JP4946308B2 - Electric storage device and electrode used for electric storage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power storage device and a cluster electrode coping with problems in one using a conventional organic radical of how to more fully load an organic radical and stabilize an operation. <P>SOLUTION: The power storage device 1 is provided with electrolyte 7 and an anode 9 in a way in contact with the electrolyte 7. The device is also provided with a base board 3 in a way in contact with the electrolyte 7, and a cluster electrode 5 as a cathode on the surface of the base board at an electrolyte 7 side. A polymer film 11 is fitted between the anode 9 and the base board 3. The cluster electrode 5 has a structure in which an organic radical is carried by an oxide semiconductor in hydrogen bond. As the organic radical, a nitroxyl compound of a five-membered ring or a six-membered ring structure is used. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a high-capacity electricity storage device using organic radicals and an electrode (cluster electrode) used in the electricity storage device.

In recent years, with rapid market expansion of notebook personal computers, mobile phones, electric vehicles and the like, small, high capacity, high output power storage devices are required.
Among these, lithium ion batteries using a lithium-containing transition metal oxide for a positive electrode and a carbon material for a negative electrode are used in various portable devices as high energy density power storage devices having excellent charge / discharge characteristics.

On the other hand, the lithium ion battery cannot be said to have a high reaction rate of the electrode reaction, and when a large current is passed, the capacity may be significantly reduced.
For example, the discharge rate of a normal lithium ion battery is about 1 C (1 C when the full capacity is released in 1 hour).

Therefore, an electricity storage device has been developed in which at least one of the positive electrode and the negative electrode contains a radical compound (Patent Document 1).
There are various types of radical compounds, but examples of the materials used as the active material of the positive electrode of the electricity storage device include organic radicals such as low-molecules or polymers of nitroxyl compounds (Patent Document 2).

The power storage devices using these radical compounds are said to be capable of transferring electrons at a high rate 100 times that of a normal lithium ion battery with a discharge rate of 100 C because of the power storage mechanism involving radicals (non-non-volatile). Patent Document 1).
JP 2002-151084 A JP 2004-259618 A Hiroyuki Nishide, “Organic Radical Battery”, 04-4 Polymer Frontier 21 Abstracts, Society of Polymer Science, November 26, 2004, p. 17-20

However, an electrode using an organic radical does not depend on a polymer or a low molecule, and an organic radical is an insulator, so a conductive aid such as carbon is often added to reduce impedance.
In this case, in order to adhere the organic radical and carbon, it is necessary to add a fluorine-based polymer or the like as a binder.

Therefore, there is a problem that the density of organic radicals in the electrode is lowered and the capacity is lowered.
Regardless of polymer or low molecule, the organic radical has a density of about 1 g / cm ³ and has a smaller capacity per volume than an inorganic active material such as lithium.
Furthermore, especially in the case of low-molecular organic radicals, since there is no strong interaction with conductive assistants and binders, organic radicals that are active materials are eluted into the electrolyte during charge and discharge, and the performance as an electricity storage device is reduced. There was also a problem.
On the other hand, high molecular organic radicals have little leaching problems observed in low molecules due to molecular entanglement, but conversely, because they contain an extra polymer main skeleton that has insulation and low density, The problem of degradation is even greater than for low molecular organic radicals.

  In view of these problems, the present inventors have intensively studied and as a result of using a cluster electrode in which an organic radical is supported on the surface of an oxide semiconductor as an electrode of an electricity storage device, the density of the organic radical in the electrode is reduced. It has been found that it is possible to prevent the organic radical from leaking into the electrolyte during charging and discharging, and the present invention has been achieved.

  An object of the present invention is to provide an electricity storage device and an electrode used in the electricity storage device (cluster electrode) that have overcome the problems of conventional electricity storage devices using organic radicals, such as high filling of organic radicals and stabilization of operation. Is to provide.

In order to achieve the above-described object, a first invention is an electricity storage device having at least a positive electrode, a negative electrode, and an electrolyte, wherein at least one of the positive electrode and the negative electrode is an oxide semiconductor and the oxide semiconductor. and supported organic radical, I electrode (cluster electrode) der with, and the organic radicals and the oxide semiconductor is a storage device which is characterized that you have been joined by hydrogen bonding.

