JP2020194713A - Power storage element - Google Patents

Abstract

To provide a power storage element having a large capacity and output characteristics and an excellent capacity retention rate.SOLUTION: A power storage element includes an electrode containing a conductive polymer and an electrolytic solution containing an ionic liquid, and the content of the ionic liquid in the electrolytic solution is more than 0.3 mass% and 50 mass% or less.SELECTED DRAWING: Figure 2

Description

The present invention relates to a power storage element.

In recent years, with the miniaturization and higher performance of electric devices and the improvement of the cruising range of electric vehicles, higher performance of power storage elements is required. As such a power storage element, a lithium ion secondary battery is often used. Lithium-ion secondary batteries are good at storing large amounts of energy, but they are not good at extracting energy instantaneously, so storage devices with excellent high-output characteristics such as lithium-ion capacitors may be used in combination.

By using a lithium ion secondary battery and a lithium ion capacitor together, a system having high output characteristics can be completed while storing a large amount of energy, but the control becomes complicated because two types of power storage devices are used. Therefore, there is a demand for a power storage device that has high output characteristics and can store a large energy density.

By using a polymer radical material which is an organic compound for an electrode, a technique of a power storage device having a high output and a large energy density has been proposed (see, for example, Patent Document 1). However, there is a problem that deterioration progresses as the redox of the organic compound is repeated, and the capacity retention rate deteriorates.

An object of the present invention is to provide a power storage element having a large capacity and output characteristics and an excellent capacity retention rate.

The power storage element of the present invention has an electrode containing a conductive polymer and an electrolytic solution containing an ionic liquid, and the content of the ionic liquid in the electrolytic solution is more than 0.3% by mass and 50% by mass or less. It is characterized by that.

According to the present invention, it is possible to provide a power storage element having a large capacity and output characteristics and an excellent capacity retention rate.

FIG. 1 is an overall configuration diagram showing an example of a power storage element of the present invention. FIG. 2 is a diagram showing the capacity retention rates of Examples 1 and 31 and Comparative Examples 1 and 6.

(Power storage element)
The power storage element of the present invention has at least an electrode and an electrolytic solution, and further has other members such as a separator, if necessary.
The electrodes include a conductive polymer.
The electrolytic solution contains an ionic liquid.
The content of the ionic liquid in the electrolytic solution is more than 0.3% by mass and 50% by mass or less.

In another aspect of the power storage device of the present invention, the electrode comprises an active material, and the active material comprises the conductive polymer.

By using the conductive polymer in the electrode and the ionic liquid in the electrolytic solution in combination, the power storage element has a large capacity and output characteristics, and has an excellent capacity retention rate.

<Active material>
The active material comprises a conductive polymer, preferably a carbonaceous material, and optionally other materials.

Hereinafter, in the present invention, the electrode material means a material constituting an electrode such as an active material, a conductive auxiliary agent, a binder, a thickener, and a current collector. Further, in the present invention, the active material refers to a substance directly involved in the development of capacity in the power storage element, that is, a substance having a function of storing or releasing ions in the power storage element.

The active material includes a conductive polymer. Since the active material contains a conductive polymer, the amount of the conductive auxiliary agent added can be reduced as compared with the case where the polymer radical material is used as the active material. When the amount of the conductive additive added is small, the proportion of the active material in the material constituting the electrode can be increased, and as a result, the capacity per electrode can be increased. In addition, activated carbon showing adsorption capacity may be used in combination with a conductive polymer. Activated carbon is used as an active material for electrochemical capacitors, and a high power density can be obtained. The conductive polymer and activated carbon are preferably precombined. By performing the compounding in advance, a good electron conduction path is formed, and the performance of the power storage device can be further brought out. Specifically, the development of the electron conduction path makes it possible to pass a large current and shorten the charge / discharge rate.

<< Conductive polymer >>
As the conductive polymer, a polymer capable of occluding or releasing cations or anions in a redox reaction is preferable.
The conductive polymer is not particularly limited and may be appropriately selected depending on the intended purpose. For example, polythiophene or a derivative thereof, polyaniline or a derivative thereof, polypyrrole or a derivative thereof, polyacetylene or a derivative thereof, polycarbazole or a derivative thereof. , Polyvinylpyridine or its derivatives, poly (n-vinylcarbazole) or its derivatives, polyfluorene or its derivatives, polyphenylene or its derivatives, poly (p-phenylene vinylene) or its derivatives, poly (pyridinevinylene) or its derivatives, poly Kinoxalin or a derivative thereof, polyquinolin or a derivative thereof, polyoxadiazole derivative, polyvasofenantrolin derivative, polytriazole derivative, or a polymer thereof was appropriately substituted with a substituent such as an amine group, a hydroxy group, a nitrile group, or a carbonyl group. Things and so on. These may be used alone or in combination of two or more. Among these, polythiophene or a derivative thereof, polyaniline or a derivative thereof, polypyrrole or a derivative thereof are preferable from the viewpoint that the electrode can have a high energy density.

As the polythiophene derivative, a polymer having a repeating unit represented by the following general formula (1) is preferable.
The polythiophene derivative having a repeating unit represented by the general formula (1) is a stabilized redox compound, and is a polymer that undergoes a redox reaction in at least one of a charging reaction and a discharging reaction.

In the general formula (1), Z represents a group of atoms forming a 5- to 9-membered heterocycle containing an S element, an O element, or a Se element as a ring member. Since the S element, O element, or Se element can have a large number of oxidation numbers, by including the S element, the O element, or the Se element as a ring member, the transfer of electrons associated with the oxidation and reduction reactions is a multi-electron reaction. It can be expected to progress. As a result, the capacity per active material can be increased, and a high energy density can be obtained when the energy storage element is used.

Ar represents an aromatic ring which may have a substituent or an aromatic heterocycle which may have a substituent.
Examples of the aromatic ring include benzene, biphenyl, naphthalene, anthracene, fluorene, pyrene, and derivatives thereof.
Examples of the aromatic heterocycle include pyridine, quinoline, thiophene, furan, oxazole, oxadiazole, carbazole, and derivatives thereof. Among these, thiophene and thiophene derivatives are preferable.

Examples of the substituent of the aromatic ring or the aromatic heterocycle include an alkyl group, an alkoxy group, a halogen atom and the like.
Examples of the alkyl group include a methyl group, an ethyl group, an isopropyl group, a butyl group and the like.
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group and the like.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like.

For n, a natural number of 2 or more is preferable, and a natural number of 10 to 1000 is more preferable.
m is preferably a natural number of 0 or 2 or more, and more preferably a natural number of 0 or 10 to 1000.

As the polythiophene derivative having the repeating unit represented by the general formula (1), the polythiophene derivative having the repeating unit represented by the following general formula (2) has redox stability, solvent resistance, and capacity. It is preferable from the viewpoint of.

However, in the general formula (2), R represents a substituted or unsubstituted alkylene group or a substituted or unsubstituted branched alkylene group. p represents a natural number of 1 or more. Q represents an S element, an O element, or a Se element. Ar represents an aromatic ring which may have a substituent or an aromatic heterocycle which may have a substituent. n represents a natural number of 2 or more, and m represents a natural number of 0 or 2 or more.

R represents a substituted or unsubstituted alkylene group or a substituted or unsubstituted branched alkylene group. Examples of the group substituting the alkylene group include an alkyl group, an alkoxy group, an aryl group, an aryloxy group, a thioalkyl group, an arylthio group, an alkylamino group, an arylamino group, a halogen atom and the like.

Examples of the alkyl group include a methyl group, an ethyl group, an isopropyl group, a butyl group and the like.
Examples of the alkoxy group include those in which the alkyl moiety is the alkyl group.
Examples of the aryl group include a phenyl group, a 4-toluyl group, a 4-hydroxyphenyl group, a 1-naphthyl group, a 2-naphthyl group and the like.
Examples of the aryloxy group include those in which the aryl moiety is the aryl group.
Examples of the thioalkyl group include a methylthio group, an ethylthio group, a butylthio group and the like.
Examples of the arylthio group include a phenylthio group and the like.
Examples of the alkylamino group include a diethylamino group, a dimethylamino group, a hydroxyamino group and the like.
Examples of the arylamino group include a diphenylamino group and a phenylnaphthylamino group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and the like.
p is a natural number of 1 or more representing the number of repeating units, and a natural number of 1 to 3 is preferable.

