JPH069139B2 - Secondary battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a secondary battery, and more particularly to a secondary battery using a novel conductive polymer made of an organic material as an electrode material.

<Prior Art> In recent years, a secondary battery has been proposed in which a conductive polymer made of various organic materials is used as an electrode material.

The conductive polymer, which is the electrode material of this type of secondary battery, usually has a small conductivity, but it is possible to dope and undope the dopants such as various anions and cations. Sexuality rises dramatically. Then, a conductive polymer doped with anions is used as a positive electrode material, a conductive polymer doped with cations is used as a negative electrode material, and a solution containing the above dopant is used as an electrolytic solution. That is, a battery that can be charged and discharged is constructed by performing electrochemically and reversibly.

As such a conductive polymer, various polymers having a conjugated double bond in the main chain such as polyacetylene, polythiophene, and polypyrrole have been conventionally known. If polyacetylene is used as an example, polyacetylene is used as a positive electrode or a negative electrode. Used as at least one electrode material of BF ₄ ⁻ ,
Anion such as ClO ₄ ⁻ , SbF ₆ ⁻ , PF ₆ ⁻ or a cation such as Li ⁺ , Na ⁺ , R ₄ −N ⁺ (R represents an alkyl group), which is electrochemically reversibly doped;
The undoped structure is adopted.

However, a conductive polymer having a conjugated double bond in the main chain of this kind, such as polyacetylene, has poor stability in air and is easily oxidized by oxygen in the air in a doped or undoped state, It also has the drawback that it tends to undergo thermal transformation and thermal decomposition at temperatures above 300 ° C. For this reason, there is a problem that the management of the electrode production environment becomes serious and extremely difficult, not only the electrode production work becomes difficult and complicated, but also the storability of the electrode itself is poor. In addition to this, when incorporated into a battery, the presence of trace amounts of oxygen and water will cause deterioration or deterioration of the material due to transformation or decomposition, which will lead to deterioration of battery characteristics, and overcharging will cause a problem. There are drawbacks such as the possibility that molecules may be denatured and decomposed, resulting in a sharp increase in charging voltage, a decrease in charge / discharge efficiency, a decrease in cycle life, and the like, which is a serious problem as an electrode material.

By the way, recently, a conductive polymer having no conjugated double bond in its main chain has been found, and its application to an electrode material is being studied. This type of conductive polymer is generally stable in air, is not oxidized, and is not thermally decomposed at a temperature of 300 ° C. or higher. For this reason, the management of the electrode manufacturing environment is not so important, the manufacturing work is easy, and the preservability of the electrode itself is very good. Not only is there no deterioration of characteristics, but there is also the advantage that there is little transformation / decomposition even after overcharging, and there is the advantage that charging / discharging can be repeated over a long period of time.

<Problems to be Solved by the Invention> However, such a conductive polymer having no conjugated double bond in the main chain is generally a conductive polymer having a conjugated double bond in the main chain such as polyacetylene. In comparison with, there is a disadvantage that the conductivity is low when undoped or at low boop, so when it is used as an electrode material,
In particular, there is a problem that the internal resistance of the battery is likely to increase at the beginning of the charge / discharge cycle, which causes deterioration of charge / discharge characteristics and a decrease in cycle life. Further, this type of conductive polymer has a drawback that the battery capacity is small when it is used as a battery electrode because of its low doping level.

<Means for Solving Problems> The present inventors have studied to solve the above problems by using, as an electrode material, a novel organic conductor having the above-mentioned drawbacks instead of the conventional conductive polymer. However, as shown below, when an organic semiconductor obtained by polymerizing a specific pyrrole compound or aniline compound in the presence of a specific polymer having no conjugated double bond in the main chain is used, Completed the invention by realizing that they could achieve their initial objectives.

