JP2010009760A - Active material, secondary battery, and novel radical fullerene compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an active material capable of minimizing usage of a collector of carbon graphite or the like when forming an electrode active material layer, and having a very small difference between a theoretical capacity and a battery actual capacity since it has high energy density (1), it is chemically and electrically stable (2) and it has superior conductivity (3), to provide a secondary battery using the same, and to provide a novel radical fullerene compound. <P>SOLUTION: In the active material containing a compound having at least both of one or more and five or less of nitroxy radicals in a molecule and a radical capable of forming a carbene under existence of a base, the active material, the secondary battery and the novel radical fullerene compound are characterized in that the carbene formed from the compound is a reaction product obtained by subjecting a carbon-carbon double bond of fullerene to addition reaction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an active material having high energy density, chemical and electrical stability, and excellent electrical conductivity, a secondary battery using the active material, and a novel radical / fullerene compound.

  Currently, information-related equipment is a social infrastructure that is indispensable for our citizens' lives and economic activities, and sufficient stability and reliability are required. However, these devices are vulnerable to disturbance phenomena from the system such as instantaneous power failure or voltage drop, and the uninterruptible power supply (UPS) ensures reliability. However, UPS has a problem that a large amount of energy is lost due to repeated AC / DC conversion. As a method of improving this loss, a method of connecting a battery inside the device is conceivable, but a high-power battery that can be built in an information-related device that is becoming smaller has not been developed.

  On the other hand, many radical polymers obtained by polymerizing stable radical molecules have been synthesized as one of redox resins since the 1970s. Such a radical polymer is represented by a polymer of an acrylate or a styrene derivative substituted with 2,2,6,6-tetramethylpiperidine-1-oxy (hereinafter abbreviated as “TEMPO”). Catalytic ability to oxidize to aldehydes and ketones.

  The mechanism of action of the radical polymer is in a reversible redox (redox) pair. Taking nitroxide radical as an example, the mechanism of action is shown below. As shown below, the nitroxide radical is oxidized by one electron to become an oxoammonium cation, and when the oxoammonium cation is reduced, the radical is regenerated. In the other redox pair, the nitroxide radical is reduced by one electron to be converted into an aminoxy anion, and when this aminoxy anion is oxidized, redox is caused to return to the radical.

  In recent years, research has been actively focused on the redox couple of radicals as an electrode active material of a secondary battery having at least a positive electrode, a negative electrode, and an electrolyte as a power storage material. Secondary batteries used as materials have been disclosed (see Patent Documents 1 to 7). Since a radical redox pair is incorporated as an electrode active material, it is called an organic radical battery (see Non-Patent Documents 1 and 2). The radical compound used as the electrode active material has not only moldability and adhesion as an electrode, but also a property that the electrolyte solution can easily penetrate (affinity with the electrolyte solution) and a property that it does not elute into the electrolyte solution (electrolysis) Resistant to liquids), oxidation-reduction characteristics that enable high-speed transfer of electrodes and electrons during charge and discharge, and high energy density that realizes higher battery capacity.

  The advantages of using the polymer having the nitroxide radical in the molecular structure as the electrode active material can be summarized as follows. (1) Chemically very stable. For example, there are polymers whose radical concentration does not decrease over a half year at room temperature. (2) The spin density is localized at N—O, and the molecular weight per radical is small, so the charge capacity per mass is large. (3) Since all monomer units can carry charges, the ultimate heavy doping of nearly 100% becomes possible. (4) Pure organic substance. Incineration, odorlessness, and low toxicity are advantages not found in conventional electrode materials. (5) The redox speed is extremely high, and the battery exhibits high rate characteristics and high output. As such polymers having a nitroxide radical in the molecular structure, acrylate polymers, vinyl polymers, norbornene polymers, etc., in which the TEMPO moiety is substituted with a monomer structural unit have been reported recently (see Patent Documents 1 to 7).

