JPH06243715A - Manufacture of polypyrrole molding - Google Patents

Abstract

PURPOSE:To enable the charge and discharge at a high current density, and to obtain a comp molding effective as the active material for polymer secondary battery having a high charge and discharge capacity by dipping negative ion, which is included in polypyrrole obtained by the electrolytic polymerizing method, in the polar organic solvent before/after changing the negative ion to smaller negative ion. CONSTITUTION:Polypyrrole is obtained by dipping an electrode substrate for polymerization in the solvent, in which support salt including negative ion and positive ion at a large ion size and pyrrole are dissolved evenly, and performing the electrolytic oxidation polymerization. The negative ion at a large ion size is surrounded by the polymer at the time of polymerizing polypyrrole, and the operation for exchanging the negative ion with a smaller negative ion is performed. When this polypyrrole negative ion is exchanged, polypyrrole is dipped in the organic solvent having a high affinity with the polypyrrole before or after the exchange. Movement of the small negative ion for diffusion is thereby facilitated to obtain a molding having a high charge and discharge capacity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polypyrrole molded article suitable for an improved polymer secondary battery electrode.

[0002]

2. Description of the Related Art Generally, it is known that a conductive polymer has a property of being oxidized and reduced electrochemically in addition to exhibiting a high conductivity. It is known that the anions contained in the conductive polymer come in and out with the oxidation / reduction reaction of the conductive polymer. An electrode using polypyrrole, polythiophene, polyaniline, or the like has been proposed by utilizing this function as an electrode.

However, when the conventionally proposed conductive polymer is used as these electrodes, it is difficult to obtain a high charge / discharge capacity. This phenomenon is observed especially in charge and discharge at high current density. For example, in the case of a high-capacity type thick film electrode, it is difficult to obtain a high output.

In order to solve these problems, a conductive polymer containing an anion having a large ionic radius is prepared in advance in Japanese Patent Laid-Open No. 62-2468 and Japanese Patent Laid-Open No. 2-119051 to prepare a battery. It has been proposed to use an electrolyte containing anions having a small ionic radius for incorporation. However, even with this method, some effects are recognized in the case of a thin film, but the effects are not sufficient in a thick film.

Further, in Japanese Patent Application Laid-Open No. 4-181652, thick film polypyrrole polymerization is carried out by repeating electrolytic polymerization and undoping of polypyrrole containing a large anion in advance, that is, while anion is being taken in and out. A method of exchanging small anions by an electrochemical method or a chemical method has been proposed.
This method is based on the idea that the anion diffusion passages (channels) are secured by moving anions in and out during polymerization, and the anions are facilitated by exchanging with smaller anions. According to this method, a considerably high charge / discharge capacity can be obtained even at a high current density, but it still does not reach a sufficient capacity.

[0006]

SUMMARY OF THE INVENTION In view of the drawbacks of the polymer secondary battery, the present invention provides a polymer secondary battery which can be charged and discharged at a high current density and can obtain a high charge and discharge capacity. The purpose is to obtain a polypyrrole molded product useful as a substance.

For that purpose, it is effective to enhance the emission of anions in the polypyrrole molded article. In dense compacts such as polypyrrole, in order to smoothly move in and out of anions associated with charging and discharging, that is, to facilitate the diffusion of anions in the compact, polypyrrole containing large anions is preliminarily electropolymerized and undoped. It is an effective method to repeat the above procedure to polymerize while anion is taken in and out, and then to exchange it with a smaller anion, but the operation alone is not always sufficient.

[0008]

The present invention provides a method for producing a polypyrrole molded article, which comprises exchanging anions contained in a polypyrrole obtained by an electrolytic polymerization method with smaller anions, before and / or after exchange. Alternatively, it is a method for producing a polypyrrole molded article, which comprises immersing the substrate in a polar organic solvent after replacement.

The present inventors have paid attention to the point of further increasing the inflow / outflow (diffusion) of anions in polypyrrole, and in the above-mentioned anion exchange, a polar organic solvent having a high affinity with polypyrrole before and / or after exchange. It was thought that the channel formation of ion diffusion would proceed smoothly by immersing it in, and as a result of intensive studies, the present invention was completed.

The polypyrrole of the present invention is a conjugated conductive polymer composed of an unsubstituted or substituted pyrrole having a five-membered heterocyclic ring. Examples of those having a substituent include those in which the 3-position and / or the 4-position are substituted with an alkyl group, an alkoxy group, a carboxy group, a carboxymethyl group or the like.

