JP2008159275A - Electrode active material and power storage device using the same - Google Patents

Abstract

（式（１）中、Ｒ₁〜Ｒ₄は、それぞれ独立して、水素原子、フッ素原子、アルキル基、不飽和脂肪族基または飽和脂肪族基であり、前記アルキル基、前記不飽和脂肪族基および前記飽和脂肪族基は、ハロゲン原子、チッソ原子、酸素原子、イオウ原子またはシリコン原子を含んでいてもよく、前記不飽和脂肪族基および前記飽和脂肪族基は、直鎖状でもよく、環状でもよい。また、ｎは１以上の整数である。）で表される構造を有する化合物を含む。
【選択図】なしA power storage device having high output, high capacity, and excellent repetitive characteristics using a novel electrode active material is provided.
An electrode active material for an electricity storage device includes at least a general formula (1):
[Chemical 1]

(In Formula (1), R < ₁ > -R < ₄ > is respectively independently a hydrogen atom, a fluorine atom, an alkyl group, an unsaturated aliphatic group, or a saturated aliphatic group, The said alkyl group, the said unsaturated aliphatic group Group and the saturated aliphatic group may contain a halogen atom, a nitrogen atom, an oxygen atom, a sulfur atom or a silicon atom, and the unsaturated aliphatic group and the saturated aliphatic group may be linear, The compound may be cyclic, and n is an integer of 1 or more.
[Selection figure] None

Description

  The present invention relates to an electricity storage device having high output, high capacity, and excellent repeatability.

  In recent years, with the spread of hybrid vehicles that can be driven by both gasoline and electric energy, and electronic devices such as uninterruptible power supplies, mobile communication devices, and portable devices, the performance of power storage devices used as power sources has been improved. The demand is very high. Specifically, a high-performance battery having high output, high capacity, and excellent repetitive characteristics is required.

Various efforts are being made to improve the performance of such batteries. Since increasing the energy density of electrode materials, particularly positive electrode materials and negative electrode materials, directly leads to increasing the energy density of the battery itself, positive electrode materials and negative electrode materials are being actively studied.
For example, Patent Documents 1 and 2 propose secondary batteries using an organic compound having a disulfide bond as an electrode material. This compound is bonded to each other through an SS bond by an electrochemical oxidation reaction,
M ⁺ − ⁻ S−R−S−S−R−S−S−R−S ⁻ −M ⁺
(R is an aliphatic or aromatic organic group, S is sulfur, and M ⁺ is a proton or metal cation). The polymer thus produced returns to the original monomer by an electrochemical reduction reaction. Secondary batteries using this reaction for charge / discharge reactions have been proposed.

In Patent Document 3, it is proposed to use simple sulfur as an electrode material.
Further, Patent Documents 4 and 5 propose an electricity storage device using an organic compound having a π-electron conjugated cloud as a new electrode active material that is expected to be charged and discharged at a high rate.
This organic compound can reversibly cause an electrochemical reaction at a high rate. For example, tetrathiafulvalene (hereinafter referred to as TTF) can provide a high energy density of 260 (mAh / g).
US Patent No. 5,833,048 U.S. Pat.No. 2,715,778 US Patent No. 5,523,179 JP 2004-111374 A JP 2004-342605 A

  In the disulfide materials described in Patent Documents 1 and 2, a high capacity can be obtained, but on the other hand, the cycle characteristics are deteriorated. This is because the oxidation-reduction reaction occurs due to the dissociation / recombination of disulfide bonds and the frequency of recombination is low once dissociated. As described above, the disulfide-based material has a problem that even if it has a theoretically high energy density, all the reaction sites do not contribute to the reaction efficiently, and in fact, a high energy density cannot be obtained. .

The organic compound having a π-electron conjugated cloud described in Patent Documents 4 and 5 may be dissolved in an electrolyte. For this purpose, for example, the formation and derivatization of TTF has been studied. However, since the introduction of a site that does not participate in the redox reaction is indispensable for derivatization and polymerization of TTF, the energy density becomes 260 (mAh / g) or less as a result, and it is difficult to increase the energy density. Become.
Accordingly, an object of the present invention is to provide an electricity storage device having a high output, a high capacity, and excellent repetitive characteristics using a novel electrode active material in order to solve the above-described conventional problems.

