KR20060045321A - Copolymer compound and elcectrochemical cell therewith - Google Patents

Abstract

The present invention relates to a copolymer compound obtained by copolymerizing two or more types of monomers selected from indool and indool derivatives, and by using the copolymer compound as an electrode active material, an electrochemical cell having improved capacity and cycleability is provided. Can provide.

Electrochemical cell

Description

Copolymer Compound and electrochemical cell using the same {Copolymer Compound and elcectrochemical Cell therewith}

SEM image of a copolymerization compound. Figure 1 (a) is an embodiment. Figure 1 (b) is a comparative example.

 {FIG. 2} The graph which shows the evaluation result of TG of a copolymerization compound.

{FIG. 3} The graph which shows the measurement result of polymerization potential.

 4 is a schematic cross-sectional view showing an example of a basic cell of an electrochemical cell according to the prior art.

This invention relates to the electroconductive compound used for the electrode active material of the electrochemical cell represented by a secondary battery and an electric double layer capacitor, and the electrochemical cell using this electroconductive compound, More specifically, without impairing cycling property. The present invention relates to a polymer compound capable of improving the appearance capacity and an electrochemical cell using the same.

Electrochemical cells, such as a tertiary battery and an electric double layer capacitor, which use a pluton-conducting compound as an electrode active material, have been proposed and provided for practical use. 4, typical sectional drawing of an example of the basic cell 1 which comprises the electrochemical cell by a prior art is shown.

In the conventional electrochemical cell, as shown in FIG. 4, the positive electrode 2 containing the pluton-conducting compound as the electrode active material is formed on the positive electrode current collector 4, and the plow is formed on the negative electrode current collector 5. Negative electrode electrodes 3 each containing a conductive compound as an electrode active material are formed, and these are bonded to each other via a separator 6, and an aqueous solution or a non-aqueous solution containing a pluton source is filled as an electrolyte solution, and a gasket is provided. It is sealed by (7). In this electrochemical cell, only Floton is involved as a charge carrier in its operation.

The positive electrode 2 and the negative electrode 3 are formed in the powder of the dope or undoped pluton-conducting compound using an electrode material containing a conductive aid and a binder as necessary. As a manufacturing method of an electrode, there exists a method of pressure-molding an electrode material, and the method of depositing the slurry of an electrode material on a conductive base material. The positive electrode 2 and the negative electrode 3 thus formed can be disposed to face each other via the separator 6 to constitute the basic cell 1.

As the pluton-conducting compound used as the electrode active material, polyaniline, polythiophene, polypyrrole, polyacetylene, poly-p-phenylene, polyphenylene vinylene, polyperinaphthalene, polyprene, polyflurane, poly Πconjugated polymers such as thienylene, polypyridinediyl, polyisothianaphthene, polykinoxarin, polypyridine, polypyrimidine, polyindool, poly amino anthraquinone, polyimidazole and derivatives thereof, indool 3 Quinone type compounds, such as indool type (pi) conjugate compounds, such as a dimer, benzoquinone, a naphthoquinone, and anthraquinone, and quinone type polymers, such as a polyanthraquinone, a poly naphthoquinone, and a polybenzoquinone (the oxygen of a quinone is a hydroxyl group And the copolymer which has 2 or more types of units of the monomer which comprises an electrical polymer, etc. are mentioned. By doping to such a compound, a redox band is formed and electroconductivity is expressed. Such a compound is selected and used as an electrode active material of a positive electrode and a negative electrode by adjusting the difference of the redox potential suitably.

Moreover, as electrolyte solution, the aqueous solution electrolyte which consists of an acid aqueous solution, and the non-aqueous electrolyte electrolyte which added electrolyte to the organic solvent are known, When using a Floton conduction type compound, the former aqueous solution electrolyte has especially high cell capacity. It is used only in that it can provide. As the acid, an organic acid or an inorganic acid is used, and for example, inorganic acids such as sulfuric acid, acetic acid, hydrochloric acid, phosphoric acid, tetrafluoroboric acid, hexafluorophosphoric acid and hexafluorofluoric acid, saturated monocarboxylic acid, aliphatic carboxylic acid, and oxycarbox Organic acids, such as a main acid, p-toluene sulfonic acid, polyvinyl sulfonic acid, and lauric acid, are mentioned.

As a compound used as an electrode active material as described above, compounds obtained by trimerizing indool or indool derivatives (indool trimers) are disclosed in Japanese Patent Application Laid-Open Nos. 2-082-93419, 2003-142O99, and 2OO3-249221. Is disclosed.