That is, the secondary battery of the present invention has at least the general formula Or general formula (Wherein R ^{1 to} R ⁴ represent hydrogen atom, alkyl group, alkoxy group, aryl group, aryloxy group, thioether group, amino group, halogen atom, cyano group, nitro group) In the presence of at least one of the general formula (Wherein R ⁵ and R ⁶ represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, an allyloxy group, a thioether group and a halogen atom, and R ⁷ represents a hydrogen atom, an alkyl group and an aryl group). Compounds or general formula (Wherein R ⁸ and R ⁹ represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, and an aryloxy group, and R ¹⁰ and R ¹¹ represent a hydrogen atom, an alkyl group, and an aryl group). The gist is that an organic semiconductor obtained by polymerizing one of the compounds is used as at least one of a positive electrode and a negative electrode.

In the vinylcarbazole-based polymer represented by the general formula (1) and the acenaphthylene-based polymer represented by the general formula (2), in the formula, R ^{1 to} R ⁴ are a hydrogen atom, a methyl group, an ethyl group, and n-propyl. Group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group and other alkyl groups, methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group Groups such as alkoxy groups, phenyl groups, toluyl groups, naphthyl groups and other aryl groups, phenoxy groups, methylphenoxy groups, naphthoxy groups and other allyloxy groups, methylthioether groups, ethylthioether groups and other thioether groups, amino groups, fluorine atoms Represents a halogen atom such as chlorine atom, bromine atom and iodine atom, an aldehyde group, a cyano group and a nitro group.

Specifically, among the vinylcarbazole-based polymers, polyvinylcarbazole, 4-methylpolyvinylcarbazole, 4,7-dimethylpolyvinylcarbazole, 4-ethylpolyvinylcarbazole, 4-methoxypolyvinylcarbazole, 4-ethoxypolyvinylcarbazole, 4
-Phenyl polyvinyl carbazole, 4,7-diphenyl polyvinyl carbazole, 4-naphthyl polyvinyl carbazole, 4-phenoxy polyvinyl carbazole, 4
-Methylthiopolyvinylcarbazole, 4-aminopolyvinylcarbazole, 4,7-dibromopolyvinylcarbazole, polyvinylcarbazole-4-aldehyde, 4
-Aminopolyvinylcarbazole, 4,7-dinitropolyvinylcarbazole and the like can be mentioned.

Further, as the acenaphthylene-based polymer, polyacenaphthylene, 5-methylpolyacenaphthylene, 5-ethylpolyacenaphthylene, 5-methoxypolyacenaphthylene, 5
-Ethoxypolyacenaphthylene, 5,6-dimethoxypolyacenaphthylene, 5-phenylpolyacenaphthylene, 5
-Toluyl polyacenaphthylene, 5-naphthyl polyacenaphthylene, 5-phenoxy polyacenaphthylene, 5-
Methylthiopolyacenaphthylene, 5-aminopolyacenaphthylene, 5-bromopolyacenaphthylene, 5,6-dibromopolyacenaphthylene, polyacenaphthylene-5-aldehyde, 5-cyanopolyacenaphthylene, 5 , 6 dinitropolyacenaphthylene, and the like.

The molecular weight of the vinylcarbazole-based polymer and acenaphthylene-based polymer used is 5000 to 800,000, preferably
It is 1000 to 500000.

In the pyrrole-based compound represented by the general formula (3), R ⁵ and R ⁶ are a hydrogen atom, a methyl group, an ethyl group, n-
Alkyl groups such as propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, alkoxy such as methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, etc. Group, phenyl group,
Toluyl group, naphthyl group, and other aryl groups, phenoxy group, methylphenoxy group, naphthoxy group, and other allyloxy groups, methylthioether group, ethylthioether group, and other thioether groups, fluorine atom, chlorine atom, bromine atom, halogen atom, iodine atom, etc. And R ⁷ represents a hydrogen atom, an alkyl group such as a methyl group, an ethyl group, an n-propyl group and an iso-propyl group, and an aryl group such as a phenyl group, a toluyl group and a naphthyl group.

