JP2002117854A - Secondary battery and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new secondary battery which has high energy density, large capacity, and excellent stability. SOLUTION: In the secondary battery using oxidation-reduction reaction of the active material in the charging/discharging process, the secondary battery containing the organic compound which is processed by ozone, is manufactured by the manufacturing method including a process in which the organic compound is made into an active material by the ozone processing, as the active material for both or either a positive electrode or a negative electrode. Thus, the secondary battery, which can perform charging/discharging of electricity with high energy density, and has excellent stability and safety with large capacity, and its simple manufacture, can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a secondary battery using an oxidation-reduction reaction of an active material in a charge / discharge process, and a method for manufacturing the same. More specifically, a secondary battery that utilizes the oxidation-reduction reaction of an active material in a charge / discharge process, which contains an organic compound subjected to ozone treatment as a main active material, has a high energy density, and has stability and safety. The present invention relates to an excellent secondary battery and a manufacturing method thereof.

[0002]

2. Description of the Related Art With the rapid market expansion of notebook personal computers, mobile phones, and the like, there is an increasing demand for small and large-capacity batteries with a large energy density used for these. In order to meet this demand, secondary batteries have been developed using an alkali metal ion such as lithium ion as a charge carrier and utilizing an electrochemical reaction accompanying the charge transfer. Among them, lithium ion secondary batteries are used in various electronic devices as large-capacity batteries with excellent stability and high energy density. In such a lithium ion secondary battery,
For example, a lithium-containing transition metal oxide is used for a positive electrode and carbon is used for a negative electrode as an active material, and charge / discharge is performed using a lithium ion insertion reaction and a desorption reaction with respect to these active materials.

However, this lithium ion secondary battery has a problem that the battery capacity per unit mass is not sufficient because a transition metal oxide having a large specific gravity is used as the active material of the positive electrode.

[0004] Therefore, attempts have been made to develop a large-capacity battery using a lighter electrode material. For example, U.S. Pat.No. 4,833,048 and U.S. Pat.
Japanese Patent Application Laid-Open Publication No. H11-139,086 discloses a battery using an organic compound having a disulfide bond as an active material of a positive electrode. This utilizes the electrochemical redox reaction of an organic compound based on the formation and dissociation of disulfide bonds as the principle of a battery. However, since this battery uses an organic compound mainly composed of an element having a low specific gravity such as sulfur or carbon as an electrode material, although a certain effect can be obtained in terms of forming a high capacity battery with a high energy density, In addition, there has been a problem that the dissociation of dissociated disulfide bonds has a low recombination efficiency and the stability in a charged state or a discharged state is insufficient.

[0005] Also, as a battery using an organic compound as an active material, a battery using a conductive polymer as an electrode material has been proposed. This is a battery based on the principle of doping and undoping reactions of electrolyte ions with respect to a conductive polymer. The doping reaction described here is defined as a reaction in which excitons such as charged solitons and polarons generated by an electrochemical oxidation or reduction reaction of a conductive polymer are stabilized by counter ions. Is defined as the reverse reaction of the doping reaction, that is, the reaction of electrochemically oxidizing or reducing excitons stabilized by counter ions.

US Pat. No. 4,442,187 discloses a battery using such a conductive polymer as a positive electrode or negative electrode active material. Since this battery uses, as an electrode material, an organic compound consisting only of an element having a low specific gravity, such as carbon or nitrogen, it was expected to be developed as a large-capacity battery. However, conductive polymers have the property that excitons generated by electrochemical oxidation-reduction reactions delocalize over a wide range of π-electron conjugated systems and interact with each other. However, there is a problem that the capacity of the battery is limited. Therefore, in a battery using such a conductive polymer as an electrode material, although a certain effect can be obtained in terms of reducing the weight of the battery, in terms of increasing the capacity of the battery,
It was still insufficient.

On the other hand, an ozone treatment technique has been developed as one of surface treatment methods for various materials. This technique generally aims to improve the wettability and adhesion of a substrate surface by contact with ozone gas or ultraviolet irradiation in an oxygen atmosphere, and has been industrially implemented in various fields.

In the field of secondary batteries, attempts have been made to improve the repetitive life and stability of batteries by using such ozone treatment. For example,
JP-A-11-16572 and JP-A-11-176439 disclose a method for producing a large-capacity cathode material without lithium deficiency by pyrolyzing or calcining a nickel compound and a lithium compound under an ozone atmosphere. Have been.

Japanese Unexamined Patent Application Publication No. 11-25970 discloses a secondary battery in which ozone-treated manganese oxide is used as a positive electrode material and whose capacity is less deteriorated with cycling. Furthermore, Japanese Patent Application Laid-Open No. 11-389852 discloses a battery in which the aging process can be shortened by using an ultraviolet-treated separator. However, these ozone treatments have a certain effect in terms of improving the stability and the like of the battery, but do not have a sufficient effect in terms of increasing the capacity of the battery.