This patent document describes a secondary battery and a capacitor using an indoleol trimer having a condensed ring structure bonded between the 2nd and 3rd positions of the indool having a substituent as the electrode active material of the positive electrode. have.

Formula (4) shows the reaction mechanism of charge / discharge in the electrolyte solution containing a Floton source with respect to the indool trimer which has a substituent. In Formula (4), R represents arbitrary substituents and X <^-> represents arbitrary anions. The dashed line is the redox inactive site.

{Formula 4}

As is apparent from this equation, in the compound, there are three redox active sites, but only two are used for the redox reaction in the actual electrochemical cell. Therefore, the capacity which can be obtained becomes only 2/3 of the theoretical capacity computed from a monomer, the capacity density per mass of the indool trimer which has a substituent falls, and the appearance capacity of the electrochemical cell using this as an electrode active material is small. Has a problem.

In addition, in the indool trimer having a substituent, the crystal structure changes due to the repetition of the dope and the undope due to the charge and discharge, and as a result, the cycleability decreases due to the increase of the internal resistance of the electrode. there is a problem.

An object of the present invention is to improve the cycleability by increasing the capacity per weight of an electrode active material in an electrochemical cell using a compound obtained from an indool derivative as an electrode active material.

This invention is made | formed in order to achieve the said objective, It is characterized by using the compound obtained by reacting 2 or more types of indool derivatives from which a kind and substituent of a substituent differs as an electrode active material.

This invention is a copolymerization compound characterized by copolymerizing two or more types of monomers chosen from the indool and indool derivative represented by Formula (1).

{Formula 1}

R in the formulas each independently represents an atom or group selected from a hydrogen atom, a nitro group, a carboxyl group, a carboxylic acid ester group, a cyano group, an acetyl group, an aldehyde group and a halogen atom.

Moreover, this invention relates to said copolymer compound which has a unit represented by Formula (1A), and a unit represented by Formula (1B) or Formula (1C).

R in the formulas each independently represents an atom or group selected from a hydrogen atom, a nitro group, a carboxyl group, a carboxylic acid ester group, a cyano group, an acetyl group, an aldehyde group and a halogen atom.

Moreover, this invention is represented by Formula (2), It is a former copolymer compound characterized by the above-mentioned.

{Formula 2}

R in the formulas each independently represents an atom or group selected from a hydrogen atom, a nitro group, a carboxyl group, a carboxylic acid ester group, a cyano group, an acetyl group, an aldehyde group, and a halogen atom, and n represents a natural number.

Moreover, this invention relates to the above-mentioned copolymer compound in which an electric monomer contains the indool derivative which has a substituent other than hydrogen in at least 3 positions.

Moreover, this invention is a former copolymer compound characterized by the above-mentioned represented by Formula (3).

{Formula 3}

R in the formulas each independently represents an atom or group selected from a hydrogen atom, a nitro group, a carboxyl group, a carboxylic acid ester group, a cyano group, an acetyl group, an aldehyde group, and a halogen atom, and n represents a natural number.

Moreover, this invention relates to the above-mentioned copolymer compound in which the former monomer contains the indool derivative which has a substituent other than hydrogen in at least a 2nd position.

Moreover, this invention is the former copolymer compound characterized by the above-mentioned, It is a pluton conduction type compound which causes an electrochemical redox reaction in the solution containing a floton source.

Moreover, this invention is the electrochemical cell containing at least 1 sort (s) chosen from the former copolymerization compound as an electrode active material.

Moreover, this invention contains 10-100 weight% of total amounts with respect to the electrode active material whole quantity in the electrode which contains at least 1 sort (s) chosen from the former copolymerization compound, The electrochemical cell characterized by the above-mentioned. to be.

Moreover, this invention is the electrochemical cell containing at least 1 sort (s) chosen from the former copolymerization compound as an electrode active material of a positive electrode.

The present invention is characterized in that at least one kind of the copolymer compound selected from the former copolymer compound as the electrode active material of the positive electrode is contained in a total amount of 10 to 100% by weight based on the total amount of the electrode active material of the positive electrode. It is a chemical cell.

Moreover, this invention is an electrochemical cell which has the electrolyte containing a pluton source, and in which the redox reaction accompanying charge and discharge WHEREIN: Floton functions as a charge carrier.