Since the above polymer is poorly soluble in electrolyte solvents (ethylene carbonates) and is an electrical insulator, when an electrode active material layer is formed, a current collector such as carbon graphite and a solvent are added and uniformly pulverized. After the mixed slurry is prepared, the slurry is applied to the electrode substrate, and the solvent is removed by drying. In this method, when the mixing amount of the current collector with respect to the polymer is 50% by mass or less, there are problems that the smoothness of the electrode surface is lowered and the output is lowered. Therefore, at present, the actual battery capacity is 50% or less with respect to the theoretical capacity of the radical polymer. An active material capable of expressing an actual capacity equivalent to the theoretical capacity has been eagerly desired.
JP 2002-151084 A JP 2002-11168 A JP 2002-117853 A JP 2005-209498 A JP 2007-070384 A JP 2007-157696 A JP 2007-184227 A K. Nakahara et al. , Chem. Phys. Lett. , 359, 351-354 (2002). H. Nishi et al. Electrochim. Acta. , 50, 827-831 (2004) NEDO 2004 Research Project Report “Research and Development of High-Power Organic Radical Batteries for Backup” NEC Corporation, pages 11-14

  The objects of the present invention are (1) high energy density, (2) chemically and electrically stable, and (3) excellent electrical conductivity. Therefore, when an electrode active material layer is formed, a current collector such as carbon graphite is used. The object is to provide an active material that can be used in an extremely small amount and that has a very small difference between the theoretical capacity and the actual battery capacity, a secondary battery using the active material, and a novel radical / fullerene compound.

  The above object of the present invention can be achieved by the following configuration.

  1. Results of addition reaction of a carbene formed from a compound having at least 1 to 5 nitroxy radical groups in one molecule and a group capable of forming a carbene in the presence of a base to a carbon-carbon double bond of fullerene An active material characterized by containing a body.

  2. 2. The active material as described in 1 above, wherein the fullerene is C60.

  3. 3. The active material as described in 1 or 2 above, wherein the active material is a mixture of a product having a carbene addition number of 1 or more and 12 or less per molecule of the fullerene.

  4). The compound having both 1 and 5 or less nitroxy radical groups in one molecule and a group capable of forming a carbene in the presence of a base is selected from the compounds represented by the following general formulas (1) to (4). The active material according to any one of 1 to 3, which is at least one kind.

(Wherein R _{1 to} R ₁₈ each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. X _{1 to} X ₄ each independently represent> CH ₂ or> N—O.). Ts represents a p-toluenesulfonyl group.)
5). 5. The active material as described in 4 above, which contains at least one compound represented by the following general formulas (5) to (8).

(Wherein, fullerene skeleton is _C60, R 1 _{to R 18} and _X 1 to X ₄ is _R 1 _{to R 18} and _X 1 to X ₄ of the compound represented by the general formula (1) to (4) The two dotted lines in the formula represent that they are attached to the (5,6) bond at an arbitrary position of fullerene C60, and q, n, m, and p are 0 or more and 11 or less, respectively. Represents the number of
6). A secondary battery comprising the active material according to any one of 1 to 5 above.

  7). A radical / fullerene compound represented by the following general formulas (16) to (18):

(In the formula, the fullerene skeleton is C60, R _{25 to} R ₃₈ each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. X _{11 to} X ₁₄ are each independently> CH ₂ or> N-O .. Two dotted lines in the formula indicate that they are attached to the (5,6) bond at an arbitrary position of fullerene C60, and n1, m1, and p1 are each a number of 0 or more and 11 or less. Represents.)

  According to the present invention, since the energy density is high, chemically and electrically stable, and excellent in electrical conductivity, it is possible to extremely reduce the amount of a collector such as carbon graphite when forming an electrode active material layer. Thus, an active material having a very small difference between the theoretical capacity and the actual battery capacity, a secondary battery using the active material, and a novel radical / fullerene compound could be provided.

  The present invention will be described in more detail.

<Compound having both 1 and 5 or less nitroxy radical groups in the molecule and a group capable of forming a carbene in the presence of a base>
The nitroxyl radical group is represented by the following formula (A1). It is particularly excellent in terms of radical stability.