As described above, various types of batteries have been proposed to realize a large-capacity battery. However, a battery having a high energy density, a large capacity and excellent stability, and such a battery have been proposed. A simple method for manufacturing a battery has not yet been established.

[0011]

As described above, in the lithium ion battery using the transition metal oxide as the active material of the positive electrode, the specific gravity of the element is large, so that it is difficult in principle to manufacture a large-capacity battery exceeding the current state. Met. Also, a method of ozone treatment of electrodes and active materials has been performed, but a sufficient effect has not been obtained from the viewpoint of increasing the capacity of the battery. Accordingly, the present inventors have conducted intensive studies and found that an organic compound which was electrochemically inactive and could not be used as an electrode active material until now was subjected to ozone treatment, thereby being electrochemically inactive. It has been found that it is possible to carry out a simple oxidation-reduction reaction, and it can be used as an active material of a battery.
Therefore, the present invention uses such a specific organic compound as the active material of the electrode, the energy density is high, a secondary battery excellent in stability with a large capacity, and such a secondary battery is simple and It is an object of the present invention to provide a production method which can be obtained efficiently.

[0012]

According to the present invention, there is provided a secondary battery using a redox reaction of an active material in a charging / discharging process. A secondary battery containing an ozone-treated organic compound as an active material is provided. With such a configuration, an organic compound treated with ozone, which is a strong oxidizing gas, can be easily used as an active material, and a secondary battery having high energy density, large capacity, and excellent stability can be easily obtained. Can be obtained.

In general, ozone is a gas having a strong oxidizing power and is excellent in reactivity with organic compounds. Therefore, ozone has been used as a surface treatment method for improving the wettability of plastics and preventing static charge. Used by In addition, according to previous studies, for example, a plastic or the like is treated with ozone to form a hydroxyl group (-OH group) or a carbonyl group (-C (=
O) -group) and a carboxyl group (-COOH group).

In constituting the present invention, the ozone-treated organic compound is a polymer radical compound containing a structural unit represented by the following general formula (1) and / or one of the general formulas (2): It is preferable that

[0015]

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[In the general formula (1), the substituent R ¹ is a substituted or unsubstituted alkylene group, alkenylene group or arylene group, and X is an oxy radical group, a nitroxyl radical group, a sulfur radical group, a hydra group. It is a gall radical group, a carbon radical group, or a boron radical group. ]

[0017]

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[In the general formula (2), R ² and R ³ are mutually independent and are a substituted or unsubstituted alkylene group, alkenylene group or arylene group, and Y is a nitroxyl radical group or a sulfur radical group. , A hydrazyl radical group, or a carbon radical group. ]

With this configuration, since the oxidation-reduction reaction proceeds only at the radical site in the polymer radical compound, a secondary battery excellent in stability whose cycle characteristics do not depend on diffusion of the active material can be easily obtained. Obtainable. Further, in a polymer radical compound having such a structural unit, the unreacted unreacted electron is localized at the radical atom, and as a result, the concentration of the reaction site can be increased, so that a high energy density and a large capacity are obtained. Can be obtained.

In general, radicals are reactive chemical species having unpaired electrons, and most of them disappear with a certain lifetime due to interaction with surrounding substances. Some solvated states can be stable radical species. It is also conceivable that radicals generated on the surface of the organic compound diffuse inside.

In constituting the secondary battery of the present invention, it is preferable that the ozone-treated organic compound is an aromatic compound. With such a structure, the organic compound can be composed only of elements such as carbon, hydrogen, and oxygen having a small mass, so that a secondary battery having a large energy density per unit mass can be easily obtained. .

Further, in constituting the secondary battery of the present invention, the spin concentration of the ozone-treated organic compound in an electron spin resonance (hereinafter abbreviated as ESR) spectrum is preferably 10 ²⁰ spin / g or more. . With this configuration, the energy density is high,
A secondary battery having high capacity and excellent stability can be easily obtained. Note that the above stable radical species is generally ESR
The spin concentration in the spectrum is 10
It is known that in ^{19-10 23} within the spin / g.

In constituting the secondary battery of the present invention, it is preferable that the secondary battery is a lithium ion secondary battery. With this configuration, a large-capacity secondary battery with excellent stability can be obtained.

In the present invention, an ozone-treated organic compound is used as an active material for an electrode. As described above, an ozone treatment is performed on an active material such as a nickel compound or a carbon material to improve the wettability and the like. Has already been performed as a conventional technique. So, for example,
When an organic compound is used as a binder or the like constituting the active material layer, there is a possibility that an organic compound subjected to ozone treatment may be generated as a result. It is only about wt.%.
That is, even when such an organic compound is subjected to ozone treatment, the capacity and energy density of the obtained battery hardly change, and it is considered that the specific effects as in the present invention cannot be obtained.