The polythiophene derivative having the repeating unit represented by the general formula (1) must be a polythiophene derivative having the repeating unit represented by the following general formula (3) in terms of redox stability, solvent resistance, and capacity. Preferred from the point of view. Since the sulfur atom is an atom showing various oxidation numbers, its capacity can be increased.

However, in the general formula (3), R represents a substituted or unsubstituted alkylene group or a substituted or unsubstituted branched alkylene group. p represents a natural number of 1 or more. Ar represents an aromatic ring which may have a substituent or an aromatic heterocycle which may have a substituent. n represents a natural number of 2 or more, and m represents a natural number of 0 or 2 or more.

Specific examples of the polythiophene derivative having the repeating unit represented by the general formulas (1) to (3) are shown below, but the present invention is not limited thereto. However, in the following formula, n represents a natural number of 2 or more, and m represents 0 or a natural number of 2 or more.
When the polythiophene derivative having the repeating unit represented by the general formulas (1) to (3) is a copolymer (when m is a natural number of 2 or more), the polythiophene derivative is a random copolymer. It may be an alternating copolymer, a block copolymer, or a block copolymer.

Among the exemplified compounds of the polythiophene derivatives exemplified above, the exemplified compounds (2), (3), (4), (5), (8), (from the viewpoint of the size of the discharge capacity and the ease of synthesis. 10), (11), (16), (26), (32), (36), (44) and (62) are particularly preferable.

As the polythiophene derivative, a polymer having a repeating unit represented by the following general formula (61) is preferable. The polymer represented by the following general formula (61) can easily carry electrons and can increase the current flowing through the power storage element.
However, in the general formula (61), n1 and n2 each represent a natural number of 2 or more, and a natural number of 10 to 1000 is more preferable.

The conductive polymer is preferably a polymer having a structure represented by the following general formula (4) in the repeating unit. Since the redox state of the polymer having the following general formula (4) is stabilized by the aromatic ring or aromatic heterocycle constituting around the nitrogen atom, the performance of the power storage element should be maintained even if the redox reaction is repeated. Can be done.
However, in the general formula (4), Ar ₁ , Ar ₂ , and Ar ₃ represent an aromatic ring that may have a substituent or an aromatic heterocycle that may have a substituent, respectively.
Examples of the aromatic ring include benzene, biphenyl, naphthalene, anthracene, fluorene, pyrene, and derivatives thereof.
Examples of the aromatic heterocycle include pyridine, quinoline, thiophene, furan, oxazole, oxadiazole, carbazole, and derivatives thereof. Among these, thiophene and thiophene derivatives are preferable.
Examples of the substituent of the aromatic ring or the aromatic heterocycle include an alkyl group, an alkoxy group, a halogen atom and the like.
Examples of the alkyl group include a methyl group, an ethyl group, an isopropyl group, a butyl group and the like.
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group and the like.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like.

Examples of the conductive polymer having the structure represented by the general formula (4) in the repeating unit include, but are not limited to, the following exemplary compounds. However, in the following formula, n represents a natural number of 2 or more.

As the conductive polymer, a polymer having a repeating unit represented by the following general formula (5) is preferable.
However, in the general formula (5), R ₁ , R ₂ and R ₃ represent a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted branched alkyl group, respectively. Ar ₁ , Ar ₂ , and Ar ₃ represent an aromatic ring which may have a substituent or an aromatic heterocycle which may have a substituent. n represents a natural number of 2 or more.

Examples of the alkyl group in R ₁ , R ₂ and R ₃ include a methyl group, an ethyl group, a propyl group, a butyl group and the like.
Examples of the branched alkyl group in R ₁ , R ₂ and R ₃ include an isopropyl group, an isobutyl group, a sec-butyl group, a tert-butyl group and the like.
Examples of the aromatic ring in Ar ₁ , Ar ₂ , and Ar ₃ include benzene, biphenyl, naphthalene, anthracene, fluorene, pyrene, and derivatives thereof.
Examples of the aromatic heterocycle in Ar ₁ , Ar ₂ , and Ar ₃ include pyridine, quinoline, thiophene, furan, oxazole, oxadiazole, carbazole, and derivatives thereof. Among these, thiophene and thiophene derivatives are preferable.

Examples of the substituent of the alkyl group, the branched alkyl group, the aromatic ring or the aromatic heterocycle include an alkyl group, an alkoxy group, a halogen atom and the like.
Examples of the alkyl group include a methyl group, an ethyl group, an isopropyl group, a butyl group and the like.
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group and the like.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like.
For n, a natural number of 2 or more is preferable, and a natural number of 10 to 1000 is more preferable.

Examples of the conductive polymer represented by the general formula (5) include, but are not limited to, the following exemplary compounds. However, in the following formula, n represents a natural number of 2 or more.

As the conductive polymer, a polymer having a repeating unit represented by the following general formula (63) is preferable.
However, in the general formula (63), n is preferably a natural number of 2 or more, and more preferably 10 to 1000.

As the conductive polymer, a polymer having a repeating unit represented by the following general formula (64) is preferable.
However, in the general formula (64), n is preferably a natural number of 2 or more, and more preferably 10 to 1000.

The conductive polymer preferably has an oxidation potential of 3 V or more and 5 V or less based on the lithium metal electrode standard (vs. Li / Li ⁺ ), and more preferably has an oxidation potential of 3 V or more and 4.5 V or less.
Further, at a potential of 5 V or higher based on the lithium metal electrode (vs. Li / Li ⁺ ), the non-aqueous solvent used for the non-aqueous electrolytic solution is oxidatively decomposed, so that the oxidation potential of the conductive polymer (vs. Li / Li /). When Li ⁺ ) is 5 V or higher, the capacity at that potential cannot be utilized. Therefore, the oxidation potential of the conductive polymer based on the lithium metal electrode (vs. Li / Li ⁺ ) is preferably 3 V or more and 5 V or less. If the oxidation potential is less than 3 V, the voltage of the power storage element is lowered and the energy density is lowered, so that it cannot be effectively used. The oxidation potential can be measured, for example, by a cyclic voltammetry (CV) method.

<< Carbonaceous material >>
The carbonaceous material is not particularly limited and may be appropriately selected depending on the intended purpose. For example, acetylene black, ketjen black, graphite (artificial graphite, natural graphite), graphene, carbon nanofibers, carbon nanotubes, etc. Activated carbon, mesographite carbon and the like can be mentioned. At least a part of the surface of the carbonaceous material may be modified by surface treatment or the like. Modifications include, for example, modification with a functional group.
Even if these carbonaceous materials are polymers, they do not belong to the conductive polymer.

-Activated carbon-
The activated carbon is a charcoal that has strong adsorptivity and is mostly composed of carbonaceous material, and is made from raw materials such as phenolic resin, petroleum pitch, petroleum coke, coconut husk, or coal-based coke, and inert gas such as nitrogen gas and argon gas. A material obtained by calcining by firing in an atmosphere and activating the obtained material with steam or an alkali activator can be used. In addition, as a kind of activated carbon, mesoporous carbon obtained by molding a barbed material having a three-dimensional network structure and a starting material which is an organic substance as a carbon material forming source and calcining it by firing at 2,000 ° C. or higher. Can also be used. By dissolving mesoporous carbon with an acid or alkali, the traces of the dissolution of the mesoporous carbon become a plurality of mesopores that form a three-dimensional network structure, which can be intentionally formed, resulting in a large specific surface area. Can have.

The activated carbon is not particularly limited, and an appropriately produced activated carbon may be used, or a commercially available product may be used.

-Graphite-
Examples of the graphite include natural scaly graphite, natural earthy graphite, artificial graphite, pyrolyzed graphite and the like, but natural scaly graphite and artificial graphite are preferable.
Natural scaly graphite is a naturally occurring graphite that contains most of the plate-like, scaly, foliate, and needle-like appearances.
The artificial graphite is preferably one obtained by pulverizing a lump obtained by firing a carbon source such as a mixture of coke and pitch at a high temperature, or one having a high degree of crystallinity produced by vapor phase growth.
Pyrolysis graphite is obtained by calcining a carbon source such as coke at a high temperature of about 3000 ° C. to graphitize it.
Compared to natural earthy graphite, these natural scaly graphite, artificial graphite, and pyrolyzed graphite have less ash, impurities, and volatile components such as silicon dioxide and silicate compounds, and are excellent in heat resistance and lubricity.

