JP5526399B2 - Electrode active material, method for producing the same, and secondary battery - Google Patents

Description

  The present invention provides an electrode active material having a high capacity density and capable of extracting a large current, a battery having a high energy density and a large output, and an electrode active material having the above characteristics. It relates to a possible radical compound.

  In recent years, portable electronic devices such as notebook computers and mobile phones are rapidly spreading with the development of communication systems, and their performance is also improving year by year. In particular, portable devices tend to increase power consumption as performance improves. Therefore, demands for high energy density, high output, etc. are increasing for the battery as the power source.

  As a high energy density battery, a lithium ion battery has been developed and widely used since the 1990s. This lithium ion battery uses, for example, lithium-containing transition metal oxides such as lithium manganate and lithium cobaltate for the positive electrode and carbon for the negative electrode as the electrode active material. Charging / discharging is performed using a separation reaction. Such a lithium ion battery has high energy density and excellent cycle characteristics, and is used in various electronic devices such as mobile phones. However, since the reaction rate of the electrode reaction is small, the battery performance is significantly lowered when a large current is taken out. For this reason, it is difficult to produce a large output, and there is a disadvantage that it takes a long time for charging.

  An electric double layer capacitor is known as an electricity storage device capable of producing a large output. Since a large current can be discharged at one time, it is possible to produce a large output, and it has excellent cycle characteristics, and is being developed as a backup power supply. However, since the energy density is very small and it is difficult to reduce the size, it is not suitable as a power source for portable electronic devices.

  In order to obtain an electrode material that is lightweight and has a large energy density, a battery using a sulfur compound or an organic compound as an electrode active material has been developed. For example, Patent Documents 1 and 2 disclose batteries using an organic compound having a disulfide bond as a positive electrode. This is an electrochemical redox reaction involving generation and dissociation of disulfide bonds, which is used as a battery principle. Since this battery is composed of an electrode material mainly composed of an element having a small specific gravity such as sulfur or carbon, it has a certain effect in terms of a high-capacity battery having a high energy density. However, due to the low efficiency with which the dissociated bonds are recombined and the diffusion of the electrode active material into the electrolyte, there are drawbacks in that the capacity tends to decrease with repeated charge / discharge cycles.

  In addition, as a battery using an organic compound, a battery using a conductive polymer as an electrode material has been proposed. This is a battery based on the principle of doping and dedoping of electrolyte ions with respect to a conductive polymer. The dope reaction is a reaction in which a charged radical generated by oxidation or reduction of a conductive polymer is stabilized by a counter ion. Patent Document 3 discloses a battery using such a conductive polymer as a positive electrode or negative electrode material. This battery was composed only of elements having a small specific gravity such as carbon and nitrogen, and was expected as a high capacity battery. However, conductive polymers have the property that charged radicals generated by redox are delocalized over a wide range of π-electron conjugated systems and interact with each other, resulting in electrostatic repulsion and radical disappearance. . This limits the generated charged radicals, that is, the doping concentration, and limits the capacity of the battery. For example, it has been reported that the doping rate of a battery using polyaniline as a positive electrode is 50% or less, and 7% in the case of polyacetylene. A battery using a conductive polymer as an electrode material has a certain effect in terms of weight reduction, but a battery having a large energy density has not been obtained.

  As a battery using an organic compound as a battery electrode active material, a battery using a redox reaction of a radical compound has been proposed. For example, Patent Document 4 discloses an organic radical compound such as a nitroxide radical compound, an aryloxy radical compound, and a polymer compound having a specific aminotriazine structure as an active material, and the organic radical compound is used as a positive electrode or a negative electrode. A battery used as a material is disclosed. Further, Patent Document 5 discloses a power storage device using a compound having a cyclic nitroxide structure as an electrode active material among nitroxide compounds. Further, the radical compound used as an electrode active material therefor is 2, m-chloroperbenzoic acid after polymerization by reacting 2,2,6,6-tetramethylpiperidine methacrylate with azobisisobutyronitrile as a polymerization initiator. It is synthesized by oxidizing with an acid.

US Pat. No. 4,833,048 Japanese Patent No. 2715778 U.S. Pat. No. 4,442,187 JP 2002-151084 A JP 2002-304996 A

  As described above, in a lithium ion battery using a transition metal oxide for the positive electrode, it is difficult to manufacture a battery having a high energy density per weight and a large output. Moreover, although the electric double layer capacitor has a large output, the energy density per weight is low and it is difficult to increase the capacity. In addition, a battery using a sulfur compound or a conductive organic compound as an electrode active material has not yet obtained a battery having a high energy density. Moreover, the battery using the oxidation-reduction reaction of the organic radical compound has a problem that the electrode is cracked by the battery manufacturing method and cannot be easily manufactured. Therefore, a new electrode manufacturing process that is simpler and a new material that can simplify the process are desired. In addition, materials with greater energy density are also desired.

  An object of the present invention is to provide an electrode active material having a high capacity density and capable of taking out a large current, and a battery having a high energy density and capable of producing a large output.

Further, the present invention aims at providing a method of manufacturing the electrode Katsubutsu quality.

  As a result of intensive studies by the present inventors, a specific organic compound that has not been used as an electrode active material until now, that is, a radical compound having a partial structure represented by the following general formula (1) in the molecule is used as an electrode active. It discovered that the said subject could be solved by utilizing as a substance. That is, according to the present invention, by using a radical compound having a partial structure represented by the following general formula (1) in the molecule as an electrode active material, a novel battery using the redox of this site is obtained. A novel battery capable of producing a high energy density and a large output (more specifically, capable of discharging a large current) can be provided.