On the other hand, since the secondary battery of the present invention uses an organic compound subjected to ozone treatment as a main active material, a secondary battery having high energy density, large capacity and excellent stability can be easily obtained. . In the present invention, the amount of the organic compound subjected to the ozone treatment with respect to the entire active material layer is not particularly limited as long as this material can be a main active material.
Generally, it is performed at 10 wt.% Or more at which a large capacity and a high energy density are remarkable.

Another aspect of the present invention is a method for manufacturing a secondary battery using an oxidation-reduction reaction of an active material in a charging / discharging process, comprising the steps of: converting an organic compound into an active material by ozone treatment; It is characterized by including a forming step and an aging step. By doing so, a secondary battery having a high energy density, a large capacity, and excellent stability can be easily manufactured.

In carrying out the method of manufacturing a secondary battery according to the present invention, a step of forming a coating by mixing a binder and a solvent with an organic compound is included in the step of forming the electrode.
Applying the coating material to the current collector to form an organic compound layer on the current collector. By doing so, a secondary battery having a high energy density, a large capacity, and excellent stability can be easily manufactured.

In practicing the method of manufacturing a secondary battery according to the present invention, the step of forming the active material may be performed as a step before the step of preparing the paint or a step after the step of forming the organic compound layer. preferable. By doing so, a secondary battery having a high energy density, a large capacity, and excellent stability can be easily manufactured.

In carrying out the method for manufacturing a secondary battery according to the present invention, it is preferable that the ozone treatment is performed by irradiating ultraviolet rays in an ozone gas atmosphere or an oxygen atmosphere. By doing so, the ozone treatment of the organic compound can be performed efficiently.

In carrying out the method of manufacturing a secondary battery according to the present invention, it is preferable to irradiate the ultraviolet rays with a low-pressure mercury lamp or an excimer UV lamp. By doing so, the ultraviolet treatment can be reliably performed, and the ozone treatment of the organic compound can be efficiently performed.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Secondary Battery] In a secondary battery according to an embodiment of the present invention, for example, as shown in FIG. 1, a negative electrode layer 1 and a positive electrode layer 2 are interposed via a separator 5 containing an electrolyte. It has a configuration in which it is superposed. In the present invention, the active material used for the negative electrode layer 1 or the positive electrode layer 2 is an organic compound subjected to ozone treatment. FIG. 2 shows a cross-sectional view of the stacked battery. In the structure, a negative electrode current collector 3, a negative electrode layer 1, a separator 5 containing an electrolyte, a positive electrode layer 2, and a positive electrode current collector 4 are sequentially stacked. It has a structure. In the present invention, the method for laminating the positive electrode layer and the negative electrode layer is not particularly limited, and a multi-layered structure, a combination of the current collectors laminated on both surfaces, a wound current collector, and the like can be used.

(1) Active Material Material 1 In the present invention, an organic compound is used as a material for performing ozone treatment. The organic compound is subjected to ozone treatment to generate radicals on the surface of the organic compound,
This is because the radical can be used as an active material capable of performing an electrochemical redox reaction. Accordingly, the type of the organic compound to be subjected to the ozone treatment is not particularly limited, but is preferably an organic compound that can be used in the charge and discharge process of the battery by the electrochemical oxidation-reduction reaction after the ozone treatment.

The ozone-treated organic compound is excellent in processability in forming an electrode active material layer, and is therefore represented by the general formula (1) and / or (2). It is preferably a polymer radical compound containing a structural unit. Examples of such a polymer radical compound include compounds represented by the following general formulas (3) to (11).

[0034]

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In addition to the above-mentioned polymer radical compound, the ozone-treated organic compound may be represented by the following formula (1)
It is preferable to use a low molecular radical compound represented by 2) to (19) or an unsaturated radical compound from the viewpoint of capacity development after ozone treatment. In addition, these radical compounds can be used alone or in combination of two or more.

[0036]

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In the present invention, the term “organic compound” is a generic term for all carbon compounds with a few exceptions. However, a crystal developed only from carbon atoms typified by graphite, diamond, fullerene, and the like, and a polycrystal in which crystals composed only of carbon atoms typified by soft carbon, hard carbon, and the like are aggregated are treated with ozone. The effect obtained by is small. The reason is that in these compounds, radicals are formed on the surface by the ozone treatment, but the subsequent diffusion of the radicals into the bulk is suppressed, so that the effect is limited only to the surface of the solid. It is thought to be. On the other hand, in general organic compounds other than the above compounds, radicals generated on the surface, including molecular crystals, can easily diffuse into the bulk, and can be effectively used as an active material.

Material 2 In the present invention, as described above, the ozone-treated organic compound can be used as the active material of the positive electrode and / or the negative electrode. It is preferable to use an organic compound treated with ozone.

