JPWO2014073562A1 - Secondary battery - Google Patents

Abstract

The electrode active material has in the structural unit at least one selected from a dithione compound having a dithione structure, a dione compound having a dione structure, an organic radical compound having a stable radical group, and a diamine compound having a diamine structure. The main component is an organic compound, and the solvent contains at least one selected from a cyclic sulfone compound, a cyclic ether compound, and a nitrile compound. A positive electrode 4 is produced using this electrode active material, an Li salt as an electrolyte salt is dissolved in this solvent to prepare an electrolyte solution 9, and a secondary battery is formed using the positive electrode 4 and the electrolyte solution 9. To do. As a result, a secondary battery having a large energy density, high output, and good cycle characteristics with little decrease in capacity even after repeated charge and discharge is realized.

Description

  The present invention relates to a secondary battery, and more particularly to a secondary battery that contains an electrode active material and an electrolyte solution, and 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 order to meet such demands, secondary batteries using an alkali metal ion such as lithium ion as a charge carrier and utilizing an electrochemical reaction associated with charge exchange have been developed. In particular, lithium ion secondary batteries having a relatively large 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 charging and discharging of the battery. To do. Therefore, as described above, the electrode active material has a central role of the secondary battery in terms of system.

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

  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. In other words, in the above-described lithium ion secondary battery, the migration rate of lithium ions in the lithium-containing transition metal oxide of the positive electrode is slower than that of the electrolyte and the negative electrode, so that the battery reaction rate at the positive electrode is rate-limiting and charged. As a result, the discharge rate was limited, and as a result, there was a limit to increasing the output and shortening the charging time.

  In order to solve such problems, research and development of organic secondary batteries using organic compounds such as organic sulfur compounds as electrode active materials have been actively conducted in recent years.

  For example, in Patent Document 1, an organic sulfur compound as a positive electrode material has an S—S bond in a charged state, and at the time of discharging the positive electrode, the S—S bond is cleaved to form an organic sulfur metal salt having a metal ion. New metal-sulfur battery cells have been proposed.

  In Patent Document 1, a disulfide-based organic compound represented by the general formula (1 ′) (hereinafter referred to as “disulfide compound”) is used as a positive electrode active material.

R-S-S-R (1 ')
Here, R represents an aliphatic organic group or an aromatic organic group, and each includes the same or different cases.

  The disulfide compound can undergo a two-electron reaction, and the S—S bond is cleaved in a reduced state (discharge state), thereby forming an organic thiolate (R—SH). This organic thiolate forms an S—S bond in the oxidized state (charged state) and is restored to the disulfide compound represented by the general formula (1 ′). That is, since the disulfide compound forms an S—S bond having a small binding energy, a reversible redox reaction occurs using the bond and cleavage by the reaction, and thus charge and discharge can be performed.

Patent Document 2 discloses the following formula (2 ′):
-(NH-CS-CS-NH) (2 ')
A battery electrode containing rubeanic acid or a rubeanic acid polymer that has a structural unit represented by the formula (II) and can be bonded to lithium ions has been proposed.

  The rubeanic acid or rubeanic acid polymer containing the dithione structure represented by the general formula (2 ′) binds to lithium ions during reduction, and releases the bound lithium ions during oxidation. Charging / discharging can be performed by utilizing such a reversible oxidation-reduction reaction of rubeanic acid or rubeanic acid polymer.

  On the other hand, the volume of the electrode active material of the secondary battery is greatly changed by a chemical change associated with the charge / discharge reaction. As a result, the solid state electrode active material collapses or dissolves in the electrolyte solution, It may stop functioning. In particular, unlike a lithium ion battery that charges and discharges while maintaining a crystalline system, in an organic secondary battery that charges and discharges using a redox reaction of the molecule itself, the electrode active material dissolves in the electrolyte. Therefore, it is considered to suppress dissolution of such an electrode active material in an electrolyte.

  For example, Patent Document 3 proposes a battery including a negative electrode, a solid composite positive electrode having an electroactive sulfur-containing substance, and an electrolyte inserted therebetween.

  In this Patent Document 3, as a preferable form of an electrolyte, one or more ionic electrolyte salts, N-methylacetamide, acetonitrile, carbonate, sulfolane, sulfone, N-alkylpyrrolidone, dioxolane, aliphatic ether, cyclic ether, glyme And mixtures with one or more electrolyte solvents selected from siloxanes. Then, an electrolyte solution is prepared using 1,3-dioxolane and dimethoxyethane as an electrolyte solvent, and a battery containing an electroactive sulfur-containing substance as a positive electrode material is manufactured.

US Pat. No. 4,833,048 (Claim 1, column 5, line 20 to column 28) JP 2008-147015 A (Claim 1, paragraph number [0011], FIG. 3, FIG. 5) JP 2002-532854 A (claim 1, claim 83, paragraph numbers [0031], [0088], etc.)

  However, Patent Document 1 uses a low-molecular disulfide compound in which two electrons are involved. However, since it repeatedly binds and cleaves with other molecules along with the charge / discharge reaction, it lacks stability, and charge / discharge reaction is not performed. If it is repeated, the capacity may decrease.

  In Patent Document 2, rubeanic acid having a dithione structure or a rubeanic acid polymer is used to cause a two-electron reaction. However, a low molecular weight compound such as rubeanic acid has dissolved or dissolved in an electrolyte solution. Contamination of the electrode with a compound is likely to occur, and therefore, stability against repeated charge and discharge is lacking. In addition, when a polymer compound such as rubeanic acid polymer is used, dissolution in the electrolyte solution and electrode contamination can be suppressed, but the intermolecular interaction in the rubeanic acid polymer is large. For this reason, the movement of ions is hindered, and the proportion of the active material that can be used effectively is reduced.

  Patent Document 3 uses a sulfur-based compound as a positive electrode active material and produces an electrolyte solution using oxolane or the like as a solvent to form a battery. However, even if such an electrolyte solution is used, it is stable. It is difficult to obtain a secondary battery having good cycle characteristics.

  That is, an organic secondary battery using an organic compound as an electrode active material is more reactive than a conventional lithium ion secondary battery using a lithium-containing transition metal oxide as an electrode active material. Elution of the electrode active material into the electrolyte solution easily occurs, and in addition to the oxidation-reduction reaction involved in charge / discharge, an irreversible reaction easily occurs, leading to deactivation of the electrode active material. Technical issues.

  However, the above-described conventional technology cannot sufficiently solve the above technical problem, and thus, a long-life secondary battery having a sufficiently high energy density, high output and good cycle characteristics is realized. The current situation is that we have not been able to.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a secondary battery having a high energy density, high output, and good cycle characteristics with little decrease in capacity even after repeated charge and discharge. To do.

  The present inventors use an organic compound having a dithione structure, a dione structure, a stable radical group, and a diamine structure in a structural unit, which can obtain an electrode active material having good charge / discharge efficiency and a high capacity density. As a result of earnest research, the electrolyte solution contains at least one of a specific solvent species, that is, a cyclic sulfone compound, a cyclic ether compound, and a nitrile compound. It has been found that an irreversible reaction can be suppressed between the two, whereby a secondary battery having good cycle characteristics and a long life can be obtained.

  The present invention has been made based on such knowledge, and the secondary battery according to the present invention includes an electrode active material and an electrolyte solution in which an electrolyte salt is dissolved in a solvent. A secondary battery that is repeatedly charged and discharged by a battery electrode reaction, wherein the electrode active material has a dithione compound having a dithione structure, a dione compound having a dione structure, an organic radical compound containing a stable radical group, and a diamine structure Mainly composed of an organic compound having at least one selected from diamine compounds in the structural unit, the electrolyte salt is formed of a lithium salt, and the solvent is a cyclic sulfone compound, a cyclic ether compound, and a nitrile compound. It contains at least one selected from the above.

  Further, in the secondary battery of the present invention, the cyclic sulfone compound has the general formula:

で表わされるのが好ましい。

Is preferably represented by:

  Here, in the above general formula, Z represents an alkylene group having 1 to 7 carbon atoms, and includes both straight and branched chains.

  Further, in the secondary battery of the present invention, the cyclic ether compound has the general formula:

で表わされるのが好ましい。

Is preferably represented by:

Here, in the above general formula, p and q is an integer of 0 to 3, R ₁ to R ₃ represents an alkylene group having 1 to 8 carbon atoms, and includes a case having a fluorine atom. Furthermore, when these R _{1 to} R ₃ are the same, they include both straight and branched chains.

Further, in the secondary battery of the present invention, the nitrile compound has a general formula of R ₄ —C≡N, N≡C—R ₅ —C≡N, and R ₆ OR ₇ —C≡N.
Is preferably represented by any of the above.

Here, in the general formula, _{R 4} and _{R 6} represents an alkyl group having 1 to 4 carbon atoms, _{R 5} and _{R 7} represents an alkylene group having a carbon number of 1-7, these _R 4 to R ₇ Includes both straight and branched chains.

  Further, in the secondary battery of the present invention, the electrolyte salt has a general formula.

及び、

のいずれかで表されるアニオンを含有しているのが好ましい。

as well as,

It is preferable to contain the anion represented by either.

Here, in said general formula, R < ₈ > -R < ₁₂ > shows either one of a fluorine atom and a fluoroalkyl group, and these R < ₈ > -R < ₁₂ > includes the same case. R ₁₃ represents a fluoroalkylene group, and R ₁₄ represents a fluoroalkyl group having 1 to 7 carbon atoms.

  In the secondary battery of the present invention, the dithione compound has the general formula:

又は

で表されるのが好ましい。

Or

It is preferable to be represented by

Here, in the above general formula, n is an integer of 1 or more, and R _{15 to} R ₁₇ and R ₁₉ are a substituted or unsubstituted amino group, a substituted or unsubstituted imino group, a substituted or unsubstituted alkyl group. Substituted or unsubstituted alkylene group, substituted or unsubstituted aryl group, substituted or unsubstituted aralkyl group, substituted or unsubstituted cycloalkyl group, substituted or unsubstituted alkoxyl group, substituted or unsubstituted alkenyl group, Substituted or unsubstituted aryloxy group, substituted or unsubstituted arylamino group, substituted or unsubstituted alkylamino group, substituted or unsubstituted thioaryl group, substituted or unsubstituted thioalkyl group, substituted or unsubstituted heterocyclic ring Group, substituted or unsubstituted formyl group, substituted or unsubstituted silyl group, substituted or unsubstituted Any one of a cyano group, a substituted or unsubstituted nitro group, a substituted or unsubstituted nitroso group, a substituted or unsubstituted carboxyl group, a substituted or unsubstituted alkoxycarbonyl group, and a linking group comprising one or more combinations thereof R _{15 to} R ₁₇ and R ₁₉ are the same, and include a case where they are linked to each other to form a saturated or unsaturated ring structure, and R ₁₈ is a substituted or unsubstituted alkylene group, substituted or It represents at least one of an unsubstituted arylene group and an imino group, and includes a case where the imino groups are linked to each other.

  Furthermore, in the secondary battery of the present invention, the dione compound has the general formula:

又は

で表されるのが好ましい。

Or

It is preferable to be represented by

Here, in the above general formula, n is an integer of 1 or more, and R _{20 to} R ₂₂ and R ₂₄ are a substituted or unsubstituted amino group, a substituted or unsubstituted imino group, a substituted or unsubstituted alkyl group. Substituted or unsubstituted alkylene group, substituted or unsubstituted aryl group, substituted or unsubstituted aralkyl group, substituted or unsubstituted cycloalkyl group, substituted or unsubstituted alkoxyl group, substituted or unsubstituted alkenyl group, Substituted or unsubstituted aryloxy group, substituted or unsubstituted arylamino group, substituted or unsubstituted alkylamino group, substituted or unsubstituted thioaryl group, substituted or unsubstituted thioalkyl group, substituted or unsubstituted heterocyclic ring Group, substituted or unsubstituted formyl group, substituted or unsubstituted silyl group, substituted or unsubstituted Any one of a cyano group, a substituted or unsubstituted nitro group, a substituted or unsubstituted nitroso group, a substituted or unsubstituted carboxyl group, a substituted or unsubstituted alkoxycarbonyl group, and a linking group comprising one or more combinations thereof R _{20 to} R ₂₂ and R ₂₄ are the same and include the case where they are linked to each other to form a saturated or unsaturated ring structure, and R ₂₃ is a substituted or unsubstituted alkylene group, substituted or It represents at least one of an unsubstituted arylene group and an imino group, and includes a case where the imino groups are linked to each other.

