JPWO2012133204A1 - battery - Google Patents

Abstract

The present invention provides a battery capable of suppressing elution of electrode components into an electrolyte solution. The present invention is a battery having an electrode containing a pyrroline-based nitroxide polymer and an electrolytic solution, wherein the electrolytic solution contains a polyethylene glycol.

Description

The present invention relates to a battery capable of suppressing elution of electrode components into an electrolyte solution.

In recent years, the performance of portable electronic devices such as notebook computers and mobile phones has been increasing. As a power source for such a portable electronic device, a secondary battery having a high energy density and a long life is expected.
Currently, lithium ion secondary batteries using a lithium-containing transition metal compound as a positive electrode and a lithium storage compound such as a carbon material as a negative electrode are widely used as power sources for such portable electronic devices.
However, the energy density of the lithium ion secondary battery is approaching the theoretical limit, and development of a new secondary battery capable of realizing a high capacity is demanded. Moreover, since the reaction rate of an electrode reaction is small in a lithium ion secondary battery, the battery performance is remarkably lowered when a large current is passed. Furthermore, when the lithium ion secondary battery is downsized, the capacity and output are often much lower than expected, and charging needs to be performed for a long time.

Therefore, in order to solve such problems of secondary batteries, research and development of secondary batteries using an organic radical compound (resin) as a reaction product or product of an electrode reaction have been actively conducted in recent years.
A secondary battery using an organic radical compound as an electrode active material charges and discharges using a radical oxidation-reduction reaction, and thus has a high reaction rate. Therefore, it has the characteristics that it has high output and charging is completed in a relatively short time.

As radical compounds used in such secondary batteries, polymer compounds having a pyrroline cyclic nitroxide structure have been proposed (see Patent Documents 1 and 2). By using such a polymer compound, a secondary battery having a high energy density and a large capacity can be obtained.

International Publication WO2009 / 038125 Pamphlet International Publication WO 2010/104002 Pamphlet

However, when the polymer compound having a pyrroline cyclic nitroxide structure described in Patent Documents 1 and 2 is used for an electrode for a secondary battery, a component contained in the electrode is eluted in an electrolytic solution such as diethyl carbonate. There is a problem. As described above, the component eluted in the electrolytic solution causes the separator to be clogged, so that the battery performance deteriorates every time charging and discharging are repeated, and the function as the battery may be significantly impaired. Moreover, there was room for improvement in terms of capacity reduction after repeated charging and discharging.

An object of this invention is to provide the battery which can suppress the elution to the electrolyte solution of an electrode component.

式（１）中、ｎは０または１を表す。
項３．ピロリン系ニトロキシド重合体が、下記一般式（２）で表されるピロリン系ニトロキシド化合物を重合して得られる重合体である項１に記載の電池、

項４．ポリエチレングリコール類の使用量が、電解液１００質量部に対して、０．０５〜３０質量部である項１に記載の電池、
に関する。
以下に本発明を詳細に説明する。The present invention
Item 1. A battery having an electrode containing a pyrroline-based nitroxide polymer and an electrolytic solution, wherein the electrolytic solution contains a polyethylene glycol,
Item 2. Item 2. The battery according to Item 1, wherein the pyrroline nitroxide polymer is a polymer obtained by polymerizing a pyrroline nitroxide compound represented by the following general formula (1).

In formula (1), n represents 0 or 1.
Item 3. Item 2. The battery according to Item 1, wherein the pyrroline nitroxide polymer is a polymer obtained by polymerizing a pyrroline nitroxide compound represented by the following general formula (2).

Item 4. Item 2. The battery according to Item 1, wherein the amount of polyethylene glycol used is 0.05 to 30 parts by mass with respect to 100 parts by mass of the electrolyte solution.
About.
The present invention is described in detail below.

The battery according to the present invention has an electrode containing a pyrroline-based nitroxide polymer.
The pyrroline nitroxide polymer is obtained by polymerizing a pyrroline nitroxide compound.

The pyrroline nitroxide polymer is preferably a polymer obtained by polymerizing a pyrroline nitroxide compound represented by the following general formula (1).

式（１）中、ｎは０または１を表す。

In formula (1), n represents 0 or 1.

Examples of the pyrroline nitroxide compound represented by the general formula (1) include 3-oxiranyl-2,2,5,5-tetramethylpyrrolin-1-oxyl where n is 0, and pyrroline nitroxide where n is 1. Examples thereof include substituted glycidyl ethers.

The 3-oxiranyl-2,2,5,5-tetramethylpyrroline-1-oxyl is, for example, 3-carbamoyl-2,2,5,5-tetramethylpyrroline-, as shown in the following formula (3): It can be produced by a method using 1-oxyl (Tetrahedron Letters, 43 (4), 553-555 (2002)).
Specifically, 3-carbamoyl-2,2,5,5-tetramethylpyrrolin-1-oxyl is hydrolyzed using an aqueous sodium hydroxide solution or the like to give 3-carboxy-2,2,5,5-tetra Methylpyrroline-1-oxyl is then reduced, and this is reduced using 3-aluminum-2,2,2, by using lithium aluminum hydride-tert-butoxide or the like in an inert gas atmosphere such as argon gas or nitrogen gas. 5-Oxylanyl-2,2,5,5-tetramethylpyrrolin-1-oxyl is produced by cyclizing 5,5-tetramethylpyrroline-1-oxyl with trimethylsulfonium iodide and the like. can do.