These organic compounds were used as a positive electrode and a negative electrode.
When used as the active material of one of the electrodes
Uses the materials listed below as active materials for other electrodes
be able to. That is, ozone is used as the active material of the negative electrode layer.
When using a treated organic compound, the active material of the positive electrode layer
Metal oxide particles, disulfide compounds, and
An electrically conductive polymer or the like is used. Here, as metal oxide
Is, for example, LiMnO ₂, Li_xMn₂O₄(0 <x
<2) Lithium manganate or spinel structure
Lithium manganate, MnO₂, LiCoO₂,
LiNiO₂Or Li_xV₂O₅(0 <x <2) etc.
However, as disulfide compounds, dithioglycol,
2,5-dimercapto-1,3,4-thiadiazole,
S-triazine-2,4,6-trithiol, etc.
In addition, as conductive polymers, polyacetylene and polyphenylene are used.
Nylene, polyaniline, polypyrrole, etc.
Can be In the present invention, these positive electrode layer materials may be used alone or as a single material.
Can be used in combination of two or more.

On the other hand, when an ozone-treated organic compound is used as the active material of the positive electrode layer, graphite, amorphous carbon, lithium metal, lithium alloy, lithium ion storage carbon, One kind of a polymer or the like or a combination of two or more kinds is used. The shape is not particularly limited, for example,
As the lithium metal, a bulk metal, a solidified powder, a fibrous metal, a flake metal, and the like can be used in addition to the thin film metal. Further, a conventionally known active material and an organic compound obtained by ozone treatment may be mixed and used as a composite active material.

(2) Auxiliary Conductive Material and Ion Conduction Aid In the present invention, when forming an electrode layer containing an organic compound subjected to ozone treatment, an auxiliary conductive material and an ion conduction auxiliary material are mixed for the purpose of lowering impedance. It can also be done. Examples of these materials include, as an auxiliary conductive material, carbonaceous fine particles such as graphite, carbon black, and acetylene black; and conductive polymers such as polyaniline, polypyrrole, polythiophene, polyacetylene, and polyacene. Examples thereof include a molecular gel electrolyte and a polymer solid electrolyte.

(3) Binder In the present invention, in order to strengthen the binding between the constituent materials,
Binders can also be used. Examples of such a binder include polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, styrene-butadiene copolymer rubber, polypropylene, polyethylene, polyimide, and various polyurethanes. And the like.

(4) Catalyst In the present invention, a catalyst for accelerating the oxidation-reduction reaction can be used in order to carry out the electrode reaction more lubricatingly. Examples of such a catalyst include conductive polymers such as polyaniline, polypyrrole, polythiophene, polyacetylene, and polyacene; basic compounds such as pyridine derivatives, pyrrolidone derivatives, benzimidazole derivatives, benzothiazole derivatives, and acridine derivatives; and metal ion complexes. Is mentioned.

(5) Current Collector In the present invention, nickel, aluminum, copper, gold, silver, aluminum alloy,
And a metal foil such as stainless steel, a metal flat plate, a mesh electrode, a carbon electrode, and the like. Further, such a current collector may have a catalytic effect, or the active material and the current collector may be chemically bonded. On the other hand, it is also preferable to use a separator or a nonwoven fabric made of a porous film so that the positive electrode and the negative electrode do not come into contact with each other.

(6) Electrolyte In the present invention, the electrolyte 5 is for transporting charge carriers between the two electrodes of the negative electrode layer 1 and the positive electrode layer 2.
And a 0 ^-5 -10 ion conductive ^-1 S / cm. In the present invention, for example, an electrolyte in which an electrolyte salt is dissolved in a solvent can be used as the electrolyte. Such electrolyte salts include, for example, LiPF ₆ , LiClO
₄ , LiBF ₄ , LiCF ₃ SO ₃ , Li (CF ₃ SO
₂ ) ₂ N, Li (C ₂ F ₅ SO ₂ ) ₂ N, Li (CF ₃ SO
₂ ) ₃ C, a conventionally known material such as Li (C ₂ F ₅ SO ₂ ) ₃ C can be used. Further, as the solvent for the electrolyte salt, for example, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, γ-butyrolactone,
Organic solvents such as tetrahydrofuran, dioxolan, sulfolane, dimethylformamide, dimethylacetamide, and N-methyl-2-pyrrolidone can be used.
In the present invention, these solvents can be used alone or as a mixed solvent of two or more.

Further, in the present invention, a solid electrolyte can be used as the electrolyte. Examples of the polymer compound used for such a solid electrolyte include polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-ethylene copolymer, vinylidene fluoride-monofluoroethylene copolymer, and fluoropolymer. Vinylidene fluoride polymers such as vinylidene fluoride-trifluoroethylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, and acrylonitrile-methyl Methacrylate copolymer, acrylonitrile-methyl acrylate copolymer, acrylonitrile-ethyl methacrylate copolymer, acrylonitrile-ethyl acrylate copolymer, acrylonitrile-methacrylic acid copolymer, acrylonitrile- Acrylic acid copolymers, acrylonitrile - acrylonitrile polymers such as vinyl acetate copolymer, further polyethylene oxide, ethylene oxide - propylene oxide copolymers, and polymers of these acrylates body or methacrylate body thereof. The solid electrolyte may be a gel formed by adding an electrolytic solution to these polymer compounds, or may be used alone with the polymer compound alone.