  The electrode active material for an electricity storage device of the present invention has at least the general formula (1):

(In Formula (1), R < ₁ > -R < ₄ > is respectively independently a hydrogen atom, a fluorine atom, an alkyl group, an unsaturated aliphatic group, or a saturated aliphatic group, The said alkyl group, the said unsaturated aliphatic group Group and the saturated aliphatic group may contain a halogen atom, a nitrogen atom, an oxygen atom, a sulfur atom or a silicon atom, and the unsaturated aliphatic group and the saturated aliphatic group may be linear or cyclic. In addition, n is an integer of 1 or more), and includes a compound having a structure represented by:

  Further, the present invention is an electricity storage device including a positive electrode including a positive electrode active material, a negative electrode including a negative electrode active material, and an electrolyte, wherein at least one of the positive electrode active material and the negative electrode active material is represented by the general formula (1) ):

(In Formula (1), R < ₁ > -R < ₄ > is respectively independently a hydrogen atom, a fluorine atom, an alkyl group, an unsaturated aliphatic group, or a saturated aliphatic group, The said alkyl group, the said unsaturated aliphatic group Group and the saturated aliphatic group may contain a halogen atom, a nitrogen atom, an oxygen atom, a sulfur atom or a silicon atom, and the unsaturated aliphatic group and the saturated aliphatic group may be linear or cyclic. In addition, the present invention relates to an electricity storage device including a compound having a structure represented by: n is an integer of 1 or more.

In the general formula (1), R _{1 to} R ₄ are hydrogen atoms, and n = 1 is preferable.
In the general formula (1), R _{1 to} R ₄ are hydrogen atoms, and n = 2 is preferable.
The compound preferably has a plurality of structures represented by the general formula (1).
The electrolyte comprises a non-aqueous solvent and a salt composed of an anion and a cation dissolved in the non-aqueous solvent. The non-aqueous solvent has a relative dielectric constant of 10 or less and a relative dielectric constant of 30 or more. It is preferable to use a mixture with a solvent, wherein the mixture has a relative dielectric constant of 10 or more and 30 or less.
The solvent having a relative dielectric constant of 10 or less is at least one selected from the group consisting of a chain carbonate ester, a chain ester, and a chain ether, and the solvent having a relative dielectric constant of 30 or more is a cyclic carbonate ester. And at least one selected from the group consisting of cyclic ethers.

  According to the present invention, by using a novel electrode active material, an electricity storage device having high output, high capacity, and excellent repetitive characteristics can be obtained.

The present inventors examined the electrode active material for an electricity storage device as follows.
The condition of the compound used as the electrode active material for the electricity storage device is “a redox reaction is possible”. That is, the valence of the organic compound changes with the oxidation-reduction reaction to form an oxidant or a reductant, and both the oxidant and the reductant exist stably without performing a reaction such as decomposition. For example, (a) a redox reaction using a dissociation / recombination reaction (disulfide reaction), (b) an oxidation-reduction reaction in which the oxidant and the reductant take a neutral state / radical state, (c) the oxidant and It is considered that at least one of the reductants is a compound having a structure that satisfies the Hückel rule.

However, in the disulfide-based reaction (i) above, the repetitive characteristics are lowered. In the above (b), the compound needs to form a radical stably. In general, radicals are unstable, but examples of compounds that form stable radicals include compounds represented by 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl. In this compound, a stable radical can be obtained by arranging four sterically large methyl groups on both sides of the NO position where the radical is generated. However, the presence of methyl groups that do not participate in the reaction and radical compounds that are difficult to form a large number of radical sites in the molecule are very disadvantageous from the viewpoint of energy density, and it is difficult to increase the energy density.
Therefore, the present inventors have selected a material that satisfies the above condition (c).