  In the secondary battery of the present invention, the organic radical compound is preferably a nitroxyl radical compound.

  Furthermore, in the secondary battery of the present invention, it is preferable that the nitroxyl radical-based compound contains 2,2,6,6-tetramethylpiperidine-N-oxyl radical in the molecular structure.

  In the secondary battery of the present invention, the diamine compound has the general formula

で表わされるのが好ましい。

Is preferably represented by:

In the above general formula, R ₂₅ and R ₂₆ are a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, a substituted or unsubstituted carbonyl group, a substituted or unsubstituted acyl group. Group, substituted or unsubstituted alkoxycarbonyl group, substituted or unsubstituted ester group, substituted or unsubstituted ether group, substituted or unsubstituted thioether group, substituted or unsubstituted amino group, substituted or unsubstituted amide group , Substituted or unsubstituted sulfone groups, substituted or unsubstituted thiosulfonyl groups, substituted or unsubstituted sulfonamido groups, substituted or unsubstituted imino groups, substituted or unsubstituted azo groups, and combinations of one or more of these Any one of the linking groups consisting of X _{1 to} X ₄ are a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a cyano group, a carboxyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted cycloalkyl group, Substituted or unsubstituted aryl 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 Represents 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 are This includes the case where a substituent forms a ring structure.

  In the secondary battery of the present invention, it is preferable that 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.

  Furthermore, the secondary battery of the present invention preferably has a positive electrode and a negative electrode, and the positive electrode is mainly composed of the electrode active material.

  According to the secondary battery of the present invention, the electrode active material is selected from a dithione compound having a dithione structure, a dione compound having a dione structure, an organic radical compound having a stable radical group, and a diamine compound having a diamine structure. An organic compound having at least one of the above-mentioned constituents in a structural unit, the electrolyte salt of the electrolyte solution is formed of a lithium salt, and the solvent is selected from a cyclic sulfone compound, a cyclic ether compound, and a nitrile compound. In addition, since at least one kind is contained, the electrode active material can be prevented from causing an irreversible reaction. Accordingly, the electrode active material can contribute only to the battery electrode reaction, the charge / discharge efficiency is good, and the charge / discharge reaction can be stably repeated. That is, by suppressing the occurrence of unnecessary irreversible reactions of the electrode active material, the movement of ions during the charge / discharge reaction is facilitated, and a smooth and stable charge / discharge reaction occurs. This makes it possible to obtain a secondary battery having a large energy density and a long cycle life.

  In addition, since the electrode active material is mainly composed of organic compounds, the environmental load is low and safety is taken into consideration.

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.

  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.

  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. And the positive electrode 4 which formed the positive electrode active material (electrode active material) in the sheet form is distribute | arranged to the center of the bottom part of the positive electrode case 2 which comprises a positive electrode collector. A separator 5 formed of a porous film such as polypropylene is laminated on the positive electrode 4, and a negative electrode 6 is further laminated on the separator 5. As the negative electrode 6, for example, one obtained by superimposing a lithium metal foil on Cu or one obtained by applying a lithium storage material such as graphite or hard carbon to the metal foil can be used. A negative electrode current collector 7 made of Cu or the like is laminated on the negative electrode 6, and a metal spring 8 is placed on the negative electrode current collector 7. In addition, the electrolyte solution 9 is injected into 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 is sealed via the gasket 10.

  And in the said secondary battery, the positive electrode active material has mainly the organic compound which contained the specific structure in the structural unit. Specifically, the organic compound includes at least one selected from a dithione compound having a dithione structure, a dione compound having a dione structure, an organic radical compound having a stable radical group, and a diamine compound having a diamine structure. Contained in structural units.

  The electrolyte solution 9 contains an electrolyte salt formed of a lithium salt and a solvent that dissolves the electrolyte salt, and is selected from a cyclic sulfone compound, a cyclic ether compound, and a nitrile compound in the solvent. It contains at least one specific solvent species. That is, the electrolyte solution 9 is interposed between the positive electrode 4 and the negative electrode 6 that is the opposite electrode of the positive electrode 4 and transports charge carriers between the two electrodes. In this embodiment, the electrolyte solution 9 is formed of a lithium salt. The obtained electrolyte salt is used by dissolving or dissolving it in a solvent containing the above-mentioned specific solvent species. And since generation | occurrence | production of the unnecessary irreversible reaction of an electrode active material is suppressed by this, the movement of the ion at the time of charging / discharging reaction becomes easy, and it becomes possible to produce smooth and stable charging / discharging reaction. As a result, charging in a short time or discharging at high output becomes possible, and a secondary battery having an electrode active material having a large energy density and a long life can be realized.

  That is, in recent years, electrode active materials mainly composed of organic compounds have attracted attention. Among them, the above-described dithion compounds, dione compounds, organic radical compounds, and diamine compounds have good charge / discharge efficiency and high capacity density. Is promising as a possible active material.

  However, in these organic compounds, when a low molecular weight compound is used, dissolution in the electrolyte solution 9 and contamination of the electrode by the dissolved compound are likely to occur, and therefore, stability against repeated charge and discharge is lacking. On the other hand, when a polymer compound is used, the intermolecular interaction in the polymer compound is large, which may hinder the movement of ions and reduce the proportion of the active material that can be used effectively.

  Moreover, these organic compounds are liable to cause irreversible reactions in the electrolyte solution 9 in addition to the oxidation-reduction reactions involved in charge and discharge, and may cause deactivation of the electrode active material.

  However, as a result of intensive studies by the present inventors, the positive electrode active material mainly composed of the organic compound is contained in the electrolyte solution 9 by using the electrolyte solution 9 containing the above-mentioned specific solvent species in the solvent. Can be effectively suppressed, and as a result, unnecessary irreversible reactions can be suppressed and stabilized in the electrolyte solution 9, thereby facilitating the movement of ions during the charge / discharge reaction. It has been found that the discharge reaction proceeds smoothly and that charging in a short time and discharging at a high output can be performed stably.

  Therefore, in the present embodiment, the solvent of the electrolyte solution 9 contains the specific solvent species (at least one selected from a cyclic sulfone compound, a cyclic ether compound, and a nitrile compound), whereby the energy density is increased. A large secondary battery having a long cycle life with little reduction in capacity even after repeated charging and discharging at high output is obtained.

  Such a specific solvent species is not particularly limited as long as it belongs to a cyclic sulfone compound, a cyclic ether compound, and a nitrile compound, but a compound represented by the following general formula is preferably used. .

  That is, as the cyclic sulfone compound, those represented by the general formula (1) can be preferably used.

  Here, in the general formula (1), Z represents an alkylene group having 1 to 7 carbon atoms, and includes both straight and branched chains.

  Even in the case of a cyclic sulfone compound, when the number of carbon atoms is 8 or more, it becomes a long chain and the viscosity becomes high, which is not preferable.

  Examples of the cyclic sulfone compound belonging to the category of the general formula (1) include sulfolane represented by the following chemical formula (1a), 3-methylsulfolane represented by the following chemical formula (1b), 2,4-dimethylsulfolane represented by the following chemical formula (1c), Examples include 2,3-dimethylsulfolane represented by the following chemical formula (1d).

  Moreover, as a cyclic ether compound, what is represented by General formula (2) can be used preferably.

Here, in the above general formula (2), p and q is an integer of 0 to _3, R 1 to R ₃ represents an alkylene group having 1 to 8 carbon atoms, and includes a case having a fluorine atom . Furthermore, when these R _{1 to} R ₃ are the same, they include both straight and branched chains.

  Even in the case of a cyclic ether compound, when the number of carbon atoms is 9 or more and p and q are 4 or more, the chain becomes long and the viscosity becomes high, which is not preferable.

  Examples of the cyclic ether compound belonging to the category of the general formula (2) include tetrahydrofuran represented by the following chemical formula (2a), 2-methyltetrahydrofuran represented by the following chemical formula (2b), 1,3-dioxolane represented by the following chemical formula (2c), Examples include 1,4-dioxane represented by the following chemical formula (2d), 12-crown-4-ether represented by the following chemical formula (2e), 18-crown-6-ether represented by the following chemical formula (2f), and the like.

  Moreover, as a nitrile type compound, what is represented by general formula (3)-(5) can be used preferably.

R ₄ —C≡N (3)
N≡C—R ₅ —C≡N (4)
R ₆ OR ₇ —C≡N (5)

Here, in the general formulas (3) to (5), R ₄ and R ₆ are each an alkyl group having 1 to 4 carbon atoms, and R ₅ and R ₇ are each an alkylene group having 1 to 7 carbon atoms. These R _{4 to} R ₇ include both straight and branched chains.

  Examples of the nitrile compound belonging to the category of the general formula (3) include acetonitrile represented by the following chemical formula (3a), propionitrile represented by the following chemical formula (3b), and the like. Examples of the nitrile compound belonging to the category of the general formula (4) include adiponitrile represented by the following chemical formula (4a), glutaronitrile represented by the following chemical formula (4b), and the like. Examples of the nitrile compound belonging to the category of the general formula (5) include valeronitrile represented by the following chemical formula (5a), methoxyacetonitrile represented by the following chemical formula (5b), methoxypropionitrile represented by the following chemical formula (5c), and the like. Can do.

  Although content of these specific solvent seed | species is not specifically limited, In order to exhibit an expected effect, 50 mass% or more is preferable in a solvent. Moreover, it is important to contain at least one of these specific solvent species. Therefore, among the specific solvent species, two or more compounds belonging to the same category (for example, a combination of sulfolane and 3-methylsulfolane) are contained, or two or more compounds belonging to different categories (for example, A combination of sulfolane and acetonitrile, etc.) may be contained, and if necessary, compounds other than these specific solvent species may be contained as additives.

  The electrolyte salt that dissolves in the solvent in the electrolyte solution 9 is not particularly limited, but lithium salts containing anions represented by the general formulas (6) to (9) can be preferably used. .

Here, in said general formula (6)-(9), R < ₈ > -R < ₁₂ > shows either one of a fluorine atom and a fluoroalkyl group, and these R < ₈ > -R < ₁₂ > include the case where it is the same. Yes. R ₁₃ represents a fluoroalkylene group, and R ₁₄ represents a fluoroalkyl group having 1 to 7 carbon atoms.

  Examples of the anion belonging to the category of the general formula (6) include those represented by the following chemical formulas (6a) to (6d).

(FSO ₂ ) ₂ N ⁻ (6a)
(CF ₃ SO ₂ ) ₂ N ⁻ (6b)
(C ₂ F ₅ SO ₂ ) ₂ N ⁻ (6c)
(CF ₃ SO ₂ ) (C ₂ F ₅ SO ₂ ) N ⁻ (6d)

  Examples of the anion belonging to the category of the general formula (7) include those represented by the following chemical formulas (7a) to (7e).

(FSO ₂ ) ₃ C ⁻ (7a)
(CF ₃ SO ₂ ) ₃ C ⁻ (7b)
(C ₂ F ₅ SO ₂ ) ₃ C ⁻ (7c)
(CF ₃ SO ₂ ) ₂ (C ₂ F ₅ SO ₂ ) C ⁻ (7d)
_{(C 2 F 5 SO 2)} 2 (CF 3 SO 2) C - ... (7e)

  Examples of the anion belonging to the category of the general formula (8) include those represented by the following chemical formulas (8a) to (8c).

  Examples of the anion belonging to the category of the general formula (9) include those represented by the following chemical formulas (9a) to (9c).

CF ₃ SO ₃ ⁻ (9a)
C ₂ F ₅ SO ₃ ⁻ (9b)
C ₃ F ₇ SO ₃ ⁻ (9c)

The content of the electrolyte salt in the electrolyte solution 9 is not particularly limited, but is preferably 10 to 80% by mass in order to exhibit the desired effect. In addition, with respect to the anion species contained in the electrolyte salt, two or more compounds belonging to the same category (for example, (CF ₃ SO ₂ ) ₂ N ⁻ and (C ₂ F ₅ SO _{2) 2} N ^- combinations) may be contained with, or different categories belonging compound 2 or more _{(e.g., (C} 2 _{F 5} SO ₂₎ 2 N ^- and _CF 3 SO ₃ ^- and combinations of Etc.) It can also be contained.

  Next, each organic compound that is a main component of the positive electrode active material will be described in detail.