A general embodiment of the present invention is as follows. That is, polypyrrole can be obtained by immersing a polymerization electrode substrate in a solution in which a supporting salt containing an anion and a cation having a large ionic size and pyrrole are uniformly dissolved and electrolytically oxidatively polymerizing the electrode substrate. The anion having a large ion size is incorporated into the polymer when the polypyrrole is polymerized, and an operation of exchanging the anion with a smaller anion is added. When exchanging the anions of the polypyrrole, the polypyrrole is immersed in a specific polar organic solvent having a high affinity before or after the exchange. Hereinafter, description will be made step by step.

(Electrolytic Polymerization) The anion of the supporting salt used for electrolytic polymerization in the present invention must be sufficiently larger than the anion contained in the polypyrrole molded product, that is, the molded product when it is used as an electrode. Otherwise, even if the anions are exchanged, the ion diffusion will not proceed smoothly. For that purpose, the molecular weight of the anion of the supporting salt used for electrolytic polymerization is preferably 150 or more. The size of the anion of the supporting salt is preferably 8 angstroms or more. Here, the ion size of the anion is the length in the major axis direction of the molecule including the ionized atom.

The shadow of these large ionic size supporting salts
As an ion, C_nF_{2n + 1}SO₃ ^-(N = 4 to 12)
A perfluoroalkanesulfonate ion represented by
General formula C_nH_{2n + 1}SO₃ ^-(N = 4 to 12)
Rucan sulfonate ion, general formula C_nF_{2n + 1}OSO₃ ^-
Perfluoroalkyl sulfuric acid represented by (n = 4 to 12)
Ester ion, general formula C_nH_{2n + 1}OSO₃ ^-(N = 4
~ 12) alkyl sulfate ester ion
Substituted and substituted benzenesulfonic acid, naphthalene sulfone
Each ion of sulfonic acids such as acid can be used. Well
Further, as the carboxylic acid, unsubstituted and substituted benzoic acids are
Can be mentioned. Of these, more preferred is ion
Size and shape, benzenesulfonic acid, toluene
Rufonic acid, p-tert-butylbenzenesulfonic acid,
2,4,6-triisopropylbenzenesulfonic acid, o
Cutylbenzene sulfonic acid, dodecyl benzene sulfone
Alkylbenzene sulfonic acid such as acid, methoxybenze
Acid, 5-sulfoisophthalic acid, 5-sulfoi
Sophthalic acid dimethyl ester, 5-sulfoisophthalic acid
Dihydroxyethyl ester, naphthalene sulfonic acid
Which can be mentioned.

The supporting salt containing these as components is
Tetramethylammonium ion, tetraethylammonium ion, tetrapropylammonium ion, tetrabutylammonium ion, and other tetraalkylammonium ion salts, which are counterions of these anions, salts of alkali metal ions such as Li, Na, and K, etc. Is mentioned.

In the electrolytic polymerization of the present invention, the supporting salt containing an anion having a large ion size is used as an electrolyte in an amount of 0.0001M to 1M, preferably 0.001M, with respect to the solvent.
Conducted using an electrolytic solution dissolved at a concentration of 0.5M.

The solvent used in the electrolytic solution of the electropolymerization of the present invention is a solvent generally used in electrochemical reactions such as acetonitrile, benzonitrile, water, propylene carbonate, ethylene carbonate, nitrobenzene, tetrahydrofuran, nitromethane, sulfolane,
Dimethoxyethane, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and the like, and mixed solvents thereof are used.

The electrode used in the electrolytic polymerization is not particularly limited, but metals such as platinum, palladium, gold, silver, nickel, stainless steel, etc. used in the electrochemical reaction, or conductive materials similar to these or carbon are used. The material such as an electrode is used.

The electropolymerization of polypyrrole in the present invention is performed by, for example, "conductive polymer material" (supervised by Hiroyuki Sparrow, CMC, published in 1983), "new conductive polymer material" (supervised by Hiroyuki Sparrow, CMC). , 1987), "Handbood of Conducting Polymers" (TA S
Kotheim (ed.), Marcel Dekker, New York, 1986).