Next, physical properties of organic compounds required for an electrode active material for an electricity storage device excellent in high capacity, high output, and repetitive characteristics were considered. These are described in (A) to (C) below.
(A) A condition for realizing a high capacity is that the number of reaction electrons per unit molecule is large.
The energy density of the active material for an electricity storage device is defined by the following (Formula 1).
Energy density [mAh / g] = [(number of reaction electrons × 96500) / (molecular weight)] × (1000/3600) (Formula 1)
From the above, it is essential that the number of reaction electrons is large and the molecular weight is small.

Examples of the organic compound that satisfies the condition (c) include conductive polymers typified by polyaniline and polypyrrole. In these molecules, since the π-electron conjugated cloud spreads widely in the molecule, the number of reaction electrons per unit unit (per pyrrole ring or aniline ring) is 0.5 electron reaction or less. Therefore, it can be said that the structure in which the π-electron conjugated clouds spread uniformly is not suitable for increasing the energy density.
(B) As a condition for realizing high output, the reaction rate of oxidation-reduction is high.
One that inhibits the rate of the oxidation-reduction reaction is a large structural change during the reaction. Therefore, for high output, it is required that the structure does not change greatly during the oxidation-reduction reaction.
(C) As a condition for realizing excellent repetitive characteristics, it is not a bond formation / separation reaction such as a coordination reaction on a molecule.

As a result of intensive studies in consideration of the above points, when a compound represented by the following general formula (1) is used as an electrode active material for an electricity storage device, excellent high capacity, high output, and repeatability are obtained. It has been found that an electricity storage device having the following can be obtained.
General formula (1):

In formula (1), R _{1 to} R ₄ are each independently a hydrogen atom, a fluorine atom, an alkyl group, an unsaturated aliphatic group or a saturated aliphatic group, and the alkyl group and the unsaturated aliphatic group. And the saturated aliphatic group may contain a halogen atom, a nitrogen atom, an oxygen atom, a sulfur atom or a silicon atom, and the unsaturated aliphatic group and the saturated aliphatic group may be linear or cyclic. . N is an integer of 1 or more.

  The structure of the compound having the structure represented by the general formula (1) does not change during the redox reaction. This compound has structural symmetry and planar structure. In addition, its molecular structure has a double structure as a carbon-carbon bond at the center and a cyclic structure containing a heteroelement having an isoelectronic lone pair such as sulfur and oxygen. A π-electron conjugate is formed. Electrons can be transferred into the π-electron conjugated electron cloud spreading on the molecule. This electron transfer proceeds by oxidation / reduction reactions to this substance. For example, during the reduction reaction (discharge reaction), the compound having the structure represented by the general formula (1) in the molecule is reduced, and the anion species in the electrolyte are coordinated. The subsequent oxidation reaction (charging reaction) is a reaction in which the anion species coordinated on the compound having the structure represented by the general formula (1) in the molecule is eliminated. This reaction can be used as a battery reaction. A compound that is an active material in this series of oxidation-reduction reactions does not cause a large structural change such as disengagement / recombination of bonds. This reaction satisfies the above conditions (A) and (B), and an electrode active material for an electricity storage device having high capacity, high output, and excellent repetitive characteristics can be obtained.

Moreover, as what has the same reaction principle, the TTF type compound of the said patent documents 4 and 5 is mentioned. These compounds have high capacity, high output, and excellent repetitive properties, but when they are polymerized to suppress dissolution in the electrolyte, substituents such as ethylenedithio groups are added to both ends of the TTF skeleton. It is necessary to introduce. By introducing these substituents, the physical properties change greatly, but since the introduced groups do not contribute to the reaction, it is difficult to increase the energy density.
On the other hand, the compound having the structure represented by the general formula (1) of the present invention, unlike the TTF compound, has a structure expanded only by a five-membered ring containing two sulfur elements as redox sites. Have. In this case, since it is possible to construct a multimeric molecule without introducing a portion that does not contribute to the reaction, a high energy density can be realized.