  That is, the present invention is an electrode active material comprising a radical compound having a partial structure represented by the following general formula (1).

（一般式（１）においてＡは、窒素を含む複素環が５〜７員環を形成する置換基を有する。Ｒ^１、Ｒ^２、Ｒ^３、Ｒ^４はそれぞれ異なっていてもよく、水素原子またはメチル基を示す。Ｒ^５は水素原子、ハロゲン原子、置換もしくは非置換のアルキル基、置換もしくは非置換の芳香族炭化水素基、置換もしくは非置換の芳香族複素環基、置換もしくは非置換のアルコキシ基、置換もしくは非置換のアリールオキシ基、置換もしくは非置換のシリルオキシ基等を表す。）

(In General Formula (1), A has a substituent in which a nitrogen-containing heterocyclic ring forms a 5- to 7-membered ring. R ¹ , R ² , R ³ , and R ⁴ may be different from each other, and may be a hydrogen atom. Or R ⁵ represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, a substituted or unsubstituted group; Represents an alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted silyloxy group, etc.)

  In the battery of the present invention, the radical compound having the partial structure represented by the general formula (1) undergoes an oxidation-reduction reaction as shown in the following scheme (I) or (II) during the charge / discharge process. In the oxidation-reduction reaction of scheme (I), when a radical compound having a partial structure represented by the general formula (1) is used for the positive electrode, the state changes from (A) to (B) by charging, and electrons are released. The The state changes from (B) to (A) by discharging, and receives electrons. In addition, in the oxidation-reduction reaction of (II), when a polymer is used for the positive electrode, the state changes from (C) to (A) by charging, and electrons are emitted. The state changes from (A) to (C) by discharge, and receives electrons. In view of the stability of the oxidation-reduction reaction of the polymer, it is preferable to perform charge / discharge using the oxidation-reduction of scheme (I).

  In the battery, the electrode active material is oxidized or reduced by charge / discharge, and therefore the electrode active material takes two states, a starting state and a reduced state. In the present invention, the electrode active material has a structure represented by the general formula (1) in either a charged state or a discharged state.

  The present invention has been made based on the finding that a radical compound having a partial structure represented by the general formula (1) is excellent as an electrode active material. This is because the radical compound having the partial structure represented by the general formula (1) causes a reversibly stable redox reaction at a rate of almost 100% which hardly causes side reactions. That is, a battery using a radical compound having a partial structure represented by the general formula (1) as an electrode active material can be stably charged and discharged, and has excellent cycle characteristics. A battery using a radical compound having a partial structure represented by the general formula (1) as an electrode active material has excellent high output characteristics as compared with a conventional lithium ion battery. This is because a substituent of the radical compound having the partial structure represented by the general formula (1) has a large electrode reaction rate, and thus a large current can be discharged at a time. Moreover, the radical compound which has a partial structure represented by General formula (1) can be comprised only from elements with small mass, such as carbon, nitrogen, hydrogen, and oxygen. For this reason, the mass of the electrode active material can be reduced, and the capacity density per unit mass of an electrode manufactured using the same can be increased. As a result, when a battery is produced using this electrode active material, the energy density per mass is Becomes a big battery.

  In the present invention, the radical compound having the partial structure represented by the general formula (1) may directly contribute to the electrode reaction at the positive electrode or the negative electrode, and the electrode used as the electrode active material is the positive electrode or the negative electrode. It is not limited to any of the above. However, from the viewpoint of energy density, it is particularly preferable to use a radical compound having a partial structure represented by the general formula (1) as the electrode active material of the positive electrode. In addition, the battery of the present invention is preferably a lithium battery using carbon in which metallic lithium or lithium ions can be inserted and removed from the negative electrode, particularly a lithium secondary battery, from the viewpoint that a high voltage and a large capacity can be obtained.

  In addition, the radical compound used as an electrode active material by this invention can be manufactured with the following method. That is, in the present invention, in the presence of a transition metal catalyst, at least a radical-substituted alcohol compound represented by the following general formula (3) is reacted with a silicone compound represented by the following general formula (4) to give a general formula (1) A radical compound having a partial structure represented by the formula:

（一般式（３）においてＡは、窒素を含む複素環が５〜７員環を形成する置換基を有する。Ｒ^１、Ｒ^２、Ｒ^３、Ｒ^４はそれぞれ異なっていてもよく、水素原子またはメチル基を示す。）

(In General Formula (3), A has a substituent in which a nitrogen-containing heterocyclic ring forms a 5- to 7-membered ring. R ¹ , R ² , R ³ , and R ⁴ may be different from each other, and a hydrogen atom Or represents a methyl group.)

（一般式（４）において、Ｒは水素原子、ハロゲン原子、置換もしくは非置換のアルキル基、置換もしくは非置換の芳香族炭化水素基、置換もしくは非置換の芳香族複素環基、置換もしくは非置換のアルコキシ基、置換もしくは非置換のアリールオキシ基、置換もしくは非置換のシリルオキシ基等を表す。）

(In the general formula (4), R represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, substituted or unsubstituted. Represents an alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted silyloxy group, etc.)

The present invention proposes an electrode active material containing a radical compound having a partial structure represented by the general formula (1) and a new battery using this electrode active material. Thereby, it is possible to provide an electrode active material having a high capacity density and capable of extracting a large current, and a battery having a high energy density and a large output. Therefore, according to the present invention, it is possible to produce a battery composed of a light and safe element that does not contain heavy metals as an electrode active material, and has a high capacity (per mass) and a charge / discharge cycle. It is possible to realize a battery that is excellent in stability and can produce a larger output. Moreover, the manufacturing method of the electrode active material containing said radical compound can be provided.