(7) Shape The shape of the secondary battery is not particularly limited as long as the active material is an organic compound subjected to ozone treatment, and it is not limited to a cylindrical battery, a coin battery, a square battery, a film battery, and a button. It can be applied to shapes such as a battery.

[Manufacturing Method] The embodiment of the manufacturing method according to the present invention is a method for manufacturing a secondary battery using an oxidation-reduction reaction of an active material in a charging / discharging process. , An electrode forming step, and an aging step.

In the present invention, the ozone treatment is a method for treating an organic compound using ozone gas. Examples of such a method include a method in which an organic compound is held in an atmosphere containing ozone gas, a method in which ultraviolet light is irradiated under an oxygen atmosphere, and an organic compound is treated by generating ozone gas from oxygen atoms. . In general,
When the oxygen molecules are irradiated with ultraviolet light, the oxygen molecules become 185 nm.
Absorbs the light of the light to produce ozone, and this ozone is 2
It is known that light of 54 nm generates active oxygen.

In the present invention, a hydrogen discharge tube, a xenon lamp,
Ultraviolet light can be generated using an ultraviolet lamp such as a low-pressure mercury lamp and an excimer UV lamp, but it is particularly preferable to use a low-pressure mercury lamp and an excimer UV lamp because of their excellent ozone treatment efficiency. Among them, as the low-pressure mercury lamp, for example, a straight tube lamp such as SUV110D manufactured by Sen Special Light Source Co., Ltd. is used. As the excimer UV lamp, a coherent excimer laser, an incoherent dielectric barrier discharge excimer lamp, or the like is used. Examples of such an excimer laser include an argon fluoride laser and a krypton fluoride laser, and examples of the dielectric barrier discharge excimer lamp include a xenon excimer lamp and a krypton chloride excimer lamp.
Further, in the present manufacturing method, it is possible to irradiate ultraviolet rays in an ozone gas atmosphere.

In the present production method, there is no particular limitation on the timing of performing the ozone treatment on the organic compound.
For example, when the secondary battery of the present invention is manufactured as a cylindrical or prismatic battery, as a process of forming an electrode, a process of preparing a paint by mixing a binder and a solvent with an organic compound, or collecting the paint by a current collector A step of forming an organic compound layer on the current collector by applying to the body is included, but in this case, the step of converting the organic compound into an active material by ozone treatment may be performed before the step of preparing the paint. Alternatively, it may be performed after the step of forming the organic compound layer. In the present invention, the temperature, time, ozone concentration, and the like for performing the ozone treatment are not particularly limited, and are appropriately selected in consideration of the effect of the treatment.

In the present invention, the radical compound generated by the ozone treatment is stabilized by performing an aging operation involving charging or discharging. Therefore, whether the aging operation is performed in the discharging process after battery formation,
Alternatively, whether the reaction is performed in the charging step can be determined depending on in which step of charging and discharging of the battery the reaction (chlorination) between the radical compound and a cation such as lithium is performed. In such an aging operation, a mechanism is considered in which the radical compound generated by the ozone treatment reacts with a cation such as lithium to diffuse into the solid. The conditions of the aging operation in the present invention are not particularly limited, but are preferably performed at room temperature or higher, and more preferably in a heating state at 40 ° C. or higher, from the viewpoint that the effect is effectively exhibited.

[0053]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. Example 1 (1) Preparation of Lithium Ion Secondary Battery Polyphenylene sulfide powder (particle diameter: 10 μm) was spread evenly on a glass plate and held in a glass container with air containing 5% by volume of ozone for 6 hours. Processing. A part of this powder was taken out and its ESR spectrum was measured. The spin concentration was 10 ¹⁷ spin / ozone treatment.
g to 2 × 10 ²⁰ spin / g. From this, it was confirmed that radicals were generated in the polyphenylene sulfide fine particles.

Next, 1 g of the ozone-treated polyphenylene sulfide powder was dispersed in 50 g of N-methylpyrrolidone, and graphite powder 6 was used as an auxiliary conductive material.
When 0 mg was further added and mixed until the whole became uniform, a black slurry was obtained. 2g of this slurry
To an aluminum foil with lead wires (area: 1.5 cm
× 1.5 cm, thickness: 100 μm), and developed with a wire bar so that the whole becomes uniform thickness.
After drying under reduced pressure at 120 ° C. for 6 hours, the solvent was evaporated to form an electrode layer containing ozone-treated polyphenylene sulfide fine particles on the aluminum foil.