The average particle size of the graphite is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the average particle size measured by a laser diffraction method may be 1 μm to 100 μm or 4 μm to 80 μm. It may be 5 μm to 60 μm.

The graphite is not particularly limited, and an appropriately produced graphite may be used, or a commercially available product may be used. Examples of commercially available products include CPB-3 (natural scaly graphite), CPB-30, CPB-3000 of Chuetsu Graphite Industry Co., Ltd., CP of Nippon Graphite Industry Co., Ltd., Toku CP, CPB, and Timcal's "Timelex KS". -44 "(artificial graphite) and the like.

-Carbon nanotubes-
The carbon nanotube has a nanoscale tubular structure in which a graphene sheet is wound, and is classified into a single layer and a multi-walled structure according to the number of laminated graphene sheets. By controlling the fiber diameter, length, crystallinity, and aggregated state of carbon nanotubes depending on the raw material and the synthesis method, it is possible to control various physical properties such as the specific surface area and conductivity of the material. In consideration of synthesis cost and handling, multi-walled carbon nanotubes may be preferable to single-walled carbon nanotubes.

The carbon nanotube is not particularly limited, and an appropriately manufactured carbon nanotube may be used, or a commercially available product may be used. Examples of commercially available carbon nanotubes include carbon nanotubes manufactured by Showa Denko Corporation such as VGCF, VGCF-H, and VGCF-X, and carbon nanotubes manufactured by Meijo Nanocarbon Co., Ltd.

The mass ratio (carbonaceous material / conductive polymer) of the carbonaceous material and the conductive polymer in the active material or the electrode is not particularly limited and may be appropriately selected depending on the intended purpose. It is preferably 80 or more and 95/5 or less, and more preferably 30/70 or more and 80/20 or less. By setting the mass ratio of the carbonaceous material and the conductive polymer within this range, both capacitance and output characteristics can be highly compatible.

<< Complex active material (mixture) >>
A composite active material can be obtained by combining the conductive polymer with the carbonaceous material. By using the composite active material, electrons are transferred more smoothly due to the redox of the conductive polymer, so that the capacity of many conductive polymers contained in the active material is expressed and the energy density is increased. In particular, activated carbon, Ketjen black, and mesoporous carbon are preferable as the carbonaceous material used for compositing because the carbonaceous material itself has an adsorption capacity and therefore the output characteristics can be increased.

The mass ratio (carbonaceous material / conductive polymer) when the carbonaceous material and the conductive polymer are composited is preferably 5/95 or more and 99/1 or less, and more preferably 20/80 or more and 95/5 or less. , 30/70 or more and 80/20 or less are particularly preferable. By setting the mass ratio of the carbonaceous material and the conductive polymer within this range, it is possible to achieve both capacitance and output characteristics at a high level.

<<< Manufacturing method of composite active material >>>
The composite active material can be produced, for example, by applying a shearing force to the carbonaceous material and the conductive polymer using a particle composite device under predetermined conditions.
Examples of the particle composite device include Nobilta (registered trademark) and Mechanofusion (registered trademark) manufactured by Hosokawa Micron Co., Ltd., a paint shaker device manufactured by Asada Iron Works Co., Ltd., and Miracle K.K. C. K (Kneading Disperser), Dry Star (registered trademark) manufactured by Ashizawa Finetech Co., Ltd., Sigma Dry (registered trademark), MIRALO (registered trademark) manufactured by Nara Kikai Seisakusho Co., Ltd. ), Nanomec Reactor (registered trademark) manufactured by Techno Eye Co., Ltd., etc.

The active material can be used as either a positive electrode active material or a negative electrode active material, but is preferably a positive electrode active material from the viewpoint of obtaining a power storage element having both high energy density and high output characteristics.

<Electrolytic solution>
The electrolytic solution contains an ionic liquid.
An example of the electrolytic solution is a non-aqueous electrolytic solution containing at least an electrolyte salt and an ionic liquid in a non-aqueous solvent.

<< Ionic liquid >>
Examples of the cation constituting the ionic liquid include an alkylammonium cation and an alkylsulfonium cation. Examples of the alkylammonium cation include a quaternary alkylammonium cation such as pyrrolidinium cation and piperidinium cation, and an aromatic alkylammonium cation such as pyridinium cation and imidazolium cation.
Examples of the cations constituting the ionic liquid include tetraethylammonium ion, triethylmethylammonium ion, N, N, N-trimethyl-N-propylammonium ion, N, N-diethyl-N-methyl-methoxyethylammonium ion, 1 -Methyl-1-propylpyrrolidinium ion, 1-butyl-1-methylpyrrolidinium ion, 1-butyl-3-methylimidazolium ion, 1-methyl-3-butylimidazolium ion, 1-ethyl-3-methyl Imidazolium ion, 1-hexyl-3-methylimidazolium ion, 1-methyl-3-hexylimidazolium ion, 1-octyl-3-methylimidazolium ion, 1-methyl-3-octylimidazolium ion, 1- Ethyl-2,3-dimethylimidazolium ion, 1-butyl-2,3-dimethylimidazolium ion, 1-hexyl-2,3-dimethylimidazolium ion, 1-methyl-1-propylpiperidium ion, 1- Butyl-1-methylpiperidium ion, 1-ethylpyridinium ion, 1-butylpyridinium ion, 1-hexylpyridinium ion, tributyl-n-octylphosphonium ion, tetraphenylphosphonium ion, tetraethylphosphonium ion, tetra-n-octylphosphonium Ion, methyltriphenylphosphonium ion, isopropyltriphenylphosphonium ion, methoxycarbonylphosphonium ion, (1-naphthylmethyl) triphenylphosphonium ion, trimethylsulfonium ion, (2-carboxyethyl) dimethylsulfonium ion, diphenylmethylsulfonium ion, tri Examples thereof include -n-butyl sulfonium ion, tri-p-tolyl sulfonium ion, triphenyl sulfonium ion, cyclopropyl diphenyl sulfonium ion and the like.
Among these, as the ionic liquid cation, an alkylammonium cation is preferable, a cation represented by the following general formula (A) is more preferable, and 1-butyl-1-methylpyrrolidinium ion or 1-methyl-1- Propylpyrrolidinium ions are particularly preferred.

However, in the general formula (A), m represents an integer of 1 to 4, and n represents an integer of 2 to 12.

Examples of the anion constituting the ionic liquid, for ^{_{example, PF 6 -, BF 4 -}} , N (SO 2 F) 2 -, N (SO 2 CF 3) 2 -, N (SO 2 C 2 F 5) 2 -, Examples include SO ₃ CF _3- ^{and the} like.
Among these, bisfluorosulfonylimide ion (N (SO ₂ F) ₂ ⁻ ) and tetrafluoroboroborate ion (BF ₄ ⁻ ) are particularly preferable.

The content of the ionic liquid in the electrolytic solution is more than 0.3% by mass and 50% by mass or less, preferably 0.5% by mass or more and 50% by mass or less, more preferably 3% by mass or more and 45% by mass or less, and 5% by mass. % To 30% by mass is particularly preferable.
When the content is 0.3% by mass or less, the electrode is deteriorated and the capacity retention rate of the power storage element is significantly lowered. When the content exceeds 50% by mass, the viscosity of the electrolytic solution becomes high. Further, when the content exceeds 50% by mass, a large amount of reaction products (SEI) with the active material is formed, the resistance of the electrode is increased, and the capacity retention rate of the power storage element is greatly reduced.
When the content is 5% by mass or more, the resistance of the electrode is lowered, so that the deterioration of the electrode is suppressed and the capacity retention rate of the power storage element becomes higher. When the content is 30% by mass or less, an increase in the viscosity of the electrolytic solution due to the addition of the ionic liquid can be suppressed. Further, when the content is 30% by mass or less, the production of the reaction product (SEI) with the active material is small, so that the resistance of the electrode is unlikely to increase, and the capacity retention rate of the power storage element is further increased. Can be done.