Examples of the compound having the structure represented by the general formula (1) used for the electrode active material include compounds having the structures represented by the following chemical formulas (2) and (3).
Chemical formula (2):

Chemical formula (3):

Moreover, as an electrode active material, the high molecular compound containing two or more structures represented by the said General formula (1) is mentioned. Examples of these compounds include compounds having structures represented by chemical formulas (4) to (6) shown below. For example, n is 1 to 6 and m is an integer of 1 or more.
Chemical formula (4):

Chemical formula (5):

Chemical formula (6):

Further, as the electrode active material, two or more kinds of the compounds mentioned above may be used in combination.
As in the chemical formulas (4) to (6), a high molecular compound having a structure represented by the general formula (1) and formed by combining a plurality of molecules having a large molecular weight is lower than a low molecular compound. Since this compound is difficult to dissolve in an electrolyte, when this compound is used as an electrode material, elution into the electrolyte can be suppressed, and excellent storage characteristics and repetitive characteristics can be obtained. The high molecular compound generally has a molecular weight of 10,000 or more.
In the electricity storage device of the present invention, at least one of the positive electrode and the negative electrode uses a compound having a structure represented by the general formula (1) in the molecule. For example, a compound having a structure represented by the general formula (1) in the molecule is used for one of the positive electrode and the negative electrode, and the active electrode generally used in a secondary battery is used for the other electrode. Substance materials can be used. More specifically, when a compound having a structure represented by the general formula (1) in the molecule is used as the positive electrode active material, the negative electrode active material includes, for example, an amorphous carbon material such as graphite and activated carbon, Lithium metal, lithium-containing composite nitrides, lithium-containing titanium oxides, tin (Sn) and composites with carbon or other metals can be used.

Further, the anode active material, when using the formula (1) compounds having the structure represented in the molecule, in the positive electrode active material, for example, LiCoO _2, LiNiO _2, metal oxides such as LiMn ₂ O ₄ Etc. can be used.
The electrode (positive electrode or negative electrode) includes, for example, an electrode current collector and an electrode mixture applied on the electrode current collector. The electrode mixture includes, for example, an active material, an electron conduction aid, an ion conduction aid for reducing electrode resistance, and a binder for improving the binding properties of the active material and the conduction aid.

As the electron conduction auxiliary agent, for example, carbon materials such as carbon black, graphite, and acetylene black, and conductive polymers such as polyaniline, polypyrrole, and polythiophene are used. As the ion conduction aid, for example, a solid electrolyte such as polyethylene oxide, or a gel electrolyte such as polymethyl methacrylate or polymethyl methacrylate is used.
As the binder, polyfucavinylidene, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, polytetrafluoroethylene, styrene-butadiene copolymer rubber, polypropylene, polyethylene, polyimide, etc. Can be used.

As the electrode current collector, for example, a metal foil such as nickel, aluminum, gold, silver, copper, stainless steel, aluminum alloy, or a mesh shape is used. Alternatively, carbon or the like may be applied to the current collector to reduce resistance or to be a catalyst, and the active material and the current collector may be chemically or physically bonded.
In the present invention, an electrolyte is contained in a separator disposed between a positive electrode and a negative electrode.
The electrolyte includes a non-aqueous solvent and a supporting salt that dissolves in the non-aqueous solvent.
As the supporting salt, a fluorine-containing compound typified by a halogen salt of an alkali metal such as lithium, sodium or potassium or an alkaline earth metal such as magnesium, perchlorate, or trifluoromethanesulfonate is used. Specifically, for example, lithium fluoride, lithium chloride, lithium perchlorate, lithium trifluoromethanesulfonate, lithium tetraborofluoride, lithium bistrifluoromethylsulfonylimide, lithium thiocyanate, magnesium perchlorate, trifluoromethane Examples thereof include magnesium sulfonate and sodium tetraborofluoride.

In order to cause an electrochemical reaction in the electricity storage device, for example, the supporting salt needs to be dissolved and dissociated in a non-aqueous solvent. For this reason, it is requested | required that the dielectric constant of a nonaqueous solvent is high. Depending on the type of organic compound, the electrode active material may be easily dissolved in a non-aqueous solvent having a high relative dielectric constant. Therefore, in the electricity storage device of the present invention, it is necessary to use a non-aqueous solvent having an appropriate relative dielectric constant for the electrolyte. As a method for controlling the relative dielectric constant of the non-aqueous solvent, a plurality of types of solvents having different relative dielectric constants may be mixed.
From the above viewpoint, the nonaqueous solvent is preferably a mixture of a solvent having a relative dielectric constant of 10 or less and a solvent having a relative dielectric constant of 30 or more, and the relative dielectric constant of the mixture is preferably from 10 to 30. Examples of the solvent having a relative dielectric constant of 10 or less include a chain carbonate ester, a chain ester, and a chain ether. Examples of the solvent having a relative dielectric constant of 30 or more include cyclic carbonates and cyclic ethers.

