JP5534589B2 - Electrode active material and secondary battery - Google Patents

Description

  The present invention relates to an electrode active material and a secondary battery, and more particularly to an electrode active material using an organic compound, and a secondary battery that repeats charging and discharging using a battery electrode reaction of the electrode active material.

  With the expansion of the market for portable electronic devices such as mobile phones, notebook computers, and digital cameras, secondary batteries with high energy density and long life are expected as cordless power sources for these electronic devices.

  In response to such demands, secondary batteries have been developed that use an alkali metal ion such as lithium ion as a charge carrier and use an electrochemical reaction associated with the charge exchange. In particular, lithium ion secondary batteries having a high energy density are now widely used.

  Among the constituent elements of the secondary battery, the electrode active material is a substance that directly contributes to a battery electrode reaction such as a charge reaction and a discharge reaction, and has a central role of the secondary battery. That is, the battery electrode reaction is a reaction that occurs with the transfer of electrons by applying a voltage to an electrode active material that is electrically connected to an electrode disposed in the electrolyte, and proceeds during charge and discharge of the battery. . Therefore, as described above, the electrode active material has a central role of the secondary battery in terms of system.

  In the lithium ion secondary battery, a lithium-containing transition metal oxide is used as a positive electrode active material, a carbon material is used as a negative electrode active material, and lithium ion insertion reaction and desorption reaction with respect to these electrode active materials. Charging and discharging is performed using

  However, the lithium ion secondary battery has a problem that the rate of charge and discharge is limited because the movement of lithium ions in the positive electrode is rate-limiting. That is, in the lithium ion secondary battery described above, the movement rate of lithium ions in the transition metal oxide of the positive electrode is slower than that of the electrolyte and the negative electrode, and therefore the battery reaction rate at the positive electrode is rate-limiting and the charge / discharge rate is increased. As a result, there is a limit to increasing the output and shortening the charging time.

  Therefore, in order to solve such problems, in recent years, secondary batteries using an organic compound as a positive electrode active material have been proposed. Research and development of secondary batteries using organic radical compounds among these organic compounds are being actively conducted.

  The organic radical compound has a radical which is an unpaired electron in the outermost shell of the electron orbit. This radical is generally a highly reactive chemical species that disappears with a certain lifetime due to interaction with surrounding substances, but depending on the resonance effect, steric hindrance, and solvation state. It will be stable.

  In addition, since radicals have a high reaction rate, it is possible to complete the charging time in a short time by performing charge / discharge using a redox reaction of a stable radical. Furthermore, the organic radical compound has the opposite unpaired electrons localized in the radical atom, so that the concentration of the reaction site can be increased, and this can be expected to realize a high-capacity secondary battery. it can.

  Patent Document 1 proposes an active material for a secondary battery using a nitroxyl radical compound, an oxy radical compound, and a nitrogen radical compound having a radical on a nitrogen atom.

  This Patent Document 1 describes an example using a highly stable nitroxyl radical or the like as a radical. For example, a secondary battery using an electrode layer containing a nitronyl nitroxide compound as a positive electrode and a lithium-bonded copper foil as a negative electrode. After repeatedly charging and discharging, it has been confirmed that charging and discharging is possible over 10 cycles.

  Patent Document 2 proposes a positive electrode active material in which lithium-containing transition metal oxide particles are coated with a conductive polymer compound in which a compound containing a pyrrole ring or thiophene ring and a stable radical are integrated. .

  In Patent Document 2, conductivity is exhibited by a pyrrole ring or a thiophene ring, and since the positive electrode active material has a radical site, the battery reaction proceeds quickly, and as a result, a secondary having a high initial output is obtained. A battery can be obtained.

  Patent Document 3 discloses that at least one of a positive electrode and a negative electrode has a first organic compound having a quinone moiety capable of taking out electron transfer associated with a redox reaction as electric energy, and lithium ions. A secondary battery including a second organic compound capable of forming a chelate complex has been proposed.

  In Patent Document 3, the charge density of the first organic compound containing a quinone moiety is obtained by adding a second organic compound capable of forming a chelate complex with lithium ions and lowering the apparent charge density of the lithium ions. This improves the reversibility of the reaction between lithium ions and the first organic compound.

  Further, Patent Document 4 proposes an organic radical secondary battery in which at least one of the positive electrode and the negative electrode contains an active compound containing a radical compound and a quinone derivative.

  In Patent Document 4, the mixture of a radical compound and a quinone derivative is included in the electrode active material, so that the battery voltage at the time of charging / discharging can be multi-staged, thereby easily detecting the state of charge based on the battery voltage. I have to.

JP 2004-207249 A (paragraph numbers [0278] to [0282]) JP 2009-283418 A (paragraph numbers [0025], [0075], [0081]) JP 2008-112630 A (paragraph numbers [0016] to [0020], [0055] to [0059] and FIG. 1) JP 2009-29597A (Claim 6, paragraph numbers [0031], [0057], [0107])

  However, in Patent Document 1, although an organic radical compound such as a nitroxyl radical compound is used as an electrode active material, the charge / discharge reaction is limited to a one-electron reaction involving only one electron. That is, in the case of an organic radical compound, when a multi-electron reaction involving two or more electrons is caused, the radical lacks stability and decomposes, and the radical disappears and the reversibility of the charge / discharge reaction is lost. . For this reason, the organic radical compound of Patent Document 1 must be limited to a one-electron reaction, and it is difficult to realize a multi-electron reaction that can be expected to have a high capacity.

  In Patent Document 2, although the positive electrode active material has a radical site to improve the initial output, the capacity is not sufficient yet, and it is difficult to obtain an electrode active material having a high capacity and good cycle characteristics. it is conceivable that.

  Although Patent Document 3 improves the reversibility of the reaction between lithium ions and the first organic compound containing a quinone moiety, the stability in the redox state is not sufficient and the capacity is insufficient. As a result, it has not yet been put to practical use.

  Furthermore, although Patent Document 4 is multi-staged by including radical compounds and quinone derivatives having different oxidation-reduction potentials and facilitates detection of a charged state by battery voltage, a desired high-capacity secondary battery can still be obtained. Not in a situation.

  As described above, in conventional secondary batteries such as Patent Documents 1 to 4, even when an organic radical compound or a compound having a quinone structure is used as an electrode active material, the capacity is increased by a multi-electron reaction and the stability against charge / discharge cycles is increased. Therefore, it is difficult to make the electrode active materials compatible with each other. Therefore, an electrode active material having a sufficiently high energy density, high output, good cycle characteristics, and long life has not been realized.

  The present invention has been made in view of such circumstances, and provides an electrode active material and a secondary battery that have high energy density, high output, and good cycle characteristics with little decrease in capacity even after repeated charge and discharge. For the purpose.