前記酸化物半導体は、アナタ−ゼ型ＴｉＯ_２であるのが望ましい。 The organic radical is any one of a compound having a nitroxyl radical, a compound having an oxy radical, a compound having a nitrogen radical, a compound having a sulfur radical, a compound having a boron radical, and a compound having a carbon radical, and the oxidation It has a functional group capable of hydrogen bonding with a physical semiconductor.
The organic radical preferably has a molecular weight per radical of 250 or less.
The functional group is a carboxyl group and / or a sulfo group.
The organic radical is preferably a compound represented by any of the following chemical formulas (1) to (3).

The oxide semiconductor is preferably anatase TiO ₂ .

The second invention is an electrode for use in an electricity storage device (cluster electrode), oxide and semiconductor, have a, and supported organic radicals on the surface of the oxide semiconductor, the oxide and the organic radical and the semiconductor is an electrode which is characterized that you have been joined by hydrogen bonding (cluster electrode).

前記酸化物半導体は、アナタ−ゼ型ＴｉＯ_２であるのが望ましい。 The organic radical is any one of a compound having a nitroxyl radical, a compound having an oxy radical, a compound having a nitrogen radical, a compound having a sulfur radical, a compound having a boron radical, and a compound having a carbon radical, and the oxidation It has a functional group capable of hydrogen bonding with a physical semiconductor.
The organic radical preferably has a molecular weight per radical of 250 or less.
The functional group is a carboxyl group and / or a sulfo group.
The organic radical is preferably a compound represented by any of the following chemical formulas (1) to (3).

The oxide semiconductor is preferably anatase TiO ₂ .

  In the present invention, the electricity storage device includes an oxide semiconductor and an electrode (cluster electrode) made of an organic radical supported on the oxide semiconductor, and the organic radical transfers electrons.

  According to the present invention, an electricity storage device includes an oxide semiconductor and a cluster electrode composed of an organic radical supported on the oxide semiconductor, and does not require a conductive additive or a binder. Therefore, the capacity is higher than that of a conventional power storage device.

  In addition, according to the present invention, the oxide semiconductor in the cluster electrode acts as a capacitor by polarization of the electric double layer and has a power storage function, so that the power storage device has a higher capacity.

  Furthermore, according to the present invention, since the organic radical is supported on the surface of the oxide semiconductor by a hydrogen bond, even if the organic radical is a low molecule, it does not ooze into the electrode, and the electricity storage device is stable. Performance can be demonstrated.

DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail based on the drawings. FIG. 1 is a cross-sectional view showing an electricity storage device 1 according to this embodiment.
As shown in FIG. 1, the electricity storage device 1 includes an electrolyte 7, and a negative electrode 9 is provided so as to be in contact with the electrolyte 7.

  A substrate 3 is provided so as to be in contact with the electrolyte 7, and a cluster electrode 5 as a positive electrode is provided on the surface of the substrate 3 on the electrolyte 7 side.

  Further, a polymer film 11 is provided between the negative electrode 9 and the substrate 3 to prevent a short circuit between the substrate 3 and the negative electrode 9 and to prevent the electrolyte 7 from leaking to the outside.

The electrolyte 7 transports a charge carrier between the negative electrode 9 and the cluster electrode 5, and an electrolytic solution or a gel electrolyte containing a supporting salt can be used.
Examples of the supporting salt include LiPF ₆ , LiClO ₄ , LiBF ₄ , Li (CF ₃ SO ₂ ) ₂ N, (C ₂ H ₅ ) ₄ NBF ₄ , (C ₄ H ₉ ) ₄ NBF ₄ , (C ₂ H ₅ ). Known supporting salts such as ₄ NPF ₆ and (C ₄ H ₉ ) ₄ NPF ₆ can be used.

  As the solvent of the electrolytic solution, an organic solvent used in conventional secondary batteries and capacitors such as ethylene carbonate, propylene carbonate, gamma butyl lactone, diethyl carbonate, dimethyl carbonate, or a mixed solvent thereof can be used.