Examples of the chain carbonate include dimethyl carbonate, diethyl carbonate, di-n-propyl carbonate, dibutyl carbonate, diisopropyl carbonate, and methyl ethyl carbonate.
Examples of the chain ester include methyl formate, ethyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, methyl butyrate, and methyl valerate.
Examples of chain ethers include cyclic ethers such as 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, 2-methyltetrahydrofuran, 3-methyl-1,3-dioxolane, 2-methyl-1,3-dioxolane, and the like. 1,2-dimethoxyethane, 1,2-diethoxyethane, diethyl ether, dimethyl ether, methyl ethyl ether, dipropyl ether.
Examples of the cyclic carbonate include propylene carbonate and ethylene carbonate. Examples of the cyclic ether include tetrahydrofuran.

Further, as the electrolyte, a solid electrolyte or a gel polymer electrolyte may be used.
As the solid electrolyte, Li ₂ S—SiS _{(2 + a)} (a is at least one selected from the group consisting of Li ₃ PO ₄ , LiI, Li ₄ SiO ₄ ), Li ₂ SP ₂ O ₅ , Li ₂ SB ₂ S ₅ , Li ₂ SP ₂ S ₅ -GeS ₂ , sodium / alumina (Al ₂ O ₃ ), amorphous, low phase transition temperature (Tg) polyether, amorphous vinylidene fluoride Examples thereof include copolymers, blends of different polymers, and polyethylene oxide.
As the gel polymer electrolyte, a polyacrylonitrile, a copolymer of ethylene and acrylonitrile, or a crosslinked polymer to which a low molecular weight nonaqueous solvent such as ethylene carbonate or propylene carbonate is added and a supporting salt is added thereto is used.
In addition, as an electrical storage device of this invention, a primary battery, a secondary battery, an electrochemical capacitor etc. are mentioned, for example.

Examples of the present invention will be described in detail below, but the present invention is not limited to these examples.
Example 1
The coin type battery shown in FIG. 1 was produced as an electricity storage device of the present invention by the following procedure. FIG. 1 is a longitudinal sectional view of a coin-type battery.

(1) Production of positive electrode As an electrode active material for an electricity storage device, a structure represented by the above chemical formula (3), in which R _{1 to} R ₄ are hydrogen atoms and n = 2 in general formula (1) The case where the compound which has is used is shown. The organic compound having the structure represented by the chemical formula (3) is prepared based on the method described in non-patent literature Yohji Misaki et al., Cryst. Liq. Cryst., 1996, 284, P.337-344. did.

  In a dry box equipped with a gas purifier and in an argon gas atmosphere, uniformly 30 mg of the compound having the structure represented by the above chemical formula (3) as an active material and 30 mg of acetylene black as a conductive auxiliary agent. After mixing, 1 mL of N-methylpyrrolidone as a solvent was added to this mixture. Furthermore, for the purpose of binding the active material and the conductive agent, 5 mg of polyvinylidene fluoride was added as a binder and mixed uniformly to obtain a slurry-like positive electrode mixture. This was applied onto a positive electrode current collector 12 made of an aluminum foil, and then vacuum-dried at room temperature for 1 hour to form a positive electrode mixture layer 13 on the positive electrode current collector 12. After drying, this was punched out on a disk having a diameter of 13.5 mm to obtain a positive electrode. The thickness of the positive electrode after drying was about 60 μm.