Specifically, pyrrole, N-methylpyrrole, N-ethylpyrrole, Nn-propylpyrrole, 3-methylpyrrole, 3-ethylpyrrole, 3-methyl-N-methylpyrrole, 3-ethyl-N-methyl. Pyrrole, 3-methoxypyrrole, 3-ethoxypyrrole, 3-methoxy-
N-methylpyrrole, 3-ethoxy-N-ethylpyrrole, 3-phenylpyrrole, 3-phenyl-N-methylpyrrole, 3-phenoxypyrrole, 3-naphthoxypyrrole, 3-methylthiopyrrole, 3-ethylthiopyrrole, 3-bromopyrrole, 3,4-dibromopyrrole,
Examples include 3,4-dimethylpyrrole and 3,4-diethyl-N-methylpyrrole.

In the aniline-based compound represented by the general formula (4), R ⁸ and R ⁹ are hydrogen atom, methyl group, ethyl group, n-
Alkyl group such as propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group, methoxy group, ethoxy group, n-propoxy group, is
Represents an alkoxy group such as o-propoxy group and n-butoxy group, an aryl group such as phenyl group, toluyl group and naphthyl group, and an allyloxy group such as phenoxy group, methylphenoxy group and naphthoxy group, and R ¹⁰ and R ¹¹ Is a hydrogen atom, an alkyl group such as a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, and an n-butyl group, a phenyl group,
It represents an aryl group such as a toluyl group and a naphthyl group.

Specifically, aniline, 3-methylaniline, 3,5-dimethylaniline, 3-ethylaniline, 3-n-propylaniline, 3-methoxyaniline, 3,5-dimethoxyaniline, 3-ethoxyaniline, 3, 5-diethoxyaniline, 3-phenylaniline, 3,5-diphenylaniline, 3-naphthylaniline, 3-toluylaniline,
2,5-dimethylaniline, 3-phenoxyaniline, 3
-Naphthoxyaniline, N, N-dimethylaniline,
N, N-diethylaniline, 3-methyl N, N-dimethylaniline, 3,5-dimethyl N, N-diethylaniline, 3-ethyl N, N-dimethylaniline, 3-methoxy N, N-dimethylaniline, 3 5,5-dimethoxy N, N
-Dimethylaniline, 3-phenoxy N, N-dimethylaniline, and the like.

The amount of the pyrrole compound or aniline compound used relative to the vinylcarbazole polymer or acenaphthylene polymer is 0.01 to 100 times mol, preferably 0.0
It is 5 to 50 times mol.

The polymerization reaction of the monomer compound represented by the general formula (3) or (4) in the presence of the polymer represented by the general formula (1) or (2) can be carried out in any phase of solid phase, liquid phase and gas phase. Can be carried out in, the polymerization reaction of the monomer compound represented by the general formula (3) or (4) in the presence of an organic solvent in which the polymer represented by the general formula (1) or (2) is uniformly dissolved Is preferably performed. In particular,
By performing the reaction in a completely homogeneous solution system in which the monomer compound represented by the general formula (3) or (4) is uniformly dissolved in a homogeneous solution containing the polymer represented by the general formula (1) or (2), ( The polymer of 1) or (2) and the polymer of the monomer compound of (3) or (4) are homogeneously dispersed.

In the polymerization reaction of the monomer compound represented by the general formula (3) or (4), a metal salt having a strong acid residue, halogen or cyan, a peroxide or a nitrogen oxide is usually used. Specifically, Fe (ClO ₄ ) ₃ , Fe (BF ₄ ) ₃ , Fe ₂ (Si
_{F 6) 3, Cu (ClC} 4) 2, Cu (BF 4) 2, C
uSiF ₆ , FeCl ₃ , CuCl ₂ , K ₃ [Fe (C
N) ₆ ], RuCl ₃ , MoCl ₅ , WCl ₆ , (NH
₄ ) ₂ S ₂ O ₈ , K ₂ S ₂ O ₈ , Na ₂ S ₂ O ₈ , Na
BO ₃ , H ₂ O ₂ , NOBF ₄ , NO ₂ BF ₄ , NOC
lO _4, NORsF _6, NOPF _6, and the like.

The amount used is 0.01 to 100 times mol, preferably 0.05 to 50 times mol, of the monomer compound.

As the organic solvent to be used, any solvent can be optionally used as long as it uniformly dissolves the polymer represented by the general formula (1) or (2), but tetrahydrofuran, dioxane, chloroform, dichloroethane, dichloromethane, dichloro Benzene or the like can be used as a good solvent.