(1) Dithione compound The dithione compound is excellent in stability during charge and discharge (oxidized state and reduced state), and can perform a multi-electron reaction of two or more electrons by an oxidation-reduction reaction. Therefore, by using the dithione compound as the positive electrode active material and using the solvent containing the above-mentioned specific solvent species in the electrolyte solution 9, the dithione compound as the positive electrode active material is suppressed from causing an irreversible reaction. Thus, since the electrolyte solution 9 is stabilized, the charge / discharge of the multi-electron reaction can be stably repeated, and a secondary battery having good charge / discharge efficiency and high capacity density can be obtained.

  Such a dithione compound is not particularly limited as long as it has a dithione structure in the structural unit, but a compound represented by the following general formula (10) or (11) is preferably used. Can do.

Here, in the above chemical formulas (10) and (11), n is an integer of 1 or more, and R _{15 to} R ₁₇ and R ₁₉ are a substituted or unsubstituted amino group, a substituted or unsubstituted imino group, a substituted Or an unsubstituted alkyl group, a substituted or unsubstituted alkylene group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkoxyl group, substituted or Unsubstituted alkenyl group, substituted or unsubstituted aryloxy group, substituted or unsubstituted arylamino group, substituted or unsubstituted alkylamino group, substituted or unsubstituted thioaryl group, substituted or unsubstituted thioalkyl group, substituted Or an unsubstituted heterocyclic group, a substituted or unsubstituted formyl group, a substituted or unsubstituted silyl group, It consists of a substituted or unsubstituted cyano group, a substituted or unsubstituted nitro group, a substituted or unsubstituted nitroso group, a substituted or unsubstituted carboxyl group, a substituted or unsubstituted alkoxycarbonyl group, and a combination of one or more thereof. Any one of linking groups is shown, and R _{15 to} R ₁₇ and R ₁₉ are the same, and include cases where they are linked to each other to form a saturated or unsaturated ring structure. R ₁₈ represents at least one of a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, and an imino group, and includes a case where the imino groups are connected to each other.

  And as a dithione compound which belongs to the category of the said General formula (10), the organic compound shown to following Chemical formula (10a)-(10i) can be mentioned.

  The following chemical reaction formula (I) shows an example of a charge / discharge reaction expected when the dithione compound represented by the chemical formula (10a) is used as the positive electrode active material and Li is used as the cation of the electrolyte salt.

  Examples of the dithione compound belonging to the category of the chemical formula (11) include organic compounds represented by the following chemical formulas (11a) to (11g).

  The following chemical reaction formula (II) shows an example of a charge / discharge reaction expected when the dithione compound shown in the chemical formula (11a) is used as the positive electrode active material and Li is used as the cation of the electrolyte salt. .

  The molecular weight of the organic compound constituting the positive electrode active material is not particularly limited. However, when the portion other than the dithione structure is increased, the molecular weight is increased, so that the storage capacity per unit mass, that is, the capacity density is reduced. Therefore, it is preferable that the molecular weight of the portion other than the dithione structure is small.

(2) Dione Compound Like the dithione compound, the dione compound is excellent in stability during charge and discharge (oxidized state and reduced state), and can perform a multi-electron reaction of two or more electrons by an oxidation-reduction reaction. Therefore, by using the dione compound as the positive electrode active material and using the solvent containing the above-mentioned specific solvent species in the electrolyte solution 9, the dione compound as the positive electrode active material can suppress the occurrence of an irreversible reaction. Thus, since the electrolyte solution 9 is stabilized, the charge / discharge of the multi-electron reaction can be stably repeated, and a secondary battery having good charge / discharge efficiency and high capacity density can be obtained.

  The dione compound is not particularly limited as long as it has a dione structure in the structural unit, but preferably uses a compound represented by the following general formula (12) or (13). Can do.

Here, in the above chemical formula (12) or (13), n is an integer of 1 or more, and R _{20 to} R ₂₂ and R ₂₄ are a substituted or unsubstituted amino group, a substituted or unsubstituted imino group, a substituted Or an unsubstituted alkyl group, a substituted or unsubstituted alkylene group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted alkoxyl group, substituted or Unsubstituted alkenyl group, substituted or unsubstituted aryloxy group, substituted or unsubstituted arylamino group, substituted or unsubstituted alkylamino group, substituted or unsubstituted thioaryl group, substituted or unsubstituted thioalkyl group, substituted Or an unsubstituted heterocyclic group, a substituted or unsubstituted formyl group, a substituted or unsubstituted silyl group, It consists of a substituted or unsubstituted cyano group, a substituted or unsubstituted nitro group, a substituted or unsubstituted nitroso group, a substituted or unsubstituted carboxyl group, a substituted or unsubstituted alkoxycarbonyl group, and one or more combinations thereof Any of the linking groups is shown, and these R _{20 to} R ₂₂ and R ₂₄ include the same case and the case where they are connected to each other to form a saturated or unsaturated ring structure. R ₂₃ represents at least one of a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, and an imino group, and includes a case where the imino groups are linked to each other.

  And as a dione compound which belongs to the category of the said General formula (12), the organic compound shown to following Chemical formula (12a)-(12e) can be mentioned.

  The following chemical reaction formula (III) shows an example of a charge / discharge reaction expected when the dione compound represented by the chemical formula (12a) is used as the positive electrode active material and Li is used as the cation of the electrolyte salt. .

  Examples of the dione compound belonging to the category of the chemical formula (13) include organic compounds represented by the following chemical formulas (13a) to (13f).

  The following chemical reaction formula (IV) shows an example of a charge / discharge reaction expected when the dione compound represented by the chemical formula (13a) is used as the positive electrode active material and Li is used as the cation of the electrolyte salt.

  The molecular weight of the organic compound constituting the positive electrode active material is not particularly limited. However, when the portion other than the dione structure is increased, the molecular weight is increased, so that the storage capacity per unit mass, that is, the capacity density is reduced. Therefore, the molecular weight of the portion other than the dione structure is preferably small.

(3) Organic radical compound An organic radical compound having a stable radical group can rapidly advance a charge / discharge reaction.

  That is, the organic radical compound has a radical which is an unpaired electron in the outermost shell of the electron orbit. These radicals are generally highly reactive chemical species, and many of them disappear with a certain lifetime due to interaction with surrounding substances, but they are stable depending on the state of resonance effect, steric hindrance, and solvation. It becomes a stable radical that exists stably for a long time. In addition, since radicals have a high reaction rate, it is possible to charge and discharge using a redox reaction of a stable radical.

  And in this organic radical compound, since the unpaired electron which reacts exists and localizes in a radical atom, the density | concentration of a reaction site can be increased and, thereby, realization of a high capacity secondary battery is possible. .

  Therefore, by using an organic radical compound as the positive electrode active material and using a solvent containing the above-mentioned specific solvent species in the electrolyte solution 9, the organic radical compound that is the positive electrode active material undergoes an irreversible reaction. Since it is suppressed and stabilized in the electrolyte solution 9, it is possible to stably repeat charge and discharge of a multi-electron reaction, and to obtain a secondary battery with good charge and discharge efficiency and high capacity density.

  As a stable radical group contained in such an organic radical compound, a nitroxyl radical group, a nitrogen radical group, an oxygen radical group, a thioaminyl radical group, a sulfur radical group, a boron radical group, etc. can be used. It is preferable to use a nitroxyl radical group represented by the chemical formula (14).

  The chemical reaction formula (V) below shows an example of a charge / discharge reaction expected when a nitroxyl radical compound containing a nitroxyl radical group is used as an electrode active material and Li is used as a cation of an electrolyte salt. Yes.

  Further, among nitroxyl radical compounds, a compound containing a 2,2,6,6-tetramethylpiperidine-N-oxyl radical structure represented by the general formula (15) in the molecular structure has a stable charge / discharge reaction. It is particularly preferable because it proceeds.

  As an organic compound contained in the category of the said General formula (15), what is shown to Chemical formula (15a)-(15e), the copolymer which makes these some repeating units, etc. can be mentioned, for example.

  The molecular weight of the organic compound constituting the positive electrode active material is not particularly limited, but when a portion other than a portion involving a stable radical group such as a 2,2,6,6-tetramethylpiperidine-N-oxyl radical structure becomes large. In addition, since the molecular weight increases, the storage capacity per unit mass, that is, the capacity density decreases. Therefore, it is preferable that the molecular weight of the portion other than the portion involving the stable radical group is small.

(4) Diamine compound Like the dithione compound and dione compound, the diamine compound is excellent in stability during charge and discharge (oxidized state and reduced state), and can perform a multi-electron reaction of two or more electrons by an oxidation-reduction reaction. . Therefore, by using the diamine compound as the positive electrode active material and using the solvent containing the above-mentioned specific solvent species in the electrolyte solution 9, the diamine compound as the positive electrode active material suppresses the occurrence of an irreversible reaction. Thus, since the electrolyte solution 9 is stabilized, the charge / discharge of the multi-electron reaction can be stably repeated, and a secondary battery having good charge / discharge efficiency and high capacity density can be obtained.

  Such a diamine compound is not particularly limited as long as it has a diamine structure in the structural unit, but an organic compound represented by the following general formula (16) can be preferably used.

In the general formula (16), R ₂₅ and R ₂₆ are 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 an unsubstituted 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 Any one of these linking groups consisting of one or more combinations is shown. X _{1 to} X ₄ are a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a cyano group, a carboxyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted cycloalkyl group, Substituted or unsubstituted aryl 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 Represents 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 are This includes the case where a substituent forms a ring structure.

  And as an organic compound contained in the category of the said General formula (16), the organic compound which contains the phenazine structure which the aryl group couple | bonded across the pyrazine ring in a structural unit is more preferable, for example, chemical formula (16a)-( The organic compounds shown in 16f) can be preferably used.

  The following chemical reaction formula (VI) shows an example of a charge / discharge reaction expected when the organic compound shown in the chemical formula (16b) is used as the electrode active material and Li is used as the cation of the electrolyte salt.

  The molecular weight of the diamine compound is not particularly limited. However, when the portion other than the diamine structure is increased, the molecular weight increases, so that the storage capacity per unit mass, that is, the capacity density is reduced. Accordingly, the molecular weight of the portion other than the diamine structure is preferably small.

  The substituents listed in the general formulas (10) to (13) and (16) are not limited as long as they belong to the respective categories, but as the molecular weight increases, the unit of the positive electrode active material Since the amount of charge that can be accumulated per mass is small, it is preferable to select a desired substituent so that the molecular weight is about 250.

  Since the positive electrode active material is reversibly oxidized or reduced by charge / discharge, the positive electrode active material takes a different structure and state depending on the charged state, discharged state, or intermediate state. Is contained in at least one of a reaction starting material (a substance that causes a chemical reaction in a battery electrode reaction), a product (a substance resulting from a chemical reaction), and an intermediate product. A secondary battery having a positive electrode active material with good discharge efficiency and high capacity density can be realized.

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

  First, a positive electrode active material is formed into an electrode shape. That is, one of the organic compounds described above is prepared. Then, this organic compound is mixed with a conductive agent and a binder, a solvent is added to produce a slurry for active material, and the slurry for active material is coated on the positive electrode current collector by an arbitrary coating method. The positive electrode active material layer is formed on the positive electrode current collector by drying, whereby the positive electrode 4 is produced.

  Here, the conductive 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, carbon nanotube, and carbon nanohorn, polyaniline, and polypyrrole. , Conductive polymers such as polythiophene, polyacetylene, and polyacene can be used. Further, two or more kinds of conductive agents can be mixed and used. In addition, as for the content rate in the positive electrode active material of a electrically conductive agent, 10 to 80 weight% is preferable.

  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 used for the slurry for the active material is not particularly limited. For example, bases such as dimethyl sulfoxide, dimethylformamide, N-methylpyrrolidone, propylene carbonate, diethyl carbonate, dimethyl carbonate, and γ-butyrolactone are used. A non-aqueous solvent such as acetonitrile, tetrahydrofuran, nitrobenzene, and acetone, and a protic solvent such as methanol and ethanol can be used.

  Note that the type of solvent, the compounding ratio of the organic compound and the solvent, the type of conductive agent and binder, and the amount added thereof can be arbitrarily set in consideration of the required characteristics and productivity of the secondary battery. it can.

  Next, an electrolyte solution 9 is prepared. That is, a solvent containing a specific solvent type (at least one selected from a cyclic sulfone compound, a cyclic ether compound and a nitrile compound), preferably 50% by mass or more, is prepared, more preferably a general formula (6) An electrolyte salt made of a lithium salt containing an anion represented by (9) is prepared. And this electrolyte salt is dissolved in the said solvent, and the electrolyte solution 9 is produced.