It is a conceptual diagram which shows an example of a structure of the battery of this invention.

  FIG. 1 shows the configuration of one embodiment of the battery of the present invention. The battery shown in FIG. 1 has a configuration in which a positive electrode 5, a negative electrode 3, and a separator 4 containing an electrolyte are stacked so as to face each other, and a positive electrode current collector 6 is 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. . In addition, when using solid electrolyte and gel electrolyte as electrolyte, it can replace with the separator 4 and can also be made into the form which interposes these electrolytes between electrodes.

  In the present invention, in such a configuration, the electrode active material used for the negative electrode 3 or the positive electrode 5 or both electrodes is an electrode active material containing a radical compound having a partial structure represented by the following general formula (1). It is characterized by being.

  From the viewpoint of battery capacity, the battery of the present invention is preferably a lithium battery using the above electrode active material as a positive electrode active material, particularly a lithium secondary battery.

[1] Electrode active material The electrode active material of the electrode in the present invention is a material that directly contributes to electrode reactions such as charge reaction and discharge reaction, and plays a central role in the battery system.

  In the present invention, an electrode active material containing the radical compound represented by the general formula (1) is used as the electrode active material.

  In the battery of the present invention, the electrode active material may be fixed to the electrode, or may be dissolved or dispersed in the electrolyte. However, when used in a state of being fixed to the electrode, in order to suppress a decrease in capacity due to dissolution in the electrolytic solution, it is preferably insoluble or low-soluble in the electrolytic solution in the solid state. At this time, it may swell as long as it is insoluble or has low solubility in the electrolytic solution. This is because when the solubility in the electrolytic solution is high, the electrode active material is eluted from the electrode into the electrolytic solution, so that the capacity may decrease with the charge / discharge cycle.

  Therefore, the radical compound having a partial structure represented by the general formula (1) preferably has a number average molecular weight of 500 or more, more preferably a number average molecular weight of 2000 or more, and a number average molecular weight of 5000. More preferably, it is the above. This is because when the number average molecular weight is 500 or more, it is difficult to dissolve in the battery electrolyte, and when the number average molecular weight is 2000 or more, it is almost insoluble. The shape may be any of a chain, a branch, and a mesh. In addition, the obtained polymer is difficult to dissolve in dimethylformamide, tetrahydrofuran, etc., and the molecular weight may not be measured. A structure that is crosslinked with a crosslinking agent may also be used. The number average molecular weight is a value calculated by measuring the DMF soluble part of the sample by GPC using dimethylformamide (DMF) as an eluent.

  As said radical compound, the homopolymer which has only the partial structure represented by General formula (1) can be used, and the copolymer which has another partial structure can also be used. For the convenience of synthesis, a homopolymer is preferred. In the case of a copolymer, the partial structure represented by the general formula (1) is preferably 60 mol% or more, more preferably 70 or more mol%, more preferably 80 mol% with respect to the entire polymer compound. More preferably, it is 90 mol%. This is because the battery capacity increases as the proportion of the partial structure represented by the general formula (1) in the radical compound increases.

  Moreover, as said radical compound, you may have a disiloxane (Si-O-Si) bond partially. This is because some side reactions may occur at the stage of introducing radicals into silicone.

  Examples of the radical compound having a partial structure represented by the general formula (2) include radical compounds having a partial structure represented by the following formulas (5) to (9).

The radical compound having a partial structure represented by the above formula (5) can be synthesized, for example, by the route shown in the following synthesis scheme (10). That is, it can be synthesized by a method in which a radical-substituted alcohol compound and a silicone compound are reacted in the presence of a transition metal catalyst. As the silicone compound, polymethylhydrosiloxane (PMHS) can be used. Examples of the transition metal catalyst used include [RhCl (cod)] ₂ , RhCl (PPh ₃ ) ₃ (Wilkinson's catalyst) complex, (Bu ₄ N) ₂ PtCl ₆ , K ₂ PtCl ₆ , and the like. It can be synthesized by reacting hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO-OH).

  The compound represented by the above formula (5) can also be synthesized by a similar method. In that case, the target radical compound can be synthesized by appropriately changing the synthesis scheme, raw materials to be used, reaction conditions and the like, and combining known synthesis techniques. This reaction is preferably performed in an organic solvent. As the organic solvent, a general organic solvent such as tetrahydrofuran, toluene, dimethylformamide, dichloromethane, chloroform, etc. can be used, but from the viewpoint of monomer solubility, it is preferably carried out in a tetrahydrofuran solvent.

  Moreover, in the electrode active material of one electrode of the battery of the present invention, the radical compound having the partial structure represented by the general formula (1) can be used alone, but two or more kinds may be used in combination. good. Moreover, you may use in combination with another electrode active material. At this time, the electrode active material preferably contains 10 to 90% by mass of a radical compound having a partial structure represented by the general formula (1), more preferably 20 to 80% by mass. preferable.