{The best sun for carrying out the invention}

The copolymer compound of the present invention is very suitable as an electrode material of an electrochemical cell containing a pluton-conducting compound as an electrode active material, and an indool represented by formula (1) as an electrode active material, preferably as a positive electrode electrode active material and By using the copolymerized compound synthesize | combined from 2 or more types of compounds chosen from its derivative, the electrochemical cell with improved appearance capacity and cycling property can be provided.

As such a copolymer compound, the copolymer compound which has a unit represented by Formula (1A) and a unit represented by Formula (1B) or Formula (1C) is preferable, and the copolymer compound represented by Formula (2) or Formula (3) Can be mentioned. As an alkyl part of the carboxylic acid ester group in such a formula, a C1-C8 alkyl group is mentioned, As a halogen atom, fluorine, chlorine, cancellation | release, oxo are mentioned.

The copolymerization composition ratio of this copolymer compound is represented by the molar ratio ((1A) :( 1B) or / and (1C)) between the unit of formula (1A) and the unit of formula (1B) or / and the unit of formula (1C). From the point of improving the appearance capacity and the copolymerizability, 2: 1 to 1: 5 are preferable, 1: 0.9 to 1: 5 are more preferable, and 1: 1 to 1: 5 are even more preferable. . In particular, an alternating copolymer of 1: 1 can be suitably used as an electrode active material.

The copolymer compound can be suitably used as an electrode active material having a weight average molecular weight of 2, OOO to 2O, OOO, preferably 2, OOO to 10, OOO, more preferably 3, OOO to 6, OOO Can be used. This average molecular weight can be measured by gel permeation chromatography (GPC) using polystyrene as a standard sample.

When synthesize | combining the copolymerization compound of this invention, as a compound used as a starting material, it can select arbitrarily from indool and indool derivatives. Specifically, indool, 2-nitro indool, 3-nitro indool, 4-nitro indool, 5-nitro indool, 6-nitro indool, 7-nitro indool, indool-2-carboxylic acid Indool-3-carboxylic acid, indool-4-carboxylic acid, indool-5-carboxylic acid, indool-6-carboxylic acid, indool-7-carboxylic acid, indool-2-carboxylic acid methyl ester , Indool-3-carboxylic acid methyl ester, Indool-4-carboxylic acid methyl ester, Indool-5-carboxylic acid methyl ester, Indool-6-carboxylic acid methyl ester, Indool-7-carboxylic acid methyl ester , Indool-2-carboxylic acid ethyl ester, Indool-3-carboxylic acid ethyl ester, Indool-4-carboxylic acid ethyl ester, Indool-5-carboxylic acid ethyl ester, Indool-6-carboxylic acid ethyl ester Indool-7-carboxylic acid ethyl ester, 2-cyanoindool, 3-cyanoindool, 4-cyanoindool, 5-cyanoindool, 6-cyanoindool, 7-cyanoindool, 2-ace Indool, 3-acetyl indool, 4-acetyl indool, 5-acetyl indool, 6-acetyl indool, 7-acetyl indool, indool-2-aldehyde, indool-3-aldehyde, indool- 4-aldehyde, indool-5-aldehyde, indool-6-aldehyde, indool-7-aldehyde, 2-promerdool, 3-promerdool, 4-promerdodool, 5- Promerdool, 6-promerdoolol, 7-promerdoolol, indool-2, 6-dicarboxylic acid, indool-3, 6-dicarboxylic acid, indool-4, 5-dicar Main acid, indool-4, 6-dicarboxylic acid, indool-5, 6-dicarboxylic acid, indool-2, 6-dicarboxylic acid methyl ester, indool-3, 6-dicarboxylic acid methyl ester, Indool-4, 5-dicarboxylic acid methyl ester, Indool-4, 6-dicarboxylic acid methyl ester, Indool-5, 6-dicarboxylic acid methyl ester, Indool-2, 6-dicarboxylic acid ethyl Ester, indool-3, 6-dicarboxylic acid ethyl ester, indool-4, 5-dicarboxylic acid ethyl ester, indool-4, 6-di Levonic acid ethyl ester, indool-5, 6-dicarboxylic acid ethyl ester, 2, 6-diacetylindool, 3, 6-diacetylindool, 4, 5-diacetylindool, 4,6-di Acetyl indool, 5,6-diacetyl indool, 2-acetyl indool-6-carboxylic acid methyl ester, 3-acetyl indool-6-dicarboxylic acid methyl ester, 2-acetyl indool-5, 6- And monosubstituted monomers, disubstituted monomers and trisubstituted monomers such as dicarboxylic acid methyl ester, 3-acetylindool-5, and 6-dicarboxylic acid methyl ester. Two or more types can be selected arbitrarily from such a monomer, and it can superpose | polymerize and obtain a copolymer compound.

