive electrode 21 and attaching the negative electrode terminal 12 to the negative electrode 22, the separator 24, the positive electrode 21, the separator 24, and the negative electrode 22 are sequentially stacked and wound, and the protective tape 25 is attached to the outermost peripheral portion. A wound electrode body is formed by bonding. Further, the wound electrode body is sandwiched between the exterior members 30, and the outer peripheral edge except one side is heat-sealed to form a bag shape.

  Thereafter, a non-aqueous electrolyte composition containing the above-described chain carbonate, an electrolyte salt such as lithium hexafluorophosphate, and a non-aqueous solvent such as ethylene carbonate is prepared and wound from the opening of the exterior member 30. It inject | pours into the inside of an electrode body, the opening part of the exterior member 30 is heat-sealed and sealed. Thereby, the nonaqueous electrolyte composition layer 23 is formed, and the secondary battery shown in FIGS. 1 and 2 is completed.

In addition, you may manufacture this secondary battery as follows.
For example, instead of injecting the nonaqueous electrolyte composition after producing the wound electrode body, the nonaqueous electrolyte composition is applied on the positive electrode 21 and the negative electrode 22 or the separator 24 and then wound, and the exterior member 30 is wound. You may make it enclose inside.
When a polymer-type non-aqueous electrolyte secondary battery having a gel-like non-aqueous electrolyte composition is produced, a polymer compound such as polyvinylidene fluoride described above on the positive electrode 21 and the negative electrode 22 or the separator 24 is used. The gel-like non-aqueous electrolyte composition may be formed by injecting the above-described non-aqueous electrolyte composition after the monomer is applied and wound and housed in the exterior member 30. However, it is preferable to polymerize the monomer inside the exterior member 30 because the bondability between the non-aqueous electrolyte composition and the separator 24 is improved and the internal resistance can be lowered. Moreover, it is preferable to inject the nonaqueous electrolyte composition into the exterior member 30 to form a gel-like nonaqueous electrolyte composition because it can be easily manufactured with fewer steps.

  In the secondary battery described above, when charged, lithium ions are released from the positive electrode active material layer 21 </ b> B and inserted into the negative electrode active material layer 22 </ b> B through the nonaqueous electrolyte composition layer 23. When discharge is performed, lithium ions are released from the negative electrode active material layer 22 </ b> B and inserted into the positive electrode active material layer 21 </ b> B through the nonaqueous electrolyte composition layer 23.

Here, the nonaqueous electrolyte composition included in the nonaqueous electrolyte composition layer 23 includes a cyclic acid anhydride of phosphoric acid monoester, a cyclic acid anhydride of arylphosphonic acid, or a cyclic acid anhydride of alkylphosphonic acid. It contains at least one selected from the group consisting of dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate in a predetermined range, and is effective in suppressing battery swelling.
The present invention can be applied not only to the laminate type battery as described above, but also to a cylindrical battery, a square type battery, etc. In addition, it is more effective when applied to a thin prismatic battery.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited to these Examples.
Specifically, the operations described in the following examples were performed to produce a laminate type battery as shown in FIGS. 1 and 2, and its performance was evaluated.

(Example 1)
First, 94 parts by weight of lithium-cobalt composite oxide (LiCoO ₂ ) as a positive electrode active material, 3 parts by weight of graphite as a conductive material, and 3 parts by weight of polyvinylidene fluoride (PVdF) as a binder were mixed homogeneously. N-methylpyrrolidone was added to obtain a positive electrode mixture coating solution.
Next, the obtained positive electrode mixture coating solution was uniformly applied on both surfaces of an aluminum foil having a thickness of 20 μm and dried to form a positive electrode mixture layer having a concentration of 40 mg / cm ² per side. This was cut into a shape having a width of 50 mm and a length of 300 mm to produce a positive electrode, and a positive electrode terminal was attached.

Next, 97 parts by weight of graphite as a negative electrode active material and 3 parts by weight of PVdF as a binder were homogeneously mixed, and N-methylpyrrolidone was added to obtain a negative electrode mixture coating solution.
Next, the obtained negative electrode mixture coating solution was uniformly applied on both surfaces of a 15 μm-thick copper foil serving as a negative electrode current collector, and dried to form a negative electrode mixture layer of 20 mg / cm ² per side. This was cut into a shape with a width of 50 mm and a length of 300 mm to prepare a negative electrode, and a negative electrode terminal was attached.