  Further, ionic liquids such as 1-methyl-3-propylimidazolium bis (trifluorosulfonyl) imide and 1-ethyl-3-butylimidazolium tetrafluoroborate can also be used.

  The concentration of the supporting salt may be 0.1 to 2.0M (M is mol / liter), but is preferably 0.8 to 1.2M.

As the gel electrolyte, a known gel electrolyte can be used. For example, a polymer such as polyvinylidene fluoride , polyethylene glycol or polyacrylonitrile, a sugar such as an amino acid derivative or sorbitol derivative, and an electrolyte containing a supporting salt are included. And a gel electrolyte.
A nitroxyl compound may be included in the electrolytic solution or gel electrolyte as described in JP-A-2005-228712.

The negative electrode 9 is made of graphite, amorphous carbon, lithium metal, lithium alloy, lithium ion storage carbon, conductive polymer, or the like.
A transparent conductive glass baked with platinum can also be used.

The substrate 3 is a member that holds the cluster electrode 5 and needs to be a material that can collect electricity. Such materials include transparent conductive materials such as InSnO ₂ , SnO ₂ , ZnO, In ₂ O _3, fluorine-doped tin oxide (SnO ₂ : F), antimony-doped tin oxide (SnO ₂ : Sb), tin-doped oxide A single layer or a laminate of such materials doped with impurities such as indium (In ₂ O ₃ : Sn), ZnO, Al-doped zinc oxide (ZnO: Al), and Ga-doped zinc oxide (ZnO: Ga) is formed of glass. And those formed on a polymer.

The thickness of the substrate 3 is not particularly limited, but is about 3 nm to 10 μm.
The surface shape of the glass or polymer may be flat or may have irregularities on the surface. Further, as the substrate 3, a metal plate such as stainless steel, aluminum, or copper may be used.

  The cluster electrode 5 as a positive electrode is composed of an oxide semiconductor and an organic radical supported on the oxide semiconductor.

The oxide semiconductor is a material that supports the conduction of electrons between the organic radical and the substrate 3 and supports the organic radical.
In the present invention, the oxide semiconductor also functions as a capacitor by polarization of the electric double layer and has a power storage function.
Therefore, the electricity storage device 1 has a higher capacity than a conventional electricity storage device to which a conductive additive or binder is added.

Examples of the oxide semiconductor include TiO ₂ , ZnO, SnO ₂ , Nb ₂ O ₅ ,
In ₂ O ₃ , WO ₃ , ZrO ₂ , La ₂ O ₃ ,
TaO _5, SrTiO _3, BaTiO _3, and the like. Of these oxide semiconductors, it is desirable to use anatase TiO ₂ . Although rutile TiO ₂ can be used, the rutile type is about 80% of the anatase type in terms of photoelectric conversion ability. This is presumably because there is a slight difference in the energy level between the rutile-type and anatase-type TiO ₂ conductors.

The shape of the oxide semiconductor may be nanoparticles, nanofibers, nanosheets, and a mixture thereof.
Nanoparticles and nanofibers can be produced by a known synthesis method. For example, a metal alkoxide can be produced by hydrothermal synthesis under pressure.

  Nanosheets can be obtained by acid treatment of layered salts made of the corresponding metal carbonates and oxides, followed by ammonium salt treatment.

  The oxide semiconductor is prepared by applying a paste obtained by dissolving or dispersing oxide semiconductor nanoparticles, nanofibers, or nanosheets together with a surfactant and a water-soluble polymer in water on the substrate 5 at a high temperature. It is formed on the substrate 5 by heat treatment and sintering. The thickness of the oxide semiconductor after sintering is preferably 5 to 25 μm.

Organic radicals are electrode active materials.
A radical is a chemical species having an unpaired electron, but since it is highly reactive, it generally exists only as an intermediate during a chemical reaction.
That is, such radicals combine with other radicals to form electronically symmetric bonds and disappear in a short time.

However, some radicals exist stably over a relatively long period of time due to steric hindrance by organic protecting groups and delocalization of π electrons.
Such a radical is also called a stable radical compound and can be used as an electrode active material.
The organic radical used in the present invention is this stable radical compound.