Formula (A1)> NO
Specific examples of the group capable of forming a carbene in the presence of a base include a diazo group and an acyl hydrazide group, and an acyl hydrazide group, particularly a tosyl hydrazide group is preferable. Preferred bases include alkali metal salts of lower alcohols, with sodium methoxide being particularly preferred. As a carbene formation condition, a method using a small excess of base at 100 ° C. to 200 ° C. in an inert gas atmosphere is preferable.

Representative examples of the notation compounds include those represented by the general formulas (1) to (4). Particularly preferred is a compound represented by formula (4). In the general formula (4), X _{1 to} X ₄ represent> CH ₂ or> N—O ·, but X ₁ is preferably> N—O ·. In the compounds represented by the general formulas (1) to (4), R _{1 to} R ₁₈ each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, preferably a hydrogen atom or a methyl group. It is. In the general formulas (1) to (3), a methyl group is particularly preferable, and in the general formula (4), a hydrogen atom.

<Fullerene>
There is no restriction | limiting in particular in fullerene used by this invention, C60, C70, C74, C78, C80, C82, C84 etc. and these dimers are mentioned. C60 and C70 are preferable, and C60 is particularly preferable. The fullerene may contain a metal. For example, if it is C60, one containing scandium, lanthanum, cerium, or titanium is preferable.

<Results of carbene addition reaction to carbon-carbon double bond of fullerene>
The molar ratio of carbene and fullerene during the addition reaction is not particularly limited, but the carbene is preferably 1 mol or more and 20 mol or less with respect to 1 mol of fullerene. As reaction conditions, it is preferable to carry out at 100 degreeC or more and 200 degrees C or less under inert gas atmosphere. The resulting product can be purified and isolated by GPC, but can be used in the present invention as a mixture having different carbene addition numbers and addition positions. The addition number of carbene is preferably 1 or more and 12 or less. The resulting product is preferably a compound represented by the general formulas (5) to (8). In the general formulas (5) to (8), R _{1 to} R ₁₈ each independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and in the general formulas (1) to (4), It is synonymous. In the general formula (8), X _{1 to} X ₄ represent> CH ₂ or> N—O., But X ₁ is preferably> N—O. q, n, m, and p each represent a number from 0 to 11, but when the compound is single, it represents the number of carbene additions per molecule minus 1, and the compound represents the number of additions and the position of addition. In the case of different mixtures, the average addition number represents minus one. The average added number is expressed by rounding off the second decimal place. The compound can determine the molecular weight, the carbene addition number, and the carbene average addition number from the mass spectrum and the measurement of the radical spin concentration using ESR. In the general formula, two dotted lines indicate that they are added to the (5,6) bond at an arbitrary position of fullerene C60. The (5,6) bond is a condensed part of a 5-membered ring and a 6-membered ring in the molecule. Represents the bond of.

Particularly preferred results are compounds represented by general formulas (16) to (18). R _{25 to} R ₃₈ each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. X _{11 to} X ₁₄ each independently represent> CH ₂ or> N—O. In the general formula (18), X _{11 to} X ₁₄ represent> CH ₂ or> N—O., But X ₁₁ is preferably> N—O. n1, m1, and p1 each represent a number of 0 or more and 11 or less, but when the compound is a single compound, it represents a carbene addition number per molecule minus 1, and the compound has a different number of additions and addition positions. Represents an average added number minus one. The average added number is expressed by rounding off the second decimal place. The compound can determine the molecular weight, the carbene addition number, and the carbene average addition number from the mass spectrum and the measurement of the radical spin concentration using ESR. In the general formula, two dotted lines indicate that they are added to the (5,6) bond at an arbitrary position of fullerene C60. The (5,6) bond is a condensed part of a 5-membered ring and a 6-membered ring in the molecule. Represents the bond of.

  Specific examples of the compounds represented by the general formulas (5) to (8) and the general formulas (16) to (18) of the present invention are given below, but the present invention is not limited thereto.