  On the other hand, as the non-aqueous electrolyte composition, as a cyclic acid anhydride of alkylphosphonic acid, a propylphosphonic anhydride cyclic trimer represented by the chemical formula (8) is added, that is, ethylene carbonate (EC) / diethyl carbonate. (DEC) / Vinylene carbonate (VC) / Propylphosphonic anhydride cyclic trimer = 19/80 / 0.5 / 0.5 ratio (weight ratio) to solvent 86 mixed with hexafluorophosphoric acid What melt | dissolved in the ratio (weight ratio) of lithium 14 was used.

  This positive electrode and negative electrode are an example of an exterior member made of an aluminum laminate film by laminating and winding the positive electrode and negative electrode on both sides of a 7 μm-thick microporous polyethylene film via a separator coated with polyvinylidene fluoride to a thickness of 2 μm. Put it in a bag. After injecting 2 g of the non-aqueous electrolyte composition into the bag, the bag was heat-sealed to prepare a laminated battery. The capacity of this battery is 700 mAh.

This battery was charged at 700 mA at 23 ° C. and 4.2 V as the upper limit for 3 hours and then stored at 90 ° C. for 4 hours, and the battery thickness changed (swelled) when it was stored at 90 ° C. for 4 hours. After charging for 3 hours at an upper limit of 2 V, discharging capacity to 3.0 V at 700 mA was measured 300 times, and the discharge capacity retention rate was measured.
Thus, by adding a cyclic acid anhydride of alkylphosphonic acid and combining a low-viscosity solvent mixed in a predetermined ratio, the swelling of the battery during storage at 90 ° C. for 4 hours, as described later, It turns out that it is reducing significantly compared with the battery of the comparative example 1 which uses the nonaqueous electrolyte composition which does not add the cyclic acid anhydride of the above alkylphosphonic acids.

(Examples 2 to 4)
Except having changed the ratio of ethylene carbonate and diethyl carbonate as shown in Table 1, the same operation as Example 1 was repeated, and the laminate type batteries of Examples 2 to 4 were obtained. In the same manner as described above, the swelling of the battery when stored at 90 ° C. for 4 hours and the discharge maintenance ratio after 300 cycles were obtained, and the obtained results are also shown in Table 1.
As shown in Table 1, it can be seen that even when the ratio of ethylene carbonate and diethyl carbonate is changed, the swelling of the battery during high temperature storage is less than that of the battery of Comparative Example 1. Note that the swelling of the battery tends to increase as the ethylene carbonate / diethyl carbonate ratio increases.

(Examples 5 to 8)
Except for replacing diethyl carbonate with ethyl methyl carbonate (EMC), the same operations as in Examples 1 to 4 were repeated to obtain laminate type batteries of Examples 5 to 8, respectively. In the same manner as described above, the swelling of the battery when stored at 90 ° C. for 4 hours and the discharge maintenance ratio after 300 cycles were measured, and the obtained results are also shown in Table 1.
As shown in Table 1, when diethyl carbonate is replaced with ethyl methyl carbonate, the discharge capacity retention rate after 300 cycles is slightly improved, but a tendency to increase the swelling of the battery during storage at 90 ° C. for 4 hours is recognized. However, the swelling of the battery during high temperature storage is less than that of the battery of Comparative Example 1, and it can be seen that both are 0.5 mm or less.

(Examples 9 to 12)
The same operations as in Examples 1 to 4 were repeated except that 10% of ethyl methyl carbonate was added and the amount of diethyl carbonate was reduced by that amount to obtain laminate type batteries of Examples 9 to 12, respectively. And the swelling of the battery when it preserve | saved at 90 degreeC for 4 hours and the discharge maintenance factor after 300 cycles were measured similarly, and the obtained result is combined with Table 1, respectively.
Thus, when ethyl methyl carbonate is added, the discharge capacity retention rate after 300 cycles is slightly improved as compared with the results of Examples 1 to 4, but the battery swelling during high-temperature storage tends to increase slightly. Is recognized.