When a radical compound having a partial structure represented by the general formula (1) is used for the positive electrode, a metal oxide, a disulfide compound, another stable radical compound, a conductive polymer, or the like is combined as another electrode active material. Can do. 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 _y V ₂ O ₅ (0 <y <2), olivine-based material LiFePO ₄ , a material obtained by substituting a part of Mn in the spinel structure with another transition metal, 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 0.8 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. Other stable radical compounds include poly (4-methacryloyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl), poly (4-acryloyloxy-2,2,6,6-tetramethylpiperidine -N-oxyl), poly (4-vinyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl) and the like. Examples of the conductive polymer include polyacetylene, polyphenylene, polyaniline, and polypyrrole. Among these, it is particularly preferable to combine with lithium manganate or LiCoO ₂ . In the present invention, these other electrode active materials can be used alone or in combination of two or more.

  When the radical compound having the partial structure represented by the general formula (1) is used for the negative electrode, as other electrode active materials, graphite, amorphous carbon, metallic lithium, lithium alloy, lithium ion occlusion carbon, metallic sodium, conductive Can be used. Moreover, you may use another stable radical compound. Other stable radical compounds include poly (4-methacryloyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl), poly (4-acryloyloxy-2,2,6,6-tetramethylpiperidine -N-oxyl), poly (4-vinyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl) and the like. These shapes are not particularly limited. For example, metallic lithium is not limited to a thin film shape, and may be a bulk shape, a powdered shape, a fiber shape, a flake shape, or the like. Among these, it is preferable to combine with metallic lithium or graphite. These other electrode active materials can be used alone or in combination of two or more.

  The battery of the present invention uses a radical compound having a partial structure represented by the general formula (1) as an electrode active material in one electrode reaction of the positive electrode or the negative electrode, or in both electrode reactions. When using as an electrode active material, conventionally well-known electrode active materials as exemplified above can be used as the electrode active material in the other electrode. These electrode active materials can be used alone or in combination of two or more kinds, and a combination of at least one of these electrode active materials and a radical compound having a partial structure represented by the general formula (1). It may be used. Moreover, the radical compound which has the partial structure represented by General formula (1) can also be used independently.

In the present invention, the radical compound having the partial structure represented by the general formula (1) may directly contribute to the electrode reaction at the positive electrode or the negative electrode, and the electrode used as the electrode active material is either a positive electrode or a negative electrode. It is not limited to crab. However, from the viewpoint of energy density, it is particularly preferable to use a radical compound having a partial structure represented by the general formula (1) as the electrode active material of the positive electrode. At this time, as the positive electrode active material, a radical compound having a partial structure represented by the general formula (1) is preferably used alone. However, it can also be used in combination with another positive electrode active material, and as the other positive electrode active material at that time, lithium manganate or LiCoO ₂ is preferable. Furthermore, when using said positive electrode active material, it is preferable to use metallic lithium or graphite as a negative electrode active material.

[2] Conductivity-imparting agent (auxiliary conductive material) and ion conduction auxiliary material When forming an electrode using the radical compound represented by the general formula (1), the impedance is lowered, and the energy density and output characteristics are improved. For the purpose, a conductivity-imparting agent (auxiliary conductive material) or an ion conduction auxiliary material may be mixed. Among these materials, auxiliary conductive materials include carbonaceous fine particles such as graphite, carbon black, and acetylene black, carbon fibers such as vapor grown carbon fiber (VGCF) and carbon nanotube, polyaniline, polypyrrole, polythiophene, polyacetylene, and polyacetylene. Examples of the ionic conduction auxiliary material include a polymer gel electrolyte and a polymer solid electrolyte. Among these, it is preferable to mix carbon fibers. By mixing carbon fiber, the tensile strength of the electrode is increased, and the electrode is less likely to crack or peel off. More preferably, it is more preferable to mix vapor growth carbon fiber. These materials can be used alone or in admixture of two or more. As a ratio of these materials in an electrode, 10-80 mass% is preferable.

[3] Binder A binder can also be used to strengthen the connection between the constituent materials of the electrode. Examples of such binders include polytetrafluoroethylene, polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, styrene / butadiene copolymer rubber, polypropylene, and polyethylene. Resin binders such as polyimide and various polyurethanes. These resin binders can be used alone or in admixture of two or more. As a ratio of the binder in an electrode, 5-30 mass% is preferable.

[4] Catalyst In order to perform the electrode reaction more smoothly, a catalyst that assists the redox reaction can be used. Examples of such catalysts 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. Can be mentioned. These catalysts can be used alone or in admixture of two or more. The ratio of the catalyst in the electrode is preferably 10% by mass or less.

[5] Current collector and separator As the negative electrode current collector and the positive electrode current collector, foils made of nickel, aluminum, copper, gold, silver, aluminum alloy, stainless steel, carbon, etc., metal flat plates, mesh shapes, etc. Things 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, a separator such as a porous film or non-woven fabric made of polyethylene, polypropylene, or the like can be used so that the positive electrode and the negative electrode are not in contact with each other.

[6] Electrolyte In the present invention, the electrolyte 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 electrolyte, 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 ) ₃ C Conventionally known materials such as Li (C ₂ F ₅ SO ₂ ) ₃ C can be used. These electrolyte salts can be used alone or in admixture of two or more.

  When a solvent is used for the electrolytic solution, examples of the solvent include ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, γ-butyrolactone, tetrahydrofuran, dioxolane, sulfolane, dimethylformamide, dimethylacetamide, N-methyl- An organic solvent such as 2-pyrrolidone can be used. These solvents can be used alone or in admixture of two or more.

  Furthermore, in the present invention, a solid electrolyte can be used as the electrolyte. Polymer compounds used in these solid electrolytes include polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-ethylene copolymer, vinylidene fluoride-monofluoroethylene copolymer, 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 Le 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 compounds may be used in the form of a gel containing an electrolytic solution, or only a polymer compound containing an electrolyte salt may be used as it is.