  Then, the positive electrode 4 is impregnated with the electrolyte solution 9 so that the positive electrode 4 is impregnated with the electrolyte solution 9, and then the separator 5 impregnated with the electrolyte solution 9 is laminated on the positive electrode 4, and further, the negative electrode 6 and the negative electrode The current collectors 7 are sequentially stacked, and then the electrolyte solution 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.

  Thus, according to the present embodiment, the electrolyte solution 9 containing a specific solvent species (cyclic sulfone compound, cyclic ether compound, nitrile compound) that contributes to stabilization of the positive electrode active material in the solvent, and charge / discharge Since the secondary battery is configured using the positive electrode active material having good efficiency and high capacity density, the positive electrode active material can be prevented from causing an irreversible reaction, and thus ions during the charge / discharge reaction can be suppressed. Is easy to move, and a smooth and stable charge / discharge reaction can be repeated. In other words, charging in a short time and discharging at high output are possible, thereby obtaining a secondary battery with a long life and good cycle characteristics with a large energy density and high output, with little capacity decrease even after repeated charging and discharging. It becomes possible.

  In addition, since the positive electrode active material is mainly composed of an organic compound, the environmental load is low and the safety is taken into consideration.

  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 compounds are only examples of organic compounds that are the main components of the positive electrode active material, and cyclic sulfone compounds, cyclic ether compounds, nitrile compounds, and electrolyte salts. Absent. That is, if the electrode active material is mainly composed of the above-described organic compound and the electrolyte solution 9 contains a cyclic sulfone compound, a cyclic ether compound, or a nitrile compound, the electrode active material suppresses the occurrence of an irreversible reaction. Thus, it is considered that a desired rapid oxidation-reduction reaction proceeds. Therefore, a secondary battery having a large energy density and excellent stability can be obtained.

  Moreover, in the said embodiment, although the organic compound was used for the positive electrode active material, you may use it for a negative electrode active material.

  In the above embodiment, the coin-type secondary battery has been described. However, the battery shape is not particularly limited, and can be applied to a cylindrical type, a square type, a sheet type, 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.

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

  In addition, the Example shown below is an example and this invention is not limited to the following Example.

[Production of battery]
As an active material, rubeanic acid represented by chemical formula (10a) was prepared, and as an electrolyte solvent, sulfolane represented by chemical formula (1a) was prepared.

  Then, rubeanic acid: 300 mg, graphite powder as a conductive agent: 600 mg, and polytetrafluoroethylene resin as a binder: 100 mg were weighed and kneaded while mixing so as to obtain a uniform mixture. It was.

  Next, this mixture was pressure-molded to produce a sheet-like member having a thickness of about 150 μm. Next, this sheet-like member was dried at 70 ° C. for 1 hour in a vacuum, and then punched into a circle having a diameter of 12 mm to produce a positive electrode active material mainly composed of rubeanic acid.

Next, LiN (C ₂ F ₅ SO ₂ ) ₂ (electrolyte salt) having a molar concentration of 1.0 mol / L was dissolved in sulfolane, thereby preparing an electrolyte solution.

  Next, a positive electrode active material is applied onto a positive electrode current collector, and a 20 μm thick separator made of a polypropylene porous film impregnated with the electrolyte solution is further laminated on the positive electrode active material, and further from a copper foil. A negative electrode obtained by attaching lithium to the negative electrode current collector was laminated on a separator to form a laminate.

  And 0.2 mL of this electrolyte solution was dripped at the said laminated body, and it was made to impregnate.

Thereafter, a metal spring was placed on the negative electrode current collector, and the negative electrode case was joined to the positive electrode case with a gasket disposed on the periphery, and the outer casing was sealed with a caulking machine. Thus, a sealed coin-type battery in which the positive electrode active material is mainly composed of rubeanic acid, the negative electrode active material is metallic lithium, the electrolyte solution is LiN (C ₂ F ₅ SO ₂ ) ₂ and the electrolyte salt is sulfolane. Was made.

[Battery operation check]
The coin-type battery produced as described above was charged with a constant current of 0.1 mA until the voltage reached 4.0 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 capacity density of 600 Ah / kg at the time of discharge having a voltage flat portion at two places where the charge / discharge voltages were 2.4 V and 2.0 V.

  Subsequently, charging / discharging was repeated 20 cycles in the range of 4.0-1.5V. As a result, it was found that an initial discharge capacity of 90% or more can be secured. That is, it was possible to obtain a secondary battery having a long cycle life excellent in stability with little decrease in capacity even after repeated charge and discharge. This is probably because the positive electrode active material was stabilized in the electrolyte solution, and thus the charge and discharge of the multi-electron reaction could be stably repeated.

[Production of battery]
As a solvent for the electrolyte solution, 1,3-dioxolane represented by the chemical formula (2c) and methoxypropionitrile represented by the chemical formula (5c) were prepared.

  Then, two types of coin-type batteries were produced according to the same method and procedure as in [Example 1] except that these solvents were used instead of sulfolane.

[Battery operation check]
The batteries produced as described above were charged and discharged under the same conditions as in Example 1, and the operation was confirmed. As a result, the two types of batteries were charged at a charge / discharge voltage of 2.3 V and 2.0 V, respectively. It was confirmed that the secondary battery had a flat capacity and a capacity density at the time of discharge of 400 Ah / kg.

  Then, charging / discharging was repeated 20 cycles in the range of 4.0-1.5V. As a result, it was possible to secure an initial discharge capacity of 80% or more in all the two types of batteries. That is, since the positive electrode active material is stabilized in the electrolyte solution, the charge / discharge of the multi-electron reaction can be stably repeated, and a secondary battery having a long cycle life with little decrease in capacity even after repeated charge / discharge is obtained. I was able to.

(Synthesis of organic compounds)
According to the synthesis scheme (A), a condensate (10d) of rubeanic acid and adipic acid dichloride was synthesized.

First, 0.01 mol of rubeanic acid (10d ₁ ) was dissolved in an aqueous sodium hydroxide solution (molar concentration of sodium hydroxide: 0.02 mol). Next, after the whole was cooled to 0 ° C., an aqueous solution containing 0.1 mol of adipic acid dichloride (10d ₂ ): 0.1 mol was added dropwise with vigorous stirring. Then, the mixture is stirred for 1 hour to react rubeanic acid (10d ₁ ) and adipic acid dichloride (10d ₂ ), washed and dried to synthesize a light brown solid, that is, a condensate (10d) of rubeanic acid and adipic acid dichloride. did.

[Production of battery]
A coin-type battery of Example 3 was produced in the same manner and procedure as in [Example 1] except that the condensate (10d) was used as the positive electrode active material.

[Battery operation check]
The battery produced as described above was charged and discharged under the same conditions as in Example 1, and the operation was confirmed. At the time of discharge having voltage flat portions at two places where the charge / discharge voltage was 2.4 V and 2.0 V. It was confirmed that the secondary battery had a capacity density of 400 Ah / kg.

  Thereafter, when charging and discharging were repeated 20 cycles in the range of 4.0 to 2.0 V, the initial discharge capacity of 80% or more could be secured even after 20 cycles. That is, since the positive electrode active material is stabilized in the electrolyte solution, it is possible to stably charge and discharge the multi-electron reaction, and to provide a secondary battery excellent in stability with little decrease in capacity even after repeated charging and discharging. I was able to get it.

(Synthesis of organic compounds)
According to the synthesis scheme (B), a condensate of rubeanic acid and terephthalic acid dichloride was synthesized. A condensate of rubeanic acid and adipic acid dichloride (10e) was synthesized.

First, 0.01 mol of rubeanic acid (10e ₁ ) was dissolved in an aqueous sodium hydroxide solution (molar concentration of sodium hydroxide: 0.02 mol). Next, after the whole was cooled to 0 ° C., an aqueous solution containing 0.1 mol of terephthalic acid dichloride (10e ₂ ): 0.1 mol was added dropwise with vigorous stirring. The mixture is stirred for 1 hour to react rubeanic acid (10e ₁ ) with terephthalic acid dichloride (10e ₂ ), washed and dried to synthesize a light brown solid, that is, a condensate of rubeanic acid and terephthalic acid dichloride (10e). did.

[Production of battery]
A coin-type battery of Example 4 was produced in the same manner and procedure as in [Example 1] except that the condensate (10e) was used as the positive electrode active material.

[Battery operation check]
The battery produced as described above was charged and discharged under the same conditions as in Example 1, and the operation was confirmed. At the time of discharge having voltage flat portions at two places where the charge / discharge voltage was 2.4 V and 2.0 V. It was confirmed that the secondary battery had a capacity density of 200 Ah / kg.

  Thereafter, when charging and discharging were repeated 10 cycles in the range of 4.0 to 2.0 V, the initial discharge capacity of 80% or more could be secured even after 10 cycles. That is, since the positive electrode active material is stabilized in the electrolyte solution, it is possible to stably charge and discharge the multi-electron reaction, and to provide a secondary battery excellent in stability with little decrease in capacity even after repeated charging and discharging. I was able to get it.

[Production of battery]
A coin-type battery of Example 4 was produced in the same manner and procedure as in [Example 1] except that thiocarbamoylthiourea represented by the chemical formula (11a) was used as the positive electrode active material.

[Battery operation check]
The battery produced as described above was charged and discharged under the same conditions as in Example 1, and its operation was confirmed. As a result, the discharge capacity having a voltage flat portion at a charge / discharge voltage of 2.0 to 2.8 V was 200 Ah / kg. The secondary battery was confirmed.

  Thereafter, when charging and discharging were repeated 10 cycles in the range of 4.0 to 2.0 V, the initial discharge capacity of 80% or more could be secured even after 10 cycles. That is, since the positive electrode active material is stabilized in the electrolyte solution, it is possible to stably charge and discharge the multi-electron reaction, and to provide a secondary battery excellent in stability with little decrease in capacity even after repeated charging and discharging. I was able to get it.

(Synthesis of organic compounds)
According to the synthesis scheme (C), a condensate (13d) of selenourea and succinyl chloride was synthesized.

First, 0.62 g of selenourea (13d ₁ ) was dissolved in 50 mL of pure water. Subsequently, the whole was cooled to 0 ° C., and then an aqueous solution containing 0.77 g of succinyl chloride (13d ₂ ) was added dropwise with vigorous stirring. After stirring for 1 hour, selenourea (13d ₁ ) and succinyl chloride (13d ₂ ) were reacted, washed and dried to synthesize a light brown solid, that is, a condensate (13d) of selenourea and succinyl chloride.

[Production of battery]
A coin-type battery of Example 6 was produced in the same manner and procedure as in [Example 1] except that the condensate (13d) was used as the positive electrode active material.

[Battery operation check]
The battery produced as described above was charged and discharged under the same conditions as in Example 1, and its operation was confirmed. As a result, the capacity density at the time of discharge having a voltage flat portion at a charge / discharge voltage of 1.5 to 3.2 V was obtained. Was confirmed to be a 200 Ah / kg secondary battery.

  Subsequently, when charging and discharging were repeated 10 cycles in the range of 4.0 to 2.0 V, the initial discharge capacity of 80% or more could be secured even after 10 cycles. That is, since the positive electrode active material is stabilized in the electrolyte solution, it is possible to stably charge and discharge the multi-electron reaction, and to provide a secondary battery excellent in stability with little decrease in capacity even after repeated charging and discharging. I was able to get it.

[Production of battery]
A coin-type battery was produced in the same manner as in [Example 1] except that poly (2,2,6,6-tetramethylpiperidinoxymethacrylate) represented by chemical formula (15c) was used as the positive electrode active material. .

[Battery operation check]
The battery produced as described above was charged and discharged under the same conditions as in Example 1, and its operation was confirmed. As a result, the capacity density at the time of discharge having a voltage flat portion at a charge / discharge voltage of 3.6 V was 100 Ah / kg. The secondary battery was confirmed.

  Thereafter, when charging and discharging were repeated 100 cycles in the range of 4.0 to 2.0 V, an initial discharge capacity of 90% or more could be secured even after 100 cycles. That is, the positive electrode active material is stabilized with the electrolyte solution, and the movement of ions in the charge / discharge reaction is facilitated, so that the charge / discharge reaction proceeds smoothly, and charging in a short time or discharging at high output becomes possible. A secondary battery having a long cycle life excellent in stability with little decrease in capacity even after repeated charge and discharge could be obtained.