(Examples 13 to 16)
Except that 40% of dimethyl carbonate (DMC) was mixed and the amount of diethyl carbonate was reduced by that amount, the same operations as in Examples 1 to 4 were repeated to obtain laminated batteries of Examples 13 to 16, respectively. In the same manner as described above, the swelling of the battery when stored at 90 ° C. for 4 hours and the discharge maintenance ratio after 300 cycles were obtained, and the results are also shown in Table 1.
Thus, when dimethyl carbonate is mixed up to the upper limit, the discharge capacity retention rate after 300 cycles is slightly improved, while the tendency of the battery to swell during storage at 90 ° C. for 4 hours increases. It can be seen that the swelling is smaller than that of the battery of Comparative Example 1, and both are 0.5 mm or less.

(Examples 17 to 19)
Propylphosphonic acid anhydride cyclic trimer, phenylphosphonic acid anhydride cyclic trimer represented by chemical formula (6), methylphosphoric acid anhydride cyclic trimer represented by chemical formula (3), and chemical formula (4), respectively. The laminate type batteries of Examples 17 to 19 were obtained by repeating the same operation as in Example 3 except that the phosphoric acid anhydride cyclic trimer was used. Then, the swelling of the battery when stored at 90 ° C. for 4 hours and the discharge maintenance rate after 300 cycles were obtained in the same manner as described above, and the results are also shown in Table 1, respectively.
Thus, even when the cyclic acid anhydride of alkylphosphonic acid is replaced with another cyclic acid anhydride of phosphonic acid or phosphoric acid monoester, the battery swells during high-temperature storage and the discharge capacity retention rate after 300 cycles It can be seen that there is almost no change.

(Examples 20 to 23)
The same operations as in Example 3 and Examples 17 to 19 were repeated, respectively, except that ethylene carbonate was increased by that amount without adding vinylene carbonate to obtain laminate type batteries of Examples 20 to 23, respectively. Then, the swelling of the battery when stored at 90 ° C. for 4 hours and the discharge maintenance rate after 300 cycles were obtained in the same manner as described above, and the results are also shown in Table 1, respectively.
From Table 1, it can be seen that without adding vinylene carbonate, the swelling of the battery during high-temperature storage slightly increases and the discharge capacity maintenance rate after 300 cycles slightly decreases.

(Comparative Example 1)
The same procedure as in Example 3 was repeated except that ethylene carbonate was increased by that amount without adding the propylphosphonic acid anhydride cyclic trimer to obtain a laminate type battery of this example. And the swelling of a battery when it preserve | saved at 90 degreeC for 4 hours, and the discharge maintenance factor after 300 cycles are calculated | required similarly, The result is combined with Table 1, and is shown.
Thus, it can be seen that without using a cyclic acid anhydride of phosphonic acid or phosphoric acid monoester, the amount of swelling of the battery when stored at 90 ° C. for 4 hours is increased as compared with Examples 1-23.

(Comparative Example 2)
The same procedure as in Example 1 was repeated except that the diethyl carbonate mixing ratio was increased to 90% and ethylene carbonate was reduced by that amount to obtain a laminate type battery of this example. And the swelling of a battery when it preserve | saved at 90 degreeC for 4 hours, and the discharge maintenance factor after 300 cycles are calculated | required similarly, The result is combined with Table 1, and is shown.
Thus, when the mixing ratio of diethyl carbonate exceeds 80%, it can be seen that the discharge maintenance rate after 300 cycles is significantly deteriorated as compared with the batteries of Examples 1 to 4, and is reduced to 50% or less.

(Comparative Example 3)
The same procedure as in Example 1 was repeated except that the mixing ratio of diethyl carbonate was reduced to 40% and the amount of ethylene carbonate was increased accordingly, to obtain a laminate type battery of this example. And the swelling of a battery when it preserve | saved at 90 degreeC for 4 hours, and the discharge maintenance factor after 300 cycles are calculated | required similarly, The result is combined with Table 1, and is shown.
Thus, when the mixing ratio of diethyl carbonate is less than 50%, the discharge maintenance rate after 300 cycles is significantly degraded as compared with the batteries of Examples 1 to 4, and becomes 50% or less.