The amount of the polymer represented by the general formula (1) or (2) with respect to the solvent is 0.1 to 60% by weight, preferably 1 to 50% by weight.
Is. The reaction temperature is -20 to 100 ° C, preferably 0 to 8
It is 0 ° C., and the reaction time is related to the reaction temperature, but is usually 0.5 to 100 hours, preferably 1 to 50 hours.

The reaction product is a dark brown to black solid substance. In the reaction in the presence of a solvent, after completion of the reaction, the solvent should be removed by a usual method or transferred to water or alcohol, and the product should be collected and washed. Can be easily separated and purified by.

This reaction product is electrically conductive as described in the examples. In the present invention, the reaction product is molded into a desired shape by a known method such as pressure molding and used as an electrode of a secondary battery. At this time, such a reaction product can be used alone, but in order to increase the mechanical strength of the electrode and increase the conductivity to improve the battery characteristics, a thermoplastic resin or an appropriate conductive member is used. Etc. are preferably added. Such a thermoplastic resin can be used without particular limitation as long as it is substantially insoluble in the electrolytic solution of the battery. Usually, those having a molecular weight of 10,000 or more are used. Specific examples include polyethylene, polypropylene,
Ethylene-propylene copolymer, ethylene-tetrafluoroethylene copolymer, polytetrafluoroethylene,
Polytrifluoroethylene, polydifluoroethylene,
Tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, polytrifluoroethylene chloride, polyvinylidene fluoride, tetrafluoroethylene-ethylene copolymer, chlorotrifluoro Ethylene-ethylene copolymer, polyamide,
Examples thereof include polyester, polycarbonate, and modified polyolefin.

Further, if the conductive member is a material that does not dissolve even after repeated charging and discharging, for example, a member such as stainless steel, metal such as gold, platinum, nickel, copper, molybdenum, titanium, carbon, carbon fiber, etc. There is no particular limitation,
Particularly, a lightweight and highly conductive material is preferable. Specific examples include a metal net made of such a metal, a metal plated fiber, a metal vapor-deposited fiber, a metal-containing synthetic fiber, and a net, a woven fabric and a non-woven fabric made of carbon fiber, carbon composite fiber and the like. .

The thermoplastic resin and the conductive member may be added in an amount of 0.02 to 1000 parts by weight of the thermoplastic resin and 2 to 100 parts by weight of the conductive member with respect to 100 parts by weight of the reaction product (organic semiconductor). preferable.

In the secondary battery of the present invention, an electrode formed by using such a reaction product as an electrode material is used for both positive and negative electrodes, and this electrode is used for only one electrode, and the other electrode is made of metal or metal. In some cases, an oxide or other inorganic compound, or a known conductive polymer other than the reaction product of the present invention, an organic compound, an organometallic compound, or the like is used as an electrode material. Using an electrode using this reaction product only for the positive electrode,
Taking the case of using a metal as the electrode material of the negative electrode, it is preferable to use a metal having an electronegativity of 1.6 or less as the metal forming the negative electrode. Examples of such metals include Li, Na, Examples thereof include K, Mg, Al or alloys thereof. In particular, Li and Li alloy having the highest battery negative degree are preferable from the viewpoint of ensuring a high energy density.