  The present inventors have intensively studied to obtain an organic compound that can be used as an active material of a secondary battery that repeats charge and discharge by a battery electrode reaction. As a result, the unit molecule contains a conjugated dione structure and a stable radical structure. The organic compound is capable of multi-electron reaction and is excellent in stability during charging and discharging, and thus has been found to be able to charge a large amount of electricity with a small molecular weight.

で表される共役ジオン構造と安定ラジカル構造を単位分子中に含有する有機化合物を主体とすることを特徴としている。 The present invention was made based on such findings, the electrode active material according to the present invention is an electrode active material to be used as an active material for a secondary battery repeats charging and discharging by the battery electrode reaction, generally formula

It is characterized by mainly comprising an organic compound containing a conjugated dione structure and a stable radical structure represented by

In the formula , n ₁ is an integer of 1 or more, R ₁ is a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, a substituted or unsubstituted carbonyl group, substituted or unsubstituted Acyl group, substituted or unsubstituted alkoxycarbonyl group, substituted or unsubstituted ester group, substituted or unsubstituted ether group, substituted or unsubstituted thioether group, substituted or unsubstituted amine group, substituted or unsubstituted An amide group, a substituted or unsubstituted sulfone group, a substituted or unsubstituted thiosulfonyl group, a substituted or unsubstituted sulfonamido group, a substituted or unsubstituted imine group, a substituted or unsubstituted azo group, and one or more thereof represents at least any one of a linking group comprising a combination of, R ₂ is a hydrogen atom, Logen atom, hydroxyl group, nitro group, cyano group, carboxyl group, substituted or unsubstituted alkyl group, substituted or unsubstituted alkenyl group, substituted or unsubstituted cycloalkyl group, substituted or unsubstituted aromatic hydrocarbon group Substituted or unsubstituted aromatic heterocyclic group, substituted or unsubstituted aralkyl group, substituted or unsubstituted amino group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aryloxy group, substituted or unsubstituted Indicate at least one of an alkoxycarbonyl group, a substituted or unsubstituted aryloxycarbonyl group, a substituted or unsubstituted acyl group, and a substituted or unsubstituted acyloxy group, and these substituents form a ring structure with each other and Nde including the case.

で表される共役ジオン構造と安定ラジカル構造を単位分子中に含有する有機化合物を主体とすることを特徴としている。 The electrode active material according to the present invention is an electrode active material used as an active material of a secondary battery that repeats charging and discharging by a battery electrode reaction, and has a general formula

It is characterized by mainly comprising an organic compound containing a conjugated dione structure and a stable radical structure represented by

In the formula , n ₂ is an integer of 1 or more, R ₃ is a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, a substituted or unsubstituted carbonyl group, substituted or unsubstituted Acyl group, substituted or unsubstituted alkoxycarbonyl group, substituted or unsubstituted ester group, substituted or unsubstituted ether group, substituted or unsubstituted thioether group, substituted or unsubstituted amine group, substituted or unsubstituted An amide group, a substituted or unsubstituted sulfone group, a substituted or unsubstituted thiosulfonyl group, a substituted or unsubstituted sulfonamido group, a substituted or unsubstituted imine group, a substituted or unsubstituted azo group, and one or more thereof represents at least any one of a linking group comprising a combination of, R ₄ is a hydrogen atom, Logen atom, hydroxyl group, nitro group, cyano group, carboxyl group, substituted or unsubstituted alkyl group, substituted or unsubstituted alkenyl group, substituted or unsubstituted cycloalkyl group, substituted or unsubstituted aromatic hydrocarbon group Substituted or unsubstituted aromatic heterocyclic group, substituted or unsubstituted aralkyl group, substituted or unsubstituted amino group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aryloxy group, substituted or unsubstituted Indicate at least one of an alkoxycarbonyl group, a substituted or unsubstituted aryloxycarbonyl group, a substituted or unsubstituted acyl group, and a substituted or unsubstituted acyloxy group, and these substituents form a ring structure with each other and Nde including the case.

で表される共役ジオン構造と安定ラジカル構造を単位分子中に含有する有機化合物を主体とすることを特徴としている。 The electrode active material according to the present invention is an electrode active material used as an active material of a secondary battery that repeats charging and discharging by a battery electrode reaction, and has a general formula

It is characterized by mainly comprising an organic compound containing a conjugated dione structure and a stable radical structure represented by

In the formula , n ₃ and n ₄ are integers of 1 or more, R ₅ and R ₆ are substituted or unsubstituted alkyl groups, substituted or unsubstituted alkylene groups, substituted or unsubstituted arylene groups, substituted or unsubstituted carbonyls. Group, substituted or unsubstituted acyl group, substituted or unsubstituted alkoxycarbonyl group, substituted or unsubstituted ester group, substituted or unsubstituted ether group, substituted or unsubstituted thioether group, substituted or unsubstituted amine group Substituted or unsubstituted amide group, substituted or unsubstituted sulfone group, substituted or unsubstituted thiosulfonyl group, substituted or unsubstituted sulfonamido group, substituted or unsubstituted imine group, substituted or unsubstituted azo group , And at least any one of linking groups consisting of one or more combinations thereof, R ₇ is a hydrogen atom, halogen atom, hydroxyl group, nitro group, cyano group, carboxyl group, substituted or unsubstituted alkyl group, substituted or unsubstituted alkenyl group, substituted or unsubstituted cycloalkyl group, substituted or unsubstituted Aromatic hydrocarbon group, substituted or unsubstituted aromatic heterocyclic group, substituted or unsubstituted aralkyl group, substituted or unsubstituted amino group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aryloxy group , A substituted or unsubstituted alkoxycarbonyl group, a substituted or unsubstituted aryloxycarbonyl group, a substituted or unsubstituted acyl group, and a substituted or unsubstituted acyloxy group. In which a ring structure is formed .

  By the way, a stable radical structure generally generates a cation by an oxidation reaction and generates an anion by a reduction reaction. However, when stable radicals are used alone as in Patent Document 1 and Patent Document 2, the reduction reaction that generates anions is unstable, and it has been considered difficult to utilize for battery electrode reactions. .

  However, the present inventors have studied in detail the electrochemical properties of the conjugated dione structure and the stable radical structure. When both are contained in the unit molecule, the stability increases, and the redox potential of the conjugated dione structure is further increased. It was found that by making the stable radical structure larger than the redox potential during the reduction reaction, the reversibility of the system can be stabilized also on the reduction reaction side, and this can be effectively used for the battery electrode reaction.

  That is, in the electrode active material of the present invention, the organic compound contains both the conjugated dione structure and the stable radical structure in a unit molecule, and the redox potential of the conjugated dione structure is a reduction reaction of the stable radical structure. It is characterized by being larger than the redox potential at the time.