<Active material>
An active material is a composition containing a substance that emits or takes up electrons by a chemical reaction with an electrode and / or an electrolyte. In the present invention, the substance is a product according to claims 1 to 5. In addition, the active material includes a current collector, a binder, a catalyst, an electrolyte, a solvent, and the like.

<Current collector>
The current collector is added for the purpose of reducing the impedance. Typical examples include carbonaceous fine particles such as graphite, carbon black, and acetylene black, conductive polymers such as PEDOT-PSS, polyaniline, polypyrrole, polythiophene, and polyacene, gel electrolytes, and solid electrolytes.

<Binder>
The binder is added in order to strengthen the bond between the materials of the active material structure. Representative examples include resins such as polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, polytetrafluoroethylene, styrene-butadiene copolymer rubber, polypropylene, polyethylene, and polyimide. A binder is mentioned.

<Catalyst>
In the present invention, a catalyst may be used to perform the electrode reaction more smoothly. 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.

<Other radical compounds usable in the present invention>
Examples of other radical compounds that can be used in the present invention include compounds described in Japanese Patent No. 3687736, Japanese Patent Application Laid-Open No. 2003-132891, and Japanese Patent Application Laid-Open No. 2007-184227. Specific examples of the radical compound include compounds such as the following general formulas (RA-1) to (RA-14), but are not limited thereto.

<Non-radical compound contained in active material>
In the present invention, a material that generates a radical compound during the charge / discharge reaction can be used by being included in the active material of the positive electrode and / or the negative electrode. From the viewpoint of energy density, the positive electrode is particularly preferable. It is preferable to use for.

When these materials are used for either the positive electrode or the negative electrode, the following materials can be used for other electrodes. That is, when a material that generates a radical compound is used for the negative electrode layer, non-radical compound metal oxide particles, disulfide compounds, conductive polymers, and the like are used for the positive electrode layer. Here, examples of the metal oxide include lithium manganate such as LiMnO ₂ and Li _x Mn ₂ O ₄ (0 <x <2) or lithium manganate having a spinel structure, MnO ₂ , LiCoO ₂ , LiNiO ₂ , Or Li _x V ₂ O ₅ (0 <x <2) and the like, and disulfide compounds include dithioglycol, 2,5-dimercapto-1,3,4-thiadiazole, S-triazine-2,4,6-trithiol. In addition, examples of the conductive polymer include polyacetylene, polyphenylene, polyaniline, and polypyrrole. In the present invention, these positive electrode layer materials can be used singly or in combination of two or more, and it is also preferable to use a mixture of a conventionally known active material and these materials.

  On the other hand, when a radical compound is used for the positive electrode layer, the negative electrode layer includes one or more of graphite, amorphous carbon, lithium metal, lithium alloy, lithium ion occlusion carbon, and conductive polymer. A combination is used. These shapes are not particularly limited. For example, in addition to a thin film of lithium metal, a bulk shape, a powdered shape, a fiber shape, a flake shape, or the like can be used.

<Secondary battery>
The secondary battery is also called a storage battery or a rechargeable battery, and is a chemical battery that can be used repeatedly by storing electricity and being used as a battery.

The feature of the secondary battery in the present invention is that it contains the active material of the present invention. The secondary battery of the present invention uses the active material of the present invention in both the positive electrode layer and the negative electrode layer, and when used in either one of them, the secondary electrode is applied to the other electrode layer. Conventionally known materials can be used as the battery active material. For example, when the active material of the present invention is used for the negative electrode layer, examples of the positive electrode layer include metal oxide particles, disulfide compounds, and conductive polymers. Here, as the metal oxide, for example, lithium manganate such as LiMnO ₂ , Li _x Mn ₂ O ₄ (0 <x <2) or lithium manganate having a spinel structure, MnO ₂ , LiCoO ₂ , LiNiO ₂ , Alternatively, Li _x V ₂ O ₅ (0 <x <2) and the like, and examples of the conductive polymer include polyacetylene, polyphenylene, polyaniline, and polypyrrole.