<< Non-aqueous solvent >>
As the non-aqueous solvent, an aprotic organic solvent is preferable.
Examples of the aprotic organic solvent include carbonate-based organic solvents, and low-viscosity solvents are preferable.
Examples of the carbonate-based organic solvent include chain carbonates and cyclic carbonates. These may be used alone or in combination of two or more.
Among these, chain carbonate is preferable because it has a high dissolving power of the electrolyte salt.
Examples of the chain carbonate include dimethyl carbonate (DMC), diethyl carbonate (DEC), and methyl ethyl carbonate (EMC). These may be used alone or in combination of two or more. Among these, dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC) are preferable.
When a mixed solvent in which dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC) are combined is used, the mixing ratio of dimethyl carbonate (DMC) and methyl ethyl carbonate (EMC) is not particularly limited and is appropriate depending on the purpose. You can choose.

Examples of the cyclic carbonate include propylene carbonate (PC), ethylene carbonate (EC), butylene carbonate (BC), vinylene carbonate (VC), fluoroethylene carbonate (FEC) and the like. These may be used alone or in combination of two or more. Among these, propylene carbonate (PC) and ethylene carbonate (EC) are preferable.
When a mixed solvent in which ethylene carbonate (EC) is used as the cyclic carbonate and dimethyl carbonate (DMC) is used as the chain carbonate, the mixing ratio of ethylene carbonate (EC) and dimethyl carbonate (DMC) is particularly limited. However, it can be appropriately selected according to the purpose.

Examples of the ester-based organic solvent include cyclic esters and chain esters.
Examples of the cyclic ester include γ-butyrolactone (γBL), 2-methyl-γ-butyrolactone, acetyl-γ-butyrolactone, γ-valerolactone and the like.
Examples of the chain ester include propionic acid alkyl ester, malonic acid dialkyl ester, acetic acid alkyl ester, formic acid alkyl ester and the like.
Examples of the acetic acid alkyl ester include methyl acetate (MA) and ethyl acetate.
Examples of the formic acid alkyl ester include methyl formate (MF) and ethyl formate.

Examples of the ether-based organic solvent include cyclic ethers and chain ethers.
Examples of the cyclic ether include tetrahydrofuran, alkyl tetrahydrofuran, alkoxy tetrahydrofuran, dialkoxytetrahydrofuran, 1,3-dioxolane, alkyl-1,3-dioxolane, 1,4-dioxolane and the like.
Examples of the chain ether include 1,2-dimethosicietan (DME), ethylene glycol dialkyl ether, diethylene glycol dialkyl ether, triethylene glycol dialkyl ether, and tetraethylene glycol dialkyl ether.

<< Electrolyte salt >>
As the electrolyte salt used in the non-aqueous electrolyte solution, a lithium salt is preferable.
The lithium salt is not particularly limited as long as it is soluble in a non-aqueous solvent and exhibits high ionic conductivity, and can be appropriately selected depending on the intended purpose. For example, lithium hexafluorophosphate (LiPF ₆ ). , Lithium perchlorate (LiClO ₄ ), lithium chloride (LiCl), lithium borofluoride (LiBF ₄ ), lithium hexafluorophosphate (LiAsF ₆ ), lithium trifluoromethsulfonate (LiCF ₃ SO ₃ ), lithium bistri Fluoromethanesulfonylimide (LiN (SO ₂ CF ₃ ) ₂ ), Lithium bisperfluoroethylsulfonylimide (LiN (SO ₂ C ₂ F ₅ ) ₂ ), Lithium bisfluorosulfonylimide (LiN (SO ₂ F) ₂ ), etc. Can be mentioned. These may be used alone or in combination of two or more. Among these, LiPF ₆ , LiBF ₄ , and LiN (SO ₂ F) ₂ are preferable from the viewpoint of the amount of anion occluded in the electrode.
The concentration of the electrolyte salt is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of achieving both discharge capacity and output, 1.0 mol / L or more and 6 mol / L or less in a non-aqueous solvent. Is preferable, and 1.5 mol / L or more and 4 mol / L or less are more preferable.

<Electrode>
An example of the electrode contains the active material and, if necessary, has other members.
The electrode may be either a positive electrode or a negative electrode, but a positive electrode is preferable because a power storage element having both high energy density and high output characteristics can be obtained.

<< Positive electrode >>
The positive electrode is, for example, a flat plate-shaped electrode portion including a positive electrode current collector and a positive electrode material.
The positive electrode material contains, for example, a positive electrode active material, a binder, a conductive auxiliary agent, a thickener, and a conductive auxiliary agent, and further contains other components as necessary.

-Positive electrode active material-
As the positive electrode active material, an anion can be inserted or released, and the active material is preferably used, but it may be used in combination with a positive electrode active material other than the active material. For example, lithium metal oxide may be used in combination. Examples of the lithium metal oxide include lithium cobalt oxide (LiCoO ₂ ), lithium nickel oxide (LiNiO ₂ ), lithium manganate (LiMn ₂ O ₄ ), olivine-type lithium iron phosphate (LiFePO ₄ ), and Li _p Ni. _x Co _y Mn _z O ₂ manganese can be represented by the composition formula - cobalt - nickel ternary oxide lithium _{(e.g., LiNi 1/3 Co 1/3 Mn 1/3 O} 2) , and the like.

-Binder and thickener-
The binder is a binder for binding the positive electrode active materials or the positive electrode active material and the positive electrode current collector to maintain the electrode structure.
As the binder material, for example, any one of a fluorine-based binder, an acrylate-based latex, and carboxymethyl cellulose (CMC) is preferably used.
Examples of the fluorine-based binder include polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE).
In addition to the above, the binder material includes, for example, ethylene-propylene-butadiene rubber (EPBR), styrene-butadiene rubber (SBR), isoprene rubber, acrylate-based latex, carboxymethyl cellulose (CMC), methyl cellulose, hydroxymethyl cellulose, and ethyl cellulose. , Polyacrylic acid, polyvinyl alcohol, alginic acid, oxidized starch, phosphate starch, casein and the like. These may be used alone or in combination of two or more.
The binder is not particularly limited as long as it is a solvent used in manufacturing the electrode, an electrolytic solution, and a material stable to the applied potential, and is appropriately selected depending on the intended purpose.

-Conductive aid-
In the present invention, the conductive auxiliary agent refers to a conductive material that is dispersed in the electrodes and is used to reduce the resistance of the electrodes, plays a role of assisting the conductivity between the electrode materials, and has a function of forming a conductive network. Has.
As the conductive auxiliary agent, it is preferable to use a metallic material or a carbonaceous material in accordance with the positive electrode active material. These may be used alone or in combination of two or more.
Examples of the metal material used for the conductive auxiliary agent include copper and aluminum.
Examples of the carbonaceous material used for the conductive auxiliary agent include acetylene black, ketjen black, artificial graphite, natural graphite, graphene, carbon nanofibers, and carbon nanotubes. Among these, acetylene black and ketjen black are preferable.
These conductive aids can also be used in combination with the active material. By doing so, the conductivity can be improved.

-Positive current collector-
The positive electrode current collector is not particularly limited as long as it can be used for the power storage element, and can be appropriately selected depending on the intended purpose.
The material of the positive electrode current collector is formed of a conductive material, and is not particularly limited as long as it is stable with respect to the applied potential, and can be appropriately selected depending on the intended purpose. For example, nickel, aluminum, titanium, tantalum and the like can be mentioned. Among these, stainless steel and aluminum are preferable.
The type (shape and presence / absence of processing) of the positive electrode current collector is not particularly limited as long as it can be used in the process of the positive electrode manufacturing method described later, and may be appropriately selected according to the purpose. It can be made, and examples thereof include plain foil, perforated foil, edged foil, penetrating foil, protruding foil, and expanded metal. Among these, plain foil, perforated foil, edged foil, penetrating foil, and protruding foil are preferable.
A coating foil in which a carbonaceous material used for the conductive auxiliary agent is previously applied onto the positive electrode current collector may be used as the positive electrode current collector. At this time, as the carbonaceous material used as the coating layer, the same carbonaceous material as the carbonaceous material used as the conductive auxiliary agent already described in the conductive auxiliary agent can be used. Among these, acetylene black, ketjen black, artificial graphite, and natural graphite are preferable.