  In addition, when the molecular weight of the organic compound becomes excessively large, the amount of charge accumulated per unit mass of the electrode active material decreases. Therefore, the molecular weight is preferably 700 or less.

  That is, the electrode active material of the present invention is characterized in that the organic compound has a molecular weight of 700 or less.

  In the secondary battery according to the present invention, any of the electrode active materials described above is included in at least one of a reaction starting material, a product, and an intermediate product in the discharge reaction of the battery electrode reaction. It is characterized by that.

  Moreover, the secondary battery of the present invention has a positive electrode, a negative electrode, and an electrolyte, and the positive electrode is mainly composed of the electrode active material.

According to the electrode active material of the present invention, the main component is an organic compound containing a conjugated dione structure and a stable radical structure represented by the above general formula in a unit molecule, so that a multi-electron reaction is possible. It is also excellent in stability during charging and discharging, and therefore an electrode active material having a high capacity and good cycle characteristics can be obtained.

  In addition, since the organic compound has a redox potential of the conjugated dione structure larger than a redox potential at the time of the reduction reaction of the stable radical structure, the reduction reaction side of the stable radical structure can also be used for the battery electrode reaction. It becomes possible. Therefore, more electrons can be involved in the reaction in the battery electrode reaction, and the capacity density can be further improved. As a result, it is possible to realize an electrode active material having higher energy density, better cycle characteristics, and higher capacity and higher output.

  In addition, since the organic compound has a molecular weight of 700 or less, a large amount of electricity can be accumulated per unit mass, and a high-capacity electrode active material can be realized.

  According to the secondary battery of the present invention, since the electrode active material is included in at least one of a reaction starting material, a product, and an intermediate product in the discharge reaction of the battery electrode reaction, It is possible to achieve both stability with respect to the charge / discharge cycle, high energy density, high output, and a long-life secondary battery with good cycle characteristics with little reduction in capacity even after repeated charge / discharge.

It is sectional drawing which shows one Embodiment of the coin-type battery as a secondary battery which concerns on this invention.

  Next, an embodiment of the present invention will be described in detail.

  The electrode active material of the present invention is mainly composed of an organic compound containing a conjugated dione structure and a stable radical structure in a unit molecule. As a result, a multi-electron reaction of 3 electrons or more can be performed, the stability during charging / discharging can be improved, and a secondary battery having a large energy density and excellent stability can be obtained.

  Examples of the conjugated dione structure include a conjugated quinone system as shown in chemical formula (1), and examples of the stable radical structure include 2,2,6,6-tetramethylpiperidine-1 as shown in chemical formula (2). -Oxyl (hereinafter referred to as “TEMPO”) type radical, 2,2,5,5-tetramethylpyrrolidin-1-yloxy (hereinafter referred to as “PROXYL”) type radical as shown in chemical formula (3). be able to.

  Therefore, as a specific form of the organic compound, as shown in the following general formula (4), an organic compound containing a conjugated quinone and a TEMPO radical, and as shown in the following general formula (5), a conjugated quinone Examples of the organic compound containing a system and a PROXYL radical, and organic compounds containing a conjugated quinone series, a TEMPO radical, and a PROXYL radical as shown in the following general formula (6).

Here, n _{1 to} n ₄ are integers of 1 or more. R ₁ , R ₃ , R ₅ and R ₆ are substituted or unsubstituted alkyl groups, substituted or unsubstituted alkylene groups, substituted or unsubstituted arylene groups, substituted or unsubstituted carbonyl groups, substituted or unsubstituted Acyl group, substituted or unsubstituted alkoxycarbonyl group, substituted or unsubstituted ester group, substituted or unsubstituted ether group, substituted or unsubstituted thioether group, substituted or unsubstituted amine group, substituted or unsubstituted An amide group, a substituted or unsubstituted sulfone group, a substituted or unsubstituted thiosulfonyl group, a substituted or unsubstituted sulfonamido group, a substituted or unsubstituted imine group, a substituted or unsubstituted azo group, and one or more thereof At least any one of the linking groups consisting of the combinations is shown. R ₂ , R ₄ and R ₇ are hydrogen atom, halogen atom, hydroxyl group, nitro group, cyano group, carboxyl group, substituted or unsubstituted alkyl group, substituted or unsubstituted alkenyl group, substituted or unsubstituted A cycloalkyl group, a substituted or unsubstituted aromatic hydrocarbon group, a substituted or unsubstituted aromatic heterocyclic group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted amino group, a substituted or unsubstituted alkoxy group, At least one of a substituted or unsubstituted aryloxy group, a substituted or unsubstituted alkoxycarbonyl group, a substituted or unsubstituted aryloxycarbonyl group, a substituted or unsubstituted acyl group, and a substituted or unsubstituted acyloxy group In which a ring structure is formed by these substituents.

  Further, each of the above-listed substituents is not limited as long as it belongs to each category. However, as the molecular weight increases, the amount of charge that can be accumulated per unit mass of the electrode active material decreases, so that the molecular weight increases. It is preferable to select in the range of 700 or less.

  And as an organic compound contained in the category of the said General formula (4), the substance represented by Chemical formula (7A)-(7I) can be mentioned, for example.

  Moreover, as an organic compound contained in the category of the said General formula (5), the substance represented by chemical formula (8A)-(8C) can be mentioned, for example.

  Moreover, as an organic compound contained in the category of the said General formula (6), the substance represented by chemical formula (9A)-(9B) is mentioned, for example.

  It is considered that the electrode active material undergoes a redox reaction at each site of a stable radical structure and a conjugated dione structure by an electrochemical redox reaction.

Chemical reaction formulas (10) and (11) show charge and discharge reactions when the organic compound represented by the general formula (4) is used as an electrode active material and LiPF ₆ is used as an electrolyte salt. Chemical reaction formula (10) is a charge / discharge reaction with a stable radical structure, and chemical reaction formula (11) is a charge / discharge reaction with a conjugated dione structure.

  As shown in the chemical reaction formula (10), in the stable radical structure (I), one electron per unit participates in the reaction to generate a cation (II). Further, as shown in the chemical reaction formula (11), in the conjugated dione structure (II), two electrons per unit are involved to generate an anion (IV).

  That is, when only an organic radical compound is used as the electrode active material, only one electron is involved in the battery electrode reaction as shown in the chemical reaction formula (10).

  On the other hand, in the case of an organic compound having a stable radical structure and a conjugated quinone structure in the unit molecule, at least three electrons are involved in the battery electrode reaction, so that the capacity density can be increased.

  Among the organic compounds described above, it is more preferable that the redox potential of the conjugated dione structure is larger than the redox potential during the reduction reaction of the stable radical structure.

  That is, in an organic compound containing a stable radical structure, as shown in the chemical reaction formula (12), there are an oxidation reaction that generates a cation (II) and a reduction reaction that generates an anion (V).