[7] Battery shape In the present invention, the shape of the battery is not particularly limited, and a conventionally known battery can be used. Examples of the 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, etc. A mold, a coin mold, and a sheet mold are used, but the present invention is not limited to these.

[8] Battery Manufacturing Method The battery manufacturing method is not particularly limited, and a method appropriately selected according to the material can be used. For example, a solvent is added to an electrode active material, a conductivity-imparting agent, etc. to form a slurry, which is applied to an electrode current collector, and the electrode is produced by heating or volatilizing the solvent at room temperature, and this electrode is sandwiched between a counter electrode and a separator. And then wrapped or wrapped in an outer package, and an electrolyte solution is injected and sealed. Solvents for slurrying include ether solvents such as tetrahydrofuran, diethyl ether and ethylene glycol dimethyl ether, amine solvents such as N, N-dimethylformamide and N-methylpyrrolidone, and aromatic carbonization such as benzene, toluene and xylene. Hydrogen solvents, aliphatic hydrocarbon solvents such as hexane and heptane, halogenated hydrocarbon solvents such as chloroform, dichloromethane, dichloroethane, trichloroethane and carbon tetrachloride, alkyl ketone solvents such as acetone and methyl ethyl ketone, methanol, ethanol, Examples include alcohol solvents such as isopropyl alcohol, dimethyl sulfoxide, and the like. In addition, as a method for manufacturing an electrode, there is a method in which an electrode active material, a conductivity-imparting agent, and the like are kneaded in a dry method and then thinned and laminated on an electrode current collector. In the production of electrodes, in particular, in the case of a method in which a solvent is added to an organic electrode active material, a conductivity imparting agent, etc. and applied to an electrode current collector, and the solvent is volatilized by heating or at room temperature, peeling of the electrode, cracking, etc. Is likely to occur. When a radical compound having a partial structure represented by the general formula (2) of the present invention is used, and an electrode having a thickness of preferably 80 μm or more and 500 μm or less is produced, the electrode is less likely to be peeled off or cracked, and the like. This makes it possible to produce a simple electrode.

When manufacturing a battery, the case where the battery is manufactured using the radical compound itself represented by the general formula (1) as the electrode active material, and the radical compound represented by the general formula (1) by the electrode reaction In some cases, a battery is produced using a changing polymer. Examples of the polymer that changes to the radical compound represented by the general formula (1) by such an electrode reaction include an anion body obtained by reducing the radical compound represented by the general formula (2), lithium ion, and sodium. lithium salt or sodium salt consisting electrolyte cations such as ions, or the general formula (1) oxidizing a compound represented by the cationic material and PF ₆ ^-, and the like salts comprising a like electrolyte anion ^- or BF ₄ .

  In the present invention, a conventionally known method can be used as a method for manufacturing a battery for other manufacturing conditions such as taking out leads from electrodes and packaging.

  Hereinafter, although the detail of this invention is concretely demonstrated by a synthesis example and an Example, this invention is not limited to these Examples.

(Synthesis Example 1)
According to the synthesis scheme (11) shown below, a radical compound having a partial structure represented by the above formula (5) was synthesized.

Poly [methyl (2,2,6,6-tetramethylpiperidine-N-oxyl-4-oxy) siloxane] (A1)

Under an argon atmosphere, TEMPO-OH 17.2 g (100 mmol), tetrahydrofuran 100 mL, chloro (1,5-cyclooctadiene rhodium (I), dimer ([RhCl (cod)] ₂ 98 mg (0.2 mmol; 25 mol%) and 5.0 g (83.2 mmol) of polymethylhydrosiloxane (PMHS) were added and stirred at room temperature for 6 hours After the reaction was completed, the solvent was distilled off by an evaporator, and then hexane was added and stirred at room temperature ( Washed by adding diethyl ether and stirring at room temperature (500 mL × 3 times), followed by vacuum drying (40 ° C.) to obtain Poly [methyl (2,2,6, 6-tetramethylpiperidine-N-oxyl-4-oxy ) Siloxane] was obtained in a yield of 44%, and the obtained polymer (A) was insoluble in an organic solvent, and its molecular weight could not be measured, and the spin density of the radical compound determined by ESR spectrum was 2.50 ×. 10 ²¹ spin / g (96%) The glass transition temperature of the radical compound was observed at 44 ° C.

(Synthesis Example 2)
According to the synthesis scheme (12) shown below, a radical compound having a partial structure represented by the above formula (5) was synthesized using a catalyst different from Synthesis Example 1.

[2] Synthesis of Poly [methyl (2,2,6,6-tetramethylpiperidine-N-oxyl-4-oxy) siloxane] (A2)

Under an argon atmosphere, TEMPO-OH 17.2 g (100 mmol), tetrahydrofuran 100 mL, chlorotris (triphenylphosphine) rhodium (I) (RhCl (PPh ₃ ) ₃ ) 196 mg (0.2 mmol; 0.25 mol%), poly Add 5.0 g (83.2 mmol) of methylhydrosiloxane (PMHS) and stir at room temperature for 6 h. After completion of the reaction, the solvent was removed by an evaporator, hexane was added, and the mixture was stirred at room temperature (500 mL × 3 times). Furthermore, diethyl ether was added and it wash | cleaned by stirring at room temperature (500 mL x 3 times). After washing, it was vacuum dried (40 ° C.) to obtain Poly [methyl (2,2,6,6-tetramethylpiperidine-N-oxyl-4-oxy) siloxane] with a yield of 46%. The obtained polymer (A2) was insoluble in an organic solvent, and the molecular weight could not be measured. The spin density of the radical compound determined by ESR spectrum was 2.48 × 10 ²¹ spin / g (95%). The glass transition temperature of the radical compound was observed at 44 ° C.