(Comparative Example 4)
The same procedure as in Example 5 was repeated, except that the mixing ratio of ethylmethyl carbonate was increased to 90% and ethylene carbonate was decreased by that amount to obtain a laminate type battery of this example. And the swelling of a battery when it preserve | saved at 90 degreeC for 4 hours, and the discharge maintenance factor after 300 cycles are calculated | required similarly, The result is combined with Table 1, and is shown.
Thus, when the mixing ratio of ethyl methyl carbonate exceeds 80%, it can be seen that the discharge maintenance ratio after 300 cycles is deteriorated as compared with the batteries of Examples 5 to 8, and is reduced to 50% or less.

(Comparative Example 5)
The same procedure as in Example 5 was repeated except that the mixing ratio of ethylmethyl carbonate was reduced to 40% and the amount of ethylene carbonate was increased accordingly, to obtain a laminate type battery of this example. And the swelling of a battery when it preserve | saved at 90 degreeC for 4 hours, and the discharge maintenance factor after 300 cycles are calculated | required similarly, The result is combined with Table 1, and is shown.
Thus, when the mixing ratio of diethyl carbonate is less than 50%, the discharge maintenance rate after 300 cycles is deteriorated as compared with the batteries of Examples 5 to 8, and becomes 50% or less.

(Comparative Examples 6-9)
The same procedure as in Examples 1 to 4 or Examples 13 to 16 was repeated except that the amount of dimethyl carbonate was 50% and diethyl carbonate was reduced by that amount, and the laminated batteries of Comparative Examples 6 to 9, respectively. Got. In the same manner as described above, the swelling of the battery when stored at 90 ° C. for 4 hours and the discharge maintenance ratio after 300 cycles were obtained, and the results are also shown in Table 1.
As described above, when dimethyl carbonate is mixed in excess of the upper limit of 40%, the swelling of the battery during storage at 90 ° C. for 4 hours increases more than those in Examples 1 to 4 and Examples 13 to 16, and Was also found to exceed 0.5 mm.

(Comparative Example 10)
The same procedure as in Example 3 was repeated except that the amount of ethylene carbonate was increased without adding the propylphosphonic anhydride cyclic trimer and vinylene carbonate, to obtain a laminate type battery of this example. And the swelling of a battery when it preserve | saved at 90 degreeC for 4 hours, and the discharge maintenance factor after 300 cycles are calculated | required similarly, The result is combined with Table 1, and is shown.
As described above, when vinylene carbonate is not added to the cyclic acid anhydride of phosphonic acid or phosphoric acid monoester, the amount of swelling of the battery during high-temperature storage is further increased as compared with Comparative Example 1, and discharge after 300 cycles. It can be seen that the maintenance rate also deteriorates.

(Example 24)
The same procedure as in Example 1 was repeated except that 5% of propylene carbonate (PC) was added and the amount of ethylene carbonate was reduced by that amount to obtain a laminate type battery of this example. And the swelling of a battery when it preserve | saved at 90 degreeC for 4 hours, and the discharge maintenance factor after 300 cycles are calculated | required similarly to the above, The result is combined with Table 2, and is shown.
From Table 2, by adding a cyclic acid anhydride of alkylphosphonic acid and combining a low-viscosity solvent mixed at a predetermined ratio, the swelling of the battery during storage at 90 ° C. for 4 hours, as described later, It can be seen that it is significantly smaller than the battery of Comparative Example 11 using the non-aqueous electrolyte composition to which the cyclic acid anhydride of alkylphosphonic acid as described above is not added, and is 0.5 mm or less.

(Examples 25-27)
Except having changed the ratio of ethylene carbonate and diethyl carbonate as shown in Table 1, the same operation as in Example 24 was repeated to obtain laminated batteries of Examples 25 to 27, respectively. And the swelling of the battery when it preserve | saved at 90 degreeC for 4 hours and the discharge maintenance factor after 300 cycles were calculated | required similarly, and the obtained result is combined with Table 2, respectively.
As shown in Table 2, it can be seen that even when the ratio of ethylene carbonate and diethyl carbonate is changed, the swelling of the battery during high temperature storage is less than that of the battery of Comparative Example 11. In addition, the tendency for the swelling of a battery to increase is recognized when ethylene carbonate / diethyl carbonate ratio becomes high.