<< Manufacturing method of positive electrode >>
As a method for producing a positive electrode, a positive electrode material made into a slurry by adding a binder, a thickener, a conductive auxiliary agent, and a solvent to the positive electrode active material, if necessary, is applied onto the positive electrode current collector and dried. The method etc. can be mentioned.
Examples of the solvent include water, an aqueous solvent such as alcohol, and an organic solvent such as N-methyl-2-pyrrolidone (NMP) and toluene.
The positive electrode active material may be roll-molded to form a sheet electrode, or may be compression-molded to form a pellet electrode.

<< Negative electrode >>
The negative electrode is, for example, a flat plate-shaped electrode portion including a negative electrode current collector and a negative electrode material.
The negative electrode material contains, for example, a negative electrode active material, a binder, a conductive auxiliary agent, a thickener, and a conductive auxiliary agent, and further contains other components as necessary.

-Negative electrode active material-
The active material can be used as the negative electrode active material, but when a negative electrode active material other than the active material is used, a carbonaceous material is preferable from the viewpoint of safety and cost.
Examples of the carbonaceous material include graphite, a pyrolyzed product of an organic substance under various pyrolysis conditions, activated carbon, a lithium metal oxide, and the like.
Examples of the graphite (graphite) include coke, artificial graphite, natural graphite, easily graphitizable carbon, and non-graphitizable carbon.
However, the negative electrode active material is not particularly limited as long as it can occlude and release cations in a non-aqueous solvent system, and can be appropriately selected depending on the intended purpose.
Materials used for the negative electrode active material include, for example, carbonaceous materials capable of storing and releasing lithium ions as cations, metal oxides, metals or metal alloys that can be alloyed with lithium, and metals that can be alloyed with lithium. Examples thereof include a composite alloy compound of an alloy containing lithium and lithium, and metallic lithium nitride.
Examples of the metal oxide include antimony tin oxide and silicon monoxide.
Examples of the metal or metal alloy that can be alloyed with lithium include lithium, aluminum, tin, silicon, zinc and the like.
Examples of the composite alloy compound of lithium and an alloy containing a metal that can be alloyed with lithium and lithium include lithium titanate.
Examples of the metallic lithium titer include lithium cobalt oxide and the like.
The materials used for these negative electrode active materials may be used alone or in combination of two or more. Among these, artificial graphite, natural graphite, and lithium titanate are preferable.
As the cation, lithium ion is widely used.

-Conductive aid-
As the conductive auxiliary agent used for the negative electrode, the same conductive auxiliary agent as the conductive auxiliary agent already described for the positive electrode can be used.

-Binder and thickener-
As the binder and thickener used for the negative electrode, the same binder and thickener as those already described for the positive electrode can be used.
As the binder and thickener, for example, a fluorine-based binder, styrene-butadiene rubber (SBR), and carboxymethyl cellulose (CMC) are preferable.

-Negative electrode current collector-
The negative electrode current collector is not particularly limited and may be appropriately selected depending on the intended purpose.
The material of the negative electrode current collector is formed of a conductive material, and is not particularly limited as long as it is stable with respect to the applied potential, and can be appropriately selected depending on the intended purpose. Examples include stainless steel, nickel, aluminum and copper. Of these, stainless steel, copper and aluminum are particularly preferred.
The shape of the negative electrode current collector may be appropriately selected depending on the purpose, in addition to the flat plate shape.
The size of the negative electrode current collector is not particularly limited as long as it can be used for the power storage element, and can be appropriately selected depending on the intended purpose.

<< Manufacturing method of negative electrode >>
As a method for manufacturing a negative electrode, for example, a negative electrode material formed into a slurry by adding a binder, a thickener, a conductive auxiliary agent, a solvent, etc. to the negative electrode active material as needed is applied onto the negative electrode current collector. A drying method is used.
A thin film of the negative electrode active material is formed on the negative electrode current collector by a method of rolling the slurry negative electrode material as it is into a sheet electrode, a method of forming a pellet electrode by compression molding, vapor deposition, sputtering, plating, etc. A method or the like may be used.
As the solvent used in the method for producing the negative electrode, the same solvent as in the method for producing the positive electrode can be used.

<Separator>
The separator is provided between the positive electrode and the negative electrode in order to prevent a short circuit between the positive electrode and the negative electrode.
The material, shape, size, and structure of the separator are not particularly limited and may be appropriately selected depending on the intended purpose.
Examples of the material of the separator include paper such as kraft paper, vinylon mixed paper, synthetic pulp mixed paper, polyolefin non-woven fabric such as cellophane, polyethylene graft film, polypropylene melt blown non-woven fabric, polyamide non-woven fabric, glass fiber non-woven fabric, and micropore film. Can be mentioned. Among these, those having a porosity of 50% or more are preferable from the viewpoint of retaining the electrolytic solution.
As the shape of the separator, a non-woven fabric having a high porosity is preferable to a thin film type having micropores.
The average thickness of the separator is preferably 20 μm or more from the viewpoint of preventing short circuits and retaining the electrolytic solution.
The size of the separator is not particularly limited as long as it can be used for a non-aqueous electrolyte storage element, and can be appropriately selected depending on the intended purpose.
The separator may have a single-layer structure or a laminated structure in which a plurality of separators are superposed.

<Manufacturing method of power storage element>
The method for manufacturing the power storage element is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a positive electrode, a negative electrode, a separator, and if necessary, other constituent members are assembled into an appropriate shape. Examples thereof include a method of storing in a container and filling with an electrolytic solution.

The shape of the power storage element of the present invention is not particularly limited, and in addition to the shape shown in FIG. 1, it can be appropriately selected from various generally adopted shapes according to its application. it can.
Examples of the shape include a cylinder type in which the sheet electrode and the separator are spirally formed, a cylinder type having an inside-out structure in which the pellet electrode and the separator are combined, and a coin type in which the pellet electrode and the separator are laminated.

As shown in FIG. 1, the power storage element of the present invention includes a positive electrode 1, a negative electrode 2 provided facing the positive electrode 1, a separator 3 arranged between the positive electrode 1 and the negative electrode 2, and non-aqueous electrolysis. Has a liquid.
The power storage element 10 includes a container 5 as an outer can that surrounds and holds a positive electrode 1, a negative electrode 2, a separator 3, and a non-aqueous electrolytic solution, and a positive electrode wire 6 that penetrates the container 5 and is connected to the positive electrode 1. And similarly, it has a negative electrode wire 7 that penetrates the container 5 and is connected to the negative electrode 2. The non-aqueous electrolytic solution is spread throughout the container 5. Although the case where the power storage element 10 is a secondary battery will be described with reference to FIG. 1, it may be, for example, a capacitor or the like.

<Use>
The power storage element of the present invention can be suitably used as, for example, a non-aqueous electrolyte secondary battery, a non-aqueous electrolyte capacitor, and the like.
The application of the power storage element is not particularly limited and can be used for various purposes, for example, a notebook computer, a pen input computer, a mobile computer, an electronic book player, a mobile phone, a mobile fax, a mobile copy, a mobile printer, and a headphone. Stereo, video movies, LCD TVs, handy cleaners, portable CDs, mini discs, transceivers, electronic notebooks, calculators, memory cards, portable tape recorders, radios, motors, lighting equipment, toys, game equipment, watches, strobes, cameras, etc. Examples include a power supply and a backup power supply.

Hereinafter, examples of the present invention will be described, but the present invention is not limited to the following examples.

(Example 1)
<Preparation of active material>
A compound (2) represented by the following formula, which is a polythiophene derivative, was prepared as a conductive polymer, and activated carbon A (Belfine AP, manufactured by AT Electrode Co., Ltd.) was prepared as a carbonaceous material.

However, n is a natural number of 2 or more.

Next, activated carbon A and compound (2) were mixed at a mass ratio of 30/70 and filled in a vial containing zirconia beads. This was set in a paint shaker (manufactured by Asada Iron Works Co., Ltd.) and shaken for 3 hours. After the treatment, the active material was recovered to obtain a particulate active material. The obtained particulate active material was designated as positive electrode active material A.

<Preparation of positive electrode>
-Preparation of positive electrode slurry-
Positive electrode active material A as positive electrode active material, acrylate-based latex as binder (TRD202A, manufactured by JSR Co., Ltd.), carboxymethyl cellulose (Dycel 2200, manufactured by Dycel Co., Ltd.) as thickener, and conductive auxiliary agent (Denka Black powder, electric (Manufactured by Chemical Industry Co., Ltd.) so that the mass ratio of solid content (positive electrode active material: binder: thickener: conductive auxiliary agent) is 100: 3: 5: 10 when the positive electrode active material A is 100. The mixture was mixed using a planetary mixer (Hibismix 3D-2 type, manufactured by Primix Co., Ltd.), and water was added to adjust the viscosity to an appropriate level to obtain a positive electrode material which is a positive electrode slurry.