  Examples of the stable radical compound include a compound having a nitroxyl radical, a compound having an oxy radical, a compound having a nitrogen radical, a compound having a sulfur radical, a compound having a carbon radical, and a compound having a boron radical.

Specifically, nitroxyl radical compounds as represented by chemical formulas (1) to (9), phenoxyl radical compounds as represented by chemical formula (10), and hydrazyl radical compounds as represented by chemical formulas (11) to (13) Etc. are desirable. In addition, a carbon radical compound, a sulfur radical compound, a boron radical compound, and the like are desirable.

A compound in which a bulky alkyl group is bonded to the nitrogen atom constituting the nitroxyl radical is desirable because high stability is expected due to its steric hindrance effect. These alkyl groups are preferably tertiary butyl groups.
Examples of the compound in which the tertiary butyl group is bonded to the nitrogen atom constituting the nitroxyl radical include those represented by chemical formulas (4) to (6).

  Further, from the viewpoint of radical stability, it is desirable that a carbon atom bonded to at least two alkyl groups is bonded to a nitrogen atom constituting the nitroxyl radical.

  In particular, when two carbon atoms bonded to at least two alkyl groups are bonded to the nitrogen atom constituting the nitroxyl radical, it is expected to be a more stable radical compound.

In this case, the alkyl group is preferably a methyl group.
Examples of compounds in which the carbon atom to which these two methyl groups are bonded are bonded to the nitrogen atom constituting the nitroxyl radical include those represented by chemical formulas (1) to (6) and chemical formulas (8) to (9) Is mentioned.

Furthermore, a compound in which an aromatic group is bonded to the nitrogen atom constituting the nitroxyl radical is desirable because high stability is expected due to delocalization of electrons.
In this case, the aromatic group is preferably a substituted or unsubstituted aryl group, more preferably a substituted or unsubstituted phenyl group from the viewpoint of stability.
Examples of the compound in which an aromatic group is bonded to the nitrogen atom constituting the nitroxyl radical include those represented by chemical formulas (4) to (7).

On the other hand, when the nitrogen atom constituting the nitroxyl radical is a single atom that forms a heterocyclic ring, the intramolecular reaction of the nitroxyl radical is unlikely to occur, which is desirable because it is expected to improve the stability of the radical. .
In this case, the heterocyclic ring is preferably a piperidinoxy ring, a pyrrolidinoxy ring or a pyrrolinoxy ring from the viewpoint of stability.

  Examples in which the nitrogen atom constituting the nitroxyl radical is one atom constituting the heterocyclic ring include those represented by chemical formulas (1) to (3) and chemical formulas (8) to (9). Among them, the one shown in chemical formula (1) forms a piperidinoxy ring, the one shown in chemical formula (2) forms a pyrrolinoxy ring, and the one shown in chemical formula (3) forms a pyrrolidinoxy ring.

  Further, when the nitroxyl radical forms a nitroxyl nitroxide structure, it is desirable because the radical is expected to be stabilized because electrons are delocalized. Examples of the compound having the nitroxyl nitroxide structure include those represented by chemical formula (8) and chemical formula (9).

  On the other hand, a compound in which an aromatic group is bonded to an oxygen atom, such as a phenoxyl radical compound, is desirable because high stability can be expected due to delocalization of electrons. Examples of such compounds include those represented by chemical formula (10).

  Furthermore, a compound having a nitrogen radical in which adjacent nitrogen is bonded to an aromatic group, such as a hydrazyl radical compound, is desirable because high stability is expected due to delocalization of electrons. Examples of such compounds include those represented by chemical formulas (11) to (13).

Of the above nitroxyl radical compounds, phenoxyl radical compounds, and hydrazyl radical compounds, compounds having a small molecular weight per radical are more desirable. This is because the capacity per active material is increased.
Specifically, the molecular weight per radical is desirably 250 or less.
Examples of molecules satisfying such requirements include those shown in Table 1.