(Synthesis Example 3)
A radical compound having a partial structure represented by the following formula (6) was synthesized according to the synthesis scheme (13) shown below.

[3] Synthesis of Poly [methyl (2,2,5,5-tetramethylpyrrolidine-N-oxyl-4-oxy) siloxane] (A3)

Under an argon atmosphere, 200 mL Schlenk was charged with 15.8 g (47.1 mmol) of 3-hydroxy-2,2,5,5-tetramethylpyrrolidine-N-oxyl, 100 mL of tetrahydrofuran, chlorotris (triphenylphosphine) rhodium (I) (RhCl (PPh ₃ ) ₃ ) 196 mg (0.2 mmol; 0.25 mol%) and polymethylhydrosiloxane (PMHS) 5.0 g (83.2 mmol) are added and stirred at room temperature for 6 h. After completion of the reaction, the solvent was removed by an evaporator, hexane was added, and the mixture was stirred at room temperature (500 mL × 3 times). Furthermore, diethyl ether was added and it wash | cleaned by stirring at room temperature (500 mL x 3 times). After washing, it was vacuum dried (40 ° C.) to obtain Poly [methyl (2,2,5,5-tetramethylpyrrolidine-N-oxyl-4-oxy) siloxane] with a yield of 46%. The obtained polymer (A3) was insoluble in an organic solvent, and the molecular weight could not be measured. The spin density of the radical compound determined by ESR spectrum was 2.66 × 10 ²¹ spin / g (95%). The glass transition temperature of the radical compound was observed at 42 ° C.

Example 1
200 mg of the radical compound (A1) synthesized in Synthesis Example 1, 700 mg of graphite powder, and 100 mg of polytetrafluoroethylene (PTFE) resin binder were weighed and kneaded using an agate mortar. 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 80 ° C. in a vacuum, and then punched into a circle with a diameter of 12 mm to form a coin battery electrode. The mass of this electrode was 15.0 mg.

Next, the obtained electrode was immersed in an electrolytic solution, and the electrolytic solution was infiltrated into voids in the electrode. As the electrolytic solution, an ethylene carbonate / diethyl carbonate mixed solution (mixing volume ratio 3: 7) containing 1.0 mol / L LiPF ₆ electrolyte salt was used. The electrode impregnated with the electrolytic solution was placed on the positive electrode current collector, and a polypropylene porous film separator impregnated with the electrolytic solution was laminated thereon. Further, a lithium-laminated copper foil serving as a negative electrode was laminated, and the respective stainless steel exteriors were superposed from the positive electrode side and the negative electrode side in a state where an insulating packing was arranged around the lithium foil. By applying pressure with a caulking machine, a sealed coin-type battery using a radical compound (A1) as a positive electrode active material and metallic lithium as a negative electrode active material was obtained.

  The coin battery fabricated as described above was charged with a constant current of 0.1 mA until the voltage reached 4.0 V, and then discharged to 3.0 V with a constant current of 0.1 mA. As a result, the voltage became substantially constant for about 3 hours and 10 minutes around 3.5 V, and then dropped rapidly. The discharge capacity per electrode active material was 110 mAh / g. Similarly, charging / discharging was repeated 50 times in the range of 4.0-3.0V. As a result, in all 50 charge / discharge cycles, the voltage was constant at around 3.5 V during discharge, and (50th discharge capacity) / (1st discharge capacity) was 97%.

  Next, the coin battery was charged with a constant current of 0.1 mA until the voltage reached 4.0 V, and then discharged with a constant current of 5.0 mA. As a result, the voltage became constant around 3.4 V and then dropped rapidly. (Discharge capacity at 5.0 mA discharge) / (discharge capacity at 0.1 mA discharge) was 93%.

(Example 2)
20 g of N-methylpyrrolidone was weighed into a small homogenizer container, 300 mg of polyvinylidene fluoride (PVdF) was added, and stirred for 30 minutes to completely dissolve. Thereto, 200 mg of the radical compound (A1) was added and stirred for 5 minutes until the whole became a uniform orange color. To this was added 500 mg of vapor grown carbon fiber (VGCF), and the mixture was further stirred for 15 minutes to obtain a slurry. The obtained slurry was applied on an aluminum foil and dried at 120 ° C. to produce a positive electrode. The thickness of the positive electrode layer was 120 μm. The produced electrode was not peeled off or cracked, and the surface was uniform. This was punched out into a circle with a diameter of 12 mm to mold a coin battery electrode. In addition, the mass of this electrode was 16.2 mg (of which aluminum foil was 6.0 mg).

Next, the obtained electrode was immersed in an electrolytic solution, and the electrolytic solution was infiltrated into voids in the electrode. As the electrolytic solution, an ethylene carbonate / diethyl carbonate mixed solution (mixing volume ratio 3: 7) containing 1.0 mol / L LiPF ₆ electrolyte salt was used. The electrode impregnated with the electrolytic solution was placed on a positive electrode current collector (aluminum foil), and a polypropylene porous film separator impregnated with the electrolytic solution was laminated thereon. Furthermore, the copper foil which attached | coated the graphite layer used as a negative electrode on one side was laminated | stacked, and each stainless steel exterior was piled up from the positive electrode side and the negative electrode side in the state which has arrange | positioned the insulating packing around. By applying pressure with a caulking machine, a sealed coin-type battery using a radical compound (A1) as a positive electrode active material and graphite as a negative electrode active material was obtained.