Next, the synthesis | combining method of the copolymerization compound of this invention and the manufacturing method of an electrochemical cell are demonstrated.

First, the electrolytic polymerization method will be described.

The copolymerizing compound may contain at least two types of indole having a substituent as a monomer in a solution obtained by dissolving lithium tetrafluoroborate at a concentration of about 0.3 mol / L as an electrolyte, for example, in acetonitrile as a solvent. In addition, by using a poten shot start, the product can be synthesized under the conditions of the potential sweep range of 50 mV to 16OO mV and the potential sweep rate of 50 mV / s, and the product precipitated on the working pole is washed with a suitable solvent to obtain a powder or film solid. Can be obtained as

The other compound is also applicable to the electrolyte at this time, and is not limited to lithium tetrafluoroborate as seen from before. Specifically, perchloric acid, lithium perchlorate, sodium perchlorate, tetrabutyl ammonium perchlorate, tetraethyl ammonium perchlorate, tetrafluoroboric acid, tetraethylammonium, tetrafluoroboric acid, tetrabutylammonium, etc. are mentioned. Although the reaction time of electrolytic polymerization is not restrict | limited, From a viewpoint of suppression of a by-product, etc., Preferably, 0.1 hour-10 hours are preferable.

In addition, the synthesis | combining method of a copolymerization compound is not limited to the former electrolytic polymerization method, It is also possible according to the chemical oxidation polymerization method. It is synthesized by dissolving at least two indool having a substituent as a monomer in acetonitrile as a polymerization solvent, for example, by adding ferric chloride as an oxidizing agent and stirring, and filtering the precipitated product. And it can wash with a suitable solvent and a copolymer compound can be obtained.

Other solvents and oxidizing agents are applicable to the polymerization solvent and the oxidizing agent at this time, and are not limited to the former acetonitrile and ferric chloride. Specifically, examples of the polymerization solvent include aromatic hydrocarbons such as toluene, xylene and chlorobenzene, halogenated aliphatic hydrocarbons such as dichloromethane and chloroform, acetate esters such as methyl acetate, ethyl acetate and butyl acetate, dimethyl formamide and dimethyl. Non-flotonic polar solvents such as acetamide, N-methyl pyrrolidone, tetramethyl urea and hexamethyl phosphoric triamide (HMPA), ether solvents such as diethyl ether, tetra hydrofran, dioxane, Aliphatic hydrocarbons such as pentane and n-hexane, aliphatic alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, s-butanol and t-butanol, or acetone, acetonitrile and propionitrile Etc. can be mentioned. Preferably, acetone, acetonitrile, dioxane, dimethyl formamide and the like are preferable. The solvent may be used alone or as a mixed solvent in any mixing ratio.

Examples of the oxidizing agent include ferric chloride hexahydrate, anhydrous ferric chloride, ferric acetate hexahydrate, ferric acetate, hydrated ferric sulfate n hydrate, ferric ammonium sulfate hexahydrate, and ferric perchlorate. n hydrate, ferric tetrafluoroborate, cupric chloride, cupric sulfate, cuprous tetrafluoroborate, nitrosonium tetrafluoroborate, ammonium persulfate, sodium persulfate, potassium persulfate, sodium peroxate, Potassium peroxoate, hydrogen peroxide, ozone, hexacyano ferric potassium, ammonium tetraammonium sulfate (IV) dihydrate, cancellation, oxo and the like. Preferably ferric chloride hexahydrate, anhydrous ferric chloride, ferric acetate hexahydrate, ferric acetate, ferric sulfate n hydrate, ferric ammonium sulfate hexahydrate, ferric perchlorate n hydrate, Ferric tetrafluoroborate is used. These oxidizing agents can be used individually, respectively, or can also use 2 or more types together by arbitrary ratios.

In the chemical oxidation polymerization method, the reaction temperature can be in the range of O ° C to the reflux temperature of the solvent to be used, but the preferred range is 10 ° C to 100 ° C. In addition, the reaction time of chemical oxidation polymerization is not particularly limited, but from the viewpoint of suppressing the by-products, etc., preferably 0.1 hour to 100 hours are preferable.