For example, in the structure in which one radical is included in one molecule, such as the molecules shown in numbers 1 to 4 and 7 to 8 in Table 1, the molecular weights are 200.25, 186.23, 184.21, 208, respectively. .23, 228.22, 236.31, and the molecular weight per radical is 250 or less.
Alternatively, in a structure in which two radicals are included in one molecule like the molecule indicated by number 5, the molecular weight is 294.35, but the molecular weight per radical is 147.18, which is 250 or less.
Further, in the structure in which three radicals are contained in one molecule like the molecules shown in Nos. 6 and 9, the molecular weights are 400.45 and 444.46, respectively, but the molecular weights per radical are 133. 48, 148.15, and 250 or less.

Of the compounds represented by the chemical formulas (1) to (13), it is particularly desirable to use a nitroxyl compound having a 5-membered or 6-membered ring structure represented by the chemical formulas (1) to (3).
As such a nitroxyl compound, as shown in chemical formula (2) and chemical formula (3), a compound in which at least one functional group R is bonded to the 3-position of a 5-membered ring structure, or chemical formula (1) As shown in Table 1, there is a compound in which at least one functional group R is bonded to the 4-position of a 6-membered ring structure.
Alternatively, a compound in which at least one functional group R is bonded to the 4-position of the 5-membered ring structure, or at least one functional group R is bonded to the 3-position, 5-position of the 6-membered ring structure. There are compounds.

  Examples of such compounds include 4-carboxy-2,2,6,6-tetramethylpiperidine-1-oxyl (chemical formula (1)), 4-sulfoxy-2,2,6,6-tetramethylpiperidine. -1-oxyl (chemical formula (1)), 3,4-dicarboxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-ethylcarboxy-2,2,6,6-tetramethylpiperidine -1-oxyl (chemical formula (1)), 3-carboxy-2,2,5,5, -tetramethylpyrrolin-1-oxyl (chemical formula (2)), 3-sulfoxy-2,2,5,5, -Tetramethylpyrroline-1-oxyl (chemical formula (2)), 3-carboxy-2,2,5,5, -tetramethylpyrrolidine-1-oxyl (chemical formula (3)), 3-sulfoxy-2,2, 5, 5, Tetramethyl-1-oxyl (Formula 3), and the like.

Here, as described above, the organic radicals represented by the chemical formulas (1) to (13) all have the functional group R.
The functional group R is a substituent that causes an interaction (hydrogen bond or electrostatic interaction) with the oxide semiconductor.
As such a substituent, a carboxyl group or a sulfo group is desirable.

  Since the organic radical has a carboxyl group or a sulfo group, the hydroxyl group and / or oxygen on the surface of the oxide semiconductor and the carboxyl group or the sulfo group in the organic radical are connected by a hydrogen bond, so the organic radical is an oxide semiconductor. Strongly supported.

Therefore, in the present invention, neither a conductive auxiliary agent nor a binder is required, and the organic radical can be highly charged. Therefore, the electricity storage device 1 has a higher capacity than a conventional electricity storage device using a binder.
Moreover, even if it is a low molecular organic radical, since it does not ooze out in an electrode, the electrical storage device 1 can exhibit the stable performance.

In addition, at least one functional group R must be present in the above organic radical, but two or more functional groups R may be present.
For example, in chemical formula (4) and chemical formula (5), two or more functional groups R may be bonded to one aromatic ring.
In chemical formula (6) and chemical formula (7), functional group R may be bonded to either one of two aromatic rings, or may be bonded to both.
Furthermore, in chemical formula (11) and chemical formula (12), functional group R may be bonded to any one of the three aromatic rings, or may be bonded to any two of them. It may be bonded to all three.
Alternatively, in the chemical formula (13), the functional group R may be bonded to any one of the four aromatic rings, may be bonded to any two, or any three It may be bonded, or may be bonded to all four.

The organic radical is supported on the oxide semiconductor by immersing the cluster electrode in a solution in which the organic radical is dissolved in an organic solvent such as ethanol or acetonitrile.
The immersion time depends on the type of organic radical, but may be 24 hours to 150 hours.

The supported amount of organic radicals may be 0.5 × 10 ⁻⁷ to 10 × 10 ⁻⁷ mol / cm ³ per volume of the cluster electrode. A co-adsorbent such as chenodeoxycholic acid may be included in the organic radical solution.

  JP-A-2006-73241 proposes organic radicals having a methyl group or a phenyl group in the molecular structure, but these organic radicals cannot bind to a hydroxyl group on the surface of an oxide semiconductor. So it can not be carried.