  The coin battery fabricated as described above was charged with a constant current of 0.1 mA until the voltage reached 4.0 V, and then discharged to 3.0 V with a constant current of 0.1 mA. As a result, the voltage became substantially constant at around 3.5 V for about 2 hours and 10 minutes, and then dropped rapidly. The discharge capacity per electrode active material was 107 mAh / g. Similarly, charging / discharging was repeated 50 times in the range of 4.0-3.0V. As a result, in all 50 charge / discharge cycles, the voltage was constant at around 3.5 V during discharge, and (50th discharge capacity) / (1st discharge capacity) was 98%.

  Next, the coin battery was charged with a constant current of 0.1 mA until the voltage reached 4.0 V, and then discharged with a constant current of 5.0 mA. As a result, the voltage became constant around 3.4 V and then dropped rapidly. (Discharge capacity at 5.0 mA discharge) / (discharge capacity at 0.1 mA discharge) was 92%.

(Example 3)
Pure water (42 mL) and carboxymethyl cellulose (CMC) 400 mg (4 wt%) were added to a homogenizer cup, and completely dissolved with a homogenizer, and then 100 mg (1 wt%) of an aqueous dispersion of PTFE was added and stirred. Further, 2.5 g (15 wt%) of VGCF is added little by little and stirred until uniform. To the obtained black slurry, 7 g (70 wt%) of the radical compound (A1) was added and stirred until it became more uniform to prepare a slurry. Furthermore, after apply | coating the obtained slurry on aluminum foil (20 micrometers), the positive electrode was produced by making it dry at 50 degreeC. The produced electrode was not peeled off or cracked, and the surface was uniform. This was punched out into a circle with a diameter of 12 mm to mold a coin battery electrode. The mass of this electrode was 17.2 mg (including 6.0 mg for aluminum foil).

Next, the obtained electrode was immersed in an electrolytic solution, and the electrolytic solution was infiltrated into voids in the electrode. As the electrolytic solution, an ethylene carbonate / diethyl carbonate mixed solution (mixing volume ratio 3: 7) containing 1.0 mol / L LiPF ₆ electrolyte salt was used. The electrode impregnated with the electrolytic solution was placed on the positive electrode current collector, and a polypropylene porous film separator impregnated with the electrolytic solution was laminated thereon. Further, a lithium-laminated copper foil serving as a negative electrode was laminated, and the respective stainless steel exteriors were superposed from the positive electrode side and the negative electrode side in a state where an insulating packing was arranged around the lithium foil. By applying pressure with a caulking machine, a sealed coin-type battery using a radical compound (A1) as a positive electrode active material and metallic lithium as a negative electrode active material was obtained.

  The coin battery fabricated as described above was charged with a constant current of 0.1 mA until the voltage reached 4.0 V, and then discharged to 3.0 V with a constant current of 0.1 mA. As a result, the voltage became substantially constant at around 3.5 V for about 7 hours and 30 minutes, and then dropped rapidly. The discharge capacity per electrode active material was 103 mAh / g. Similarly, charging / discharging was repeated 50 times in the range of 4.0-3.0V. As a result, in all 50 charge / discharge cycles, the voltage was constant at around 3.5 V during discharge, and (50th discharge capacity) / (1st discharge capacity) was 96%.

Example 4
A coin battery was produced in the same manner as in Example 2 except that the radical compound (A2) was used instead of the radical compound (A1). The produced electrode was not peeled off or cracked, and the surface was uniform. The weight of the positive electrode of this coin battery was 16.8 mg.

  The coin battery was charged with a constant current of 0.1 mA until the voltage reached 4.0 V, and then discharged to 3.0 V with a constant current of 0.1 mA. As a result, a voltage flat portion was observed at around 3.5 V for 2 hours and 20 minutes. The discharge capacity per electrode active material was 108 mAh / g. As a result of repeating charge and discharge 50 times in the range of 4.0 to 3.0 V, (50th discharge capacity) / (1st discharge capacity) was 96%.

  Next, the coin battery was charged with a constant current of 0.1 mA until the voltage reached 4.0 V, and then discharged with a constant current of 5.0 mA. (Discharge capacity at 5.0 mA discharge) / (discharge capacity at 0.1 mA discharge) was 94%.

(Example 5)
A coin battery was produced in the same manner as in Example 2 except that the radical compound (A3) was used instead of the radical compound (A1). The produced electrode was not peeled off or cracked, and the surface was uniform. The coin battery had a positive electrode weight of 17.3 mg (of which aluminum foil was 6.0 mg).

  The coin battery was charged with a constant current of 0.1 mA until the voltage reached 4.0 V, and then discharged to 3.0 V with a constant current of 0.1 mA. As a result, a voltage flat part was observed at around 3.5 V for 2 hours 30 minutes. The discharge capacity per electrode active material was 116 mAh / g. As a result of repeating charge and discharge 50 times in the range of 4.0 to 3.0 V, (50th discharge capacity) / (1st discharge capacity) was 96%.

  Next, the coin battery was charged with a constant current of 0.1 mA until the voltage reached 4.0 V, and then discharged with a constant current of 5.0 mA. As a result, (discharge capacity at 5.0 mA discharge) / (discharge capacity at 0.1 mA discharge) was 95%.