In electrolytic polymerization, the polymerization potential can be used as one means of verifying the possibility of copolymerization by measuring the potential sweeping range of 50 mV to 1600 mV and the potential sweeping rate of 50 mV / s. Furthermore, the obtained copolymer compound was observed by scanning electron microscopy (hereinafter referred to as SEM) and thermogravimetric measurement (hereinafter referred to as TG) to produce a copolymer compound different from the prior art. As a means to check.

Next, in the cyclic bolton measurement (hereinafter referred to as CV measurement), the production method and test conditions of the test sample will be described. In the obtained copolymer compound, 30% by weight of VGCF (registered trademark, hereinafter referred to as VGCF) manufactured by Showa Denko Co., Ltd., which is fibrous carbon according to gas phase growth method, is added and mixed as a conductive aid. It is apply | coated on the sheet of carbon fiber (made by Toray Corporation, TGP-H-O3O), it is dried at 12O degreeC, and a measurement sample is prepared.

In the CV measurement, using 20 wt% sulfuric acid as the electrolyte, the potential sweep range is 20 mV to 1,2OO mV, and the potential sweep rate is 200 mV / s. CV capacity | capacitance calculates the integral value of the potential sweep range of 200 mV-1,200 mV, and normalizes per weight of copolymerization compound.

Next, the structure and manufacturing method of an electrochemical cell are described.

The present invention is characterized in that, in the copolymer compound used for the electrode active material, the structure of the basic cell can be the same as the conventional technique shown in FIG. 4. Therefore, here, it demonstrates with reference to FIG.

The electrochemical cell of the present invention contains a pluton-conducting electrochemical cell in which a pluton acts as a charge carrier for a redox reaction resulting from charge and discharge, more specifically, an electrolyte containing a pluton source, It is preferable to operate | move so that only adsorption-and-desorption of the ploton of an electrode active material may participate with respect to the electron transfer of a redox reaction accompanying discharge.

Such an electrochemical cell can contain a pluton-conducting compound as an active material of a positive electrode and a negative electrode, respectively, and can take the structure containing the electrolyte solution containing a pluton source as an electrolyte.

The pluton-conducting compound used as the electrode active material is not particularly limited as long as it causes a redox reaction in a solution containing a pluton source, and conventionally known compounds other than the copolymerization compound of the present invention can be used.

As the pluton-conducting compound used as the electrode active material, polyaniline, polythiophene, polypyrrole, polyacetylene, poly-p-phenylene, polyphenylene vinylene, polyperinaphthalene, polyprene, polyflurane, poly Πconjugated polymers such as thienylene, polypyridinediyl, polyisothianaphthene, polykinoxarin, polypyridine, poly pyrimidine, polyindool, polyamino anthraquinone, polyimidazole and derivatives thereof, indool 3 Quinone type compounds, such as indool type (pi) conjugate compounds, such as a dimer, benzoquinone, a naphthoquinone, and anthraquinone, and quinone type polymers, such as a polyanthraquinone, a poly naphthoquinone, and a polybenzoquinone (the oxygen of a quinone is a hydroxyl group And the copolymer which has 2 or more types of units of the monomer which comprises an electrical polymer, etc. can be mentioned. By doping such a compound, a redox band is formed and electroconductivity is expressed. Such a compound can be selectively used as an electrode active material of a positive electrode and a negative electrode by adjusting the difference of the redox potential appropriately.

The electrode of the electrochemical cell of the present invention contains a pluton-conducting compound as an electrode active material, a conductive aid and a binder as necessary, and preferably two or more kinds of indool derivatives as an electrode active material of a positive electrode as an electrode active material. It is characterized by including the copolymerization compound synthesize | combined as a monomer.

As for the ratio of the copolymer compound of this invention which occupies in the electrophoretic substance in an electrode, since the desired effect is fully acquired, 100 to 100 weight% is preferable, 20 to 100 weight% is more preferable, 3 to 100 weight% Is more preferable.

 As the positive electrode 2, for example, one containing from 10 to 100 mass% of the copolymer compound of the present invention is preferably used as the electrode active material. As the conductive aid, for example, VGCF can be mixed in an amount of 1 to 50% by weight, preferably 10 to 3% by weight, based on the positive electrode active material. As the binder, for example, polyvinylidene fluoride (hereinafter referred to as PVDF) may be added and mixed in an amount of 1 to 20% by weight, preferably 5 to 10% by weight, based on the positive electrode electrode active material. The positive electrode 2 can be obtained by pressure-molding this mixed powder at 0 degreeC-30 degreeC, Preferably it is 100 degreeC-250 degreeC.