  In the present invention, these positive electrode layer materials can be used alone or in combination. Further, a conventionally known active material and a radical compound may be mixed and used as a composite active material.

  On the other hand, when the active material of the present invention is used for the positive electrode, examples of the negative electrode layer include carbon materials such as graphite and amorphous carbon, lithium metal and lithium alloys, lithium ion storage carbon, and conductive polymers. . As these shapes, for example, lithium metal is not limited to a thin film shape, and any shape such as a bulk shape, a solidified powder, a fiber shape, and a flake shape can be used.

  In the present invention, when forming an electrode layer containing a radical compound, a conductive auxiliary material or an ion conductive auxiliary material may be mixed for the purpose of reducing impedance. As these materials, as conductive auxiliary materials, carbonaceous fine particles such as graphite, carbon black, acetylene black, or conductive polymers such as polyaniline, polypyrrole, polythiophene, polyacetylene, polyacene, and as ion conductive auxiliary materials, A gel electrolyte or a solid electrolyte may be mentioned.

  In the present invention, a binder may be used in order to strengthen the connection between the constituent materials. As the binder, polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, polytetrafluoroethylene, styrene-butadiene copolymer rubber, polypropylene, polyethylene, polyimide, etc. The resin binder is mentioned.

  In the present invention, a catalyst may be used to perform the electrode reaction more smoothly. 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.

  In the present invention, at least one of the positive electrode and the negative electrode contains the active material of the present invention, but the content is not particularly limited. However, since the capacity of the secondary battery is determined according to the amount of the radical compound contained, a content of 10% by mass or more is desirable from the viewpoint of the effect of the invention.

<Structure of secondary battery>
The secondary battery according to the present invention has a configuration as shown in FIG. 1, for example. The secondary battery shown in the figure has a configuration in which a negative electrode layer 1 and a positive electrode layer 2 are superposed via a separator 5 containing an electrolyte. In the present invention, the active material of the present invention is used for the negative electrode layer 1 or the positive electrode layer 2. The assembled structure is sealed with a sealing material 6.

  FIG. 2 is a cross-sectional view of a stacked secondary battery. The structure is a structure in which the positive electrode current collector 4, the positive electrode layer 2, the separator 5 containing an electrolyte, the negative electrode layer 1, and the negative electrode current collector 3 are sequentially stacked. In the present invention, any method can be used for laminating the positive electrode layer and the negative electrode layer, and a multilayer laminate, a combination of laminates on both sides of a current collector, a wound one, or the like can be used.

  As the negative electrode current collector 3 and the positive electrode current collector 4, a metal foil such as nickel, aluminum, copper, gold, silver, aluminum alloy, stainless steel, a metal flat plate, a mesh electrode, a carbon electrode, or the like can be used. Further, the current collector may have a catalytic effect, or the active material and the current collector may be chemically bonded. On the other hand, a separator or a nonwoven fabric made of a porous film can be used so that the positive electrode and the negative electrode are not in contact with each other.

The electrolyte contained in the separator 5 performs charge carrier transport between both electrodes of the negative electrode layer 1 and the positive electrode layer 2, and generally has an electrolyte ion conductivity of 10 ⁻⁵ to 10 ⁻¹ S / cm at room temperature. ing. In the present invention, for example, an electrolyte solution in which an electrolyte salt is dissolved in a solvent can be used as the electrolyte. As the electrolyte, for example, an electrolytic solution in which an electrolyte salt is dissolved in a solvent can be used. Examples of such solvents include organic solvents such as ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, γ-butyrolactone, tetrahydrofuran, dioxolane, sulfolane, dimethylformamide, dimethylacetamide, and N-methyl-2-pyrrolidone. A solvent is mentioned. In the present invention, these solvents may be used alone or in combination of two or more. Examples of the electrolyte salt include LiPF ₆ , LiClO ₄ , LiBF ₄ , LiCF ₃ SO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , LiC (CF ₃ SO ₂ ) _3. , LiC (C ₂ F ₅ SO ₂ ) _{3 and the} like.