(Synthesis of organic compounds)
According to the synthesis scheme (D), a polymer (16f) of a dihydrophenazine dicarbonyl compound was synthesized.

First, in an argon stream, 8.2 mmol of 5,10-dihydrophenazine (16f ₁ ) and 20 mg of 4-dimethylaminopyridine (DMAP) were dissolved in 20 mL of dehydrated pyridine, and then 5 mL of dehydrated tetrahydrofuran and 8.2 mmol. Of oxalyl chloride was added at 0 ° C. Then stirred at room temperature for 1 hour, further stirred for 4 hours at a temperature of 60 ° C., to react the 5,10-dihydro-phenazine (16f ₁₎ and oxalyl chloride (16f _2). And after completion | finish of reaction, dehydrated pyridine was removed, methanol was added after that, the black powder which precipitated was filtered, and this obtained the polymer (16f) of the dihydrophenazine dicarbonyl compound.

[Production of battery]
A coin-type battery of Example 8 was produced in the same manner and procedure as in [Example 1] except that the polymer (16f) was used as the positive electrode active material.

[Battery operation check]
The battery produced as described above was charged and discharged under the same conditions as in Example 1, and the operation was confirmed. At the time of discharging having voltage flat portions at two charging and discharging voltages of 2.8 V and 2.4 V. Was confirmed to be a secondary battery having a capacity density of 200 Ah / kg.

  Subsequently, when charging and discharging were repeated 100 cycles in the range of 4.0 to 2.0 V, the initial discharge capacity of 90% or more could be secured even after 100 cycles. That is, since the positive electrode active material is stabilized in the electrolyte solution, it is possible to stably charge and discharge the multi-electron reaction, and to provide a secondary battery excellent in stability with little decrease in capacity even after repeated charging and discharging. I was able to get it.

  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 solution

  The present invention relates to a secondary battery, and more particularly to a secondary battery that contains an electrode active material and an electrolyte solution, and 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 order to meet such demands, secondary batteries using an alkali metal ion such as lithium ion as a charge carrier and utilizing an electrochemical reaction associated with charge exchange have been developed. In particular, lithium ion secondary batteries having a relatively large 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 charging and discharging of the battery. To do. Therefore, as described above, the electrode active material has a central role of the secondary battery in terms of system.

  In the above lithium ion secondary battery, a lithium-containing transition metal oxide is used as the positive electrode active material, and a carbon material is used as the negative electrode active material. Discharging.

  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. In other words, in the above-described lithium ion secondary battery, the migration rate of lithium ions in the lithium-containing transition metal oxide of the positive electrode is slower than that of the electrolyte and the negative electrode, so that the battery reaction rate at the positive electrode is rate-limiting and charged. As a result, the discharge rate was limited, and as a result, there was a limit to increasing the output and shortening the charging time.

  In order to solve such problems, research and development of organic secondary batteries using organic compounds such as organic sulfur compounds as electrode active materials have been actively conducted in recent years.

  For example, in Patent Document 1, an organic sulfur compound as a positive electrode material has an S—S bond in a charged state, and at the time of discharging the positive electrode, the S—S bond is cleaved to form an organic sulfur metal salt having a metal ion. New metal-sulfur battery cells have been proposed.

  In Patent Document 1, a disulfide-based organic compound represented by the general formula (1 ′) (hereinafter referred to as “disulfide compound”) is used as a positive electrode active material.

R-S-S-R (1 ')
Here, R represents an aliphatic organic group or an aromatic organic group, and each includes the same or different cases.

  The disulfide compound can undergo a two-electron reaction, and the S—S bond is cleaved in a reduced state (discharge state), thereby forming an organic thiolate (R—SH). This organic thiolate forms an S—S bond in the oxidized state (charged state) and is restored to the disulfide compound represented by the general formula (1 ′). That is, since the disulfide compound forms an S—S bond having a small binding energy, a reversible redox reaction occurs using the bond and cleavage by the reaction, and thus charge and discharge can be performed.

Patent Document 2 discloses the following formula (2 ′):
-(NH-CS-CS-NH) -... (2 ')
A battery electrode containing rubeanic acid or a rubeanic acid polymer that has a structural unit represented by the formula (II) and can be bonded to lithium ions has been proposed.

  The rubeanic acid or rubeanic acid polymer containing the dithione structure represented by the general formula (2 ′) binds to lithium ions during reduction, and releases the bound lithium ions during oxidation. Charging / discharging can be performed by utilizing such a reversible oxidation-reduction reaction of rubeanic acid or rubeanic acid polymer.

  On the other hand, the volume of the electrode active material of the secondary battery is greatly changed by a chemical change associated with the charge / discharge reaction. As a result, the solid state electrode active material collapses or dissolves in the electrolyte solution, It may stop functioning. In particular, unlike a lithium ion battery that charges and discharges while maintaining a crystalline system, in an organic secondary battery that charges and discharges using a redox reaction of the molecule itself, the electrode active material dissolves in the electrolyte. Therefore, it is considered to suppress dissolution of such an electrode active material in an electrolyte.

  For example, Patent Document 3 proposes a battery including a negative electrode, a solid composite positive electrode having an electroactive sulfur-containing substance, and an electrolyte inserted therebetween.

  In this Patent Document 3, as a preferable form of an electrolyte, one or more ionic electrolyte salts, N-methylacetamide, acetonitrile, carbonate, sulfolane, sulfone, N-alkylpyrrolidone, dioxolane, aliphatic ether, cyclic ether, glyme And mixtures with one or more electrolyte solvents selected from siloxanes. Then, an electrolyte solution is prepared using 1,3-dioxolane and dimethoxyethane as an electrolyte solvent, and a battery containing an electroactive sulfur-containing substance as a positive electrode material is manufactured.

US Pat. No. 4,833,048 (Claim 1, column 5, line 20 to column 28) JP 2008-147015 A (Claim 1, paragraph number [0011], FIG. 3, FIG. 5) JP 2002-532854 A (claim 1, claim 83, paragraph numbers [0031], [0088], etc.)

  However, Patent Document 1 uses a low-molecular disulfide compound in which two electrons are involved. However, since it repeatedly binds and cleaves with other molecules along with the charge / discharge reaction, it lacks stability, and charge / discharge reaction is not performed. If it is repeated, the capacity may decrease.

  In Patent Document 2, rubeanic acid having a dithione structure or a rubeanic acid polymer is used to cause a two-electron reaction. However, a low molecular weight compound such as rubeanic acid has dissolved or dissolved in an electrolyte solution. Contamination of the electrode with a compound is likely to occur, and therefore, stability against repeated charge and discharge is lacking. In addition, when a polymer compound such as rubeanic acid polymer is used, dissolution in the electrolyte solution and electrode contamination can be suppressed, but the intermolecular interaction in the rubeanic acid polymer is large. For this reason, the movement of ions is hindered, and the proportion of the active material that can be used effectively is reduced.

  Patent Document 3 uses a sulfur-based compound as a positive electrode active material and produces an electrolyte solution using oxolane or the like as a solvent to form a battery. However, even if such an electrolyte solution is used, it is stable. It is difficult to obtain a secondary battery having good cycle characteristics.

  That is, an organic secondary battery using an organic compound as an electrode active material is more reactive than a conventional lithium ion secondary battery using a lithium-containing transition metal oxide as an electrode active material. Elution of the electrode active material into the electrolyte solution easily occurs, and in addition to the oxidation-reduction reaction involved in charge / discharge, an irreversible reaction easily occurs, leading to deactivation of the electrode active material. Technical issues.

  However, the above-described conventional technology cannot sufficiently solve the above technical problem, and thus, a long-life secondary battery having a sufficiently high energy density, high output and good cycle characteristics is realized. The current situation is that we have not been able to.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a secondary battery having a high energy density, high output, and good cycle characteristics with little decrease in capacity even after repeated charge and discharge. To do.

The inventors of the present invention conducted intensive research using an organic compound having a rubeanic acid structure in a structural unit capable of obtaining a high capacity density electrode active material with good charge / discharge efficiency. The main solvent is a specific cyclic sulfone compound such as sulfolane , so that an irreversible reaction can be suppressed between the electrode active material and the electrolyte solution. The knowledge that a secondary battery can be obtained was obtained.

で表わされるのが好ましい。 The present invention has been made based on such knowledge, and the secondary battery according to the present invention includes an electrode active material and an electrolyte solution in which an electrolyte salt is dissolved in a solvent. A secondary battery that is repeatedly charged and discharged by a battery electrode reaction, wherein the electrode active material is mainly composed of an organic compound having a rubeanic acid structure in a structural unit (hereinafter referred to as “rubberic acid compound”) , and the electrolyte salt. Is formed of a lithium salt, the solvent is mainly composed of a cyclic sulfone compound, and the cyclic sulfone compound has the general formula

Is preferably represented by:

  Here, in the above general formula, Z represents an alkylene group having 1 to 7 carbon atoms, and includes both straight and branched chains.

In the secondary battery of the present invention, the cyclic sulfone compound is preferably sulfolane.

で表されるのが好ましい。 In the secondary battery of the present invention, the rubeanic acid compound has the general formula:

It is preferable to be represented by

Here, in the formula, n is an integer of 1 or more, and R ₁ And R ₂ Represents any one of a substituted or unsubstituted imino group, a substituted or unsubstituted alkylene group, and a substituted or unsubstituted arylene group.

及び、

のいずれかで表されるアニオンを含有しているのが好ましい。 Further, in the secondary battery of the present invention, the electrolyte salt has a general formula.

as well as,

It is preferable to contain the anion represented by either.

Here, in said general formula, R < ₈ > -R < ₁₂ > shows either one of a fluorine atom and a fluoroalkyl group, and these R < ₈ > -R < ₁₂ > includes the same case. R ₁₃ represents a fluoroalkylene group, and R ₁₄ represents a fluoroalkyl group having 1 to 7 carbon atoms.

  In the secondary battery of the present invention, it is preferable that 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.

  Furthermore, the secondary battery of the present invention preferably has a positive electrode and a negative electrode, and the positive electrode is mainly composed of the electrode active material.

According to the secondary battery of the present invention, the electrode active material is mainly composed of a rubeanic acid compound, the electrolyte salt of the electrolyte solution is formed of a lithium salt, and the solvent is mainly composed of the specific cyclic sulfone compound described above . Therefore, it can suppress that an electrode active material produces an irreversible reaction. Accordingly, the electrode active material can contribute only to the battery electrode reaction, the charge / discharge efficiency is good, and the charge / discharge reaction can be stably repeated. That is, by suppressing the occurrence of unnecessary irreversible reactions of the electrode active material, the movement of ions during the charge / discharge reaction is facilitated, and a smooth and stable charge / discharge reaction occurs. This makes it possible to obtain a secondary battery having a large energy density and a long cycle life.

In addition, since the electrode active material is mainly a rubeanic acid compound that is an organic compound, the environmental load is low and the safety is taken into consideration.

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.

  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.

  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. And the positive electrode 4 which formed the positive electrode active material (electrode active material) in the sheet form is distribute | arranged to the center of the bottom part of the positive electrode case 2 which comprises a positive electrode collector. A separator 5 formed of a porous film such as polypropylene is laminated on the positive electrode 4, and a negative electrode 6 is further laminated on the separator 5. As the negative electrode 6, for example, one obtained by superimposing a lithium metal foil on Cu or one obtained by applying a lithium storage material such as graphite or hard carbon to the metal foil can be used. A negative electrode current collector 7 made of Cu or the like is laminated on the negative electrode 6, and a metal spring 8 is placed on the negative electrode current collector 7. In addition, the electrolyte solution 9 is injected into 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 is sealed via the gasket 10.

In the secondary battery, the positive electrode active material is mainly composed of an organic compound having a rubeanic acid structure in a structural unit, that is, a rubeanic acid compound.

The electrolyte solution 9 contains an electrolyte salt formed of a lithium salt and a solvent that dissolves the electrolyte salt, and the solvent is mainly composed of a cyclic sulfone compound.