(Examples 28 to 31)
Except that diethyl carbonate was replaced with ethyl methyl carbonate (EMC), the same operations as in Examples 24-27 were repeated to obtain laminated batteries of Examples 28-31, respectively. Then, as described above, the swelling of the battery when stored at 90 ° C. for 4 hours and the discharge maintenance ratio after 300 cycles were obtained, and the obtained results are also shown in Table 2.
Thus, when diethyl carbonate is replaced with ethyl methyl carbonate, the discharge capacity retention rate after 300 cycles is slightly improved, but the tendency of the battery to expand when stored at 90 ° C. for 4 hours is observed. It was found that the swelling of the battery during storage was less than that of the battery of Comparative Example 11, and both were 0.5 mm or less.

(Examples 32-35)
Except that 10% of ethyl methyl carbonate was added and the amount of diethyl carbonate was reduced by that amount, the same operation as in Examples 24 to 27 was repeated to obtain laminate type batteries of Examples 32 to 35, respectively. Similarly, the swelling of the battery when stored at 90 ° C. for 4 hours and the discharge maintenance ratio after 300 cycles were measured, and the obtained results are also shown in Table 2.
From Table 2, when ethyl methyl carbonate is added, the discharge capacity retention rate after 300 cycles is slightly improved as compared with the results of Examples 24-27, but the battery swelling during high-temperature storage tends to increase slightly. I understand.

(Examples 36 to 39)
Except that 40% of dimethyl carbonate (DMC) was mixed and the amount of diethyl carbonate was reduced by that amount, the same operations as in Examples 24 to 27 were repeated to obtain laminate type batteries of Examples 36 to 39. In the same manner as described above, the swelling of the battery when stored at 90 ° C. for 4 hours and the discharge maintenance ratio after 300 cycles were obtained, and the results are also shown in Table 2, respectively.
Thus, when dimethyl carbonate is mixed up to the upper limit, the discharge capacity retention rate after 300 cycles is slightly improved, while the tendency of the battery to swell during storage at 90 ° C. for 4 hours increases. It can be seen that the swelling is less than that of the battery of Comparative Example 11, and both are 0.5 mm or less.

(Examples 40 to 42)
Propylphosphonic anhydride cyclic trimer, phenylphosphonic anhydride cyclic trimer (chemical formula (6)), methylphosphoric anhydride cyclic trimer (chemical formula (3)), and phenylphosphoric anhydride cyclic Except having replaced with a trimer (chemical formula (4)), the same operation as Example 26 was repeated, and the laminate type batteries of Examples 40 to 42 were obtained. Then, along with the swelling of the battery when stored at 90 ° C. for 4 hours, the discharge maintenance rate after 300 cycles was determined in the same manner as described above, and the results are also shown in Table 2.
As can be seen from Table 2, even if the cyclic acid anhydride of alkylphosphonic acid is replaced with another cyclic acid anhydride of phosphonic acid or phosphoric monoester, the battery swells during high temperature storage or discharge after 300 cycles. The capacity maintenance rate is almost unchanged.

(Examples 43 to 46)
The same operations as in Example 26 and Examples 40 to 42 were repeated except that the amount of ethylene carbonate was increased by that amount without adding vinylene carbonate to obtain laminate type batteries of Examples 43 to 46, respectively. Then, similarly to the above, together with the swelling of the battery when stored at 90 ° C. for 4 hours, the discharge maintenance rate after 300 cycles was determined, and the obtained results are also shown in Table 2.
Thus, when vinylene carbonate is not added, the swelling of the battery during high-temperature storage is slightly increased and the discharge capacity retention rate after 300 cycles is slightly decreased as compared with Examples 26 and 40-42, respectively. I understand that

(Comparative Example 11)
The same procedure as in Example 26 was repeated except that ethylene carbonate was increased by that amount without adding the propylphosphonic acid anhydride cyclic trimer, to obtain a laminate type battery of this example. And the swelling of a battery when it preserve | saved at 90 degreeC for 4 hours, and the discharge maintenance factor after 300 cycles are calculated | required similarly to the above, The result is combined with Table 2, and is shown.
As shown in Table 2, if the cyclic acid anhydride of phosphonic acid or phosphoric acid monoester is not added, the swelling amount of the battery when stored at 90 ° C. for 4 hours may be increased as compared with Examples 24-46. I understand.