The pyrroline-based nitroxide-substituted glycidyl ether is, for example, a method of reacting epichlorohydrin with 4-hydroxyproxyl in the presence of sodium hydroxide using tetrabutylammonium sodium hydrogensulfate as a catalyst (Macromolecules, 26, 3227-3229 (1993)).

Examples of a method for polymerizing the pyrroline nitroxide compound represented by the general formula (1) to obtain a pyrroline nitroxide polymer include a polymerization method using a bulk polymerization method, a solution polymerization method, and the like. As a method of polymerizing using the bulk polymerization method, for example, using a reactor equipped with a stirrer, a thermometer, a gas introduction pipe for introducing an inert gas such as argon gas or nitrogen gas, and a cooling pipe, Examples thereof include a method in which a predetermined amount of a nitroxide compound is charged, deoxygenated with an inert gas, and then a polymerization initiator is added while stirring. As a method of polymerizing using the solution polymerization method, for example, in the case of polymerizing using the bulk polymerization method, an inert solvent is charged together with a predetermined amount of nitroxide compound, deoxygenated with an inert gas, and then stirred. Examples of the method include adding a polymerization initiator.

The pyrroline nitroxide polymer is preferably a polymer obtained by polymerizing a pyrroline nitroxide compound represented by the following general formula (2).

The pyrroline nitroxide compound represented by the general formula (2) is, for example, a method using 3-carbamoyl-2,2,5,5-tetramethylpyrrolin-1-oxyl as shown in the following formula (4) (CAN. J. CHEM., 64, 1482-1490 (1986)).
Specifically, 3-carbamoyl-2,2,5,5-tetramethylpyrrolin-1-oxyl is hydrolyzed using an aqueous sodium hydroxide solution or the like to give 3-carboxy-2,2,5,5-tetra Methylpyrroline-1-oxyl is then reduced, and this is reduced using 3-aluminum-2,2,2, by using lithium aluminum hydride-tert-butoxide or the like in an inert gas atmosphere such as argon gas or nitrogen gas. 3-vinyl-2,2,5,5-tetramethylpyrrolin-1-oxyl is produced by converting it to 5,5-tetramethylpyrrolin-1-oxyl and further vinylating it with methyltriphosphonium bromide or the like. can do.

Examples of a method for polymerizing the pyrroline nitroxide compound represented by the general formula (2) to obtain a pyrroline nitroxide polymer include a polymerization method using a bulk polymerization method, a solution polymerization method, and the like. As a method of polymerizing using the bulk polymerization method, for example, using a reactor equipped with a stirrer, a thermometer, a gas introduction pipe for introducing an inert gas such as argon gas or nitrogen gas, and a cooling pipe, Examples thereof include a method in which a predetermined amount of a nitroxide compound is charged, deoxygenated with an inert gas, and then a polymerization initiator is added while stirring. As a method of polymerizing using the solution polymerization method, for example, in the case of polymerizing using the bulk polymerization method, an inert solvent is charged together with a predetermined amount of nitroxide compound, deoxygenated with an inert gas, and then stirred. Examples of the method include adding a polymerization initiator.

The number average molecular weight of the pyrroline-based nitroxide polymer is preferably 500 to 5,000,000, more preferably 1,000 to 1,000,000. When the number average molecular weight is less than 500, the pyrroline-based nitroxide polymer is dissolved in the electrolytic solution, and the capacity may be reduced when the battery is used repeatedly. On the other hand, when the number average molecular weight exceeds 5,000,000, the solubility in the electrolytic solution is lowered, and the capacity may be lowered when the battery is repeatedly used.
In addition, the number average molecular weight in this invention means the value measured by the high performance liquid chromatography and converted into polystyrene of the molecular weight existing value.

The pyrroline nitroxide polymer may be used alone or in combination of two or more.

The electrode preferably comprises an electrode active material, a conductivity-imparting agent (auxiliary conductive material), an ion conduction auxiliary material, a binder, a thickener, and a catalyst in addition to the pyrroline-based nitroxide polymer.
Below, the member etc. which comprise an electrode are demonstrated.

(1) Electrode Active Material In the present invention, the “electrode active material” refers to a material that directly contributes to electrode reactions such as charge reaction and discharge reaction, and plays a central role in the battery system.
The electrode active material contains the pyrroline nitroxide polymer, and the pyrroline nitroxide polymer may be used alone or in combination of two or more as the positive electrode and / or negative electrode active material. Alternatively, the electrode active material may be combined with other electrode active materials.

When the pyrroline-based nitroxide polymer is used as a positive electrode active material, examples of other electrode active materials include metal oxides, disulfide compounds, other stable radical compounds, and conductive polymers.

Examples of the metal oxide include lithium manganate such as LiMnO ₂ and Li _x Mn ₂ O ₄ (0 <x <2), lithium manganate having a spinel structure, MnO ₂ , LiCoO ₂ , LiNiO ₂ , or Li _y V ₂ O ₅ (0 <y <2), olivine-based material LiFePO ₄ , materials obtained by substituting a part of Mn in the spinel structure with other transition metals, LiNi _0.5 Mn _1.5 O ₄ , LiCr _{0. 5} Mn _1.5 O ₄ , LiCo _0.5 Mn _1.5 O ₄ , LiCoMnO ₄ , LiNi _0.5 Mn _0.5 O ₂ , LiNi _0.33 Mn _0.33 Co _0.33 O ₂ , LiNi _{0 0.8} Co _0.2 O ₂ , LiN _0.5 Mn _1.5-z Ti _z O ₄ (0 <z <1.5) and the like.