Next, 1 mol / l of Li was used as an electrolyte salt.
Containing PF ₆ ethylene carbonate / propylene carbonate mixture solution (mixing ratio 1: 1) vinylidene fluoride 1,400 mg - hexafluoropropylene copolymer 6
00 mg was added, and 11.3 g of tetrahydrofuran was further added, followed by stirring at room temperature. After dissolving the vinylidene fluoride-hexafluoropropylene copolymer, an electrolyte solution is applied on a stepped glass plate, and left at room temperature for 1 hour to dry tetrahydrofuran naturally to a thickness of 1 mm.
Was obtained. This gel electrolyte film was cut into 2.0 cm × 2.0 cm, laminated on the previously prepared electrode layer containing ozone-treated polyphenylene sulfide fine particles, and further provided with a lithium-bonded copper foil having a lead wire (lithium film thickness 30 μm, Copper foil thickness 20μ
m) were overlaid. Thereafter, the whole was sandwiched between sheets of polytetrafluoroethylene having a thickness of 5 mm, and pressure was applied to produce a lithium ion secondary battery.

(2) Evaluation of lithium ion secondary battery When the lithium ion secondary battery produced as described above was connected to a charge / discharge tester, the open-circuit voltage was 1.8 V.
Immediately, discharge was performed to 1.0 V at a constant current of 0.01 mA. Subsequently, the battery was aged at 45 ° C. for 6 hours, and then a charge / discharge test was performed at a constant current of 0.01 mA using the electrode layer containing the ozone-treated polyphenylene sulfide fine particles as the positive electrode and the lithium-bonded copper foil as the negative electrode. Was. As a result, a voltage flat portion was observed around 1.8 V, and it was confirmed that the battery operated. Further, when the battery was repeatedly charged and discharged, it was confirmed that the battery could be charged and discharged over 10 cycles or more and operated as a secondary battery.

Example 2 (1) Preparation of Lithium Ion Secondary Battery Using the polyphenylene sulfide of Example 1, 1 g of the powder was directly dispersed in 50 g of N-methylpyrrolidone and used as an auxiliary conductive material. Graphite powder 6
When 0 mg was further added and mixed until the whole became uniform, a black slurry was obtained. 2g of this slurry
Was dropped on the surface of the aluminum foil used in Example 1,
When developed and dried under reduced pressure in the same manner as in Example 1,
An electrode layer containing polyphenylene sulfide fine particles was formed on the aluminum foil.

Next, the obtained electrode layer was subjected to ultraviolet irradiation in air using an ultraviolet irradiation apparatus equipped with a low-pressure mercury lamp (SUV110D, manufactured by Sen Special Light Source Co., Ltd.). Note that the distance between the sample and the light source was 5 cm, and the treatment was performed at 30 ° C. for 2 hours. The appearance of the sample after the ultraviolet treatment was not particularly changed as compared with that before the ultraviolet irradiation, but when a part of the sample after the treatment was taken out and the ESR spectrum was measured, the spin concentration was 10 ²⁰ spin / g. As described above, it was confirmed that radicals were generated in the polyphenylene sulfide fine particles.

The gel electrolyte layer used in Example 1 was laminated on this electrode layer, and a lithium-bonded copper foil provided with a lead wire was laminated in the same manner as in Example 1, and sandwiched with a polytetrafluoroethylene sheet. Pressure was applied to produce a lithium ion secondary battery.

(2) Evaluation of lithium ion secondary battery When the lithium ion secondary battery produced as described above was connected to a charge / discharge tester, the open-circuit voltage was 1.8 V.
Immediately, discharge was performed to 1.0 V at a constant current of 0.01 mA. Subsequently, the battery was aged at 45 ° C.
Next, a charge / discharge test was performed at a constant current of 0.01 mA using an electrode layer containing polyphenylene sulfide treated with ultraviolet light as a positive electrode and a lithium-bonded copper foil as a negative electrode. As a result, a voltage flat portion was observed around 1.8 V, and it was confirmed that the battery operated. Further, when the battery was repeatedly charged and discharged, it was confirmed that the battery could be charged and discharged over 10 cycles or more and operated as a secondary battery.

Example 3 (1) Preparation of Lithium Ion Secondary Battery Using the polyphenylene sulfide of Example 1, a black slurry was prepared in the same manner as in Example 2, developed, dried, and placed on an aluminum foil. An electrode layer containing polyphenylene sulfide fine particles was formed.

Next, the obtained electrode layer was subjected to excimer UV irradiation using a xenon excimer UV lamp (manufactured by Ushio Inc.). The distance between the sample and the light source is 5
cm, and the treatment was performed at 30 ° C. for 10 minutes. Excimer U
The appearance of the sample after the irradiation with V was not particularly changed as compared with that before the irradiation, but a part of the sample after the treatment was taken out.
When the SR spectrum was measured, the spin concentration was 10
^{It was 20} spin / g or more, and it was confirmed that radicals were generated in the polyphenylene sulfide fine particles.