Hereinafter, it demonstrates in detail based on an Example.
First, a paste was prepared by suspending commercially available TiO ₂ nanoparticles (Nippon Aerosil P25) in butyl carbitol containing hydroxypropyl cellulose (3% by weight).
Next, this paste was applied onto an F-doped transparent conductive glass substrate manufactured by Asahi Glass and baked at 450 ° C. for 30 minutes in the air to form TiO ₂ on the glass substrate.

Next, this glass substrate is immersed in 50 mL of ethanol in which 100 mg of 4-carboxy-2,2,6,6-tetramethylpiperidine-1-oxyl (Tokyo Kasei) is dissolved for one week, and the organic radicals are put on TiO ₂ . To make a cluster electrode. The cluster electrode has a size of 10 mm × 10 mm and a thickness of 10 μm.

  Next, a counter electrode having the same shape and size as the cluster electrode was prepared. First, an isopropanol (10 mg / 25 mL (milliliter)) in which chloroplatinic acid hexahydrate (Wako Pure Chemical Industries) was dissolved was spin-coated on an F-doped transparent conductive glass substrate manufactured by Nippon Glass (rotation speed of spin coating) 2500 rpm). Next, after drying this in air | atmosphere, it baked at 400 degreeC for 1 hour, and obtained the platinum sintered counter electrode. The counter electrode was previously provided with an electrolyte injection hole (diameter 1 mm).

  Next, prepare a polymer film (Hi-Milan) made by Mitsui Deupon Polychemical Co., Ltd., which has a shape that matches the size of the cluster electrode, with the cluster electrode and counter electrode facing each other through the polymer film, and bonding them together by thermal welding It was.

  Subsequently, 1 mol / liter of tetraethylammonium tetrafluoroborate (manufactured by Toyama Pharmaceutical) was injected as an electrolyte from the injection hole of the counter electrode, and after the injection, the injection hole was closed with a member made of the same material as the polymer film. The electric storage device 1 shown in FIG.

Then, using the charge / discharge system (HJ1001SM8A) of Hokuto Denko, a charge / discharge test of the electricity storage device 1 was performed at a potential of 0.1V to 1.4V. The results are shown in FIG.
As shown in FIG. 2, the electricity storage device 1 was able to charge and discharge, and the discharge capacity per supported amount of organic radicals was 320 mAh / g. According to Non-Patent Document 1, since the theoretical capacity of the organic radical is around 100 mAh / g, it was found that the electricity storage device 1 of the present invention has a very large capacity.

In Example 1, instead of the commercially available TiO ₂ particles, Aldrich ZnO particles (particle size of 1 μm or less) were used, and the rest were all produced under the same conditions as in Example 1 to produce an electricity storage device 1a (not shown). Using a charge / discharge system (HJ1001SM8A) manufactured by Hokuto Denko, a charge / discharge test of the electricity storage device was performed at a potential of 0.1 V to 1.4 V.
As a result, the discharge capacity of the electricity storage device 1a per supported amount of organic radicals was 210 mAh / g.

In Example 1, an electricity storage device 1b (not shown) was manufactured under the same conditions as in Example 1 except that SnO nanoparticles manufactured by Johnson Matthey were used instead of commercially available TiO ₂ particles. Using the charge / discharge system (HJ1001SM8A), the charge / discharge test of the electricity storage device was performed at a potential of 0.1 V to 1.4 V.
As a result, the discharge capacity of the electricity storage device 1b per supported amount of organic radicals was 235 mAh / g.

In Example 1, 3-carboxy-2,2,5,5-tetramethylpyrrolidine-1-oxyl (Tokyo Kasei) was used instead of 4-carboxy-2,2,6,6-tetramethylpiperidine-1-oxyl. , All others produced the electricity storage device 1c (not shown) under the same conditions as in Example 1, and using the Hokuto Denko charge / discharge system (HJ1001SM8A), the electricity storage device was charged between 0.1V and 1.4V. As a result, the discharge capacity per unit amount of the organic radical of the electricity storage device 1c was 155 mAh / g.