Examples of the disulfide compound include dithioglycol, 2,5-dimercapto-1,3,4-thiadiazole, S-triazine-2,4,6-trithiol and the like.

Examples of the other stable radical compound include poly (2,2,6,6-tetramethyl-4-piperidinoxymethacrylate) and the like.

Examples of the conductive polymer include polyacetylene, polyphenylene, polyaniline, and polypyrrole.

Among these, lithium manganate and LiCoO ₂ are preferably used. These other electrode active materials may be used alone or in combination with the pyrroline nitroxide polymer, or may be used in combination of two or more.

When the pyrroline-based nitroxide polymer is used as an electrode active material for a negative electrode, other electrode active materials include graphite, amorphous carbon, metallic lithium and lithium alloy, lithium ion storage carbon, metallic sodium, and other stable radical compounds. And conductive polymers.

Other stable radical compounds include poly (2,2,6,6-tetramethyl-4-piperidinoxymethacrylate) and the like.

Among these, it is preferable to combine with metallic lithium or graphite. These shapes are not particularly limited, and may be a thin film, a bulk, a powder, a fiber, a flake, or the like. These other electrode active materials may be used alone or in combination with the pyrroline nitroxide polymer, or may be used in combination of two or more.

In the present invention, from the viewpoint of energy density, the electrode active material containing the pyrroline nitroxide polymer is preferably used as a positive electrode active material, and the pyrroline nitroxide polymer is combined with the other electrode active material. More preferably, it is used alone. Moreover, it is preferable to use metallic lithium or graphite as the electrode active material of the negative electrode at this time.

(2) Conductivity imparting agent (auxiliary conductive material) and ion conductivity assisting material When the pyrroline-based nitroxide polymer is used as an electrode active material, the conductivity imparting agent is used for the purpose of reducing impedance and improving energy density and output characteristics. (Auxiliary conductive material) or ion conduction auxiliary material may be mixed.

Examples of the auxiliary conductive material include carbonaceous fine particles such as graphite, carbon black, and acetylene black, carbon fibers such as vapor grown carbon fiber (VGCF) and carbon nanotubes, polyaniline, polypyrrole, polythiophene, polyacetylene, and polyacene. Molecule.
Examples of the ion conduction auxiliary material include polymer gel electrolytes and polymer solid electrolytes. Among these, carbon fibers are preferably used, and vapor-grown carbon fibers are more preferably used. By using carbon fiber, the tensile strength of the electrode is increased, and the electrode is less likely to crack or peel off. These auxiliary conductive materials and ion conductive auxiliary materials may be used alone or in combination of two or more.
When the auxiliary conductive material or the ion conductive auxiliary material is used, the mixing ratio in the electrode is preferably 10 to 80% by mass.

(3) Binder In the electrode active material, a binder may be mixed in order to strengthen the bond between the constituent materials.
Examples of the binder include polytetrafluoroethylene, polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, styrene-butadiene copolymer rubber, polypropylene, polyethylene, and polyimide. And resin binders such as various polyurethanes. These binders may be used individually by 1 type, or may use 2 or more types together.
When using the said binder, as a mixing ratio in an electrode, 5-30 mass% is preferable.

(4) Thickener In order to make it easy to produce a slurry for forming the electrode active material, a thickener may be mixed.
Examples of the thickener include carboxymethyl cellulose, polypropylene oxide, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl hydroxyethyl cellulose, polyvinyl alcohol, polyacrylamide, hydroxyethyl polyacrylate, ammonium polyacrylate, and sodium polyacrylate. . These thickeners may be used individually by 1 type, or may use 2 or more types together.
When using the said thickener, 0.1-5 mass% is preferable as a mixing ratio in an electrode.

(5) Catalyst In the electrode active material, in order to perform the electrode reaction more smoothly, a catalyst that assists the oxidation-reduction reaction may be mixed.
Examples of the catalyst include conductive polymers such as polyaniline, polypyrrole, polythiophene, polyacetylene, and polyacene, basic compounds such as pyridine derivatives, pyrrolidone derivatives, benzimidazole derivatives, benzothiazole derivatives, and acridine derivatives, and metal ion complexes. . These catalysts may be used individually by 1 type, or may use 2 or more types together.
When the catalyst is used, the mixing ratio in the electrode is preferably 10% by mass or less.

The battery according to the present invention has an electrolytic solution.
In the battery according to the present invention, the electrolytic solution performs charge carrier transport between the negative electrode and the positive electrode, and generally has an ionic conductivity of 10 ⁻⁵ to 10 ⁻¹ S / cm at 20 ° C. Preferably it is. As the electrolytic solution, for example, an electrolytic solution in which an electrolyte salt is dissolved in a solvent can be used.

Examples of the electrolyte salt include LiPF ₆ , LiClO ₄ , LiBF ₄ , LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, Li (C ₂ F ₅ SO ₂ ) ₂ N, Li (CF ₃ SO ₂ ) Conventionally known materials such as ₃ C and Li (C ₂ F ₅ SO ₂ ) ₃ C can be mentioned. These electrolyte salts may be used individually by 1 type, or may use 2 or more types together.
Examples of the solvent include ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, γ-butyrolactone, tetrahydrofuran, dioxolane, sulfolane, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl. An organic solvent such as -2-pyrrolidone can be mentioned. These solvents may be used alone or in combination of two or more.