The negative electrode 3 is, for example, a weight ratio of, for example, phenylene black (trade name: Ketjen Black EC-6OO JD, manufactured by Ketjen Black International) as an electrode active material, for example, polyphenyl quinoxaline and a conductive aid. The powder mixed at 72:28 can be obtained by press molding and baking.

As the electrolyte solution, an aqueous solution or a non-aqueous solution containing floton can be used. An aqueous solution electrolyte is preferable in that a cell of high capacity can be provided. As the acid, an organic acid or an inorganic acid can be used, and for example, inorganic acids such as sulfuric acid, acetic acid, hydrochloric acid, phosphoric acid, tetrafluoroboric acid, hexafluorophosphoric acid, and hexafluorofluoric acid, saturated monocarboxylic acid, aliphatic carboxylic acid, and oxycarboxylic acid and organic acids such as p-toluene sulfonic acid, polyvinyl sulfonic acid and lauric acid.

The content of the tone of the electrolyte flow, 1O ^-3 mol / L ~ 18 mol / L is preferable, and more preferably from 1O ^-1 mol / L ~ 7 mol / L. This is because if this concentration is too low, the function as the electrolyte solution cannot be sufficiently expressed, and if this concentration is too high, the acidity is strong, and thus the activity of the material is reduced or dissolved.

As the separator 6, a polyolefin porous membrane or a cation exchange membrane having a thickness of 10 to 50 µm can be used. As the positive electrode current collector 4 and the negative electrode current collector 5, a rubber sheet provided with conductivity by dispersion of conductive carbon powder can be used, and for example, butyl rubber can be used as the gasket 7.

The base cell 1 can be obtained by combining the member demonstrated above. Specifically, as shown in FIG. 1, the positive electrode 2 is disposed on the positive electrode current collector 4, the negative electrode 3 is disposed on the negative electrode current collector 5, and these are separated from the separator 6. ), The electrolyte is filled, and sealed by the gasket 7. In this case, the outer shape of the cell becomes coin type, but it is possible to take a shape conventionally used, such as a lamination type and a winding type, and is not particularly limited.

EXAMPLE

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated further more concretely based on an Example.

{Example 1}

Indool-6-carboxylic acid methyl ester and 3-acetylindool were selected as monomers of the indool having a substituent, and concentrations of 20x10 ^-3 mol / L and lithium tetrafluoroborate as the electrolyte were 0.3 mol / It melt | dissolved in the acetonitrile which is a superposition | polymerization solvent so that it might become L concentration, and electrolytic polymerization was performed using a potent shotstart. Precipitation of the product was recognized on the working electrode, and the product was washed with ethanol and dried to obtain a dark green copolymer compound powder.

Next, the obtained copolymerized compound was analyzed. Here, the SEM photograph was taken first. At this time, the SEM photograph of the trimer obtained by combining 2nd and 3rd positions of the indool-6-carboxylic acid methyl ester was also taken as a comparative example. Figure 1 (a) is an example, Figure 1 (b) is a SEM image of the comparative example. In this SEM photograph, a fibrous form was observed, and a form different from the comparative example was recognized in the polymerization product.

Next, evaluation by TG was performed about the obtained copolymer compound. At this time, the same trimer of the former indool-6-carboxylic acid methyl ester was evaluated similarly. 2 shows the evaluation results of TG of the copolymerized compound. According to this result, the clear decomposition point is not recognized by the copolymer compound of an Example, and it is clear that heat resistance is improving. On the other hand, in the trimer of the indool-6- carboxylic acid methyl ester of a comparative example, a steep weight loss is recognized from around 300 degreeC, and it turns out that heat resistance is inferior to an Example.

Next, the electrochemical cell was produced using the obtained copolymer compound as a positive electrode electrode active material. Here, the copolymer compound, VGCF, and PVDF were weighed and mixed so as to be 69/23/8 in a weight ratio, and pressure molded at 20 ° C to obtain a positive electrode. The negative electrode was weighed and mixed so as to have a weight ratio of 72/28 with polyphenyl quinoxaline and Ketjen black using polyphenyl kinoxarin as an electrode active material, and prepared by a method called baking after pressure molding at 3O &lt; 0 &gt; C.

As the electrolyte, 20% by weight aqueous sulfuric acid was used, as a separator, a cation exchange membrane having a thickness of 15 µm was used, butyl rubber was used as the gasket, and a rubber sheet having conductivity was used as the current collector.

Using such a member, the electrochemical cell which consists of a basic cell shown in FIG. 1 mentioned above was produced.