(Undoping) In order to more effectively bring out the battery characteristics of the polypyrrole molded article of the present invention, it is preferable to repeatedly carry out electrolytic polymerization and undoping during the polymerization operation. Here, undoping means that anions contained in polypyrrole are extracted from the polypyrrole. To this end, in general, the potential difference between the anode and the cathode, that is, the electrolytic weight applied with a symmetrical voltage in which the voltage value changes alternately with time between positive and negative and the period of the positive voltage value is large. Take legality. It is also possible to apply an asymmetric voltage. In this case, the current during electrolysis repeats the cycle of 0 → positive → negative → zero, and during the period of 0 → positive → zero, electrolytic polymerization of polypyrrole occurs on the surface of the anode. In this period, the electrolytic polymerization proceeds and the doping of the undoped polypyrrole polymer proceeds in the preceding period. Therefore, if the positive voltage period is long, both polymerization and doping reactions can sufficiently proceed during this period.
In the period of zero → negative → zero, the above-mentioned polymerization does not occur, and undoping of polypyrrole occurs. By the above operation, the anions of the above supporting salt are repeatedly undoped and doped to form ion diffusion paths in the polypyrrole molded article.

The potential applied during the electropolymerization is carried out between the oxidation-reduction potential of the monomer and the upper limit, and below the reduction potential of the polymer and the lower limit. As the upper limit of the applied potential, a potential higher than the polymerization oxidation potential is preferably used within a range in which side reactions such as a monomer, a solvent and a supporting salt do not occur simultaneously. The lower limit of the applied potential is preferably a potential lower than the reduction potential of the polymer. The upper limit potential applied during electrolysis is
0.7 to 1.5 V (vs Ag / AgCl), preferably 0.8 to 1.2 V is used, and the lower limit potential is -1.5 to-.
0.3V, preferably -1.0 to -0.4V is used. If the potential applied to the anode is raised or lowered between a potential higher than the oxidation potential of the polymer and a potential lower than the reduction potential, anions will enter and leave, and polymerization will occur if the oxidation potential of the monomer becomes lower than the lower limit. Occur. Therefore, the potential and the holding time thereof may be set in consideration of the balance between polymer generation and anion inflow / outflow. Hereinafter, the operation of changing the potential applied to the anode between the upper limit potential and the lower limit potential with time is referred to as raising and lowering the potential.

The waveform of the potential applied to the anode is not particularly limited, but generally a rectangular wave, a triangular wave, a sine wave or a waveform in which they are superimposed is used.

The electropolymerization in the present invention is an electrolysis in which a current flowing between both electrodes is alternately changed over time between positive and negative and a positive current is supplied for a long period. The polymerization method can be used. It is also possible to apply an asymmetric voltage. In this case, the current during electrolysis repeats the cycle of 0 → positive → negative → zero, and electrolytic polymerization occurs during the period of passing the positive current. During this period, the electropolymerization proceeds and the doping of the undoped polypyrrole polymer proceeds during the preceding negative current period. Therefore,
When the positive current period is made large, both reactions of polymerization and doping can sufficiently proceed during this period. In the period of zero → negative → zero, the above-mentioned polymerization does not occur, and undoping occurs.
By the above operation, the anions of the above supporting salt are repeatedly undoped and doped to form ion diffusion paths in the polypyrrole molded article.

The positive current during electrolytic polymerization is 0.01 to 100 mA / cm ² , preferably 0.0 as the current density at the anode.
It is 5 to 50 mA / cm ² . If the current density of the positive current is too large, the anode potential may rise too much and side reactions such as monomers, solvents, supporting salts, etc. may occur at the same time. If the current density is too low, the time required for the polymerization will be long and the productivity will be extremely reduced. Negative current during electrolytic polymerization is, 0.01~100mA / cm ² as a current density at the anode, preferably 0.05~50mA / cm ^2. If the current density of the negative current is too high, undoping of anions will be insufficient. Further, if the current density of the negative current is too small, the time required for undoping becomes long, resulting in extremely low productivity. Therefore, as in the case of raising and lowering the potential, the potential and the holding time thereof may be set in consideration of the balance between polymer production and ion ingress and egress. There is no particular limitation on the waveform of the current flowing between the electrodes, but generally a rectangular wave,
A triangular wave, a sine wave, or a waveform in which they are superimposed is used.

The polymerization temperature is -50 to + 50 ° C, preferably -40 to + 40 ° C. If the temperature is lower than that, the viscosity of the system is increased, and the voltage between the electrodes is excessively increased to easily cause a side reaction, which is not preferable.

The thickness of the film formed per cycle of the repeating cycle of electrolytic polymerization and undoping treatment is 0.1 to 50 μm, more preferably 0.3 to 30 μm.
m, particularly preferably 0.5 to 15 μm.