The electrolytic solution contains polyethylene glycols. The polyethylene glycols are electrochemically stable resins.

Examples of the polyethylene glycols include polyethylene glycol and derivatives thereof, such as polyethylene glycol, sodium polyoxyethylene alkylphenyl ether alkylbenzene sulfonate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl ether methylcarboxylate. , Sodium polyoxyethylene alkyl ether ethanesulfonate, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid monoglyceride, polyoxyethylene sorbitol fatty acid partial ester, polyoxyethylene sorbitan fatty acid partial ester, polyoxyethylene lanolin Alcohol ether, polyethylene glycol fat Acid monoesters, polyethylene glycol fatty acid diesters, polyoxyethylene fatty amines, polyoxyethylene polyoxypropylene block copolymers, polyoxyethylene polyoxypropylene alkyl ether, and polyoxyethylene acetylene glycol, polyethylene oxide, and the like.

Among the above-mentioned polyethylene glycols, polyethylene glycol and polyethylene oxide are preferable, and polyethylene glycol is more preferable from the viewpoint of being easily available industrially, inexpensive, and obtaining a high effect.

The polyethylene glycols may be used alone or in combination of two or more.

The number average molecular weight of the polyethylene glycols is usually preferably 500 to 500,000, more preferably 1,000 to 50,000, still more preferably 2,000 to 40,000, and particularly preferably 5,000. ~ 20,000. When the number average molecular weight is less than 500, the affinity with the pyrroline nitroxide polymer is inferior and the solubility of the pyrroline nitroxide polymer in the electrolytic solution is increased, so that a sufficient effect may not be obtained. On the other hand, when the number average molecular weight exceeds 500,000, the solubility in the electrolytic solution is decreased, the viscosity of the electrolytic solution is increased, and the oxidation-reduction wave of the obtained battery may be reduced, or it may be used repeatedly. When doing so, the capacity may be reduced.
In addition, the number average molecular weight in this invention means the value measured by the high performance liquid chromatography and converted into polystyrene of the molecular weight existing value.

The amount of the polyethylene glycol used can be appropriately adjusted according to the molecular weight of the polyethylene glycol, but is preferably 0.05 to 30 parts by mass, and 0.5 to 10 parts by mass with respect to 100 parts by mass of the electrolytic solution. More preferred. When the amount of the polyethylene glycol used is less than 0.05 parts by mass, the effect of suppressing elution of the pyrroline nitroxide polymer into the electrolytic solution may be reduced. Moreover, when the usage-amount of the said polyethyleneglycol exceeds 30 mass parts, there is no effect corresponding to a usage-amount and it is not economical. Moreover, there exists a possibility that a battery characteristic may fall because electrolyte solution viscosity increases.

In addition to the polyethylene glycols, a polymer compound may be added to the electrolytic solution.
Examples of the polymer compound include polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-ethylene copolymer, vinylidene fluoride-monofluoroethylene copolymer, and vinylidene fluoride-trifluoroethylene copolymer. Polymer, vinylidene fluoride-tetrafluoroethylene copolymer, vinylidene fluoride-based polymer such as vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer; acrylonitrile-methyl methacrylate copolymer, acrylonitrile-methyl Acrylate copolymer, acrylonitrile-ethyl methacrylate copolymer, acrylonitrile-ethyl acrylate copolymer, acrylonitrile-methacrylic acid copolymer, acrylonitrile-acrylic acid copolymer, acryloni Lil - acrylonitrile polymers such as vinyl acetate copolymer; and polyethylene oxide, ethylene oxide - propylene oxide copolymer, polymer and the like of these acrylates body or methacrylate products thereof.

Although it does not specifically limit as a method to manufacture the said electrolyte solution, For example, the method etc. which add the said polyethyleneglycol, mixing the said electrolyte solution using stirrers, such as a homomixer, etc. are mentioned.

The battery according to the present invention preferably includes a current collector and a separator in addition to the electrode and the electrolytic solution. In particular, the current collector and the separator are preferably used in contact with an electrode active material.
Examples of the current collector used in contact with the electrode active material include nickel, aluminum, copper, gold, silver, aluminum alloy, stainless steel, carbon, etc., and those having a shape such as a foil, a metal flat plate, and a mesh shape. Can be used. Further, the current collector may have a catalytic effect, or the electrode active material and the current collector may be chemically bonded.
On the other hand, examples of the separator include porous films and nonwoven fabrics made of polyethylene, polypropylene, and the like.

The shape of the battery according to the present invention is not particularly limited, and a conventionally known battery can be used. For example, an electrode laminate or a wound body is sealed with a metal case, a resin case, or a laminate film composed of a metal foil such as an aluminum foil and a synthetic resin film, etc. Examples include molds and sheet molds.

FIG. 1 shows an example of an embodiment of a battery according to the present invention. The battery shown in FIG. 1 has a configuration in which a positive electrode 5 and a negative electrode 3 are stacked so as to face each other with a separator 4 containing an electrolytic solution, and a positive electrode current collector 6 is further stacked on the positive electrode 5. . These are externally covered with a stainless steel exterior 1 on the negative electrode side and a stainless steel exterior 1 on the positive electrode side, and an insulating packing 2 made of an insulating material such as a plastic resin is disposed between them for the purpose of preventing electrical contact therebetween. .