{Example 2}

A copolymer compound was synthesized in the same manner as in Example 1 except that indool-6-carboxylic acid methyl ester and indool-2-aldehyde were used as monomers of the indool having a substituent, to prepare an electrochemical cell.

{Example 3}

5-cyano indool and indool-5-carboxylic acid were used as monomers of the indool having a substituent, and the concentration of 5-cyanoindool was 5 × 10-3 mol / L and indool ^- 5-carboxylic acid was 25 × A copolymerization compound was synthesized in the same manner as in Example 1 except that the solution was dissolved in acetonitrile so as to have a concentration of 10 ⁻³ mol / L, and a polymerization solution was prepared to prepare an electrochemical cell.

{Example 4}

As a monomer having a substituent of India come India ol-6-carboxylic acid methyl ester is 4O × 1O ^-3 mol / L concentration, the concentration of 3-acetyl India come 2O × 1O ^-3 mol / L, Indian come -3 A copolymer compound was synthesized in the same manner as in Example 1 except that the aldehyde was dissolved in acetonitrile so as to have a concentration of 20 × 10 ⁻³ mol / L, and a polymerization solution was prepared, to prepare an electrochemical cell.

{Example 5}

Indool-6-carboxylic acid methyl ester and 3-acetyl indool were selected as monomers of the indool having a substituent, dissolved in acetonitrile as a polymerization solvent, and subjected to chemical oxidation polymerization. The oxidizing agent was reacted with ammonium persulfate with stirring at 6O <0> C for 3 hours. The precipitate was washed with ethanol and dried to give a dark green copolymer compound powder. Except having used this copolymerization compound as a positive electrode electrode active material, it carried out similarly to Example 1, and prepared the electrochemical cell.

{Example 6}

Except for using indool-6-carboxylic acid methyl ester and 3-acetylindool-6-carboxylic acid methyl ester as monomers of the indool having a substituent, a copolymerization compound was synthesized in the same manner as in Example 1, and an electrochemical cell Prepared.

{Example 7}

A copolymerization compound was synthesized in the same manner as in Example 1 except that indool-5, 6-dicarboxylic acid methyl ester and 3-acetylindool-6-carboxylic acid methyl ester were used as monomers of the indool having a substituent. An electrochemical cell was prepared.

{Example 8}

A powder obtained by mixing a copolymer having a condensed ring structure obtained by combining the copolymerized compound described in Example 1 and the indool-6-carboxylic acid methyl ester between 2nd and 3rd positions at a weight ratio of 50 / 5O. In the same manner as in Example 1, except that the electrode active material, VGCF, and PVDF were weighed and mixed at a weight ratio of 69/23/8, and the electrode formed by pressing at 20 ° C. was used as the positive electrode. Chemical cells were prepared.

{Example 9}

A powder obtained by mixing 20 / 8O in a weight ratio of a trimer having a condensed ring structure obtained by combining the copolymerized compound described in Example 1 and the indool-6-carboxylic acid methyl ester between 2nd and 3rd positions An electrochemical method was performed in the same manner as in Example 1 except that the electrode active material, VGCF, and PVDF were weighed and mixed in a weight ratio of 69/23/8, and the electrode formed by pressing at 20 ° C. was used as the positive electrode. The cell was prepared.

{Comparative Example}

A trimer (6-methylindolol trimer) having a condensed ring structure obtained by bonding between the 2nd and 3rd positions of 6-methylindool was synthesized, and an electrochemical cell using this as a positive electrode active material was prepared. The electrochemical cell was prepared in the same manner as in Example 1 except that the material obtained by weighing and mixing the 6-methylinolol trimer, VGCF, and PVDF in a weight ratio of 69/23/8 was pressed at 20 ° C to obtain a positive electrode. Prepared.

About electrolytic polymerization about such an Example and a comparative example, the measurement of superposition | polymerization potential by the conditions of the previous, and about all the copolymerization compounds of an Example and a comparative example, CV measurement by the conditions which were seen previously About the electrochemical cell, capacity | capacitance residual ratio after repeating initial stage capacity | capacitance and 5, OO cycle charge and discharge was measured.

The measurement result of a polymerization potential is shown in FIG. 3, and Table 1 shows the initial stage capacity | capacitance calculated from CV measurement, and the capacity | capacitance remaining rate after 1, OO cycle. Table 2 also shows the initial capacity for the electrochemical cell and the capacity remaining rate after 5, OO cycles.