(Comparative Example 1)
In Example 1, was immersed glass substrate with the TiO ₂ on the surface 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (Wako Pure Chemical) ethanol solution, on TiO ₂ Organic radicals were not adsorbed and a cluster electrode could not be produced.

(Comparative Example 2)
In Example 1, a glass substrate on which TiO ₂ was formed was immersed in 2,2,6,6-tetramethylpipericinyloxy radical (Wako Pure Chemical) ethanol solution, but organic radicals adsorbed on TiO _2. The cluster electrode could not be produced.

As shown in FIG. 3, a positive electrode 13 having a cluster electrode of Example 2 and a lithium metal negative electrode 15 were provided in a beaker cell 19, and a 1 mol / liter LiPF ₆ electrolyte solution 17 (solvent: ethylene carbonate and diethyl carbonate of A mixed solvent volume ratio 1: 1, Toyama Pharmaceutical Co., Ltd.) was dipped to produce an electricity storage device 1d.

Then, the potential between the positive electrode 13 and the negative electrode 15 was swept twice between 3.1 to 4.0 V at a speed of 100 mV / sec, and the presence or absence of charge / discharge was examined. The above results are shown in FIG.
As shown in FIG. 4, an oxidation current reflecting charging was observed near 3.8V, and a reduction current reflecting discharging was observed near 3.6V.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

  For example, although the cluster electrode is used for the positive electrode in this embodiment, it may be used for the negative electrode.

It is sectional drawing which shows the electrical storage device 1. It is a figure which shows the result of the charging / discharging test of the electrical storage device 1 produced in Example 1. FIG. It is a figure which shows the electrical storage device 1d produced in Example 5. It is a figure which shows the result of the charging / discharging test of the electrical storage device 1d produced in Example 5. FIG.

Explanation of symbols

1 ………… Power storage device 1d ………… Power storage device 3 ………… Substrate 5 ………… Cluster electrode 7 ………… Electrolyte 9 ………… Negative electrode 11 ……… Polymer film 13 ……… Positive electrode 15 ......... Negative electrode 17 ......... Electrolytic solution 19 ......... Beaker cell

Claims (12)

In an electricity storage device having at least a positive electrode, a negative electrode, and an electrolyte,
At least one of the positive electrode and the negative electrode is
An oxide semiconductor;
What electrode der having an organic radical which is supported on the oxide semiconductor,
Storage device wherein organic radicals and said oxide semiconductor, which is characterized that you have been joined by hydrogen bonding.   The organic radical is any one of a compound having a nitroxyl radical, a compound having an oxy radical, a compound having a nitrogen radical, a compound having a sulfur radical, a compound having a boron radical, and a compound having a carbon radical, and the oxidation The electrical storage device according to claim 1, further comprising a functional group capable of hydrogen bonding with a physical semiconductor.   The electric storage device according to claim 2, wherein the organic radical has a molecular weight of 250 or less per radical.   The electric storage device according to claim 2, wherein the functional group is a carboxyl group and / or a sulfo group. The power storage device according to claim 3 or 4, wherein the organic radical is a compound represented by any one of the following chemical formulas (1) to (3).

The power storage device according to claim 1, wherein the oxide semiconductor is anatase TiO ₂ . An electrode used in an electricity storage device,
An oxide semiconductor;
Have a, and supported organic radicals on the surface of the oxide semiconductor,
The organic radical and said oxide semiconductor is characterized that you have been joined by hydrogen bonding electrode.   The organic radical is any one of a compound having a nitroxyl radical, a compound having an oxy radical, a compound having a nitrogen radical, a compound having a sulfur radical, a compound having a boron radical, and a compound having a carbon radical, and the oxidation The electrode according to claim 7, which has a functional group capable of hydrogen bonding with a physical semiconductor.   The electrode according to claim 8, wherein the organic radical has a molecular weight of 250 or less per radical.   The electrode according to claim 8, wherein the functional group is a carboxyl group and / or a sulfo group. The electrode according to claim 9 or 10, wherein the organic radical is a compound represented by any one of the following chemical formulas (1) to (3).

The electrode according to claim 7, wherein the oxide semiconductor is anatase TiO ₂ .

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