The battery manufacturing method according to the present invention is not particularly limited, and a method appropriately selected according to the material can be used. For example, an electrode is prepared by adding a solvent to the electrode active material containing the pyrroline-based nitroxide polymer, a conductivity-imparting agent, etc., and applying it to the electrode current collector, and volatilizing the solvent at room temperature or heating. Further, this electrode is laminated or wound with a counter electrode and a separator in between, wrapped in an outer package, and sealed by injecting an electrolytic solution. Solvents for slurrying include ether solvents such as tetrahydrofuran, diethyl ether, ethylene glycol dimethyl ether and dioxane; amine solvents such as N, N-dimethylformamide and N-methyl-2-pyrrolidone; benzene, toluene and xylene Aromatic hydrocarbon solvents such as hexane, heptane, etc .; Halogenated hydrocarbon solvents such as chloroform, dichloromethane, dichloroethane, trichloroethane, carbon tetrachloride; Alkyl ketone solvents such as acetone and methyl ethyl ketone Alcoholic solvents such as methanol, ethanol and isopropyl alcohol; dimethyl sulfoxide, water and the like. In addition, as an electrode manufacturing method, there is a method in which an electrode active material, a conductivity-imparting agent, and the like are kneaded in a dry manner and then thinned and laminated on an electrode current collector.

According to the present invention, by adding polyethylene glycols to the electrolytic solution, the elution of the pyrroline nitroxide polymer into the electrolytic solution is suppressed, and as a result, the battery characteristics can be maintained over a long period of time. Can be provided. Although the mechanism is not clear, it is considered that polyethylene glycols having excellent affinity with the pyrroline nitroxide polymer protect the surface of the electrode.

It is a conceptual diagram which shows an example of embodiment of the battery which concerns on this invention.

The present invention will be specifically described below with reference to production examples and examples, but the present invention is not limited to these production examples and examples.

[Production Example 1]
(Production of pyrroline-based nitroxide compounds)
To a 100 mL four-necked flask equipped with a stirrer, thermometer, reflux condenser and flow meter was added 1.17 g and 10 wt% 3-carbamoyl-2,2,5,5-tetramethylpyrrolin-1-oxyl. An aqueous sodium hydroxide solution (16.8 mL) was charged, suspended, and held at 100 ° C. for 2 hours. Thereafter, an appropriate amount of dilute hydrochloric acid was added for neutralization to obtain a yellow solution. This was extracted with 50 mL of diethyl ether, and concentrated to obtain 1.12 g of 3-carboxy-2,2,5,5-tetramethylpyrroline-1-oxyl as yellow crystals.

The obtained 3-carboxy-2,2,5,5-tetramethylpyrroline-1-oxyl could be identified from the following physical properties.
IR (KBr): 3300, 2500, 1707 cm ⁻¹
Molecular weight (mass spectrometry by atmospheric pressure ionization method): 184

The obtained 3-carboxy-2,2,5,5-tetramethylpyrrolin-1-oxyl (1 g) was equipped with a stirrer, an argon gas introduction tube, a thermometer and a reflux condenser, and was previously substituted with argon gas in a volume of 100 mL. Were mixed and dissolved by adding a mixed solvent of benzene 12 mL / pyridine 0.44 mL.
Next, it was cooled to 5 ° C. in an argon atmosphere, 0.44 mL of thionyl chloride / 2 mL of benzene was added and stirred for 1 hour, and then the solvent was distilled off, and 10 mL of THF was added and dissolved.
Then, it cooled to -78 degreeC and 10 mL of 1 mol / L lithium aluminum hydride-tert-butoxide THF solution was dripped at the same temperature over 2 hours.
Subsequently, extraction was performed using 50 mL of ethyl acetate, followed by concentration to obtain 0.44 g of 3-formyl-2,2,5,5-tetramethylpyrroline-1-oxyl as yellow crystals.

The obtained 3-formyl-2,2,5,5-tetramethylpyrroline-1-oxyl could be identified from the following physical properties.
IR (KBr): 2834, 2736, 1688 cm ⁻¹
Molecular weight (mass spectrometry by atmospheric pressure ionization method): 168

Next, 125 mg of sodium hydride and 2 mL of dimethyl sulfoxide were charged into a 100 mL four-necked flask equipped with a stirrer, an argon gas introduction tube, a thermometer, and a reflux condenser and previously substituted with argon gas, And stirred at 65 ° C. for 1 hour.
Thereafter, 2.5 mL of THF was added, and the mixture was cooled to −10 ° C. with a salt ice bath. At the same temperature, 0.64 g of a trimethylsulfonium iodide / 2.5 mL of dimethylsulfoxide solution was added, and the mixture was stirred for 5 minutes.
The 3-formyl-2,2,5,5-tetramethylpyrrolin-1-oxyl 0.44 g / THF solution 1 mL was added dropwise at -10 ° C over 30 minutes, and the mixture was further stirred at room temperature for 2 hours.
Next, after extracting with 50 mL of ethyl acetate and concentrating, 3-oxiranyl-2,2,5,5-tetra in which n is 0 among the pyrroline nitroxide compounds represented by the general formula (1) 0.34 g of an amber liquid of methylpyrroline-1-oxyl was obtained.