On the other hand, as the electrolytic solution used in the secondary battery of the present invention, a solution prepared by dissolving an electrolyte in an organic solvent is used. Examples of such electrolytes include salts with cations such as metal cations having an electronegativity of 1.6 or less, cations such as organic cations, and anions. Examples of onium ions include quaternary ammonium ions, carbonium ions, oxonium ions and the like. Also, as anion, BF
_{^{4 -, ClO 4 -, PF}} 6 -, AsF 6 -, CF 3 SO
_{^{3 -, I -, Br -}} , Cl -, F - , and the like. Then, specific examples of such an electrolyte include lithium tetrafluoroborate (LiBF ₄ ), lithium perchlorate (LiClO ₄ ), and lithium hexafluorophosphate (L
iPF ₆ ), lithium tetrachloroaluminate (LiA
lCl ₄ ), tetraethylammonium tetrafluoroborate (Et ₄ NBF ₄ ), tetra-n-butylammonium perchlorate (nBu ₄ NClO ₄ ), lithium trifluoromethanesulfonate (LiCF ₃ SO ₃ ), lithium iodide (LiI). , Lithium bromide (LiBr), and the like, but are not limited thereto. Then, the organic semiconductor of the present invention is used for both positive and negative electrodes, and L
Taking a battery configured by using an electrolytic solution in which iBF ₄ is dissolved as an electrolyte, for example, during charging, the organic semiconductor in the positive electrode contains BF ₄ ⁻ in the electrolytic solution, and the organic semiconductor in the negative electrode contains Li ⁺ in the electrolytic solution is doped respectively. On the other hand, at the time of discharge, B doped in the positive and negative electrodes
F ₄ ⁻ and Li ⁺ are released into the electrolytic solution, respectively.

The organic solvent that dissolves the electrolyte is preferably an aprotic one having a high dielectric constant, such as nitrile, carbonate, ether, nitro compound, amide, sulfur-containing compound,
Chlorinated hydrocarbons, ketones, esters and the like can be used. Further, such solvents may be used as a mixture of two or more kinds. As typical examples of these, acetonitrile, pyropionitrile, butyronitrile, benzonitrile, propylene carbonate, ethylene carbonate,
Tetrahydrofuran, dioxolane, 1,4-dioxane, nitromethane, N, N-dimethylformamide, dimethyl sulfoxide, sulfolane, 1,2-dichloroethane, γ-butyrolactone, 1,2-dimethoxyethane, methyl phosphate, ethyl phosphate, etc. I can mention,
It is not limited to these.

And the concentration of the electrolytic solution of the present invention is usually 0.001-1.
It is used at 0 mol / mol, preferably 0.1 to 3 mol / mol.
Used in.

Such an electrolytic solution can be used not only by pouring but also by preliminarily impregnating an electrode using the organic semiconductor of the present invention.

Further, in the above, the method of forming the electrode as it is without performing the doping treatment on the organic semiconductor has been described, but the organic semiconductor is previously doped with the dopant,
After that, it can be used alone or by molding it into an electrode using the conductive material and / or the thermoplastic resin as described above.

Further, in the present invention, in order to fix the electrode in the electrolyte, the electrode may be covered with glass, Teflon, polyethylene, a plate or the like having a drainboard shape or a hole.

Further, in the battery of the present invention, a porous membrane such as glass filter paper, Teflon, polyethylene, polypropylene, nylon, etc. may be used as the separator.

<Function> The organic semiconductors as described above have excellent acid resistance and are stable in the air and in the battery. During the production of electrodes or in the battery like a conductive polymer having a conjugated double bond in the main chain such as polyacetylene. When incorporated into, the material does not deteriorate, and exhibits higher conductivity than the conventional type of conductive polymer having no conjugated double bond in the main chain. Further, since the doping level is higher than that of polyacetylene or the like, the battery capacity is improved when used as a battery electrode.

<Example> Polyvinyl carbazole (molecular weight 2
6.0 g of 10,000) was taken and 70 ml of tetrahydrofuran was added and dissolved to prepare a uniform viscous liquid. Pyrrole (2.0 g) was added to this viscous liquid to prepare a homogeneous mixture of polyvinylcarbazole and pyrrole, and the mixture was stirred at room temperature under a nitrogen stream while 10 ml of tetrahydrofuran (30 ml) in which 4.87 g of FeCl ₃ was dissolved. It was dripped over a period of minutes.
At this time, the reaction liquid was initially colorless, but turned black with the passage of time, and a black viscous liquid was obtained after 3 hours. After leaving this liquid overnight, pour it into a large amount of methanol,
The residue was washed with 200 ml of methanol three times and then dried under reduced pressure at 60 ° C. to obtain 7.18 g of a uniform black powder.

Note that polyvinylcarbazole was quantitatively recovered when the treatment was performed in the same manner except that pyrrole was not used.