  However, when a stable radical is used alone, the reduction reaction (I → V) that generates an anion is unstable, and it is difficult to use it for the battery electrode reaction.

  However, by containing a conjugated dione structure and a stable radical structure in the unit molecule, and making the redox potential of the active conjugated dione structure larger than the redox potential during the reduction reaction of the stable radical structure, the reduction reaction of the stable radical. The reversibility of the time can be improved, whereby the reaction on the reduction side can be used for the battery electrode reaction.

  And, by using the reduction reaction of the stable radical for the battery electrode reaction in this way, in addition to the two electrons per unit in the conjugated dione structure, two electrons per unit can also participate in the battery electrode reaction in the stable radical structure. Become. That is, by making the oxidation-reduction potential of the conjugated dione structure larger than the oxidation-reduction potential during the reduction reaction of the stable radical structure, at least four-electron reaction is possible, and the capacity density can be further improved. As a result, it is possible to realize an electrode active material having higher energy density, better cycle characteristics, and higher capacity and higher output.

  The effects as described above are recognized when the organic compound has a conjugated quinone structure and a stable radical structure as a synthetic product in the unit molecule. As in Patent Document 4, the organic radical compound and the quinone derivative are recognized. It is thought that it is not expressed only by mixing and containing.

  This is presumably because the bond with the cation generated by reducing the stable radical is weakened by the influence of the reduction of the conjugated quinone, and the reversibility of the reaction is maintained. In general, with a stable radical alone, the reductant forms a strong bond with a cation, so that it is stabilized in a reduced state and loses reversibility. The effect of weakening the bond between stable radicals and cations is presumed to be related to the electronic state of the whole molecule resulting from the reduction of conjugated quinone, and is effective only when each is present as a compound in a single molecule. It is considered to be accepted.

  The oxidation-reduction potentials of these conjugated dione structure and stable radical structure can be determined by cyclic voltammetry (hereinafter referred to as “CV”) method, molecular orbital method calculation, and the like.

  For example, in the CV method in which the electrode potential is swept linearly, a reduction wave is generated when the potential is swept in the negative direction, and an oxidation wave is generated when the potential is swept in the positive direction. A current-voltage curve (cyclic voltammogram) based on the reference electrode is obtained from the reduction wave and the oxidation wave. Then, the oxidation peak potential and the reduction peak potential can be obtained from this current-voltage curve, and the arithmetic average of both is the oxidation reduction potential.

Incidentally, when Li is used as a reference electrode, the redox potential of benzoquinone as a conjugated dione structure is 2.0 to 2.6 V vs. Li / Li ⁺ , and the redox potential of anthraquinone is 1.6 to 2.0 V vs. Li / Li ⁺ . On the other hand, the redox potential of the TEMPO radical or PROXYL radical as a stable radical structure is as high as 3.6 V vs. Li / Li ⁺ during the radical oxidation reaction, but 1.7 to 2.0 V vs. Li / during the reduction reaction. Li ⁺ is low.

  In this embodiment, the conjugated dione structure and the stable radical structure are selected so that the redox potential of the conjugated dione structure is larger than the redox potential at the time of the reduction reaction of the stable radical structure. Is involved in the battery electrode reaction, an electrode active material having a higher energy density and a higher capacity can be realized.

  Next, a secondary battery using the electrode active material will be described.

  FIG. 1 is a cross-sectional view showing a coin-type secondary battery as an embodiment of a secondary battery according to the present invention. In this embodiment, the electrode active material of the present invention is used as a positive electrode active material. ing.

  The battery can 1 has a positive electrode case 2 and a negative electrode case 3, and both the positive electrode case 2 and the negative electrode case 3 are formed in a disk-like thin plate shape. In the center of the bottom of the positive electrode case 2 constituting the positive electrode current collector, a positive electrode 4 in which an electrode active material is molded into a sheet shape is disposed. A separator 5 formed of a porous sheet or film such as a microporous film, a woven fabric, or a nonwoven fabric is laminated on the positive electrode 4, and a negative electrode 6 is laminated on the separator 5. As the negative electrode 6, for example, a copper foil laminated with a lithium metal foil or a lithium foil occlusion material such as graphite or hard carbon applied to the copper foil can be used. A negative electrode current collector 7 made of metal is laminated on the negative electrode 6, and a metal spring 8 is placed on the negative electrode current collector 7. The electrolyte 9 is filled in the internal space, and the negative electrode case 3 is fixed to the positive electrode case 2 against the urging force of the metal spring 8 and sealed with a gasket 10.

  Next, an example of a method for manufacturing the secondary battery will be described in detail.

  First, an electrode active material is formed into an electrode shape. For example, the electrode active material is mixed with a conductive auxiliary agent and a binder, and a solvent is added to form a slurry. The slurry is applied on the positive electrode current collector by an arbitrary coating method, and dried to obtain the positive electrode. Form.

  Here, the conductive auxiliary agent is not particularly limited, and examples thereof include carbonaceous fine particles such as graphite, carbon black, and acetylene black, carbon fibers such as vapor grown carbon fiber (VGCF), carbon nanotube, and carbon nanohorn. , Conductive polymers such as polyaniline, polypyrrole, polythiophene, polyacetylene, and polyacene can be used. Further, two or more kinds of conductive assistants can be mixed and used. In addition, as for the content rate in the positive electrode 4 of a conductive support agent, 10-80 mass% is desirable.

  Further, the binder is not particularly limited, and various resins such as polyethylene, polyvinylidene fluoride, polyhexafluoropropylene, polytetrafluoroethylene, polyethylene oxide, carboxymethylcellulose, and the like can be used.

  Further, the solvent is not particularly limited, and examples thereof include basic solvents such as dimethyl sulfoxide, dimethylformamide, N-methylpyrrolidone, propylene carbonate, diethyl carbonate, dimethyl carbonate, and γ-butyrolactone, acetonitrile, tetrahydrofuran, and nitrobenzene. In addition, non-aqueous solvents such as acetone, protic solvents such as methanol and ethanol, water, and the like can be used.

  Moreover, the kind of organic solvent, the compounding ratio of the organic compound and the organic solvent, the kind of additive and the addition amount thereof can be arbitrarily set in consideration of the required characteristics and productivity of the secondary battery. Next, the positive electrode 4 is impregnated into the electrolyte 9 so that the electrolyte 9 is impregnated with the positive electrode 4, and then the positive electrode 4 at the bottom center of the positive electrode case 2 constituting the positive electrode current collector is placed. Next, the separator 5 impregnated with the electrolyte 9 is laminated on the positive electrode 4, the negative electrode 6 and the negative electrode current collector 7 are sequentially laminated, and then the electrolyte 9 is injected into the internal space. Then, a metal spring 8 is placed on the negative electrode current collector 7, and a gasket 10 is arranged on the periphery, and the negative electrode case 3 is fixed to the positive electrode case 2 with a caulking machine or the like, and the outer casing is sealed. A type secondary battery is produced.