-Preparation of positive electrode-
Next, the obtained positive electrode material was applied to one side of a plain aluminum foil having an average thickness of 20 μm as a positive electrode current collector using a doctor blade. The average basis weight (mass of the positive electrode active material A in the coated positive electrode) after drying was set to 3.0 mg / cm ² . This was punched to a diameter of 16 mm to obtain a positive electrode.

<Separator>
As the separator, two non-woven fabric separators (average thickness 40 μm) punched out to a diameter of 16 mm were prepared.

<Negative electrode>
As the negative electrode, a lithium metal foil (average thickness 100 μm) punched to a diameter of 16 mm was used.

<Non-aqueous electrolyte>
As the non-aqueous electrolyte solution, a mixed solution of ethylene carbonate (EC): dimethyl carbonate (DMC) = 1: 2 (mass ratio) containing 1.0 mol / L LiPF ₆ electrolyte (manufactured by Kishida Chemical Co., Ltd.) is used. There was.

<Ionic liquid>
As the ionic liquid, 1-butyl-1-methylpyrrolidinium tetrafluoroborate (BMPyr-BF4) was used.

<Non-aqueous electrolyte solution with ionic liquid added>
The ionic liquid was added to the non-aqueous electrolytic solution and mixed with a magnetic stirrer until uniform to obtain an ionic liquid-added non-aqueous electrolytic solution containing 10% by mass of the ionic liquid.

<Manufacturing of non-aqueous electrolyte power storage element>
After vacuum-drying the positive electrode, the negative electrode, and the separator at 150 ° C. for 4 hours, a 2032 type coin cell as a power storage element was assembled in a glove box in a dry argon atmosphere.
50 μL of the ionic liquid-added non-aqueous electrolytic solution was injected into the 2032 type coin cell. As described above, the non-aqueous electrolyte storage element of Example 1 was produced.

The obtained non-aqueous electrolyte storage device of Example 1 was subjected to a charge / discharge test as follows. The results are shown in Table 1.

<Charge / discharge test>
The obtained non-aqueous electrolyte storage element of Example 1 was held in a constant temperature bath at 25 ° C., and an automatic battery evaluation device (1024B-7V0.1A-4, manufactured by Electrofield Co., Ltd.) was used as follows. The charge / discharge test was carried out.
The first charge / discharge was an aging process, and first, at a current value converted to a charge / discharge rate of 0.2 C, a constant current charge was performed up to 4.4 V as the final charge voltage.
Then, after suspending charging for 24 hours, constant current discharge was performed up to 1.7 V as the discharge end voltage at a current value converted to a charge / discharge rate of 1C.
The 0.2C-equivalent current value is a current value at which a non-aqueous electrolyte storage element having a capacity of a nominal capacity value is discharged at a constant current and the discharge is completed in 5 hours. The 1C-equivalent current value is a current value at which a non-aqueous electrolyte storage element having a capacity of a nominal capacity value is discharged at a constant current and the discharge is completed in 1 hour. The 10C-equivalent current value is a current value at which a non-aqueous electrolyte storage element having a capacity of a nominal capacity value is discharged at a constant current and the discharge is completed in 0.1 hour.
After the aging treatment, charging and discharging shown in the following steps were performed.
[1]: Constant current charge up to 4.4 V at charge / discharge rate 0.2 C conversion [2]: Pause for 5 minutes [3]: Constant current up to 1.7 V at charge / discharge rate 0.2 C conversion current value Discharge [4]: Pause for 5 minutes [5]: Constant current charge up to 4.4V at charge / discharge rate 10C conversion current value [6]: Pause for 5 minutes [7]: Charge / discharge rate 10C conversion current value 1. Constant current discharge up to 7V [8]: Pause for 5 minutes During the above charge / discharge test, the discharge capacity at step [3] and the discharge capacity at step [7] were measured. The discharge capacity is a converted value (mAh / g) per 1 g of the positive electrode active material A.

Next, in order to evaluate the output characteristics, the capacity ratio of the discharge capacity at the time of 10C discharge to the discharge capacity at the time of 0.2C discharge was obtained by using the following formula 1. The fact that the capacitance ratio shows a value closer to 100% means that the output characteristics are high because it means that it has good electrical conductivity that can cope with a high C rate. To do.

<Formula 1>

Next, the high output performance was evaluated based on the evaluation criteria shown below. The results are shown in Table 1.

<High output>
[Evaluation criteria for high output]
⊚: The capacity ratio of the discharge capacity at 10C discharge to the discharge capacity at 0.2C discharge is 60% or more. ◯: The capacity ratio of the discharge capacity at 10C discharge to the discharge capacity at 0.2C discharge is 50% or more and 60%. Less than ×: The capacity ratio of the discharge capacity at 10C discharge to the discharge capacity at 0.2C discharge is less than 50%.

Next, the capacity retention rate was evaluated based on the evaluation criteria shown below. The results are shown in Table 1.

<Capacity maintenance rate>
[1]: Constant current charge up to 4.4 V at charge / discharge rate 10C conversion [2]: Pause for 5 minutes [3]: Constant current discharge up to 1.7 V at charge / discharge rate 10C conversion [4] : Repeat steps [1] to [3] 1000 times.
The capacity retention rate was obtained by dividing the 1000th discharge capacity by the 1st discharge capacity. The capacity retention rate was determined based on the criteria shown below.

[Criteria for capacity retention rate]
⊚: Capacity retention rate is 90% or more ○: Capacity retention rate is 85% or more and less than 90% ×: Capacity retention rate is less than 85%

(Example 2)
In the first embodiment, the non-aqueous electrolyte storage device of the second embodiment is the same as that of the first embodiment except that the compound (2) as the conductive polymer is changed to the compound (3) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 3)
In the first embodiment, the non-aqueous electrolyte storage device of the third embodiment is the same as that of the first embodiment except that the compound (2) as the conductive polymer is changed to the compound (4) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 4)
In the first embodiment, the non-aqueous electrolyte storage device of the fourth embodiment is the same as that of the first embodiment except that the compound (2) as the conductive polymer is changed to the compound (5) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 5)
In the first embodiment, the non-aqueous electrolyte storage device of the fifth embodiment is the same as that of the first embodiment except that the compound (2) as the conductive polymer is changed to the compound (8) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 6)
In the first embodiment, the non-aqueous electrolyte storage device of the sixth embodiment is the same as that of the first embodiment except that the compound (2) as the conductive polymer is changed to the compound (10) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 7)
In the first embodiment, the non-aqueous electrolyte storage device of the seventh embodiment is the same as that of the first embodiment except that the compound (2) as the conductive polymer is changed to the compound (11) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 8)
In Example 1, the non-aqueous electrolyte storage device of Example 8 is the same as in Example 1 except that the compound (2) as the conductive polymer is changed to the compound (16) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 9)
In Example 1, the non-aqueous electrolyte storage device of Example 9 is the same as in Example 1 except that the compound (2) as the conductive polymer is changed to the compound (26) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 10)
In Example 1, the non-aqueous electrolyte storage device of Example 10 is the same as in Example 1 except that the compound (2) as the conductive polymer is changed to the compound (32) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more, and m is a natural number of 0 or 2 or more.

(Example 11)
In the first embodiment, the non-aqueous electrolyte storage device of the eleventh embodiment is the same as that of the first embodiment except that the compound (2) as the conductive polymer is changed to the compound (36) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more, and m is a natural number of 0 or 2 or more.

(Example 12)
In Example 1, the non-aqueous electrolyte storage device of Example 12 is the same as in Example 1 except that the compound (2) as the conductive polymer is changed to the compound (44) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more, and m is a natural number of 0 or 2 or more.