(Comparative Example 12)
Except that the mixing ratio of diethyl carbonate was increased to 90% and ethylene carbonate was decreased by that amount, the same operation as in Example 24 was repeated to obtain a laminated battery of this example. And the swelling of the battery when preserve | saved at 90 degreeC for 4 hours, and the discharge maintenance factor after 300 cycles are measured similarly, The result obtained is combined with Table 2, and is shown.
Thus, when the mixing ratio of diethyl carbonate exceeds 80%, it can be seen that the discharge maintenance ratio after 300 cycles is significantly degraded as compared with the batteries of Examples 24-27 and falls to 50% or less.

(Comparative Example 13)
Except that the mixing ratio of diethyl carbonate was reduced to 40% and ethylene carbonate was increased by that amount, the same operation as in Example 24 was repeated to obtain a laminated battery of this example. Similarly, the swelling of the battery when stored at 90 ° C. for 4 hours and the discharge maintenance ratio after 300 cycles were obtained, and the obtained results are also shown in Table 2.
As can be seen from Table 2, when the mixing ratio of diethyl carbonate is less than 50%, the discharge maintenance rate after 300 cycles is significantly degraded as compared with the batteries of Examples 24-27, and may be 50% or less. I understand.

(Comparative Example 14)
The same procedure as in Example 28 was repeated, except that the mixing ratio of ethylmethyl carbonate was increased to 90% and ethylene carbonate was decreased by that amount, to obtain a laminate type battery of this example. Then, the swelling of the battery when stored at 90 ° C. for 4 hours and the discharge maintenance rate after 300 cycles were similarly obtained, and the results are also shown in Table 2.
From the results in Table 2, it can be seen that when the mixing ratio of ethyl methyl carbonate exceeds 80%, the discharge maintenance rate after 300 cycles is deteriorated compared to the batteries of Examples 28 to 31, and is reduced to 50% or less.

(Comparative Example 15)
The same procedure as in Example 28 was repeated, except that the mixing ratio of ethylmethyl carbonate was reduced to 40% and ethylene carbonate was increased by that amount to obtain a laminate type battery of this example. In the same manner as described above, the swelling of the battery when stored at 90 ° C. for 4 hours and the discharge maintenance ratio after 300 cycles were obtained, and the obtained results are also shown in Table 2.
Thus, when the mixing ratio of diethyl carbonate is less than 50%, it can be seen that the discharge maintenance rate after 300 cycles is deteriorated as compared with the results of Examples 28 to 31, and is 50% or less.

(Comparative Examples 16-19)
The same procedure as in Examples 24 to 27 or Examples 36 to 39 was repeated except that the amount of dimethyl carbonate was 50% and diethyl carbonate was reduced by that amount. Got. Then, as described above, the swelling of the battery when stored at 90 ° C. for 4 hours and the discharge maintenance ratio after 300 cycles were obtained, and the obtained results are also shown in Table 2.
Thus, when dimethyl carbonate is mixed exceeding its upper limit of 40%, the swelling of the battery during storage at 90 ° C. for 4 hours increases more than in Examples 24 to 27 and Examples 36 to 39, and Was also found to exceed 0.5 mm.

(Comparative Example 20)
The same procedure as in Example 26 was repeated except that the amount of ethylene carbonate was increased without using propylphosphonic acid anhydride cyclic trimer and vinylene carbonate, and a laminated battery of this example was obtained. . Then, the swelling of the battery when stored at 90 ° C. for 4 hours and the discharge maintenance rate after 300 cycles were similarly obtained, and the results are also shown in Table 2.
Thus, if the cyclic acid anhydride of phosphonic acid or phosphoric acid monoester is not added with vinylene carbonate, the amount of swelling of the battery during high temperature storage is further increased as compared with Comparative Example 24, and discharge after 300 cycles is performed. It was confirmed that the maintenance rate also deteriorated.