The electrolyte 9 is interposed between the positive electrode (electrode active material) 4 and the negative electrode 6 which is the counter electrode, and transports charge carriers between the two electrodes. Those having an ionic conductivity of ⁻⁵ to 10 ⁻¹ S / cm can be used. For example, an electrolytic solution in which an electrolyte salt is dissolved in an organic solvent can be used.

Here, examples of the electrolyte salt include LiPF ₆ , LiClO ₄ , LiBF ₄ , LiCF ₃ SO _3, Li (CF ₃ SO ₂ ) ₂ , Li (C ₂ F ₅ SO ₂ ) ₂ N, and Li (CF ₃ SO ₂ ) ₃ C, Li (C ₂ F ₅ SO ₂ ) ₃ C, or the like can be used.

  As the organic solvent, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, γ-butyrolactone, tetrahydrofuran, dioxolane, sulfolane, dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, etc. are used. be able to.

  The electrolyte 9 may be a solid electrolyte. Examples of the polymer compound used in the solid electrolyte include polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-ethylene copolymer, vinylidene fluoride-monofluoroethylene copolymer, fluoride Vinylidene fluoride polymers such as vinylidene-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 copolymer Examples thereof include acrylonitrile polymers such as polymers, acrylonitrile-vinyl acetate copolymers, polyethylene oxide, ethylene oxide-propylene oxide copolymers, and polymers of these acrylates and methacrylates. Further, these polymer compounds containing an electrolytic solution in a gel form may be used as the electrolyte 9 or only a polymer compound containing an electrolyte salt may be used as the electrolyte 9 as it is.

  Since the electrode active material of the secondary battery is reversibly oxidized or reduced by charge and discharge, it has a different structure and state depending on the charged state, discharged state, or intermediate state. The active material is contained in at least one of a reaction starting material in the discharge reaction (a material that causes a chemical reaction in the battery electrode reaction), a product (a material resulting from the chemical reaction), and an intermediate product.

  As described above, according to this embodiment, since the secondary battery is configured using the electrode active material that undergoes multi-electron reaction, it is possible to obtain a secondary battery having a large energy density and excellent stability. it can.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible in the range which does not deviate from a summary. For example, the above-listed chemical formulas (7A) to (7I), (8A) to (8C), (9A), and (9B) are examples of the organic compounds that are the main components of the electrode active material. It is not limited. That is, if at least a conjugated dione structure and a stable radical structure are contained in a unit molecule, a battery electrode reaction substantially similar to chemical reaction formulas (10) to (12) proceeds, energy density is large, and stability is increased. It is possible to obtain a desired secondary battery excellent in. Therefore, the conjugated dione structure is not limited to the conjugated quinone type, and may be an aliphatic compound or the like. Also, the stable radical structure is not limited to TEMPO radicals or PROXYL radicals, and may be nitroxyl radicals, oxy radicals, or the like.

  In this embodiment, a coin-type secondary battery has been described. However, the battery shape is not particularly limited, and can be applied to a cylindrical shape, a square shape, a sheet shape, and the like. Also, the exterior method is not particularly limited, and a metal case, mold resin, aluminum laminate film, or the like may be used.

  In this embodiment, an organic compound is used as the positive electrode active material, but it is also useful to use it as the negative electrode active material.

  Next, examples of the present invention will be specifically described.

(Synthesis of organic compounds)
According to the following synthesis scheme (A), 2- (2,2,6,6-tetramethylpiperidinoxy-4-yloxy) -3,5,6-trichlorocyclohexa-2,5-diene-1, 4-dione (hereinafter referred to as “Compound A”) (7B) was synthesized.

First, 5.8 mmol of chloranil (2,3,5,6-tetrachloro-p-benzoquinone) (7B ₁ ) and 5.8 mmol of 4-hydroxy TEMPO (7B ₂ ) were added to 50 mL of N, N-dimethylformamide ( (CH ₃ ) ₂ NCHO) was dissolved, 12 mmol of potassium carbonate (K ₂ CO ₃ ) was added with stirring, and the mixture was reacted at room temperature for 2 hours to obtain a reaction product. Subsequently, this reaction product was filtered, and the filtrate was concentrated to obtain a crude product composed of a mixture of a mono-substituted product, a p-substituted product, and an m-substituted product. Then, the obtained crude product is fractionated by silica gel chromatography, and the solid obtained from the main product fraction is recrystallized from a mixed solvent of hexane / pentane to give a black crystalline compound A (mono-substituted product) (7B )

[Production of secondary battery]
Compound A: 300 mg, graphite powder as a conductive auxiliary agent: 600 mg, polytetrafluoroethylene resin as a binder: 100 mg, respectively, weighed and kneaded while mixing so that the whole is uniform, A mixture was obtained. And this mixture was pressure-molded and the sheet-like member about 150 micrometers thick was produced.

Next, this sheet-like member was dried in a vacuum at 80 ° C. for 1 hour, and then punched into a circle having a diameter of 12 mm to produce a positive electrode (positive electrode active material) mainly composed of the composite A. Next, the positive electrode was impregnated with an electrolytic solution, and the electrolytic solution was infiltrated into voids in the positive electrode. As the electrolytic solution, an ethylene carbonate / diethyl carbonate mixed solution, which is an organic solvent containing LiPF ₆ (electrolyte salt) having a molar concentration of 1.0 mol / L, was used. The mixing ratio of ethylene carbonate / diethyl carbonate was ethylene carbonate: diethyl carbonate = 3: 7 in volume%.

  Next, this positive electrode was placed on a positive electrode current collector, a 20 μm thick separator made of a polypropylene porous film impregnated with the electrolytic solution was laminated on the positive electrode, and lithium was further applied to both sides of the copper foil. The pasted negative electrode was laminated on the separator.

  Next, after a negative electrode current collector made of Cu was laminated on the negative electrode, an electrolytic solution was injected into the internal space. Thereafter, a metal spring was placed on the negative electrode current collector, and the negative electrode case was joined to the positive electrode case in a state where a gasket was disposed on the periphery, and the outer casing was sealed with a caulking machine. Thus, a sealed coin-type battery having the composite A as the positive electrode active material and metal lithium as the negative electrode active material was produced.

[Confirmation of secondary battery operation]
The secondary battery produced as described above was charged with a constant current of 0.1 mA until the voltage reached 4.2 V, and then discharged to 1.5 V with a constant current of 0.1 mA. As a result, it was confirmed that the secondary battery had voltage flat portions at three places of charge / discharge voltages of 3.6 V, 2.9 V, and 2.3 V and a discharge capacity of 0.2 mAh. When the capacity density per electrode active material was calculated from this capacity, it was 230 Ah / kg.