(Comparative Example 1)
A coin battery was manufactured in the same manner as in Example 1, except that the amount of graphite powder used was increased to 900 mg instead of using the radical compound (A1).

  The produced battery was charged and discharged in the same manner as in Example 1. As a result, no flat voltage portion was observed during discharge, the voltage dropped rapidly, and the battery did not operate sufficiently.

(Comparative Example 2)
A coin battery was fabricated in the same manner as in Example 1, except that LiCoO ₂ was used instead of the radical compound (A1).

  The produced battery was charged and discharged in the same manner as in Example 1, and the discharge capacity per electrode active material was calculated to be 123 mAh / g. As a result of repeating charge and discharge 50 times in the range of 4.0 to 3.0 V, (50th discharge capacity) / (1st discharge capacity) was 96%. However, (discharge capacity at 5.0 mA discharge) / (discharge capacity at 0.1 mA discharge) was 26.8%, and the capacity was greatly reduced when the discharge current value was increased.

(Comparative Example 3)
A coin battery was fabricated in the same manner as in Example 1, except that 2,2,6,6-tetramethylpiperidinoxyl (TEMPO) was used instead of the radical compound (A1).

  The initial discharge capacity per electrode active material was 35 mAh / g. However, as a result of repeating charging and discharging 12 times in the range of 4.0 to 3.0 V, charging and discharging could not be performed, and the battery could not operate.

  As described above, the radical compound of the present invention is most suitable as an electrode active material for electrodes, particularly an electrode active material for lithium secondary batteries.

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

Claims (12)

Electrode active material characterized by containing a Lula radical compound having a partial structure represented by the following general formula (1).

(In the general formula (1), A is a trivalent substituent composed of a hydrocarbon in which a nitrogen-containing heterocyclic ring forms a 5- to 7-membered ring , and R ¹ , R ² , R ³ , and R ⁴ are different from each other. R ⁵ represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, It represents any one of a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, and a substituted or unsubstituted silyloxy group .) In the electrode active material according to claim 1, the compound having the structure represented by the general formula (1), characterized in that a polymer having a repeating unit represented by the following general formula (2) electrode Active material .

(In the general formula (2), A is a trivalent substituent composed of a hydrocarbon in which a nitrogen-containing heterocyclic ring forms a 5- to 7-membered ring , and R ¹ , R ² , R ³ , and R ⁴ are different from each other. R ⁵ represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, It represents any of a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted silyloxy group , and n represents an integer of 10 to 1000.) A radical compound represented by the following general formula (2), the electrode active material characterized by containing a Lula radical compound having a repeating unit represented by the following general formula (1) 70 mol% or more.

(In general formula (2), A is a trivalent substituent composed of a hydrocarbon in which a nitrogen-containing heterocyclic ring forms a 5- to 7-membered ring. R ¹ , R ² , R ³ , and R ⁴ are different from each other. R ⁵ represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, It represents any of a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted silyloxy group, and n represents an integer of 10 to 1000.)

(In the general formula (1), A is a trivalent substituent formed of a hydrocarbon in which a nitrogen-containing heterocyclic ring forms a 5- to 7-membered ring. R ¹ , R ² , R ³ , and R ⁴ are different from each other. R ⁵ represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, It represents any one of a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, and a substituted or unsubstituted silyloxy group.) 4. The electrode active material according to claim 1 , wherein the radical compound is a homopolymer having a partial structure represented by the general formula (1). 5. Active material. The electrode active material according to any one of claims 1 to 4 , wherein the radical compound has a number average molecular weight of 2000 or more . In a battery having at least a positive electrode, a negative electrode, and an electrolyte as constituent elements, the electrode active material according to any one of claims 1 to 5 is used as an electrode active material of at least one of the positive electrode and the negative electrode. A battery characterized by. The battery according to claim 6, wherein the electrode active material is a positive electrode active material . The battery according to claim 6 or 7 , wherein the battery is a lithium battery. The battery according to claim 8 , wherein the lithium battery is a lithium secondary battery. A moiety represented by the following general formula (1) by reacting at least a radical-substituted alcohol compound represented by the following general formula (3) with a silicone compound represented by the following general formula (4) in the presence of a transition metal catalyst. generating a radical compound having a structure, a manufacturing method of an electrode active material, characterized in that to obtain an electrode active material containing the radical compound.

(In general formula (3), A is a trivalent substituent composed of a hydrocarbon in which a nitrogen-containing heterocyclic ring forms a 5- to 7-membered ring , and R ¹ , R ² , R ³ and R ⁴ are different from each other. It may be a hydrogen atom or a methyl group.)

(In the general formula (4), R represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, substituted or unsubstituted. And an alkoxy group, a substituted or unsubstituted aryloxy group, a substituted or unsubstituted silyloxy group , and n represents an integer of 10 to 1000.

(In general formula (1), A is a trivalent substituent consisting of a hydrocarbon in which a nitrogen-containing heterocyclic ring forms a 5- to 7-membered ring, and R ¹ , R ² , R ³ , and R ⁴ are different from each other. R ⁵ represents a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, It represents any one of a substituted or unsubstituted alkoxy group, a substituted or unsubstituted aryloxy group, and a substituted or unsubstituted silyloxy group.) In the manufacturing method of the electrode active material according to claim 10, as the transition metal catalyst, a manufacturing method of an electrode active material, which comprises using a Group 9 transition metal. In the manufacturing method of the electrode active material according to claim 11, as the transition metal catalyst, a manufacturing method of an electrode active material, which comprises using a rhodium compound.

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