From the above results, it is shown that by the above treatment, pyrrole was polymerized and a polymer composed of polyvirol uniformly dispersed in polyvinylcarbazole was produced.

The electric conductivity of this polymer was measured by the two-terminal method, and the result was 3.3 × 10 ⁻⁶ Scm ⁻¹ , which was found to be an organic semiconductor having conductivity in the semiconductor region.
And with polyvinylcarbazole only, 10 ^-15 Scm
^-1 is known to be an insulator. Therefore, the polymer obtained above has a significantly improved electrical conductivity.

The electric conductivity was measured as follows. First, the black powder obtained by the above treatment was finely pulverized with a milk needle, and then pressure-molded (5 tons / cm ² ) into a disk shape having a diameter of 10 mm. Then, place stainless steel discs of the same size on both sides of this disc sample, place them between Teflon bolts and nuts, and tighten these discs by crimping, and then store them in a dry box. Meter (Takeda RIKEN TR-86
51) was used to measure the electrical conductivity of the disc samples.

This organic semiconductor is used as a positive electrode material, and this, acetylene black (conductive agent), and polytetrafluoroethylene (binder) are sufficiently mixed at a weight ratio of 85: 10: 5, and then pressed into a disk shape. The molded product was used as the positive electrode. In addition, lithium was punched into a predetermined size to form a negative electrode.

Next, as shown in FIG. 1, the negative electrode portion is formed by pressing the negative electrode 2 onto the bottom surface of the negative electrode can 7 via the negative electrode current collector 8 and the positive electrode 1 via the positive electrode current collector 6 as shown in FIG. The positive electrode portion, which is in close contact with the bottom surface of the positive electrode can 5, is combined through the separator 3 made of polypropylene nonwoven fabric, and lithium tetrafluoroborate (electrolyte) is mixed at 1 mol / mol in propylene carbonate (solvent). A battery according to the present invention (invention product A) having a diameter of 24 mm and a height of 3.0 mm was produced by using the electrolytic solution obtained by dissolving Incidentally, in FIG.
Is an insulating gasket.

On the other hand, in place of polyvinylcarbazole, 6.0 g of polyacenaphthylene (molecular weight: 150,000), and FeCl ₃ 9.
Polymerization reaction of pyrrole was carried out in the presence of uniformly dissolved polyacenaphthylene in the same manner as in Example 1 except that 74 g was used. At this time, when FeCl ₃ -tetrahydrofuran was added, the color of the reaction liquid became reddish at the beginning of the reaction, but blackening progressed with the passage of time, and after 2 hours, the entire reaction liquid became a viscous black liquid. Became. The black liquid was allowed to stand overnight, transferred to a large amount of methanol, the residue was washed 4 times with 200 ml of methanol, and dried under reduced pressure at 60 ° C. to obtain 6.68 g of a uniform black solid.

In addition, polyacenaphthylene was quantitatively recovered when the treatment was carried out in the same manner except that pyrrole was not used.

The above results indicate that the above-mentioned treatment polymerized pyrrole and produced a polymer composed of polypyrrole uniformly dispersed in polyacenaphthylene. Further, from the increase in weight, it is shown that the obtained polymer is a polymer containing 0.68 g of polypyrrole in 6.0 g of polyacenaphthylene. The electric conductivity of this polymer was 4.2 × 10 ^-9 Scm ^-1 , and it was found that the polymer was an organic semiconductor having conductivity in the semiconductor region.

The present invention is used except that this organic semiconductor is used as a positive electrode material, and this, acetylene black, and polytetrafluoroethylene are mixed in a weight ratio of 85: 10 :: 5 and pressure-molded into a disk-shaped positive electrode. A battery according to the present invention (invention product B) was produced in the same manner as the product A.

On the other hand, polyacetylene powder was used as the positive electrode material, and this was mixed with acetylene black and polytetrafluoroethylene in a weight ratio of 85: 10: 5 and pressed into a disk shape to form the positive electrode. A battery for comparison (comparative product C) was produced in the same manner as in A.