  On the other hand, the theoretical capacity density Q (Ah / kg) of the secondary battery is expressed by Equation (1).

  Here, Z is the number of electrons involved in the battery electrode reaction, and W is the molecular weight of the electrode active material.

  Since the molecular weight of the synthesized product A is 382.7, when the number of electrons Z involved in the battery electrode reaction is 3, the theoretical capacity density is 210 Ah / kg from Equation (1). Therefore, it was confirmed that the composite A has a multi-electron reaction involving at least 3 electrons or more per unit molecule.

  Thereafter, when the secondary battery was repeatedly charged and discharged in the range of 4.2 to 1.5 V, the initial capacity of 50% or more could be secured even after 10 cycles. That is, it was found that a secondary battery having excellent stability with little decrease in capacity can be obtained even when charging and discharging are repeated.

(Synthesis of organic compounds)
According to the following synthesis scheme (B), 2,5-bis (2,2,6,6-tetramethylpiperidinoxy-4-yloxy) -3,6-dichlorocyclohexa-2,5-diene-1 , 4-dione (hereinafter referred to as “Compound B”) (7D) was synthesized.

In the same manner and procedure as in Example 1, chloranil (7D ₁ ) and 4-hydroxy TEMPO (7D ₂ ) are reacted, filtered, and the filtrate is concentrated, mono-substituted product, p-substituted product, m-substituted product. A crude product consisting of a mixture of bodies was obtained. Then, the obtained crude product is separated by silica gel column chromatography, and a small amount of the by-product obtained is recrystallized from acetonitrile to obtain a black-brown block crystal compound B (p-substituted product) (7D). Obtained.

[Production of secondary battery]
A secondary battery was produced in the same manner as in [Example 1] except that the composite B was used as an electrode active material.

[Confirmation of secondary battery operation]
The secondary battery produced as described above was charged with a constant current of 0.1 mA until the voltage reached 4.2 V, and then discharged to 1.5 V with a constant current of 0.1 mA. As a result, it was confirmed that the secondary battery had voltage flat portions at three locations of charge / discharge voltages of 3.5V, 2.3V, and 1.8V and a discharge capacity of 0.22 mAh. When the capacity density per electrode active material was calculated from this capacity, it was 190 Ah / kg.

  On the other hand, since the molecular weight of the composite B is 517.4, when the number of electrons Z involved in the battery electrode reaction is 4, the theoretical capacity density is 207.2 Ah / kg. Therefore, it was confirmed that the composite B has a multi-electron reaction involving at least 4 electrons per unit molecule.

  Thereafter, when the secondary battery was repeatedly charged and discharged in the range of 4.2 to 1.5 V, the initial capacity of 50% or more could be secured even after 10 cycles. That is, it was found that a secondary battery having excellent stability with little decrease in capacity can be obtained even when charging and discharging are repeated.

(Synthesis of organic compounds)
According to the following synthesis scheme (C), 2,5-bis (2,2,6,6-tetramethylpiperidinoxy-4-ylamino) -3,6-difluorocyclohexa-2,5-diene-1 , 4-dione (hereinafter referred to as “Compound C”) (7E) was synthesized.

0.56 mmol fluoranyl (2,3,5,6-tetrafluoro-p-benzoquinone) (7E ₁ ) and 1.11 mmol 4-amino TEMPO (7E ₂ ) were dissolved in 30 mL acetonitrile (CH ₃ CN). The mixture was reacted at 70 ° C. for 2 hours with stirring to obtain a reaction product. The reaction solution was then concentrated, and the resulting crude product was fractionated by silica gel chromatography. The solid obtained from the main product fraction was recrystallized from a mixed solvent of hexane / dichloromethane to obtain a compound C (7E) consisting of purple crystals.

[Production of secondary battery]
A secondary battery was produced in the same manner as in [Example 1] except that the composite C was used as an electrode active material.

[Confirmation of secondary battery operation]
The secondary battery produced as described above was charged with a constant current of 0.1 mA until the voltage reached 4.2 V, and then discharged to 1.5 V with a constant current of 0.1 mA. As a result, it was confirmed that the secondary battery had a voltage flat portion at two places where the charge / discharge voltage was 3.5 V and 2.6 V, and the discharge capacity was 0.18 mAh. When the capacity density per electrode active material was calculated from this capacity, it was 260 Ah / kg.

  On the other hand, since the molecular weight of the compound C is 482.6, the theoretical capacity density is 222.1 Ah / kg when the number of electrons Z involved in the battery electrode reaction is 4. Therefore, it was confirmed that the composite C has a multi-electron reaction involving at least 4 or more electrons per unit molecule.

  Thereafter, when the secondary battery was repeatedly charged and discharged in the range of 4.2 to 1.5 V, the initial capacity of 50% or more could be secured even after 10 cycles. That is, it was found that a secondary battery having excellent stability with little decrease in capacity can be obtained even when charging and discharging are repeated.

(Synthesis of organic compounds)
According to the following synthetic scheme (D), 2,4-bis (2,2,6,6-tetramethylpiperidinoxy-4-yloxy) -3,5-dichlorocyclohexa-2,5-diene-1 , 4-dione (hereinafter referred to as “Compound D”) (7F) was synthesized.

In the same manner and procedure as in Example 1, chloranil (7F ₁ ) and 4-hydroxy TEMPO (7F ₂ ) are reacted, filtered, and the filtrate is concentrated, mono-substituted product, p-substituted product, m-substituted product. A crude product consisting of a mixture of bodies was obtained. Then, the obtained crude product is separated by silica gel column chromatography, and a small amount of the by-product obtained is recrystallized from acetonitrile to give orange plate crystal compound D (m-substituted product) (7F). Got.

[Production of secondary battery]
A secondary battery was produced in the same manner as in [Example 1] except that the composite D was used as an electrode active material.

[Confirmation of secondary battery operation]
The secondary battery produced as described above was charged with a constant current of 0.1 mA until the voltage reached 4.2 V, and then discharged to 1.5 V with a constant current of 0.1 mA. As a result, it was confirmed that the secondary battery had a discharge capacity of 0.23 mAh having a voltage flat portion at three places of charge / discharge voltages of 3.6 V, 2.8 V, and 2.3 V. When the capacity density per electrode active material was calculated from this capacity, it was 270 Ah / kg.

  On the other hand, since the molecular weight of the compound D is 517.4, when the number of electrons Z involved in the battery electrode reaction is 4, the theoretical capacity density is 207.2 Ah / kg. Therefore, it was confirmed that the composite D has a multi-electron reaction involving at least 4 electrons per unit molecule.

  Thereafter, when the secondary battery was repeatedly charged and discharged in the range of 4.2 to 1.5 V, the initial capacity of 50% or more could be secured even after 10 cycles. That is, it was found that a secondary battery having excellent stability with little decrease in capacity can be obtained even when charging and discharging are repeated.