  A solid electrolyte may be used as the electrolyte. Polymeric substances used in these solid electrolytes include polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-ethylene copolymer, vinylidene fluoride-monofluoroethylene copolymer, and vinylidene fluoride. -Vinylidene fluoride polymers such as trifluoroethylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, and acrylonitrile-methyl methacrylate copolymer Polymer, acrylonitrile-methyl acrylate copolymer, acrylonitrile-ethyl methacrylate copolymer, acrylonitrile-ethyl acrylate copolymer, acrylonitrile-methacrylic acid copolymer, acrylonitrile-acrylic Acid copolymers, acrylonitrile - vinyl acetate copolymer, acrylonitrile-based polymer, further polyethylene oxide, ethylene oxide - propylene oxide copolymers, and polymers of these acrylates body or methacrylate body thereof. These polymer substances can be used in the form of a gel containing an electrolytic solution, or only the polymer substance may be used as it is.

  A conventionally known method can be used for the shape of the secondary battery in the present invention. Examples of the secondary battery shape include an electrode laminate or a wound body sealed with a metal case, a resin case, or a laminate film made of a metal foil such as an aluminum foil and a synthetic resin film. Examples of the external appearance include a cylindrical shape, a square shape, a coin shape, and a sheet shape, but the present invention is not limited to these.

  A conventionally known method can be used as a method for producing a secondary battery in the present invention. For example, a solvent is added to the active material to form a slurry, which is applied to the electrode current collector, laminated with a counter electrode via a separator, or wrapped around this with an outer package, and injected with an electrolytic solution and sealed. It is a method of stopping.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these. Unless otherwise specified, “%” in the examples represents “mass%”. The number of nitroxy radicals added per fullerene molecule can be calculated by obtaining the spin concentration from the ESR spectrum. The spin concentration means the number of unpaired electrons (radicals) per unit mass, and is a value obtained by the following method from the absorption area intensity of an electron spin resonance spectrum (hereinafter referred to as ESR spectrum), for example.

A specific measurement method is to grind a sample for ESR spectrum measurement with a mortar or the like. By this treatment, the skin effect (a phenomenon in which the microwave does not pass through to the inside) can be pulverized into particles having a size that can be ignored. A certain amount of the crushed sample is filled in a quartz glass capillary having an inner diameter of 2 mm or less, preferably 1-0.5 mm, degassed to 10 ⁻⁵ mmHg (1 mmHg is 133 Pa) or less, and sealed, and the ESR spectrum is measured. To do. The ESR spectrum is measured using, for example, a JEOL-JES-FR30 type ESR spectrometer. The spin concentration can be obtained by integrating the obtained ESR signal twice and comparing it with a calibration curve. However, in the present invention, any measuring machine and measurement conditions are applicable as long as the spin concentration can be measured correctly.

Example 1
(Synthesis Example 1: Synthesis of Compound Example 5-4)

  Tetrahedron, Vol. 52, no. 14, pp. Intermediate 1) 3.4 g (10 mmol) synthesized by the method described in 5103-5112 was dissolved in 30 ml of methanol, 0.65 g (12 mmol) of sodium methoxide was added, and the mixture was stirred and dissolved at room temperature for 2 hours. The solvent was distilled off under reduced pressure, and toluene was added to the residue for crystallization, followed by filtration to obtain 3.5 g (9.5 mmol, yield 97%) of sodium salt intermediate 2). Next, 3.0 g (8.3 mmol) of intermediate 2) was suspended in 50 ml of chlorobenzene, 0.75 g (1.0 mmol) of fullerene C60 was added, and the mixture was heated to reflux for 3 hours under a nitrogen stream. The solvent was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (developing solvent: toluene: ethanol = 9: 1) to obtain 1.1 g (yield 60%) of the target product 5-4.