The charge and discharge efficiency (%) of the above three batteries was repeatedly charged at 1 mA for 5 hours and then discharged at 1 mA until the battery voltage became 2.0 V. The cycle change was investigated. The results are shown in FIG.

From the figure, the characteristics of the comparative product C are temporarily stabilized after about 20 cycles, but a sharp decrease in charge / discharge efficiency is observed after about 50 cycles. Not only does it show higher charging / discharging efficiency than Comparative Product C throughout the cycle, but also the characteristics are stable after about 20 cycles and 9 even after 80 cycles.
It can be seen that the high charge / discharge rate of 0 to 95% is continuously maintained. The charge and discharge efficiencies of the products A and B of the present invention at the 80th cycle were 90 and 93%, respectively, whereas the comparative product C was
In the case of, it was only 25%. The reason why the cycle characteristic of the comparative product C is such poor is that the positive electrode material is caused by the water and oxygen adsorbed or adhered to the polyacetylene powder without being completely removed, and the dissolved oxygen and trace water in the electrolytic solution. It seems that this is due to the deterioration of the material of a certain polyacetylene powder. In the case of the products A and B of the present invention, the organic semiconductor, which is the positive electrode material, has excellent oxidation resistance, and there is no deterioration of the material due to dissolved oxygen or a trace amount of water in the electrolytic solution. As a result of having a high conductivity equivalent to that of a conductive polymer having a conjugated double bond, it seems that the cycle characteristics of the battery are thus good.

In addition, FIG. 3 shows changes over time in the battery voltage during charge and discharge in the 80th cycle. In the figure, the solid line shows the voltage change during charging and the dotted line shows the voltage change during discharging. It can be seen from FIG. 3 that the products A and B of the present invention do not have a sharp rise in voltage during charging, and the discharge voltage has a much better flatness than the comparative product C.

In the above description, the organic semiconductor is used only as the positive electrode material, but it is clear that the same effect can be obtained when the organic semiconductor is used as the negative electrode material or the positive and negative electrode material.

<Effects of the Invention> According to the secondary battery of the present invention configured as described above,
The use of an organic semiconductor as an electrode material, which has excellent oxidation resistance, is stable in the air and in the battery, and has high conductivity, makes it extremely easy to control the electrode production environment and improve the storage stability of the electrode itself. In addition to the advantages of using a conductive polymer with a conjugated double bond in the main chain as an electrode material, a conventional conductive polymer that does not have a conjugated double bond in the main chain is used. It has the advantages of excellent charge / discharge characteristics and long cycle life without the drawbacks of using it as an electrode material, and its practical value is extremely large.

[Brief description of drawings]

FIG. 1 is a sectional view showing a battery structure according to an embodiment of the present invention,
FIG. 2 is a graph showing the cycle characteristics of the product of the present invention and the comparative product, and FIG. 3 is a graph showing the change with time of the battery voltage during charge and discharge. 1 ... Positive electrode, 2 ... Negative electrode, 3 ... Separator, 5 ... Positive electrode can, 7
… Negative electrode can.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Nishio, Keihan Hon-dori, 2-18, Osaka, Moriguchi City, Osaka Prefecture Sanyo Electric Co., Ltd. (72) Nobuhiro Furukawa, Keihan Hon-Dori, 2--18, Moriguchi, Osaka Sanyo Electric Co., Ltd.

Claims (1)

[Claims] 1. At least a general formula Or general formula (Wherein R ^{1 to} R ⁴ represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, an allyloxy group, a thioether group, an amino group, a halogen atom, an aldehyde group, a cyano group or a nitro group). In the presence of any one of the polymers having at least the general formula (Wherein R ⁵ and R ⁶ represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, an allyloxy group, a thioether group and a halogen atom, and R ⁷ represents a hydrogen atom, an alkyl group and an aryl group). Compounds or general formula (Wherein R ⁸ and R ⁹ represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, and an aryloxy group, and R ¹⁰ and R ¹¹ represent a hydrogen atom, an alkyl group, and an aryl group). A secondary battery comprising an organic semiconductor obtained by polymerizing one of the compounds as at least one of a positive electrode and a negative electrode.