That is, the electrolyte solution 9 is interposed between the positive electrode 4 and the negative electrode 6 that is the opposite electrode of the positive electrode 4 and transports charge carriers between the two electrodes. In this embodiment, the electrolyte solution 9 is formed of a lithium salt. The resulting electrolyte salt is used by dissolving or dissolving in a solvent mainly composed of a specific cyclic sulfone compound . And since generation | occurrence | production of the unnecessary irreversible reaction of an electrode active material is suppressed by this, the movement of the ion at the time of charging / discharging reaction becomes easy, and it becomes possible to produce smooth and stable charging / discharging reaction. As a result, charging in a short time or discharging at high output becomes possible, and a secondary battery having an electrode active material having a large energy density and a long life can be realized.

That is, in recent years, an electrode active material mainly composed of an organic compound has attracted attention. Among them, a rubeanic acid compound having a rubeanic acid structure in a structural unit has good charge / discharge efficiency and can realize a high capacity density. Promising as an active material.

However, in the case of using a rubeanic acid compound, when a low molecular weight compound is used, dissolution in the electrolyte solution 9 and contamination of the electrode by the dissolved compound are likely to occur, and therefore, stability against repeated charge and discharge is lacking. On the other hand, when a polymer compound is used, the intermolecular interaction in the polymer compound is large, which may hinder the movement of ions and reduce the proportion of the active material that can be used effectively.

Moreover, the rubeanic acid compound is liable to cause an irreversible reaction in the electrolyte solution 9 in addition to the oxidation-reduction reaction involved in charge / discharge, and may cause deactivation of the electrode active material.

However, as a result of intensive studies by the present inventors, the positive electrode active material mainly composed of the rubeanic acid compound is contained in the electrolyte solution 9 by using the electrolyte solution 9 containing a solvent mainly composed of the cyclic sulfone compound. Can be effectively suppressed, and as a result, unnecessary irreversible reactions can be suppressed and stabilized in the electrolyte solution 9, thereby facilitating the movement of ions during the charge / discharge reaction. It has been found that the discharge reaction proceeds smoothly and that charging in a short time and discharging at a high output can be performed stably.

Therefore, in the present embodiment, the electrolyte solution 9 contains a solvent mainly composed of a cyclic sulfone compound , thereby having a large energy density and a long cycle life with little decrease in capacity even after repeated charge and discharge at high output. I try to get a secondary battery.

Here, as the cyclic sulfone compound, a compound represented by the following general formula (1) is used.

In the general formula (1), Z represents an alkylene group having 1 to 7 carbon atoms, and includes both straight and branched chains.

  Even if it is a cyclic sulfone compound, when the number of carbon atoms is 8 or more, it becomes long chain and the viscosity becomes high, which is not preferable.

  Examples of the cyclic sulfone compound belonging to the category of the general formula (1) include sulfolane represented by the following chemical formula (1a), 3-methylsulfolane represented by the following chemical formula (1b), 2,4-dimethylsulfolane represented by the following chemical formula (1c), Examples include 2,3-dimethylsulfolane represented by the following chemical formula (1d), and among these cyclic sulfone compounds, sulfolane can be preferably used.

電解質溶液９中の環状スルホン化合物の含有量は、該環状スルホン化合物が溶媒中で主体となればよく、例えば、溶媒中で５０質量％以上が好ましい。また、環状スルホン化合物の範疇に属する化合物を２種類以上（例えば、スルホランと３−メチルスルホランとの組み合わせ等）含有させてもよく、或いは環状スルホン化合物を主体とするのであれば、環状スルホン化合物以外の溶媒種、例えば、アセトニトリルやその他の添加剤を含有させてもよい。

The content of the cyclic sulfone compound in the electrolyte solution 9 may be such that the cyclic sulfone compound is mainly contained in the solvent, and for example, 50% by mass or more is preferable in the solvent. In addition, two or more kinds of compounds belonging to the category of cyclic sulfone compounds may be included (for example, a combination of sulfolane and 3-methylsulfolane), or if the main component is a cyclic sulfone compound, other than cyclic sulfone compounds These solvent species, for example, acetonitrile and other additives may be contained.

And a rubeanic acid compound is excellent in stability at the time of charging / discharging (an oxidation state and a reduction state), and a multi-electron reaction of two or more electrons is possible by oxidation-reduction reaction. Therefore, by using the rubeanic acid compound as the positive electrode active material and using the solvent containing the specific cyclic sulfone compound described above in the electrolyte solution 9, the rubeanic acid compound as the positive electrode active material undergoes an irreversible reaction. Is suppressed in the electrolyte solution 9, charging and discharging of the multi-electron reaction can be stably repeated, and a secondary battery having high charge / discharge efficiency and high capacity density can be obtained. Become.

The rubeanic acid compound is not particularly limited as long as it has a rubeanic acid structure containing a pair of C═S double bonds as a basic skeleton in the structural unit, but the following general formula (2 ) Can be preferably used.

Here, n is an integer of 1 or more, and R ₁ And R ₂ Represents any one of a substituted or unsubstituted imino group, a substituted or unsubstituted alkylene group, and a substituted or unsubstituted arylene group.

Examples of the rubeanic acid compound belonging to the category of the general formula (2) include rubeanic acid represented by the following chemical formula (2a) .

下記化学反応式（Ｉ）は、ルベアン酸（２ａ）を正極活物質に使用し、Ｌｉを電解質塩のカチオンに使用した場合に予想される充放電反応の一例を示している。

The following chemical reaction formula (I) shows an example of a charge / discharge reaction expected when rubeanic acid (2a) is used as the positive electrode active material and Li is used as the cation of the electrolyte salt.

すなわち、充放電時に二電子が反応に関与し、ルベアン酸が有する一対のＳが還元時にそれぞれＬｉ^＋と結合し、酸化時にＬｉ^＋を放出する。

That is, two electrons are involved in the reaction during charge and discharge, and a pair of S possessed by rubeanic acid binds to Li ⁺ during reduction and releases Li ⁺ during oxidation.

The electrolyte salt dissolved in the solvent in the electrolyte solution 9 is not particularly limited as long as it is a lithium salt. For example, a lithium salt containing an anion represented by the general formulas ( 3 ) to ( 6 ) is used. be able to.

ここで、上記一般式（３）〜（６）中、Ｒ_８〜Ｒ₁₂は、フッ素原子及びフルオロアルキル基のうちのいずれか一方を示し、これらＲ_８〜Ｒ₁₂は同一の場合を含んでいる。また、Ｒ₁₃はフルオロアルキレン基を示し、Ｒ₁₄は炭素数が１〜７のフルオロアルキル基を示している。

Here, in the above general formula _{(3) ~ (6),} R 8 ~R 12 indicates either one of a fluorine atom and fluoroalkyl radicals, these _R 8 to R ₁₂ may include a case identical Yes. R ₁₃ represents a fluoroalkylene group, and R ₁₄ represents a fluoroalkyl group having 1 to 7 carbon atoms.

Examples of the anion belonging to the category of the general formula ( 3 ) include those represented by the following chemical formulas ( 3a ) to ( 3d ).

(FSO ₂ ) ₂ N ⁻ (3a)
(CF ₃ SO ₂ ) ₂ N ⁻ (3b)
(C ₂ F ₅ SO ₂ ) ₂ N ⁻ (3c)
(CF ₃ SO ₂ ) (C ₂ F ₅ SO ₂ ) N ⁻ (3d)
Examples of the anion belonging to the category of the general formula ( 4 ) include those represented by the following chemical formulas ( 4a ) to ( 4e ).

(FSO ₂ ) ₃ C ⁻ (4a)
(CF ₃ SO ₂ ) ₃ C ⁻ (4b)
(C ₂ F ₅ SO ₂ ) ₃ C ⁻ (4c)
(CF ₃ SO ₂ ) ₂ (C ₂ F ₅ SO ₂ ) C ⁻ (4d)
(C ₂ F ₅ SO ₂ ) ₂ (CF ₃ SO ₂ ) C ⁻ (4e)
Examples of the anion belonging to the category of the general formula ( 5 ) include those represented by the following chemical formulas ( 5a ) to ( 5c ).

一般式（６）の範疇に属するアニオンとしては、下記化学式（６ａ）〜（６ｃ）で表されるものを挙げることができる。

Examples of the anion belonging to the category of the general formula ( 6 ) include those represented by the following chemical formulas ( 6a ) to ( 6c ).

CF ₃ SO ₃ ⁻ (6a)
C ₂ F ₅ SO ₃ ⁻ (6b)
C ₃ F ₇ SO ₃ ⁻ (6c)
The content of the electrolyte salt in the electrolyte solution 9 is not particularly limited, but is preferably 10 to 80% by mass in order to exhibit the desired effect. In addition, with respect to the anion species contained in the electrolyte salt, two or more compounds belonging to the same category (for example, (CF ₃ SO ₂ ) ₂ N ⁻ and (C ₂ F ₅ SO _{2) 2} N ^- combinations) may be contained with, or different categories belonging compound 2 or more _{(e.g., (C} 2 _{F 5} SO ₂₎ 2 N ^- and _CF 3 SO ₃ ^- and combinations of Etc.) It can also be contained.

If the positive electrode active material has a rubeanic acid structure as a main component, the molecular weight of the organic compound is not particularly limited. However, when the portion other than the rubeanic acid structure is increased, the molecular weight increases, so that the storage capacity per unit mass, that is, the capacity Density decreases. Accordingly, the molecular weight of the portion other than the rubeanic acid structure is preferably small.

  Since the positive electrode active material is reversibly oxidized or reduced by charge / discharge, the positive electrode active material takes a different structure and state depending on the charged state, discharged state, or intermediate state. Is contained in at least one of a reaction starting material (a substance that causes a chemical reaction in a battery electrode reaction), a product (a substance resulting from a chemical reaction), and an intermediate product. A secondary battery having a positive electrode active material with good discharge efficiency and high capacity density can be realized.

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

First, a positive electrode active material is formed into an electrode shape. That is, a rubeanic acid compound is prepared. Then, this rubeanic acid compound is mixed with a conductive agent and a binder, a solvent is added to prepare a slurry for active material, and the slurry for active material is coated on the positive electrode current collector by an arbitrary coating method. Then, a positive electrode active material layer is formed on the positive electrode current collector by drying, whereby the positive electrode 4 is produced.

  Here, the conductive 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, carbon nanotube, and carbon nanohorn, polyaniline, and polypyrrole. , Conductive polymers such as polythiophene, polyacetylene, and polyacene can be used. Further, two or more kinds of conductive agents can be mixed and used. In addition, as for the content rate in the positive electrode active material of a electrically conductive agent, 10 to 80 weight% is preferable.

  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 used for the slurry for the active material is not particularly limited. For example, bases such as dimethyl sulfoxide, dimethylformamide, N-methylpyrrolidone, propylene carbonate, diethyl carbonate, dimethyl carbonate, and γ-butyrolactone are used. A non-aqueous solvent such as acetonitrile, tetrahydrofuran, nitrobenzene, and acetone, and a protic solvent such as methanol and ethanol can be used.

  Note that the type of solvent, the compounding ratio of the organic compound and the solvent, the type of conductive agent and binder, and the amount added thereof can be arbitrarily set in consideration of the required characteristics and productivity of the secondary battery. it can.

Next, an electrolyte solution 9 is prepared. That is, a solvent containing preferably 50% by mass or more of the specific cyclic sulfone compound represented by the chemical formula (1) is prepared, and more preferably from a lithium salt containing anions represented by the general formulas (3) to (6). Prepare an electrolyte salt. And this electrolyte salt is dissolved in the said solvent, and the electrolyte solution 9 is produced.

  Then, the positive electrode 4 is impregnated with the electrolyte solution 9 so that the positive electrode 4 is impregnated with the electrolyte solution 9, and then the separator 5 impregnated with the electrolyte solution 9 is laminated on the positive electrode 4, and further, the negative electrode 6 and the negative electrode The current collectors 7 are sequentially stacked, and then the electrolyte solution 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.

Thus, according to the present embodiment, the electrolyte solution 9 containing a specific cyclic sulfone compound that contributes to stabilization of the positive electrode active material in the solvent, and the positive electrode active material having good charge / discharge efficiency and high capacity density. Since the secondary battery is configured using a material, the positive electrode active material can be prevented from causing an irreversible reaction. Therefore, the movement of ions during the charge / discharge reaction is facilitated, and smooth and stable charge / discharge. The reaction can be repeated. In other words, charging in a short time and discharging at high output are possible, thereby obtaining a secondary battery with a long life and good cycle characteristics with a large energy density and high output, with little capacity decrease even after repeated charging and discharging. It becomes possible.