The obtained 3-oxiranyl-2,2,5,5-tetramethylpyrroline-1-oxyl could be identified from the following physical properties.
¹ H NMR (CDCl ₃ ): 5.49, 3.27, 2.93, 2.64, 1.35, 1.30, 1.24, 1.22 ppm
¹³ C NMR (CDCl ₃ ): 142.0, 129.0, 70.2, 68.0, 49.2, 47.5, 25.7, 25.2, 25.0, 24.4 ppm
IR (KBr): 1249, 932, 846 cm ⁻¹
Molecular weight (mass spectrometry by atmospheric pressure ionization method): 182

(Manufacture of pyrroline nitroxide polymer)
A 5 mL 4-neck flask equipped with a stirrer, argon gas introduction tube, thermometer, and reflux condenser and charged with argon gas in advance was charged with 2 mL of 1 mol / L hexane solution of diethyl zinc (0.25 g of diethyl zinc). After cooling to −78 ° C., 36 μL of water was added, and the mixture was returned to room temperature and reacted for 1 hour to produce a yellow liquid diethylzinc / water-based initiator as a polymerization initiator.
Next, a 3 mL 4-neck flask equipped with a stirrer, an argon gas introduction tube, a thermometer, and a reflux condenser and previously substituted with argon gas was obtained in the same manner as in the production of the pyrroline nitroxide compound. -0.18 g (1 mmol) of oxiranyl-2,2,5,5-tetramethylpyrroline-1-oxyl was added, 0.2 mL of the diethyl zinc / water-based initiator was added, and the mixture was brought to room temperature under an argon gas atmosphere. For 48 hours. Thereafter, an appropriate amount of methanol was added to stop the reaction, and then the reaction solution was added to 50 mL of hexane, filtered, washed with 10 mL of hexane, and dried under reduced pressure to obtain an amber solid pyrroline nitroxide polymer 0. 0.03 g was obtained (15% yield).
The number average molecular weight of the obtained pyrroline nitroxide polymer was measured and found to be 180,000. The number average molecular weight is 30 ° C in N, N-dimethylformamide containing LiBr (0.01 mol / L) using gel permeation chromatography (trade name: HLC-8020, manufactured by Tosoh Corporation). Measured and calculated with reference to standard polystyrene.

[Production Example 2]
(Production of pyrroline-based nitroxide compounds)
To a 100 mL four-necked flask equipped with a stirrer, thermometer, reflux condenser and flow meter was added 1.17 g and 10 wt% 3-carbamoyl-2,2,5,5-tetramethylpyrrolin-1-oxyl. An aqueous sodium hydroxide solution (16.8 mL) was charged, suspended, and held at 100 ° C. for 2 hours. Thereafter, an appropriate amount of dilute hydrochloric acid was added for neutralization to obtain a yellow solution. This was extracted with 50 mL of diethyl ether, and concentrated to obtain 1.12 g of 3-carboxy-2,2,5,5-tetramethylpyrroline-1-oxyl as yellow crystals.
The obtained 3-carboxy-2,2,5,5-tetramethylpyrroline-1-oxyl could be identified from the following physical properties.
IR (KBr): 3300, 2500, 1707 cm ⁻¹
Molecular weight (mass spectrometry by atmospheric pressure ionization method): 184

4 mL of 100 mL capacity obtained by replacing 1 g of the obtained 3-carboxy-2,2,5,5-tetramethylpyrrolin-1-oxyl with a stirrer, an argon gas introduction tube and a thermometer and previously substituted with argon gas The flask was charged and dissolved by adding a mixed solvent of 12 mL of benzene / 0.44 mL of pyridine. Next, it was cooled to 5 ° C. in an argon atmosphere, 0.44 mL of thionyl chloride / 2 mL of benzene was added and stirred for 1 hour, and then the solvent was distilled off, and 10 mL of THF was added and dissolved. Thereafter, the mixture was cooled to −78 ° C., and 5.4 mL of a 1 mol / L lithium aluminum hydride-tert-butoxide THF solution was added dropwise at the same temperature over 2 hours. Subsequently, extraction was performed using 50 mL of ethyl acetate, followed by concentration to obtain 0.44 g of 3-formyl-2,2,5,5-tetramethylpyrroline-1-oxyl as yellow crystals.
The obtained 3-formyl-2,2,5,5-tetramethylpyrroline-1-oxyl could be identified from the following physical properties.
IR (KBr): 2834, 2736, 1688 cm ⁻¹
Molecular weight (mass spectrometry by atmospheric pressure ionization method): 168

Next, in a 100 mL four-neck flask equipped with a stirrer, an argon gas introduction tube and a thermometer and previously substituted with argon gas, at 0 ° C., 3.19 g of methyltriphosphonium bromide, 1.36 g of potassium carbonate, Tetrahydrofuran (8.4 mL) was charged, dissolved, and held for 30 minutes. Thereafter, 0.50 g of 3-formyl-2,2,5,5-tetramethylpyrroline-1-oxyl / 2.3 mL of tetrahydrofuran was added and stirred at 25 ° C. for 48 hours, followed by extraction with 50 mL of diethyl ether. Thereafter, by concentration, 0.23 g of an orange liquid of 3-vinyl-2,2,5,5-tetramethylpyrrolin-1-oxyl represented by the formula (2) was obtained.
The obtained 3-vinyl-2,2,5,5-tetramethylpyrroline-1-oxyl could be identified from the following physical properties.
¹ H NMR (CDCl ₃ ): 6.16, 5.60, 5.41, 5.11, 1.39, 1.25 ppm
¹³ C NMR (CDCl ₃ ): 131.3, 130.2, 115.1, 113.7, 69.8, 67.3, 25.3, 24.6 ppm
IR (KBr): 2974, 1635, 1593 cm ⁻¹
Molecular weight (mass spectrometry by atmospheric pressure ionization method): 166