The gel electrolyte layer used in Example 1 was laminated on this electrode layer, and a lithium-bonded copper foil provided with a lead wire was laminated in the same manner as in Example 1, and sandwiched with a polytetrafluoroethylene sheet. Pressure was applied to produce a lithium ion secondary battery.

(2) Evaluation of lithium ion secondary battery When the lithium ion secondary battery produced as described above was connected to a charge / discharge tester, the open-circuit voltage was 1.8 V.
Immediately, discharge was performed to 1.0 V at a constant current of 0.01 mA. Subsequently, the battery was aged at 45 ° C.
Next, a charge / discharge test was performed at a constant current of 0.01 mA using an electrode layer containing polyphenylene sulfide subjected to excimer UV irradiation as a positive electrode and a lithium-bonded copper foil as a negative electrode. As a result, a voltage flat portion was observed around 1.8 V, and it was confirmed that the battery operated. Further, when the battery was repeatedly charged and discharged, it was confirmed that the battery could be charged and discharged over 10 cycles or more and operated as a secondary battery.

Comparative Example 1 Using the polyphenylene sulfide of Example 1, a black slurry was prepared in the same manner as in Example 2, developed and dried to form an electrode layer containing polyphenylene sulfide fine particles on an aluminum foil. .
Next, the gel electrolyte layer used in Example 1 was directly laminated on the obtained electrode layer, and a lithium-bonded copper foil provided with a lead wire was laminated in the same manner as in Example 1 to obtain a polytetrafluoroethylene sheet. And pressurized to produce a lithium ion secondary battery. When the lithium-ion secondary battery prepared as described above was connected to a charge / discharge tester, no open-circuit voltage was recognized, and charging / discharging could not be performed.
The operation as a battery was not confirmed.

Example 4 (1) Preparation of Lithium Ion Secondary Battery Ozone treatment was performed in the same manner as in Example 1 except that polyparavinylphenol powder was used instead of the polyphenylene sulfide powder of Example 1. went. When a part of this powder was taken out and the ESR spectrum was measured, the spin concentration was increased from 10 ¹⁷ spin / g or less before treatment to 10 ²⁰ spin / g. From this, it was confirmed that radicals were generated in the polyparavinylphenol fine particles.

Next, 1 g of the ozone-treated polyparavinylphenol powder was dispersed in 50 g of tetrahydrofuran, and 60 g of graphite powder was used as an auxiliary conductive material.
g was further added and mixed until the whole became uniform, whereby a black slurry was obtained. Example of this slurry
An electrode layer containing polyparavinylphenol powder which was developed, dried and ozone-treated on an aluminum foil was formed in the same manner as in 1.

Next, the gel electrolyte layer used in Example 1 was laminated on this electrode layer, and a lithium-bonded copper foil provided with a lead wire was laminated in the same manner as in Example 1 to obtain a polytetrafluoroethylene sheet. And pressurized to produce a lithium ion secondary battery.

(2) Evaluation of lithium ion secondary battery When the lithium ion secondary battery produced as described above was connected to a charge / discharge tester, the open-circuit voltage was 1.5 V.
Immediately, discharge was performed to 1.0 V at a constant current of 0.01 mA. Subsequently, the battery was aged at 45 ° C.
Next, a charge / discharge test was performed at a constant current of 0.01 mA using the ozone-treated electrode layer containing polyparavinylphenol as a positive electrode and a lithium-bonded copper foil as a negative electrode. As a result, a voltage flat portion was observed around 1.8 V, and it was confirmed that the battery operated. Further, when the battery was repeatedly charged and discharged, it was confirmed that the battery could be charged and discharged over 10 cycles or more and operated as a secondary battery.

Example 5 (1) Fabrication of Lithium Ion Secondary Battery Instead of the polyphenylene sulfide powder of Example 1, polyvinylidene fluoride powder (manufactured by Elphatochem Co., Ltd., K
The ozone treatment was performed in the same manner as in Example 1 except that Ynar301F) was used. A part of this powder was taken out and its ESR spectrum was measured. The spin concentration was from 10 ¹⁷ spin / g or less before ozone treatment to 10 ¹⁷ spin / g or less.
Increased to ²⁰ spin / g. From this, it was confirmed that radicals were generated in the polyvinylidene fluoride fine particles.

Next, 1 g of polyvinylidene fluoride powder treated with ozone was dispersed in 50 g of N-methylpyrrolidone, and 60 mg of graphite powder was added as an auxiliary conductive material.
When the mixture was further added and mixed until the whole became uniform, a black slurry was obtained. Example of this slurry
An electrode layer containing polyvinylidene fluoride powder subjected to development, drying and ozone treatment on an aluminum foil was formed in the same manner as in 1.

Next, the gel electrolyte layer used in Example 1 was laminated on this electrode layer, and a lithium-bonded copper foil provided with a lead wire was laminated in the same manner as in Example 1 to form a polytetrafluoroethylene sheet. And pressurized to produce a lithium ion secondary battery.