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 of including the battery element 20 in which the positive electrode 21 and the negative electrode 22 are stacked and wound has been described, but a flat battery element in which a pair of positive and negative electrodes are stacked, or a plurality of battery elements The present invention can also be applied to a case where a stacked battery element in which a positive electrode and a negative electrode are stacked is provided.
In the above embodiment, the case where the film-shaped exterior member 30 is used has been described. However, the battery having other shapes such as a so-called cylindrical shape, square shape, coin shape, and button shape using a can as the exterior member. Similarly, the present invention can be applied. Furthermore, it is applicable not only to a secondary battery but also to a primary battery.

  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.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Positive electrode terminal, 12 ... Negative electrode terminal, 20 ... 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 ... non-aqueous electrolyte composition layer, 24 ... separator, 25 ... protective tape, 30 ... exterior member, 31 ... adhesion film.

Claims (12)

Electrolyte salt,
A non-aqueous solvent;
A cyclic acid anhydride of phosphoric acid monoester and / or a cyclic acid anhydride of arylphosphonic acid;
A non-aqueous electrolyte composition comprising:   The content of at least one selected from the group consisting of dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate in the components other than the electrolyte salt is 50 to 80% by mass, and the content of ethyl methyl carbonate and / or diethyl carbonate is 10%. The nonaqueous electrolyte composition according to claim 1, wherein the content of dimethyl carbonate is 40% by mass or less.   The nonaqueous electrolyte composition according to claim 1, further comprising a carbonic acid ester having a carbon-carbon multiple bond.   The nonaqueous electrolyte composition according to any one of claims 1 to 3, further comprising a polymer compound.   The non-aqueous electrolyte composition according to claim 4, wherein the polymer compound is polyvinylidene fluoride. A nonaqueous electrolyte secondary battery comprising a positive electrode and a negative electrode having a material capable of inserting and extracting lithium ions as a positive electrode active material or a negative electrode active material, a nonaqueous electrolyte composition, a separator, and an exterior member that accommodates these. ,
The non-aqueous electrolyte composition comprises an electrolyte salt,
A non-aqueous solvent;
A cyclic acid anhydride of phosphoric acid monoester and / or a cyclic acid anhydride of arylphosphonic acid;
A non-aqueous electrolyte secondary battery comprising:   The nonaqueous electrolyte secondary battery according to claim 6, wherein the exterior member is made of a laminate film. Electrolyte salt,
A non-aqueous solvent;
A cyclic acid anhydride of an alkylphosphonic acid;
Containing a polymer compound,
The non-aqueous solvent has a content of at least one selected from the group consisting of dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate in components other than the electrolyte salt, 50 to 80% by mass, ethyl methyl carbonate and / or diethyl carbonate The nonaqueous electrolyte composition is characterized in that the content of dimethyl carbonate is 10% by mass or more and the content of dimethyl carbonate is 40% by mass or less.   The non-aqueous electrolyte composition according to claim 8, wherein the polymer compound is polyvinylidene fluoride.   The nonaqueous electrolyte composition according to claim 8, further comprising a carbonic acid ester having a carbon-carbon multiple bond. A nonaqueous electrolyte secondary battery comprising a positive electrode and a negative electrode having a material capable of inserting and extracting lithium ions as a positive electrode active material or a negative electrode active material, a nonaqueous electrolyte composition, a separator, and an exterior member that accommodates these. ,
The non-aqueous electrolyte composition comprises an electrolyte salt,
A non-aqueous solvent;
A cyclic acid anhydride of an alkylphosphonic acid;
Containing a polymer compound,
The non-aqueous solvent has a content of at least one selected from the group consisting of dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate in components other than the electrolyte salt, 50 to 80% by mass, ethyl methyl carbonate and / or diethyl carbonate The nonaqueous electrolyte secondary battery is characterized in that the content of is 10% by mass or more and the content of dimethyl carbonate is 40% by mass or less.   The nonaqueous electrolyte secondary battery according to claim 11, wherein the exterior member is made of a laminate film.

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