(Manufacture of pyrroline nitroxide polymer)
3-vinyl-2,2,5,5-tetramethylpyrroline-1- obtained in the same manner as in the production of the pyrroline nitroxide compound in a 5 mL eggplant type flask equipped with a stirrer and an argon gas introduction tube. 0.17 g (1 mmol) of oxyl was charged, and while maintaining the temperature at 25 ° C., oxygen in the reaction system was removed through argon gas. Next, 0.13 mg (0.0006 mmol) of cyclopentadienyltitanium (IV) trichloride as a polymerization initiator and 11.25 mg (0.194 mmol) of methylaluminoxane were added, and the reaction was performed at 25 ° C. under an argon gas atmosphere. After the polymerization reaction for 22 hours under stirring, an appropriate amount of methanol was added to stop the reaction. After completion of the reaction, the mixture was added to 50 mL of hexane, filtered, washed with 10 mL of hexane, and dried under reduced pressure to obtain 0.02 g of a light brown pyrroline nitroxide polymer (yield 11%).
It was 26,000 when the number average molecular weight was measured about the obtained pyrroline type | system | group nitroxide polymer. The number average molecular weight was measured at 30 ° C. in N, N-dimethylformamide containing LiBr (0.01 mol / L) using gel permeation chromatography (manufactured by Shimadzu Corporation). Calculated with reference.

(Reference Example 1)
To 1.0 g of polyvinylidene fluoride, 9.0 g of N-methyl-2-pyrrolidinone (NMP) was added and dissolved to obtain a polyvinylidene fluoride solution.
Add 0.3 g of pyrroline nitroxide polymer and 0.015 g of polyethylene glycol (manufactured by Sigma-Aldrich Japan Co., Ltd., number average molecular weight 35,000) obtained in the same manner as in Production Example 1, and use a stirrer to make uniform. To obtain a radical composition.
To the obtained radical composition, 3.0 g of NMP and 3.0 g of a polyvinylidene fluoride solution were added and stirred using a stirrer until uniform to obtain a nitroxide polymer dispersion.
Thereafter, 2.4 g of graphite powder as an auxiliary conductive material was added to the obtained nitroxide polymer dispersion, and the mixture was stirred with a stirrer until uniform, thereby preparing an electrode ink.
The obtained ink for electrodes was cast on an ITO / glass electrode substrate and dried under reduced pressure at 120 ° C. for 1 hour to remove the solvent and form a film on the electrode, thereby producing a film-forming electrode.

About the obtained film forming electrode, polyethylene glycol (manufactured by Sigma Aldrich Japan Co., Ltd., number average molecular weight ≈ 8,500 to 11, by an electrochemical analyzer (manufactured by BAS, trade name: ALS model 600B electrochemical analyzer). 500) in acetonitrile (concentration of 5% by mass), tetrabutylammonium perchlorate as an electrolytic substrate (0.1 mol / L), a reference electrode as Ag / AgCl, and a scanning speed of 20 mV / s at 25 ° C. CV curve was measured.
As a result, a redox wave derived from the pyrroline-based nitroxide polymer appeared at 0.88 V, and no change was observed in the redox wave even after 1000 sweeps.

(Reference Example 2)
In Reference Example 1, in place of acetonitrile in which polyethylene glycol (manufactured by Sigma-Aldrich Japan Co., Ltd., number average molecular weight≈8,500 to 11,500) was dissolved (5% by mass concentration), acetonitrile (no addition of polyethylene glycol) was used. A CV curve was measured in the same manner as in Reference Example 1 except that was used. As a result, the curve attenuated with the sweep.

Example 1
(Battery using electrode active material containing pyrroline nitroxide polymer)
Weigh 0.01 g of a pyrroline nitroxide polymer obtained in the same manner as in Production Example 1, 0.08 g of graphite powder as an auxiliary conductive material, and 0.01 g of polytetrafluoroethylene as a binder, and prepare an agate mortar. And kneaded. The mixture obtained by dry-mixing for about 10 minutes was subjected to roller stretching under pressure to obtain a thin film having a thickness of about 150 μm. This was dried overnight at 100 ° C. in a vacuum and then punched into a circle having a diameter of 12 mm to form a coin battery electrode. The mass of this electrode was 13.1 mg.
Next, polyethylene glycol (manufactured by Sigma Aldrich Japan Co., Ltd.) was added to 1.95 parts by mass of an ethylene carbonate / diethyl carbonate mixed solution (mixing volume ratio 1: 1) containing 1.0 mol / L LiPF ₆ electrolyte salt as an electrolytic solution. (Number average molecular weight≈8,500 to 11,500) 0.10 parts by mass was added to prepare an electrolyte containing polyethylene glycol.
Next, the electrode obtained as described above was immersed in the electrolytic solution containing polyethylene glycol, and the voids in the electrode were impregnated with the electrolytic solution. Then, the electrode impregnated with the electrolytic solution is placed on a stainless steel sheath (manufactured by Kagatsu Co., Ltd.) that also serves as a positive electrode current collector, and a polypropylene porous film separator impregnated with the electrolytic solution is laminated thereon. did. Furthermore, the lithium disk used as a negative electrode was laminated | stacked, and the negative electrode side stainless steel exterior (made by Kagatsu Co., Ltd.) was piled up in the state which has arrange | positioned the insulating packing around. By applying pressure with a caulking machine, a sealed coin-type battery using the pyrroline nitroxide polymer obtained in Production Example 1 as the positive electrode active material and metallic lithium as the negative electrode active material was manufactured.