(2) Assembly of coin-type battery Using the positive electrode obtained above and a negative electrode (thickness 300 μm) made of disc-shaped lithium metal, a coin-type battery was assembled as follows. The negative electrode is composed of the negative electrode current collector 17 and the negative electrode mixture layer 16 formed on the negative electrode current collector 17 and containing the negative electrode active material. In this example, the above-described lithium metal plate was disposed on this portion. .
First, a positive electrode was disposed on the inner surface of the case 11, and a separator 14 made of a porous polyethylene sheet was disposed on the positive electrode. Next, the electrolyte was injected into the positive electrode case 11. The electrolyte used was a solution of lithium hexafluorophosphate (LiPF ₆ ) at a concentration of 1 mol / L in a mixed solvent of ethylene carbonate and propylene carbonate (weight ratio 1: 1).
Moreover, the sealing board 15 which the negative electrode was crimped | bonded to the inner surface and the sealing ring 18 was mounted | worn to the peripheral part was prepared. A sealing plate 15 was disposed in the opening of the case 11 so that the negative electrode and the positive electrode face each other. Then, the opening end of the case 11 was caulked to the peripheral edge of the sealing plate 15 via a resin sealing ring 18 with a press machine, and the case 11 was sealed with the sealing plate 15. Thus, a coin-type battery for evaluation was obtained.

(3) Battery Evaluation The coin battery prepared above is charged and discharged at a current of 0.133 mA and a voltage range of 3.0 to 4.0 (V), and the discharge capacities at the first, fifth and tenth cycles are obtained. It was.
Moreover, charge / discharge test evaluation was performed on the coin-type battery. The charge / discharge curve obtained as a result of the charge / discharge test is shown in FIG.
As shown in FIG. 2, in the battery of Example 1, it was confirmed that the charging reaction proceeded at potentials near 3.6 V and 3.8 V, and the discharging reaction proceeded at potentials near 3.7 V and 3.3 V. It was done. As for the compound having the structure represented by the chemical formula (3), there have been reports on the synthesis method so far, but no knowledge about the electrochemical characteristics has been obtained. It was confirmed that the represented compound can be electrochemically oxidized and reduced and used as an electricity storage device.

<< Comparative Example 1 >>
A positive electrode was produced by the following method using 2,5-dimercapto-1,3,4-thiadiazole (hereinafter referred to as DMcT) (manufactured by Aldrich) as an organic sulfur compound as the positive electrode active material.
In an argon gas atmosphere dry box equipped with a gas purifier, 30 mg of DMcT, 30 mg of acetylene black as a conductive agent, and 5 mg of polyvinylidene fluoride as a binder were sufficiently mixed. Furthermore, 1 ml of N-methylpyrrolidone (manufactured by Kanto Chemical Co., Inc.) was added to this mixture to obtain a positive electrode mixture. This positive electrode mixture was cast on an aluminum foil current collector and vacuum dried at room temperature for 1 hour. After drying, this was punched out on a disk having a diameter of 13.5 mm to obtain a positive electrode.
Using this positive electrode, a charge / discharge test was performed in which a coin-type battery was produced in the same manner as in Example 1. The charge / discharge test results are shown in Table 1.

  From Table 1, it was confirmed that in the battery of Comparative Example 1 using DMcT as the positive electrode active material, the initial capacity was sufficiently obtained, but the repetition characteristics were poor. On the other hand, in the battery of Example 1 using the compound represented by the chemical formula (3) as the positive electrode active material, no capacity decrease was observed even after 50 cycles, and excellent repetitive characteristics were obtained.

<< Comparative Example 2 >>
Bisethylenedithiotetrathiafulvalene (hereinafter referred to as BEDT-TTF) (manufactured by Aldrich) was used as a TTF-based organic sulfur compound for the positive electrode active material, and a positive electrode was produced by the following method.
In a dry box under an argon gas atmosphere equipped with a gas purifier, 30 mg of BEDT-TTF, 30 mg of acetylene black as a conductive agent, and 5 mg of polyvinylidene fluoride as a binder were sufficiently mixed. 1 ml of N-methylpyrrolidone (manufactured by Kanto Chemical Co., Inc.) was added to this mixture to obtain a positive electrode mixture. This positive electrode mixture was cast on an aluminum foil current collector and vacuum dried at room temperature for 1 hour. After drying, this was punched out on a disk having a diameter of 13.5 mm to obtain a positive electrode. The thickness of the positive electrode after drying was about 110 μm.
Using the positive electrode obtained above, a coin-type battery was produced in the same manner as in Example 1, and a charge / discharge test was conducted. The test results are shown in Table 1.