(Synthesis of organic compounds)
According to the following synthesis scheme (E), 9,10-dihydro-9,10-dioxoanthracen-1-yl-2,2,6,6-tetramethylpiperidinoxy-4-carboxylate (hereinafter, “ Compound 7 ”) was synthesized.

2.5 mmol 1-hydroxyanthraquinone (7G ₁ ) and 2.5 mmol 4-carboxy TEMPO (7G ₂ ) were dissolved in 20 mL dichloromethane (CH ₂ Cl ₂ ) and stirred with 3.0 mmol N, N ′ -Dicyclohexylcarbodiimide and 3.0 mmol of 4-dimethylaminopyridine were added and reacted at room temperature for 3 days to obtain a reaction product. The reaction was then filtered and the filtrate was concentrated to give a crude product. The obtained crude product was fractionated by silica gel chromatography, and the solid obtained from the main fraction was recrystallized from benzene to obtain orange needle-like crystal compound E (7G).

[Production of secondary battery]
A secondary battery was fabricated in the same manner as in [Example 1] except that the composite E was used as the electrode active material.

[Confirmation of secondary battery operation]
The secondary battery produced as described above was charged with a constant current of 0.1 mA until the voltage reached 4.2 V, and then discharged to 1.5 V with a constant current of 0.1 mA. As a result, it was confirmed that the secondary battery had voltage flat portions at three locations of charge / discharge voltages of 3.5 V, 2.4 V, and 1.9 V and a discharge capacity of 0.19 mAh. When the capacity density per electrode active material was calculated from this capacity, it was 200 Ah / kg.

  On the other hand, since the molecular weight of the composite E is 406.4, if the number of electrons Z involved in the battery electrode reaction is 3, the theoretical capacity density is 197.8 Ah / kg. Therefore, it was confirmed that the synthesized product E has a multi-electron reaction involving at least 3 electrons or more per unit molecule.

  Thereafter, when the secondary battery was repeatedly charged and discharged in the range of 4.2 to 1.5 V, the initial capacity of 50% or more could be secured even after 10 cycles. That is, it was found that a secondary battery having excellent stability with little decrease in capacity can be obtained even when charging and discharging are repeated.

(Synthesis of organic compounds)
According to the following synthesis scheme (F), 9,10-dihydro-9,10-dioxoanthracen-1-yl-2,2,6,6-tetramethylpyrrolidinoxy-3-carboxylate (hereinafter referred to as “synthesis”) Compound F ”) (8C) was synthesized.

2.7 mmol of 1-hydroxyanthraquinone (8C ₁ ) and 2.7 mmol of 3-carboxy PROXYL (8C ₂ ) are dissolved in 20 mL of dichloromethane and 3.3 mmol of N, N′-dicyclohexylcarbodiimide with stirring and 3 3 mmol of 4-dimethylaminopyridine was added and reacted at room temperature for 3 days to obtain a reaction product. The reaction was then filtered and the filtrate was concentrated to give a crude product. The obtained crude product was fractionated by silica gel chromatography, and the solid obtained from the main fraction was recrystallized from ethyl acetate to obtain orange needle-like compound F (8C).

[Production of secondary battery]
A secondary battery was fabricated in the same manner as in [Example 1] except that the composite F was used as the electrode active material.

[Confirmation of secondary battery operation]
The secondary battery produced as described above was charged with a constant current of 0.1 mA until the voltage reached 4.2 V, and then discharged to 1.5 V with a constant current of 0.1 mA. As a result, it was confirmed that the secondary battery had a discharge capacity of 0.21 mAh having a voltage flat portion at three places where the charge / discharge voltage was 3.6V, 2.3V, and 1.9V. When the capacity density per electrode active material was calculated from this capacity, it was 260 Ah / kg.

  On the other hand, since the molecular weight of the composite F is 392.4, when the number of electrons Z involved in the battery electrode reaction is 3, the theoretical capacity density is 204.9 Ah / kg. Therefore, it was confirmed that the composite F has a multi-electron reaction involving at least 3 electrons per molecule.

  Thereafter, when the secondary battery was repeatedly charged and discharged in the range of 4.2 to 1.5 V, the initial capacity of 50% or more could be secured even after 10 cycles. That is, it was found that a secondary battery having excellent stability with little decrease in capacity can be obtained even when charging and discharging are repeated.

(Synthesis of organic compounds)
According to the following synthetic scheme (G), 9,10-dihydro-1-hydroxy-2,3,6,7-tetrakis (octyloxy) -9,10-dioxoanthracen-1-yl-2,2,5 , 5-tetramethylpyrrolidinoxy-3-carboxylate-5-yl-2,2,6,6-tetramethylpiperidinoxy-4-carboxylate (hereinafter referred to as “Compound G”) (9C ) Was synthesized.

0.66 mmol of 9,10-dihydro-1,5-dihydroxy-2,3,6,7-tetrakis (octyloxy) -9,10-dioxoanthracene (9C ₁ ) and 0.66 mmol of 4-carboxy TEMPO (9C ₂ ) is dissolved in 25 mL of dichloromethane, and 1.3 mmol of N, N′-dicyclohexylcarbodiimide and 0.66 mmol of 4-dimethylaminopyridine are added with stirring and reacted at room temperature for 5 hours. Obtained. The reaction was then filtered and the filtrate was concentrated to give a crude product. The resulting crude product is separated by silica gel chromatography, and the solid obtained from the main fraction is recrystallized from acetonitrile to give 9,10-dihydro-9,10-dioxoanthracen-1-yl-2. 2,6,6-tetramethylpiperidinoxy-4-carboxylate (8B ₃ ) yellow crystals were obtained.

Next, 0.39 mmol of 9,10-dihydro-9,10-dioxoanthracen-1-yl-2,2,6,6-tetramethylpiperidinoxy-4-carboxylate (9C ₃ ) and 0 .78 mmol of 3-carboxy PROXYL (9C ₄ ) is dissolved in 12 mL of dichloromethane, and 1.57 mmol of N, N′-dicyclohexylcarbodiimide and 0.78 mmol of 4-dimethylaminopyridine are added at room temperature with stirring. The reaction was performed for a time to obtain a reaction product. The reaction was then filtered and the filtrate was concentrated to give a crude product. The obtained crude product was separated by silica gel chromatography, and the solid obtained from the main fraction was recrystallized from hexane to obtain a yellow needle-like crystal compound G (9C).

[Production of secondary battery]
A secondary battery was produced in the same manner as in [Example 1] except that the composite G was used as the electrode active material.