{Table 1}

{Table 2}

From the result shown in Table 1, the copolymer compound of the Example shown here increased 6% or more of capacity per weight of an electrode active material compared with the comparative example, and capacity | capacitance retention after 1, OO cycles, ie, cycleability, increased by 6% or more It can know that it is doing, and the effect of this invention can be confirmed. Moreover, from the result shown in Table 2, it turns out that the electrochemical cell of the Example shown here has a 10% or more increase in capacity and 18% or more in cycleability than the comparative example.

The copolymerization compound of the present invention has a chemical structure different from that of a conventional indolol trimer having a condensed polycyclic structure bonded to a second or third position, and oligomerization or polymerization in which the indool having a substituent constitutes a main chain. One compound.

When used for the electrode active material of an electrochemical cell as a 1st effect obtained by having such a structure, it becomes possible to utilize a redox active site effectively.

Moreover, as a 2nd effect, the morphology of the surface of an electrode active material changes in the form which the ion in an electrolysis liquid is easy to dope and dedope, and the charge-discharge efficiency improves.

In addition, deterioration of the electrode active material as the third effect includes preventing deterioration of the electronic conductivity due to the collapse of the crystal structure caused by the dope and dedope of the dopant accompanying charge and discharge.

By the above effects, the electrochemical cell containing the copolymer compound as the electrode active material in the electrode material has an increased capacity since the capacity per unit mass of the electrode active material increases. In addition, since the rise of the internal resistance can be prevented, the cycle performance is improved.

 As described above, by using an electrode containing the copolymerized compound according to the present invention as an electrode active material, an electrochemical cell with increased appearance capacity and excellent cycle characteristics can be provided. This uses a copolymer compound of a monomer selected from indool and indool derivatives as the electrode material, and can effectively utilize the redox active site, and the dope and dedope are By advancing smoothly and improving the charging and discharging efficiency and making it amorphous by the high molecular weight of an electrode active material, it is possible to prevent material deterioration by repetition of dope and dedope accompanying charge / discharge. Because I lost.

Claims (12)

The copolymerization compound characterized by copolymerizing two or more types of monomers chosen from the indool and indool derivative represented by Formula (1).

 (In the formula, each independently represents an atom or group selected from a hydrogen atom, a nitro group, a carboxyl group, a carboxylic acid ester group, a cyano group, an acetyl group, an aldehyde group, and a halogen atom.) The copolymer compound of Claim 1 which has a unit represented by Formula (1A) and a unit represented by Formula (1B) or Formula (1C).

(In the formula, each independently represents an atom or group selected from a hydrogen atom, a nitro group, a carboxyl group, a carboxylic acid ester group, a cyano group, an acetyl group, an aldehyde group, and a halogen atom.) The copolymerization compound according to claim 1, which is represented by Formula (2).

(In the formula, each independently represents an atom or group selected from a hydrogen group, a nitro group, a carboxyl group, a carboxylic acid ester group, a cyano group, an acetyl group, an aldehyde group, and a halogen atom, and n represents a natural number.) The copolymer compound according to claim 3, wherein the electric monomer comprises an indolol derivative having a substituent other than hydrogen on at least three. The copolymerization compound according to claim 1, which is represented by Formula (3).

(Wherein R represents a hydrogen atom, each independently, an atom or group selected from a nitro group, a carboxyl group, a carboxylic acid ester group, a cyano group, an acetyl group, an aldehyde group, a halogen atom, and n represents a natural number) The copolymer compound according to claim 5, wherein the electric monomer contains an indool derivative having a substituent other than hydrogen on at least two positions. The copolymer compound according to claim 1, which is a pluton-conducting compound which causes an electrochemical redox reaction in a solution containing a pluton source. An electrochemical cell comprising at least one member selected from copolymerized compounds according to any one of claims 1 to 7 as an electrode active material. An electrochemical cell comprising at least 1% by weight in a total amount of at least one selected from the copolymerization compounds according to any one of claims 1 to 7, based on the total amount of the electrode active material in the electrode to be contained. . An electrochemical cell comprising at least one member selected from copolymerization compounds according to any one of claims 1 to 7 as an electrode active material of a positive electrode. Electrochemical which contains at least 1 sort (s) selected from the copolymerization compound as described in any one of Claims 1-7 as a total amount with respect to the total amount of the electrode active materials of a positive electrode as 100-100 weight% as electrode active materials of a positive electrode. Cell. The electrochemical cell according to claim 8, wherein the electrochemical cell has an electrolyte including a pluton source, and the pluton functions as a charge carrier for the redox reaction involving charge and discharge.

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