(2) Evaluation of Lithium Ion Secondary Battery When the battery prepared as described above was connected to a charge / discharge tester, the open-circuit voltage was 1.6 V, and it was immediately 0.01 mA.
At a constant current of 1.0 V. Subsequently, the battery was subjected to an aging treatment at 45 ° C., and then a charge / discharge test was performed at a constant current of 0.01 mA using the electrode layer containing the ozone-treated polyvinylidene fluoride as the positive electrode and the lithium-bonded copper foil as the negative electrode. . As a result, a voltage flat portion was observed around 1.8 V, and it was confirmed that the battery operated. Furthermore, when the battery was repeatedly charged and discharged, the battery can be charged and discharged for 10 cycles or more.
It was confirmed that it operated as a secondary battery.

[0074]

As described above, the secondary battery of the present invention is a secondary battery that utilizes the oxidation-reduction reaction of an active material in a charge / discharge process. Since the organic compound contains the ozone-treated organic compound, a secondary battery having a large energy density and excellent stability and safety can be easily obtained.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing an embodiment of a secondary battery of the present invention.

FIG. 2 is a central longitudinal sectional view showing an embodiment of the secondary battery of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 negative electrode layer 2 positive electrode layer 3 negative electrode current collector 4 positive electrode current collector 5 separator containing electrolyte 6 sealing material

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08G 75/02 C08G 75/02 H01M 4/02 H01M 4/02 B 4/04 4/04 A 4/62 4/62 Z 10/40 10/40 Z (72) Inventor Yukiko Morioka 5-7-1 Shiba, Minato-ku, Tokyo Inside the NEC Corporation (72) Inventor Hiroshi Sakauchi 5-7-1 Shiba, Minato-ku, Tokyo No. 1 Inside NEC Corporation (72) Inventor Shigeyuki Iwasa 5-7-1 Shiba, Minato-ku, Tokyo NEC Corporation F-term (reference) 4J030 BA03 BA48 BD01 BD02 BF13 BG04 BG18 4J100 AB07P AL08P AT05P BA03P BA27P BA28P BC43P BC65P BC73P CA01 HA00 HA01 HB08 JA43 5H029 AJ03 AJ05 AK03 AK16 AL07 AL16 AM03 AM04 AM05 AM07 AM16 BJ03 BJ04 BJ16 CJ14 EJ12 HJ00 HJ02 5H050 AA07 AA08 EA20 CA18 CA18 EA20 BA18 CB08

Claims (11)

[Claims] 1. A secondary battery utilizing an oxidation-reduction reaction of an active material in a charging / discharging process, characterized in that the secondary battery contains an ozone-treated organic compound as an active material of a positive electrode and / or a negative electrode. Rechargeable battery. 2. The ozone-treated organic compound is a polymer radical compound containing a structural unit represented by the following general formula (1) and / or one of the general formulas (2). The secondary battery according to claim 1. Embedded image [In the general formula (1), the substituent R ¹ is a substituted or unsubstituted alkylene group, alkenylene group, or arylene group, and X is an oxy radical group, a nitroxyl radical group, a sulfur radical group, or a hydrazyl radical group. , A carbon radical group, or a boron radical group. ] [In the general formula (2), R ² and R ³ are mutually independent and are a substituted or unsubstituted alkylene group, alkenylene group, or arylene group, and Y is a nitroxyl radical group, a sulfur radical group, or hydrazyl. It is a radical group or a carbon radical group. ] 3. The secondary battery according to claim 1, wherein the ozone-treated organic compound is an aromatic compound. 4. The secondary battery according to claim 1, wherein the ozone-treated organic compound has a spin concentration of at least 10 ²⁰ spin / g in an electron spin resonance spectrum. 5. The secondary battery according to claim 1, wherein the secondary battery is a lithium ion secondary battery. 6. A method for manufacturing a secondary battery using an oxidation-reduction reaction of an active material in a charge / discharge process, comprising: a step of converting an organic compound into an active material by ozone treatment; a step of forming an electrode; and an aging step. A method for manufacturing a secondary battery, comprising: 7. The step of forming the electrode, the step of preparing a coating by mixing a binder and a solvent with the organic compound, and the step of forming the organic compound layer on the current collector by applying the coating to a current collector. The method of manufacturing a secondary battery according to claim 6, comprising: 8. The method for manufacturing a secondary battery according to claim 6, wherein the step of forming the active material is performed before the step of preparing the paint. 9. The method according to claim 6, wherein the step of forming the active material is performed after the step of forming the organic compound layer. 10. The method for manufacturing a secondary battery according to claim 6, wherein the ozone treatment is performed by irradiating ultraviolet rays in an ozone gas atmosphere or an oxygen atmosphere. 11. The method according to claim 10, wherein the ultraviolet rays are irradiated using a low-pressure mercury lamp or an excimer UV lamp.