[Confirmation of secondary battery operation]
The secondary battery produced as described above was charged with a constant current of 0.1 mA until the voltage reached 4.2 V, and then discharged to 1.5 V with a constant current of 0.1 mA. As a result, it was confirmed that the secondary battery had a discharge capacity of 0.11 mAh having a voltage flat portion at two places where the charge / discharge voltage was 3.6 V and 2.0 V. When the capacity density per electrode active material was calculated from this capacity, it was 200 Ah / kg.

  On the other hand, since the molecular weight of the composite G is 1103.6, when the number of electrons Z involved in the battery electrode reaction is 4, the theoretical capacity density is 103.6 Ah / kg. Therefore, it was confirmed that the synthesized product F has a multi-electron reaction involving at least 4 electrons per unit molecule. However, the theoretical capacity density decreased due to the large molecular weight.

  Thereafter, when the secondary battery was repeatedly charged and discharged in the range of 4.2 to 1.5 V, the initial capacity of 50% or more could be secured even after 10 cycles. That is, it was found that a secondary battery having excellent stability with little decrease in capacity can be obtained even when charging and discharging are repeated.

  A stable secondary battery with high energy density, high output, good cycle characteristics with little decrease in capacity even after repeated charge and discharge is realized.

4 Positive electrode 6 Negative electrode 9 Electrolyte

Claims (7)

An electrode active material used as an active material of a secondary battery that repeats charging and discharging by a battery electrode reaction,
General formula

[ Wherein n ₁ is an integer of 1 or more, R ₁ is a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, a substituted or unsubstituted carbonyl group, substituted or unsubstituted Substituted acyl group, substituted or unsubstituted alkoxycarbonyl group, substituted or unsubstituted ester group, substituted or unsubstituted ether group, substituted or unsubstituted thioether group, substituted or unsubstituted amine group, substituted or unsubstituted An amide group, a substituted or unsubstituted sulfone group, a substituted or unsubstituted thiosulfonyl group, a substituted or unsubstituted sulfonamido group, a substituted or unsubstituted imine group, a substituted or unsubstituted azo group, and one of these 1 represents at least one of linking groups formed of the above combinations, R ₂ represents a hydrogen atom, Halogen atom, hydroxyl group, nitro group, cyano group, carboxyl group, substituted or unsubstituted alkyl group, substituted or unsubstituted alkenyl group, substituted or unsubstituted cycloalkyl group, substituted or unsubstituted aromatic hydrocarbon group Substituted or unsubstituted aromatic heterocyclic group, substituted or unsubstituted aralkyl group, substituted or unsubstituted amino group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aryloxy group, substituted or unsubstituted Indicate at least one of an alkoxycarbonyl group, a substituted or unsubstituted aryloxycarbonyl group, a substituted or unsubstituted acyl group, and a substituted or unsubstituted acyloxy group, and these substituents form a ring structure with each other Including cases. ]
An electrode active material comprising an organic compound containing a conjugated dione structure and a stable radical structure represented by An electrode active material used as an active material of a secondary battery that repeats charging and discharging by a battery electrode reaction,
General formula

[ Wherein n ₂ is an integer of 1 or more, R ₃ is a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, a substituted or unsubstituted carbonyl group, substituted or unsubstituted Substituted acyl group, substituted or unsubstituted alkoxycarbonyl group, substituted or unsubstituted ester group, substituted or unsubstituted ether group, substituted or unsubstituted thioether group, substituted or unsubstituted amine group, substituted or unsubstituted An amide group, a substituted or unsubstituted sulfone group, a substituted or unsubstituted thiosulfonyl group, a substituted or unsubstituted sulfonamido group, a substituted or unsubstituted imine group, a substituted or unsubstituted azo group, and one of these 1 represents at least one of linking groups comprising the above combinations, and R ₄ represents a hydrogen atom , Halogen atom, hydroxyl group, nitro group, cyano group, carboxyl group, substituted or unsubstituted alkyl group, substituted or unsubstituted alkenyl group, substituted or unsubstituted cycloalkyl group, substituted or unsubstituted aromatic hydrocarbon Group, substituted or unsubstituted aromatic heterocyclic group, substituted or unsubstituted aralkyl group, substituted or unsubstituted amino group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aryloxy group, substituted or unsubstituted At least one of an alkoxycarbonyl group, a substituted or unsubstituted aryloxycarbonyl group, a substituted or unsubstituted acyl group, and a substituted or unsubstituted acyloxy group, and these substituents form a ring structure with each other Including the case of ]
An electrode active material comprising an organic compound containing a conjugated dione structure and a stable radical structure represented by An electrode active material used as an active material of a secondary battery that repeats charging and discharging by a battery electrode reaction,
General formula

[ Wherein n ₃ and n ₄ are integers of 1 or more, R ₅ and R ₆ are substituted or unsubstituted alkyl groups, substituted or unsubstituted alkylene groups, substituted or unsubstituted arylene groups, substituted or unsubstituted Carbonyl group, substituted or unsubstituted acyl group, substituted or unsubstituted alkoxycarbonyl group, substituted or unsubstituted ester group, substituted or unsubstituted ether group, substituted or unsubstituted thioether group, substituted or unsubstituted amine Group, substituted or unsubstituted amide group, substituted or unsubstituted sulfone group, substituted or unsubstituted thiosulfonyl group, substituted or unsubstituted sulfonamido group, substituted or unsubstituted imine group, substituted or unsubstituted azo And at least one of a linking group composed of one or more combinations thereof, R ₇ is a hydrogen atom, halogen atom, hydroxyl group, nitro group, cyano group, carboxyl group, substituted or unsubstituted alkyl group, substituted or unsubstituted alkenyl group, substituted or unsubstituted cycloalkyl group, substituted or non-substituted Substituted aromatic hydrocarbon group, substituted or unsubstituted aromatic heterocyclic group, substituted or unsubstituted aralkyl group, substituted or unsubstituted amino group, substituted or unsubstituted alkoxy group, substituted or unsubstituted aryloxy At least one of a group, a substituted or unsubstituted alkoxycarbonyl group, a substituted or unsubstituted aryloxycarbonyl group, a substituted or unsubstituted acyl group, and a substituted or unsubstituted acyloxy group, and these substituents This includes the case where a ring structure is formed with each other. ]
An electrode active material comprising an organic compound containing a conjugated dione structure and a stable radical structure represented by The electrode active material according to any one of claims 1 to 3 , wherein the organic compound has a redox potential of the conjugated dione structure larger than a redox potential at the time of the reduction reaction of the stable radical structure. . The electrode active material according to any one of claims 1 to 4 , wherein the organic compound has a molecular weight of 700 or less. The electrode active material according to any one of claims 1 to 5 is included in any one of a reaction starting material, a product, and an intermediate product in at least a discharge reaction of the battery electrode reaction. Secondary battery. The secondary battery according to claim 6 , comprising a positive electrode, a negative electrode, and an electrolyte, wherein the positive electrode is mainly composed of the electrode active material.

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