From the results in Table 1, it was found that the battery of Example 1 had a higher discharge potential than the battery of Comparative Example 2 using the BEDT-TTF compound, which was a TTF compound of Comparative Example 2. This indicates that the compound having the structure represented by the general formula (1) is a compound that reacts at a high potential, unlike the TTF compound, and can realize further higher voltage and higher capacity. It was confirmed that it was possible.
From the above, it was found that the battery of Example 1 had higher voltage, higher capacity, and superior repeatability than Comparative Examples 1 and 2.

  The electricity storage device of the present invention is suitably used as a power source for information equipment and portable equipment.

It is a schematic sectional drawing of the coin-type battery of Example 1 of this invention. It is a figure which shows the charging / discharging curve of the battery of Example 1 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Case 12 Positive electrode collector 13 Positive electrode mixture layer 14 Separator 15 Sealing plate 16 Negative electrode mixture layer 17 Negative electrode collector 18 Sealing ring

Claims (10)

At least the general formula (1):

(In Formula (1), R < ₁ > -R < ₄ > is respectively independently a hydrogen atom, a fluorine atom, an alkyl group, an unsaturated aliphatic group, or a saturated aliphatic group, The said alkyl group, the said unsaturated aliphatic group Group and the saturated aliphatic group may contain a halogen atom, a nitrogen atom, an oxygen atom, a sulfur atom or a silicon atom, and the unsaturated aliphatic group and the saturated aliphatic group may be linear or cyclic. And n is an integer of 1 or more.) An electrode active material for an electricity storage device, comprising a compound having a structure represented by: In Formula (1), R ₁ to R ₄ is a hydrogen atom, an electrode active material for a power storage device according to claim 1, characterized in that the n = 1. In Formula (1), R ₁ to R ₄ is a hydrogen atom, an electrode active material for a power storage device according to claim 1, characterized in that the n = 2.   The said compound has two or more structures represented by the said General formula (1), The electrode active material for electrical storage devices characterized by the above-mentioned. A power storage device including a positive electrode including a positive electrode active material, a negative electrode including a negative electrode active material, and an electrolyte,
At least one of the positive electrode active material and the negative electrode active material is represented by the general formula (1):

(In Formula (1), R < ₁ > -R < ₄ > is respectively independently a hydrogen atom, a fluorine atom, an alkyl group, an unsaturated aliphatic group, or a saturated aliphatic group, The said alkyl group, the said unsaturated aliphatic group Group and the saturated aliphatic group may contain a halogen atom, a nitrogen atom, an oxygen atom, a sulfur atom or a silicon atom, and the unsaturated aliphatic group and the saturated aliphatic group may be linear or cyclic. And n is an integer of 1 or more.) A power storage device characterized by being a compound having a structure represented by: In Formula _(1), R 1 ~R ₄ is a hydrogen atom, an electricity storage device according to claim 5, characterized in that the n = 1. In Formula _(1), R 1 ~R ₄ is a hydrogen atom, an electricity storage device according to claim 5, characterized in that the n = 2.   The power storage device according to claim 5, wherein the compound has a plurality of structures represented by the general formula (1). The electrolyte comprises a non-aqueous solvent and a salt composed of an anion and a cation dissolved in the non-aqueous solvent;
The non-aqueous solvent is a mixture of a solvent having a relative dielectric constant of 10 or less and a solvent having a relative dielectric constant of 30 or more,
The electrical storage device according to claim 5, wherein the mixture has a relative dielectric constant of 10 or more and 30 or less. The solvent having a relative dielectric constant of 10 or less is at least one selected from the group consisting of a chain carbonate ester, a chain ester, and a chain ether,
The electricity storage device according to claim 9, wherein the solvent having a relative dielectric constant of 30 or more is at least one selected from the group consisting of cyclic carbonates and cyclic ethers.

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