ESI MS m / z 1800 (M -)
(Synthesis Example 2: Synthesis of Compound Example 5-6)

  Intermediate 2) 3.0 g (8.3 mmol) was suspended in 50 ml of chlorobenzene, 0.94 g (1.3 mmol) of fullerene C60 was added, and the mixture was heated to reflux for 3 hours under a nitrogen stream. The solvent was concentrated under reduced pressure, and the residue was purified by short silica gel column chromatography (developing solvent: toluene: ethanol = 6: 1) to obtain 1.7 g (yield 75%) of the target product 5-6.

  The average addition number was determined to be 6.4 from the spin concentration measured by ESR spectrum. It was found from the MS spectrum that the main component was a mixture having an addition number of 4-8.

  (Synthesis Example 3: Synthesis of Compound Example 8-2)

Tetrahedron, Vol. 52, no. 14, pp. Intermediate 3) 3.7 g (10 mmol) synthesized according to the method described in 5103-5112 is suspended in 50 ml of chlorobenzene, 2.0 g (2.8 mmol) of fullerene C60 is added, and heating under reflux is carried out for 3 hours under a nitrogen stream. went. The solvent was concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (developing solvent: toluene: ethanol = 12: 1) to obtain 2.3 g (yield 64%) of the target product 8-2.
ESI MS m / z 1261 (M ⁻ )
(Synthesis Example 4: Synthesis of Compound Example 8-7)

  Intermediate 3) 3.7 g (10 mmol) was suspended in 50 ml of chlorobenzene, 1.3 g (1.8 mmol) of fullerene C60 was added, and the mixture was heated to reflux for 3 hours under a nitrogen stream. The solvent was concentrated under reduced pressure, and the residue was purified by short silica gel column chromatography (developing solvent: toluene: ethanol = 8: 1) to obtain 2.3 g (yield 85%) of the target product 8-7.

  The average addition number was determined to be 5.5 from the measured spin concentration by ESR spectrum. From the MS spectrum, the main component was found to be a mixture of 3 to 8 additions.

Example 2
Preparation of Battery In a dry box equipped with a gas purifier, 50 mg of Comparative Compound (1) and 60 mg of graphite powder as an auxiliary conductive material were mixed in a glass container in an argon gas atmosphere. When 20 mg of hexafluoropropylene copolymer and 1 g of tetrahydrofuran were further added and further mixed for several minutes until the whole became uniform, a black slurry was obtained.

  Subsequently, 200 mg of the obtained slurry was dropped on the surface of an aluminum foil (area: 1.5 cm × 1.5 cm, thickness: 100 μm) provided with lead wires, so that the entire thickness was uniform with a wire bar. When the mixture was allowed to stand at room temperature for 60 minutes, the solvent tetrahydrofuran evaporated, and an electrode layer was formed on the aluminum foil.

Next, 600 mg of vinylidene fluoride-hexafluoropropylene copolymer and 1,400 mg of an electrolyte solution made of a propylene carbonate solution having an acceptor number of 18.9 containing 1 mol / l LiPF ₆ as an electrolyte salt were mixed, To this was further added 11.3 g of tetrahydrofuran, and the mixture was stirred at room temperature. After the vinylidene fluoride-hexafluoropropylene copolymer is dissolved, this solution is applied onto a stepped glass plate, and allowed to stand at room temperature for 1 hour to naturally dry tetrahydrofuran, and a gel electrolyte membrane having a thickness of 1 mm A cast film was obtained.

  Next, a gel electrolyte film cut out to 2.0 cm × 2.0 cm is laminated on the aluminum foil on which the electrode layer is formed, and further a lithium-laminated copper foil (lithium film thickness 30 μm, copper foil film) provided with a lead wire After stacking 20 μm thick), the whole was sandwiched between 5 mm thick polytetrafluoroethylene sheets, and pressure was applied to produce a battery 101.

  Batteries 102 to 130 were the same as described above except that the compounds shown in Table 1 were used instead of the comparative compound (1), and the amount of carbon graphite in the auxiliary conductive material was changed to the amount shown in Table 1, respectively. Was made. The results are shown in Table 1.