In addition, since the positive electrode active material is mainly a rubeanic acid compound that is an organic compound, the environmental load is low and the safety is taken into consideration.

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, for the electrolyte salt, the above-listed compounds are just examples, and are not limited thereto. That is, if the electrode active material is mainly composed of the above-described rubeanic acid compound and contains a specific cyclic sulfone compound in the electrolyte solution 9, the electrode active material can suppress the occurrence of an irreversible reaction. Therefore, it is considered that a desired rapid oxidation-reduction reaction proceeds. Therefore, a secondary battery having a large energy density and excellent stability can be obtained.

Moreover, in the said embodiment, although the rubeanic acid compound was used for the positive electrode active material, you may use it for a negative electrode active material.

  In the above embodiment, the coin-type secondary battery has been described. However, the battery shape is not particularly limited, and can be applied to a cylindrical type, a square type, a sheet type, 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.

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

  In addition, the Example shown below is an example and this invention is not limited to the following Example.

[Production of battery]
Rubeanic acid represented by the chemical formula ( 2a ) was prepared as the active material, and sulfolane represented by the chemical formula (1a) was prepared as the electrolyte solvent.

そして、ルベアン酸：３００ｍｇ、導電剤としてのグラファイト粉末：６００ｍｇ、結着剤としてのポリテトラフルオロエチレン樹脂：１００ｍｇをそれぞれ秤量し、全体が均一になるように混合しながら混練し、混合体を得た。

Then, rubeanic acid: 300 mg, graphite powder as a conductive agent: 600 mg, and polytetrafluoroethylene resin as a binder: 100 mg were weighed and kneaded while mixing so as to obtain a uniform mixture. It was.

  Next, this mixture was pressure-molded to produce a sheet-like member having a thickness of about 150 μm. Next, this sheet-like member was dried at 70 ° C. for 1 hour in a vacuum, and then punched into a circle having a diameter of 12 mm to produce a positive electrode active material mainly composed of rubeanic acid.

Next, LiN (C ₂ F ₅ SO ₂ ) ₂ (electrolyte salt) having a molar concentration of 1.0 mol / L was dissolved in sulfolane, thereby preparing an electrolyte solution.

  Next, a positive electrode active material is applied onto a positive electrode current collector, and a 20 μm thick separator made of a polypropylene porous film impregnated with the electrolyte solution is further laminated on the positive electrode active material, and further from a copper foil. A negative electrode obtained by attaching lithium to the negative electrode current collector was laminated on a separator to form a laminate.

  And 0.2 mL of this electrolyte solution was dripped at the said laminated body, and it was made to impregnate.

Thereafter, a metal spring was placed on the negative electrode current collector, and the negative electrode case was joined to the positive electrode case with a gasket disposed on the periphery, and the outer casing was sealed with a caulking machine. Thus, a sealed coin-type battery in which the positive electrode active material is mainly composed of rubeanic acid, the negative electrode active material is metallic lithium, the electrolyte solution is LiN (C ₂ F ₅ SO ₂ ) ₂ and the electrolyte salt is sulfolane. Was made.

[Battery operation check]
The coin-type battery produced as described above was charged with a constant current of 0.1 mA until the voltage reached 4.0 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 capacity density of 600 Ah / kg at the time of discharge having a voltage flat portion at two places where the charge / discharge voltages were 2.4 V and 2.0 V.

  Subsequently, charging / discharging was repeated 20 cycles in the range of 4.0-1.5V. As a result, it was found that an initial discharge capacity of 90% or more can be secured. That is, it was possible to obtain a secondary battery having a long cycle life excellent in stability with little decrease in capacity even after repeated charge and discharge. This is probably because the positive electrode active material was stabilized in the electrolyte solution, and thus the charge and discharge of the multi-electron reaction could be stably repeated.

Reference example

Although not included in the scope of the present invention, examples having good cycle characteristics are described below as reference examples.

Reference example 1
[Production of battery]
As a solvent for the electrolyte solution, 1,3-dioxolane as a cyclic ether compound represented by the chemical formula (7) and methoxypropionitrile as a nitrile compound represented by the chemical formula (8) were prepared.

そして、スルホランに代えてこれらの溶媒を使用した以外は、〔実施例１〕と同様の方法・手順に従い、２種類のコイン型電池を作製した。

Then, two types of coin-type batteries were produced according to the same method and procedure as in [Example 1] except that these solvents were used instead of sulfolane.

[Battery operation check]
The batteries produced as described above were charged and discharged under the same conditions as in Example 1, and the operation was confirmed. As a result, the two types of batteries were charged at a charge / discharge voltage of 2.3 V and 2.0 V, respectively. It was confirmed that the secondary battery had a flat capacity and a capacity density at the time of discharge of 400 Ah / kg.

  Then, charging / discharging was repeated 20 cycles in the range of 4.0-1.5V. As a result, it was possible to secure an initial discharge capacity of 80% or more in all the two types of batteries. That is, since the positive electrode active material is stabilized in the electrolyte solution, the charge / discharge of the multi-electron reaction can be stably repeated, and a secondary battery having a long cycle life with little decrease in capacity even after repeated charge / discharge is obtained. I was able to.

Thus, it was found that even when 1,3-dioxolane, which is a cyclic ether compound, or methoxypropionitrile, which is a nitrile compound, is used as the solvent species, good cycle characteristics can be obtained.

Reference example 2
(Synthesis of organic compounds)
According to the synthesis scheme (A), a condensate of rubeanic acid and adipic acid dichloride was synthesized.

まず、ルベアン酸：０．０１モルを水酸化ナトリウム水溶液（水酸化ナトリウムのモル濃度：０．０２モル）に溶解させた。次いで、全体を０℃に冷却した後、激しく撹拌しながらアジピン酸ジクロリド：０．１モルを含む水溶液を滴下した。そして１時間撹拌し、ルベアン酸とアジピン酸ジクロリドとを反応させ、洗浄、乾燥し、淡褐色の固体、すなわちルベアン酸とアジピン酸ジクロリドの縮合物を合成した。

First, 0.01 mol of rubeanic acid was dissolved in an aqueous sodium hydroxide solution (molar concentration of sodium hydroxide: 0.02 mol). Next, after the whole was cooled to 0 ° C., an aqueous solution containing 0.1 mol of adipic acid dichloride: 0.1 mol was added dropwise with vigorous stirring. The mixture was stirred for 1 hour to react rubeanic acid and adipic acid dichloride, washed and dried to synthesize a light brown solid, that is, a condensate of rubeanic acid and adipic acid dichloride.

[Production of battery]
A coin-type battery of Reference Example 2 was produced by the same method and procedure as in [Example 1] except that the condensate was used as the positive electrode active material.

[Battery operation check]
The battery produced as described above was charged and discharged under the same conditions as in Example 1, and the operation was confirmed. At the time of discharge having voltage flat portions at two places where the charge / discharge voltage was 2.4 V and 2.0 V. It was confirmed that the secondary battery had a capacity density of 400 Ah / kg.

  Thereafter, when charging and discharging were repeated 20 cycles in the range of 4.0 to 2.0 V, the initial discharge capacity of 80% or more could be secured even after 20 cycles. That is, since the positive electrode active material is stabilized in the electrolyte solution, it is possible to stably charge and discharge the multi-electron reaction, and to provide a secondary battery excellent in stability with little decrease in capacity even after repeated charging and discharging. I was able to get it.

Reference example 3
(Synthesis of organic compounds)
According to the synthesis scheme (B), a condensate of rubeanic acid and terephthalic acid dichloride was synthesized.

まず、ルベアン酸：０．０１モルを水酸化ナトリウム水溶液（水酸化ナトリウムのモル濃度：０．０２モル）に溶解させた。次いで、全体を０℃に冷却した後、激しく撹拌しながらテレフタル酸ジクロリド：０．１モルを含む水溶液を滴下した。そして１時間撹拌し、ルベアン酸とテレフタル酸ジクロリドとを反応させ、洗浄、乾燥し、淡褐色の固体、すなわちルベアン酸とテレフタル酸ジクロリドの縮合物を合成した。

First, 0.01 mol of rubeanic acid was dissolved in an aqueous sodium hydroxide solution (molar concentration of sodium hydroxide: 0.02 mol). Next, after the whole was cooled to 0 ° C., an aqueous solution containing 0.1 mol of terephthalic acid dichloride: 0.1 mol was dropped with vigorous stirring. The mixture was stirred for 1 hour to react rubeanic acid and terephthalic acid dichloride, washed and dried to synthesize a light brown solid, that is, a condensate of rubeanic acid and terephthalic acid dichloride.

[Production of battery]
A coin-type battery of Reference Example 3 was produced in the same manner and procedure as in [Example 1] except that the condensate was used as the positive electrode active material.

[Battery operation check]
The battery produced as described above was charged and discharged under the same conditions as in Example 1, and the operation was confirmed. At the time of discharge having voltage flat portions at two places where the charge / discharge voltage was 2.4 V and 2.0 V. It was confirmed that the secondary battery had a capacity density of 200 Ah / kg.

  Thereafter, when charging and discharging were repeated 10 cycles in the range of 4.0 to 2.0 V, the initial discharge capacity of 80% or more could be secured even after 10 cycles. That is, since the positive electrode active material is stabilized in the electrolyte solution, it is possible to stably charge and discharge the multi-electron reaction, and to provide a secondary battery excellent in stability with little decrease in capacity even after repeated charging and discharging. I was able to get it.

Reference example 4
[Production of battery]
A coin-type battery of Reference Example 4 was produced in the same manner and procedure as in [Example 1] except that thiocarbamoylthiourea having a dithione structure represented by the chemical formula (9) was used as the positive electrode active material. .

〔電池の動作確認〕
以上のように作製した電池を、実施例１と同様の条件で充放電を行い、動作確認したところ、充放電電圧が２．０〜２．８Ｖに電圧平坦部を有する放電容量が２００Ａｈ／ｋｇの二次電池であることが確認された。

[Battery operation check]
The battery produced as described above was charged and discharged under the same conditions as in Example 1, and its operation was confirmed. As a result, the discharge capacity having a voltage flat portion at a charge / discharge voltage of 2.0 to 2.8 V was 200 Ah / kg. The secondary battery was confirmed.

  Thereafter, when charging and discharging were repeated 10 cycles in the range of 4.0 to 2.0 V, the initial discharge capacity of 80% or more could be secured even after 10 cycles. That is, since the positive electrode active material is stabilized in the electrolyte solution, it is possible to stably charge and discharge the multi-electron reaction, and to provide a secondary battery excellent in stability with little decrease in capacity even after repeated charging and discharging. I was able to get it.

Reference Example 5
(Synthesis of organic compounds)
According to the synthesis scheme (C), a condensate of selenourea and succinyl chloride having a dione structure was synthesized.

まず、セレノウレア：０．６２ｇを５０ｍＬの純水に溶解させた。次いで、全体を０℃に冷却した後、激しく撹拌しながらスクシニルクロリド：０．７７ｇを含む水溶液を滴下した。そして１時間撹拌し、セレノウレアとスクシニルクロリドとを反応させ、洗浄、乾燥し、淡褐色の固体、すなわちセレノウレアとスクシニルクロリドの縮合物を合成した。

First, 0.62 g of selenourea was dissolved in 50 mL of pure water. Subsequently, after cooling the whole to 0 degreeC, the aqueous solution containing succinyl chloride: 0.77g was dripped, stirring vigorously. The mixture was stirred for 1 hour to react selenourea with succinyl chloride, washed and dried to synthesize a light brown solid, that is, a condensate of selenourea and succinyl chloride.

[Production of battery]
A coin-type battery of Reference Example 5 was produced by the same method and procedure as in [Example 1] except that the condensate was used as the positive electrode active material.

[Battery operation check]
The battery produced as described above was charged and discharged under the same conditions as in Example 1, and its operation was confirmed. As a result, the capacity density at the time of discharge having a voltage flat portion at a charge / discharge voltage of 1.5 to 3.2 V was obtained. Was confirmed to be a 200 Ah / kg secondary battery.

  Subsequently, when charging and discharging were repeated 10 cycles in the range of 4.0 to 2.0 V, the initial discharge capacity of 80% or more could be secured even after 10 cycles. That is, since the positive electrode active material is stabilized in the electrolyte solution, it is possible to stably charge and discharge the multi-electron reaction, and to provide a secondary battery excellent in stability with little decrease in capacity even after repeated charging and discharging. I was able to get it.