(Example 13)
In Example 1, the non-aqueous electrolyte storage device of Example 13 is the same as in Example 1 except that the compound (2) as the conductive polymer is changed to the compound (46) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 14)
In Example 1, the non-aqueous electrolyte storage device of Example 14 is the same as in Example 1 except that the compound (2) as the conductive polymer is changed to the compound (47) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 15)
In Example 1, the non-aqueous electrolyte storage device of Example 15 is the same as in Example 1 except that the compound (2) as the conductive polymer is changed to the compound (48) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 16)
In Example 1, the non-aqueous electrolyte storage device of Example 16 is the same as in Example 1 except that the compound (2) as the conductive polymer is changed to the compound (49) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 17)
In Example 1, the non-aqueous electrolyte storage device of Example 17 is the same as in Example 1 except that the compound (2) as the conductive polymer is changed to the compound (50) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 18)
In Example 1, the non-aqueous electrolyte storage device of Example 18 is the same as in Example 1 except that the compound (2) as the conductive polymer is changed to the compound (51) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 19)
In Example 1, the non-aqueous electrolyte storage device of Example 19 is the same as in Example 1 except that the compound (2) as the conductive polymer is changed to the compound (52) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 20)
In Example 1, the non-aqueous electrolyte storage device of Example 20 is the same as in Example 1 except that the compound (2) as the conductive polymer is changed to the compound (53) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 21)
In Example 1, the non-aqueous electrolyte storage device of Example 21 is the same as in Example 1 except that the compound (2) as the conductive polymer is changed to the compound (54) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 22)
In the first embodiment, the non-aqueous electrolyte storage device of the 22nd embodiment is the same as in the first embodiment except that the compound (2) as the conductive polymer is changed to the compound (55) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 23)
In Example 1, the non-aqueous electrolyte storage device of Example 23 is the same as in Example 1 except that the compound (2) as the conductive polymer is changed to the compound (56) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 24)
In Example 1, the non-aqueous electrolyte storage device of Example 24 is the same as in Example 1 except that the compound (2) as the conductive polymer is changed to the compound (57) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 25)
In Example 1, the non-aqueous electrolyte storage device of Example 25 is the same as in Example 1 except that the compound (2) as the conductive polymer is changed to the compound (58) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 26)
In Example 1, the non-aqueous electrolyte storage device of Example 26 is the same as in Example 1 except that the compound (2) as the conductive polymer is changed to the compound (59) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 27)
In Example 1, the non-aqueous electrolyte storage device of Example 27 is the same as in Example 1 except that the compound (2) as the conductive polymer is changed to the compound (60) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 28)
In Example 1, the non-aqueous electrolyte storage device of Example 28 is the same as in Example 1 except that the compound (2) as the conductive polymer is changed to the compound (61) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n1 and n2 are natural numbers of 2 or more, respectively.

(Example 29)
In Example 1, the non-aqueous electrolyte storage device of Example 29 is the same as in Example 1 except that the compound (2) as the conductive polymer is changed to the compound (62) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 30)
In Example 1, the non-aqueous electrolyte storage device of Example 30 is the same as in Example 1 except that the compound (2) as the conductive polymer is changed to the compound (63) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 31)
In Example 1, the non-aqueous electrolyte storage device of Example 31 is the same as in Example 1 except that the compound (2) as the conductive polymer is changed to the compound (64) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Example 32)
In Example 1, the non-aqueous electrolyte storage device of Example 32 is the same as in Example 1 except that the compound (2) as the conductive polymer is changed to the compound (65) represented by the following formula. Was produced and evaluated in the same manner as in Example 1. The results are shown in Table 1.

However, n is a natural number of 2 or more.

(Examples 33 to 36)
-Change in mass ratio of carbon to conductive polymer 1-
In Example 1, the mass ratios (%) of the activated carbon A and the compound (2) which is the conductive polymer were changed as shown in Table 2, except that the mass ratios (%) were changed in the same manner as in Examples 1 to 33 to 36. The non-aqueous electrolyte storage element of No. 1 was manufactured and evaluated in the same manner as in Example 1. The results are shown in Table 2.

(Examples 37-40)
-Changing the mass ratio of carbon to conductive polymer 2-
In Example 31, the mass ratio (%) of the activated carbon A and the compound (64) which is a conductive polymer was changed as shown in Table 2, except that the mass ratios (%) were changed in the same manner as in Examples 31. The non-aqueous electrolyte power storage element of No. 31 was manufactured and evaluated in the same manner as in Example 31. The results are shown in Table 2.

(Examples 41 to 46)
− Carbon change 1-
In Example 1, as shown in Table 2, activated carbon A is represented by activated carbon B (YP-50, manufactured by Kuraray Co., Ltd.), activated carbon C (Knobel, manufactured by Toyo Carbon Co., Ltd.), and activated carbon D (carbon mesoporous, manufactured by Sigma Aldrich). ), Activated carbon E (EC600JD granular, manufactured by Lion Specialty Chemicals Co., Ltd.), Carbon A (graphite, special CP, manufactured by Nippon Graphite Industry Co., Ltd.), or Carbon B (carbon nanotube, VGCF-H, Showa Denko Co., Ltd.) The non-aqueous electrolyte storage elements of Examples 41 to 46 were manufactured in the same manner as in Example 1 except that they were changed to (manufactured by a company), and evaluated in the same manner as in Example 1. The results are shown in Table 2.

(Examples 47 to 52)
-Carbon change 2-
In Example 31, activated carbon A was changed to activated carbon B, activated carbon C, activated carbon D, activated carbon E, carbon A, or carbon B, respectively, as shown in Table 2, but the same procedure as in Example 31 was carried out. The non-aqueous electrolyte storage elements of Examples 47 to 52 were manufactured and evaluated in the same manner as in Example 31. The results are shown in Table 2.

(Examples 53 to 57)
-Change in the amount of ionic liquid added 1-
The non-aqueous electrolyte storage elements of Examples 53 to 57 were manufactured in the same manner as in Example 1 except that the amount of the ionic liquid added was changed to the amounts shown in Table 2 in Example 1, and Example 1 Evaluated in the same way. The results are shown in Table 2.

(Examples 58 to 62)
-Change in the amount of ionic liquid added 2-
The non-aqueous electrolyte power storage elements of Examples 58 to 62 were manufactured in the same manner as in Example 31 except that the amount of the ionic liquid added was changed to the amount shown in Table 2 in Example 31. Evaluated in the same way. The results are shown in Table 2.

(Example 63)
-Change of mass ratio of carbon and conductive polymer 3-
In Example 1, the non-water of Example 63 is the same as in Example 1 except that the mass ratio (%) of the activated carbon A and the compound (2) which is a conductive polymer is changed as shown in Table 2. An electrolytic solution power storage element was manufactured and evaluated in the same manner as in Example 1. The results are shown in Table 2.

(Examples 64 to 67)
− Change of ionic liquid species 1-
In Example 1, the non-aqueous electrolyte storage elements of Examples 64 to 67 were manufactured in the same manner as in Example 1 except that the BMPyr-BF4 used as the ionic liquid was changed as shown in Table 2. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 2. BMPyr-PF6, BMPyr-FSI, MPPyr-BF4, and MPPyr-FSI are 1-butyl-1-methylpyrrolidinium hexafluorophosphate and 1-butyl-1-methylpyrrolidinium bisfluorosulfonylimide, respectively. Represents −methyl-1-propylpyrrolidinium tetrafluoroborobolate, 1-methyl-1-propylpyrrolidinium bisfluorosulfonylimide.

(Comparative Example 1)
A non-aqueous electrolyte storage device of Comparative Example 1 was manufactured in the same manner as in Example 1 except that an electrolytic solution to which no ionic liquid was added was used in Example 1, and evaluated in the same manner as in Example 1. The results are shown in Table 2.

(Comparative Example 2)
In Example 1, the non-aqueous electrolyte storage element of Comparative Example 2 was manufactured in the same manner as in Example 1 except that the content of the ionic liquid in the ionic liquid-added electrolytic solution was changed to 55% by mass. It was evaluated in the same manner as 1. The results are shown in Table 2.

(Comparative Example 3)
In Example 1, the non-aqueous electrolyte storage element of Comparative Example 2 was manufactured in the same manner as in Example 1 except that the content of the ionic liquid in the ionic liquid-added electrolytic solution was changed to 70% by mass. It was evaluated in the same manner as 1. The results are shown in Table 2.

(Comparative Example 4)
In Example 1, the non-aqueous electrolyte storage element of Comparative Example 2 was manufactured in the same manner as in Example 1 except that the content of the ionic liquid in the ionic liquid-added electrolytic solution was changed to 0.3% by mass. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 2.