(Example 2)
A sealed coin-type battery was produced in the same manner as in Example 1 except that 0.02 part by mass of polyethylene glycol was used instead of 0.10 part by mass of polyethylene glycol.

(Example 3)
A sealed coin-type battery was produced in the same manner as in Example 1 except that 0.19 parts by mass of polyethylene glycol was used instead of 0.10 parts by mass of polyethylene glycol.

(Example 4)
Instead of 0.10 parts by mass of polyethylene glycol (manufactured by Sigma Aldrich Japan Co., Ltd., number average molecular weight≈8,500 to 11,500), 0.10 parts by mass of polyethylene glycol (manufactured by Sigma Aldrich Japan Co., Ltd., number average molecular weight≈ A sealed coin-type battery was manufactured in the same manner as in Example 1 except that 570 to 630) was used.

(Example 5)
Instead of 0.10 parts by mass of polyethylene glycol (manufactured by Sigma Aldrich Japan Co., Ltd., number average molecular weight≈8,500 to 11,500), 0.10 parts by mass of polyethylene glycol (manufactured by Sigma Aldrich Japan Co., Ltd., number average molecular weight≈ A sealed coin-type battery was manufactured in the same manner as in Example 1 except that 400,000) was used.

(Example 6)
Instead of 0.10 parts by mass of polyethylene glycol (manufactured by Sigma Aldrich Japan Co., Ltd., number average molecular weight≈8,500 to 11,500), 0.10 parts by mass of polyethylene glycol (manufactured by Sigma Aldrich Japan Co., Ltd., number average molecular weight≈ A sealed coin-type battery was manufactured in the same manner as in Example 1 except that 285-315) was used.

(Example 7)
Instead of 0.10 parts by mass of polyethylene glycol (manufactured by Sigma Aldrich Japan Co., Ltd., number average molecular weight≈8,500 to 11,500), 0.10 parts by mass of polyethylene glycol (manufactured by Sigma Aldrich Japan Co., Ltd., number average molecular weight≈ A sealed coin-type battery was manufactured in the same manner as in Example 1 except that 900,000) was used.

(Example 8)
Example 1 except that 0.10 g of the pyrroline nitroxide polymer obtained in the same manner as in Production Example 2 was used instead of 0.10 g of the pyrroline nitroxide polymer obtained in the same manner as in Production Example 1. Similarly, a radical composition and a sealed coin-type battery were produced.

(Comparative Example 1)
In Example 1, a coin-type battery was produced in the same manner as in Example 1 except that an electrolytic solution not containing polyethylene glycol (manufactured by Sigma-Aldrich Japan Co., Ltd., number average molecular weight≈8,500 to 11,500) was used. did.

(Evaluation)
(1) CV curve measurement The cyclic voltammogram in the potential sweep range of 3.2 to 4.2 V was measured for the coin-type batteries obtained in the examples and comparative examples.
As a result, in the coin-type batteries obtained in Examples 1 to 5 and 8, a redox wave derived from the p-type redox of the nitroxide radical appeared at 3.66 V, and the redox wave was stable even after repeated sweeps. .
In the coin-type batteries obtained in Examples 6 and 7, an oxidation-reduction wave derived from the p-type redox of the nitroxide radical appears at 3.66 V, and when repeatedly swept, compared with those of Examples 1 to 5, The redox wave was slightly smaller.
In the coin-type battery obtained in Comparative Example 1, a redox wave derived from the p-type redox of the nitroxide radical appeared at 3.66 V, and no redox wave was observed when it was repeatedly swept.
This is considered to be due to the elution of the nitroxide polymer in the electrolytic solution.

(2) Charging / discharging curve measurement About the coin-type battery obtained by the Example and the comparative example, the charging / discharging curve in constant current 0.1mA (current density 150 microampere / cm < ² >) was measured.
As a result, in the coin-type batteries obtained in Examples 1 to 5 and 8, a plateau potential appeared at 3.64 V, and no significant capacity reduction was observed even after 2000 cycles, indicating a stable charge / discharge behavior.
In the coin-type batteries obtained in Examples 6 and 7, a plateau potential appeared at 3.64 V, and after 2000 cycles, the capacity was slightly smaller than those in Examples 1-5.
On the other hand, in the coin-type battery obtained in Comparative Example 1, a plateau potential appeared at 3.64 V, but a significant capacity decrease was observed after 2000 cycles.

ADVANTAGE OF THE INVENTION According to this invention, the battery which can suppress the elution to the electrolyte solution of an electrode component can be provided.

DESCRIPTION OF SYMBOLS 1 Stainless steel exterior 2 Insulation packing 3 Negative electrode 4 Separator 5 Positive electrode 6 Positive electrode collector

Claims (4)

A battery comprising an electrode containing a pyrroline-based nitroxide polymer and an electrolytic solution, wherein the electrolytic solution contains polyethylene glycols. The battery according to claim 1, wherein the pyrroline nitroxide polymer is a polymer obtained by polymerizing a pyrroline nitroxide compound represented by the following general formula (1).

In formula (1), n represents 0 or 1. The battery according to claim 1, wherein the pyrroline nitroxide polymer is a polymer obtained by polymerizing a pyrroline nitroxide compound represented by the following general formula (2).

The battery according to claim 1, wherein the amount of polyethylene glycol used is 0.05 to 30 parts by mass with respect to 100 parts by mass of the electrolytic solution.

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