Reference Example 6
[Production of battery]
The same as [Example 1] except that poly (2,2,6,6-tetramethylpiperidinoxymethacrylate) having a nitroxyl radical structure represented by the chemical formula (10) was used as the positive electrode active material. The type battery of Reference Example 6 was produced by the method.

〔電池の動作確認〕
以上のようにして作製した電池を、実施例１と同様の条件で充放電を行い、動作確認したところ、充放電電圧が３．６Ｖに電圧平坦部を有する放電時の容量密度が１００Ａｈ／ｋｇの二次電池であることが確認された。

[Battery operation check]
The battery produced as described above was charged and discharged under the same conditions as in Example 1, and its operation was confirmed. As a result, the capacity density at the time of discharge having a voltage flat portion at a charge / discharge voltage of 3.6 V was 100 Ah / kg. The secondary battery was confirmed.

  Thereafter, when charging and discharging were repeated 100 cycles in the range of 4.0 to 2.0 V, an initial discharge capacity of 90% or more could be secured even after 100 cycles. That is, the positive electrode active material is stabilized with the electrolyte solution, and the movement of ions in the charge / discharge reaction is facilitated, so that the charge / discharge reaction proceeds smoothly, and charging in a short time or discharging at high output becomes possible. A secondary battery having a long cycle life excellent in stability with little decrease in capacity even after repeated charge and discharge could be obtained.

Reference Example 7
(Synthesis of organic compounds)
According to the synthesis scheme (D), a polymer of a dihydrophenazine dicarbonyl compound having a diamine structure was synthesized.

まず、アルゴン気流中、８．２ｍｍｏｌの５，１０-ジヒドロフェナジンと２０ｍｇの４−ジメチルアミノピリジン（ＤＭＡＰ）を２０ｍＬの脱水ピリジンに溶解させ、次いで、５ｍＬの脱水テトラヒドロフランと８．２ｍｍｏｌのオキサリルクロリドとの混合溶液を０℃で添加した。その後、室温で１時間撹拌し、さらに６０℃の温度で４時間撹拌し、５，１０-ジヒドロフェナジンとオキサリルクロリドとを反応させた。そして、反応終了後、脱水ピリジンを除去し、その後メタノールを添加し、沈殿した黒色粉末をろ過し、これによりジヒドロフェナジンジカルボニル化合物の重合体を得た。

First, in an argon stream, 8.2 mmol of 5,10-dihydrophenazine and 20 mg of 4-dimethylaminopyridine (DMAP) were dissolved in 20 mL of dehydrated pyridine, and then 5 mL of dehydrated tetrahydrofuran, 8.2 mmol of oxalyl chloride and Was added at 0 ° C. Then, it stirred at room temperature for 1 hour, and also stirred at the temperature of 60 degreeC for 4 hours, and made 5,10-dihydrophenazine and oxalyl chloride react. And after completion | finish of reaction, dehydrated pyridine was removed, methanol was added after that, the black powder which precipitated was filtered, and the polymer of the dihydrophenazine dicarbonyl compound was obtained by this.

[Production of battery]
A coin-type battery of Reference Example 7 was produced in the same manner and procedure as in [Example 1] except that the polymer was used as the positive electrode active material.

[Battery operation check]
The battery produced as described above was charged and discharged under the same conditions as in Example 1, and the operation was confirmed. At the time of discharging having voltage flat portions at two charging and discharging voltages of 2.8 V and 2.4 V. Was confirmed to be a secondary battery having a capacity density of 200 Ah / kg.

  Subsequently, when charging and discharging were repeated 100 cycles in the range of 4.0 to 2.0 V, the initial discharge capacity of 90% or more could be secured even after 100 cycles. That is, since the positive electrode active material is stabilized in the electrolyte solution, it is possible to stably charge and discharge the multi-electron reaction, and to provide a secondary battery excellent in stability with little decrease in capacity even after repeated charging and discharging. I was able to get it.

As is clear from Reference Examples 2 to 7 described above, even when an organic compound having a dithione structure, a dione structure, a nitro radical structure, or a diamine structure outside the scope of the present invention as a positive electrode active material is used. It was found that by using an electrolyte solution containing sulfolane as a solvent, a secondary battery with little capacity reduction with respect to repeated charge and discharge can be obtained.

  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 solution

Claims (14)

A secondary battery containing an electrode active material and an electrolyte solution in which an electrolyte salt is dissolved in a solvent, and repeating charge and discharge by a battery electrode reaction of the electrode active material,
The electrode active material contains at least one selected from a dithione compound having a dithione structure, a dione compound having a dione structure, an organic radical compound having a stable radical group, and a diamine compound having a diamine structure in a structural unit. Mainly composed of organic compounds
The secondary battery, wherein the electrolyte salt is formed of a lithium salt and the solvent contains at least one selected from a cyclic sulfone compound, a cyclic ether compound, and a nitrile compound. The cyclic sulfone compound has the general formula

[Wherein Z represents an alkylene group having 1 to 7 carbon atoms, and includes both straight and branched chains. ]
The secondary battery according to claim 1, wherein: The cyclic ether compound has the general formula

[Wherein, p and q are integers of 0 to 3, R _{1 to} R ₃ represent an alkylene group having 1 to 8 carbon atoms and include a fluorine atom, and further R _{1 to} R ₃ In the same case, both include straight chain and branched chain. ]
The secondary battery according to claim 1, wherein: The nitrile compound of the general formula _{R 4 -C≡N, N≡C-R 5} -C≡N, _and, R 6 _OR 7 -C≡N
[Wherein R ₄ and R ₆ represent an alkyl group having 1 to 4 carbon atoms, R ₅ and R ₇ represent an alkylene group having 1 to 7 carbon atoms, and these R _{4 to} R ₇ are linear And both branched chains. ]
The secondary battery according to claim 1, wherein the secondary battery is represented by any one of the above. The electrolyte salt has a general formula

as well as,

[Wherein R _{8 to} R ₁₂ represent any one of a fluorine atom and a fluoroalkyl group, these R _{8 to} R ₁₂ include the same case, R ₁₃ represents a fluoroalkylene group, R ₁₄ Represents a fluoroalkyl group having 1 to 7 carbon atoms. ]
5. The secondary battery according to claim 1, comprising an anion represented by any one of claims 1 to 4. The dithione compound has the general formula

[Wherein, n is an integer of 1 or more, and R ₁₅ and R ₁₆ are a substituted or unsubstituted amino group, a substituted or unsubstituted imino group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkylene, Group, substituted or unsubstituted aryl group, substituted or unsubstituted aralkyl group, substituted or unsubstituted cycloalkyl group, substituted or unsubstituted alkoxyl group, substituted or unsubstituted alkenyl group, substituted or unsubstituted aryloxy Group, substituted or unsubstituted arylamino group, substituted or unsubstituted alkylamino group, substituted or unsubstituted thioaryl group, substituted or unsubstituted thioalkyl group, substituted or unsubstituted heterocyclic group, substituted or unsubstituted Formyl group, substituted or unsubstituted silyl group, substituted or unsubstituted cyano group, substituted or Any one of an unsubstituted nitro group, a substituted or unsubstituted nitroso group, a substituted or unsubstituted carboxyl group, a substituted or unsubstituted alkoxycarbonyl group, and one or more combinations thereof, and R ₁₅ and R ₁₆ include the same case and the case where they are linked to each other to form a saturated or unsaturated ring structure. ]
The secondary battery according to claim 1, wherein the secondary battery is represented by: The dithione compound has the general formula

[Wherein, n is an integer of 1 or more, and R ₁₇ and R ₁₉ are a substituted or unsubstituted amino group, a substituted or unsubstituted imino group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkylene, Group, substituted or unsubstituted aryl group, substituted or unsubstituted aralkyl group, substituted or unsubstituted cycloalkyl group, substituted or unsubstituted alkoxyl group, substituted or unsubstituted alkenyl group, substituted or unsubstituted aryloxy Group, substituted or unsubstituted arylamino group, substituted or unsubstituted alkylamino group, substituted or unsubstituted thioaryl group, substituted or unsubstituted thioalkyl group, substituted or unsubstituted heterocyclic group, substituted or unsubstituted Formyl group, substituted or unsubstituted silyl group, substituted or unsubstituted cyano group, substituted or Any one of an unsubstituted nitro group, a substituted or unsubstituted nitroso group, a substituted or unsubstituted carboxyl group, a substituted or unsubstituted alkoxycarbonyl group, and one or more combinations thereof, and R ₁₇ and R ₁₉ include the same case and a case where they are linked to each other to form a saturated or unsaturated ring structure, and R ₁₈ represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, and It shows at least one kind of imino group, and includes the case where the imino groups are linked to each other. ]
The secondary battery according to claim 1, wherein the secondary battery is represented by: The dione compound has the general formula

[Wherein, n is an integer of 1 or more, and R ₂₀ and R ₂₁ are a substituted or unsubstituted amino group, a substituted or unsubstituted imino group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkylene, Group, substituted or unsubstituted aryl group, substituted or unsubstituted aralkyl group, substituted or unsubstituted cycloalkyl group, substituted or unsubstituted alkoxyl group, substituted or unsubstituted alkenyl group, substituted or unsubstituted aryloxy Group, substituted or unsubstituted arylamino group, substituted or unsubstituted alkylamino group, substituted or unsubstituted thioaryl group, substituted or unsubstituted thioalkyl group, substituted or unsubstituted heterocyclic group, substituted or unsubstituted Formyl group, substituted or unsubstituted silyl group, substituted or unsubstituted cyano group, substituted or Any one of an unsubstituted nitro group, a substituted or unsubstituted nitroso group, a substituted or unsubstituted carboxyl group, a substituted or unsubstituted alkoxycarbonyl group, and one or more combinations thereof, and R ₂₀ and R ₂₁ include the same case and the case where they are linked to each other to form a saturated or unsaturated ring structure. ]
The secondary battery according to claim 1, wherein the secondary battery is represented by: The dione compound has the general formula

[Wherein, n is an integer of 1 or more, and R ₂₂ and R ₂₄ are a substituted or unsubstituted amino group, a substituted or unsubstituted imino group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkylene, Group, substituted or unsubstituted aryl group, substituted or unsubstituted aralkyl group, substituted or unsubstituted cycloalkyl group, substituted or unsubstituted alkoxyl group, substituted or unsubstituted alkenyl group, substituted or unsubstituted aryloxy Group, substituted or unsubstituted arylamino group, substituted or unsubstituted alkylamino group, substituted or unsubstituted thioaryl group, substituted or unsubstituted thioalkyl group, substituted or unsubstituted heterocyclic group, substituted or unsubstituted Formyl group, substituted or unsubstituted silyl group, substituted or unsubstituted cyano group, substituted or Any one of an unsubstituted nitro group, a substituted or unsubstituted nitroso group, a substituted or unsubstituted carboxyl group, a substituted or unsubstituted alkoxycarbonyl group, and one or more combinations thereof, and R ₂₂ and R ₂₄ are the same and include a case where they are linked to each other to form a saturated or unsaturated ring structure, and R ₂₃ represents a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, and It shows at least one kind of imino group, and includes the case where the imino groups are linked to each other. ]
The secondary battery according to claim 1, wherein the secondary battery is represented by:   The secondary battery according to claim 1, wherein the organic radical compound is a nitroxyl radical compound.   The secondary battery according to claim 10, wherein the nitroxyl radical compound includes a 2,2,6,6-tetramethylpiperidine-N-oxyl radical in a molecular structure. The diamine compound has the general formula

[Wherein R ₂₅ and R ₂₆ are a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkylene group, a substituted or unsubstituted arylene group, a substituted or unsubstituted carbonyl group, a 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 amino group, substituted or unsubstituted amide group, From a substituted or unsubstituted sulfone group, a substituted or unsubstituted thiosulfonyl group, a substituted or unsubstituted sulfonamido group, a substituted or unsubstituted imino group, a substituted or unsubstituted azo group, and combinations of one or more of these Any one of the following linking groups is shown. X _{1 to} X ₄ are a hydrogen atom, a halogen atom, a hydroxyl group, a nitro group, a cyano group, a carboxyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted cycloalkyl group, Substituted or unsubstituted aryl 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 Includes the case where a substituent forms a ring structure. ]
The secondary battery according to claim 1, wherein the secondary battery is represented by:   13. The electrode active material is contained 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 1, comprising a positive electrode and a negative electrode, wherein the positive electrode is mainly composed of the electrode active material.

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