(Evaluation methods)
(Evaluation of steady operation)
The batteries 101 to 130 manufactured as described above were charged / discharged at a constant current (0.1 mA) and at a cut-off voltage (charging 4.2 V, discharging 2.5 V). The evaluation criteria are as follows.

○: A voltage flat part is recognized in the vicinity of 2.9V, and it operates as a battery, and charging / discharging is possible for 10 cycles or more. Δ: A voltage flat part is recognized in the vicinity of 2.9V, and it operates as a battery. When the battery was repeatedly charged and discharged for 5 cycles or more, the voltage was clearly reduced. ×: A flat voltage portion was not recognized and the battery did not operate.

(Evaluation of discharge duration)
In the evaluation of steady operation, the battery of the above ○ was discharged at a constant current of 0.1 mA, and the time until the voltage became 1 V or less was measured.

(Evaluation of storage stability)
In the evaluation of steady operation, a large number of the above-mentioned batteries were produced, and initial charge / discharge was performed for 10 cycles. Subsequently, after charging under the same conditions as described above, five batteries were stored in a thermostatic chamber having an explosion-proof structure set to 60 ° C. Seven days later, the battery was taken out, discharged under the same conditions as described above, and the “discharge capacity after storage” was measured. For each battery, “self-discharge rate (%)” was calculated according to the following calculation formula.

  The results obtained above are shown in Table 1.

  From Table 1, since the active material, secondary battery, and radical / fullerene compound of the present invention are excellent in conductivity, the amount of the collector such as carbon graphite can be extremely reduced when forming the electrode active material layer. It can be seen that the difference between the theoretical capacity and the actual battery capacity is extremely small.

  It can also be seen that the active material, the secondary battery, and the radical / fullerene compound of the present invention have a high energy density.

  Furthermore, it can be seen that the active material, secondary battery, and radical / fullerene compound of the present invention are chemically and electrically stable.

It is a front section of the rechargeable battery concerning the present invention. It is sectional drawing of the secondary battery which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Negative electrode layer 2 Positive electrode layer 3 Negative electrode collector 4 Positive electrode collector 5 Separator 6 Sealing material

Claims (7)

Results of addition reaction of a carbene formed from a compound having at least 1 to 5 nitroxy radical groups in one molecule and a group capable of forming a carbene in the presence of a base to a carbon-carbon double bond of fullerene An active material characterized by containing a body. The active material according to claim 1, wherein the fullerene is C60. 3. The active material according to claim 1, wherein the active material is a mixture of a product having an addition number of carbene per molecule of the fullerene of 1 or more and 12 or less. The compound having both 1 and 5 or less nitroxy radical groups in one molecule and a group capable of forming a carbene in the presence of a base is selected from the compounds represented by the following general formulas (1) to (4). It is at least 1 type, The active material as described in any one of Claims 1-3 characterized by the above-mentioned.

(Wherein R _{1 to} R ₁₈ each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. X _{1 to} X ₄ each independently represent> CH ₂ or> N—O.). Ts represents a p-toluenesulfonyl group.) The active material according to claim 4, comprising at least one compound represented by the following general formulas (5) to (8).

(Wherein, fullerene skeleton is _C60, R 1 _{to R 18} and _X 1 to X ₄ is _R 1 _{to R 18} and _X 1 to X ₄ of the compound represented by the general formula (1) to (4) The two dotted lines in the formula represent that they are attached to the (5,6) bond at an arbitrary position of fullerene C60, and q, n, m, and p are 0 or more and 11 or less, respectively. Represents the number of A secondary battery comprising the active material according to claim 1. A radical / fullerene compound represented by the following general formulas (16) to (18):

(In the formula, the fullerene skeleton is C60, R _{25 to} R ₃₈ each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. X _{11 to} X ₁₄ are each independently> CH ₂ or> N-O .. Two dotted lines in the formula indicate that they are attached to the (5,6) bond at an arbitrary position of fullerene C60, and n1, m1, and p1 are each a number of 0 or more and 11 or less. Represents.)

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