(Comparative Example 5)
In Example 1, the non-aqueous electrolyte storage element of Comparative Example 2 was manufactured in the same manner as in Example 1 except that the content of the ionic liquid in the ionic liquid-added electrolytic solution was changed to 0.1% by mass. Evaluation was performed in the same manner as in Example 1. The results are shown in Table 2.

(Comparative Example 6)
In Example 31, the non-aqueous electrolytic solution power storage element of Comparative Example 6 was manufactured in the same manner as in Example 31 except that the electrolytic solution to which the ionic liquid was not added was used, and evaluated in the same manner as in Example 31. The results are shown in Table 2.

(Comparative Example 7)
In Example 31, the non-aqueous electrolyte storage element of Comparative Example 7 was manufactured in the same manner as in Example 31 except that the content of the ionic liquid in the ionic liquid-added electrolytic solution was changed to 55% by mass. It was evaluated in the same manner as 31. The results are shown in Table 2.

(Comparative Example 8)
In Example 31, the non-aqueous electrolytic solution power storage element of Comparative Example 9 was manufactured in the same manner as in Example 31 except that the content of the ionic liquid in the ionic liquid-added electrolytic solution was changed to 0.3% by mass. Evaluation was performed in the same manner as in Example 31. The results are shown in Table 2.

(Comparative Example 9)
In Example 1, the mass ratio (%) of the activated carbon A and the compound (2) which is a conductive polymer was changed as shown in Table 2, and the same as in Example 1 except that the conductive polymer was not used. Therefore, the non-aqueous electrolyte storage element of Comparative Example 9 was manufactured and evaluated in the same manner as in Example 1. The results are shown in Table 2.

(Comparative Example 10)
In Example 1, the mass ratio (%) of the activated carbon A and the compound (2) which is a conductive polymer was changed as shown in Table 2, and an electrolytic solution to which no ionic liquid was added was used. The non-aqueous electrolyte storage element of Comparative Example 10 was manufactured in the same manner as in Example 1 and evaluated in the same manner as in Example 1. The results are shown in Table 2.

In Tables 1 and 2, the abbreviations for ionic liquids represent the following, respectively.
-BMPyr-BF4: 1-butyl-1-methylpyrrolidinium tetrafluoroborolate-BMPyr-PF6: 1-butyl-1-methylpyrrolidinium hexafluorophosphate-BMPyr-FSI: 1-butyl-1-methylpyrroli Dinium bisfluorosulfonylimide ・ MPPyr-BF4: 1-methyl-1-propylpyrrolidinium tetrafluoroborolate ・ MPPyr-FSI: 1-methyl-1-propylpyrrolidinium bisfluorosulfonylimide

Comparing the results in Tables 1 and 2, the capacity retention rate can be improved while maintaining the capacity and output characteristics by adding the ionic liquid to the electrolytic solution. However, if too much ionic liquid is added, the output characteristics will deteriorate and the capacity retention rate will decrease. Further, even when the amount of the ionic liquid added is 0.3% by mass or less, the output characteristics and the capacity retention rate are lowered. It is presumed that this is because the following phenomenon is occurring.
When the amount of ionic liquid added is large, the viscosity of the electrolytic solution increases, which hinders ionic conduction and lowers the output characteristics. Further, the constituent substances of SEI formed at the initial stage of charging / discharging change with the increase of the ionic liquid, and the electrode protection function deteriorates. As a result, more reactions between the electrodes and the electrolytic solution occur, and as a result, deposits on the electrodes increase. When the amount of deposits increases, the resistance of the entire device increases, the load on the electrodes increases, and the deterioration of the electrodes progresses and the capacity retention rate decreases.
When no ionic liquid was added or the amount of ionic liquid added was small, the assist of ion movement could not be obtained, the cell resistance remained high, and the output characteristics were lower than those of the added system. In addition, the deterioration of the electrodes gradually progressed, and the capacity retention rate also decreased.
When the conductive polymer is not used, the capacity becomes extremely low, and the problem of the present invention cannot be solved.

From the above results, according to the present invention, it is possible to provide a power storage element having a large capacity and output characteristics and an excellent capacity retention rate.

Aspects of the present invention are, for example, as follows.
<1> It has an electrode containing a conductive polymer and an electrolytic solution containing an ionic liquid.
The power storage element is characterized in that the content of the ionic liquid in the electrolytic solution is more than 0.3% by mass and 50% by mass or less.
<2> The power storage element according to <1>, wherein the conductive polymer is a polythiophene derivative having a repeating unit represented by the following general formula (1).
However, in the general formula (1), Z represents a group of atoms forming a 5- to 9-membered heterocycle containing an S element, an O element, or a Se element as a ring member. Ar represents an aromatic ring which may have a substituent or an aromatic heterocycle which may have a substituent. n represents a natural number of 2 or more, and m represents a natural number of 0 or 2 or more.
<3> The power storage element according to <1>, wherein the conductive polymer has a repeating unit represented by the following general formula (63).
However, in the general formula (63), n represents a natural number of 2 or more.
<4> The power storage element according to <1>, wherein the conductive polymer has a repeating unit represented by the following general formula (64).
However, in the general formula (64), n represents a natural number of 2 or more.
<5> The power storage element according to <1>, wherein the conductive polymer has a structure represented by the following general formula (4) in a repeating unit.
However, in the general formula (4), Ar ₁ , Ar ₂ , and Ar ₃ represent an aromatic ring that may have a substituent or an aromatic heterocycle that may have a substituent, respectively.
<6> The electrode contains a carbonaceous material and contains
The power storage device according to any one of <1> to <5>, wherein the conductive polymer is composited with the carbonaceous material.
<7> The power storage device according to <6>, wherein the mass ratio (carbonaceous material / conductive polymer) of the carbonaceous material to the conductive polymer in the composite is 20/80 or more and 95/5 or less. Is.
<8> The power storage element according to any one of <1> to <7>, wherein the content of the ionic liquid in the electrolytic solution is 5% by mass or more and 30% by mass or less.
<9> The power storage element according to any one of <1> to <8>, wherein the electrode is a positive electrode.

The power storage element according to any one of <1> to <9> can solve the conventional problems and achieve the object of the present invention.

1 Positive electrode 2 Negative electrode 3 Separator 5 Container 6 Positive electrode wire 7 Negative electrode wire 10 Power storage element

Japanese Patent No. 5228531

Claims (9)

It has an electrode containing a conductive polymer and an electrolytic solution containing an ionic liquid.
A power storage element characterized in that the content of the ionic liquid in the electrolytic solution is more than 0.3% by mass and 50% by mass or less. The power storage element according to claim 1, wherein the conductive polymer is a polythiophene derivative having a repeating unit represented by the following general formula (1).
However, in the general formula (1), Z represents a group of atoms forming a 5- to 9-membered heterocycle containing an S element, an O element, or a Se element as a ring member. Ar represents an aromatic ring which may have a substituent or an aromatic heterocycle which may have a substituent. n represents a natural number of 2 or more, and m represents a natural number of 0 or 2 or more. The power storage element according to claim 1, wherein the conductive polymer has a repeating unit represented by the following general formula (63).
However, in the general formula (63), n represents a natural number of 2 or more. The power storage element according to claim 1, wherein the conductive polymer has a repeating unit represented by the following general formula (64).
However, in the general formula (64), n represents a natural number of 2 or more. The power storage element according to claim 1, wherein the conductive polymer has a structure represented by the following general formula (4) in a repeating unit.
However, in the general formula (4), Ar ₁ , Ar ₂ , and Ar ₃ represent an aromatic ring that may have a substituent or an aromatic heterocycle that may have a substituent, respectively. The electrode contains a carbonaceous material and contains
The power storage device according to any one of claims 1 to 5, wherein the conductive polymer is composited with the carbonaceous material. The power storage device according to claim 6, wherein the mass ratio (carbonaceous material / conductive polymer) of the carbonaceous material to the conductive polymer in the composite is 20/80 or more and 95/5 or less. The power storage element according to any one of claims 1 to 7, wherein the content of the ionic liquid in the electrolytic solution is 5% by mass or more and 30% by mass or less. The power storage element according to any one of claims 1 to 8, wherein the electrode is a positive electrode.