It is preferable that the repeating period of the electrolytic polymerization and the undoping treatment is 10 to 10,000 seconds / cycle. If the repetition period of electrolytic polymerization and undoping treatment is less than 10 seconds / cycle, the anion exchange reaction cannot catch up, and sufficient ion entry / exit does not occur. On the other hand, if this cycle exceeds 10,000 seconds / cycle, the oxidation potential per cycle is held for a long time, and the thickness of the polymer film per cycle becomes thicker, and the anions in and out of the polymer flow in and out. Will be difficult.

The polypyrrole obtained here has a thickness suitable for use as an electrode of a secondary battery, that is, 50 μm or more,
It is preferably 50 to 2,000 μm.

(Exchange of Anion) When the anion of the polypyrrole obtained by the above method is exchanged for a small anion, dipping treatment is carried out in a polar organic solvent before and / or after the exchange, whereby A polypyrrole molded product is obtained.

The anions of polypyrrole are combined by the following method.
Can be exchanged. Introduce / change polypyrrole
Small anions are the supporting salts used in the polymerization of polypyrrole
Large difference in molecular weight or ion size from anion of
Is more preferable. Small anions have a molecular weight of 150 or less
Ions with an ion size of 8 Å or less
No, no₃ ^-, HSO_Four ^-, BF_Four ^-, PF₆ ^-, CF
₃SO₃ ^-, ClO_Four ^-And so on. Special
When considering the electrolyte used in the secondary battery,_Four
^-, PF₆ ^-And ClO_Four ^-Are particularly preferred.

As the solvent for dissolving the electrolyte containing the small anion, any solvent that can easily dissolve the electrolyte may be used, and examples thereof include cyclic carbonates such as propylene carbonate and ethylene carbonate, dimethylacetamide,
Basic polar solvents such as dimethylformamide, N-methylpyrrolidone, dimethylsulfoxide, tetramethylurea, sulfolane, polar solvents such as lactones such as γ-butyrolactone and β-propiolactone, and other dimethoxyethane, acetonitrile, benzo. Examples thereof include nitrile, nitrobenzene, tetrahydrofuran, dioxane, nitromethane, ethylene glycol, ethylene glycol monomethyl ether, water and the like. Among these solvents, the polar organic solvent described later is preferable from the viewpoint of making the dipping effect effective. These solvents may be used alone or as a mixed solvent.

By raising or lowering the potential applied to the polypyrrole molded body in the electrolytic solution containing the above-mentioned exchange anion, the anion of the electropolymerization supporting salt is anion with a smaller ion size (anion). Can be exchanged. The method of raising and lowering the potential may be performed according to the method and conditions according to the method at the time of polymerization.

The polar organic solvent used in the immersion treatment of the present invention includes basic polar solvents such as dimethylacetamide, dimethylformamide, N-methylpyrrolidone, dimethylsulfoxide, tetramethylurea and sulfolane, and γ-
Examples include lactones such as butyrolactone and β-propiolactone. Particularly, amide-based polar solvents such as dimethylacetamide, dimethylformamide, N-methylpyrrolidone and the like, and propylene carbonate are preferable in consideration of the effect and economical efficiency. These solvents may be used alone or as a mixed solvent.

An electrolyte is preferably dissolved in the polar organic solvent in which the polypyrrole is dipped. This is because, if the electrolyte is not added, anions may be extracted from the polypyrrole into the solvent during the dipping treatment, the polypyrrole may be inactivated, and the charge / discharge characteristics may deteriorate.
Examples of the electrolyte include alkali metal salts of inorganic or organic acids, or tetraalkylammonium salts of inorganic or organic acids. The electrolyte preferably used in the present invention is an electrolyte used when introducing or exchanging an anion having an ion size smaller than that of the supporting salt used for the electropolymerization of polypyrrole into the polypyrrole. The anion having a small ion size is an ion having a size of 8 angstroms or less and a molecular weight of 150 or less.
O ₃ ⁻ , HSO ₄ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , CF ₃ SO
₃ ⁻ , ClO ₄ ^{− and the} like can be mentioned. Especially when considering the electrolyte used in the secondary battery, BF ₄ ⁻ , P
F ₆ ⁻ and ClO ₄ ⁻ are particularly preferred.

The electrolyte concentration of the immersion solvent is not particularly limited, but is usually 0.1 M or more.

Stirring of the immersion solvent during immersion may be performed by circulating the solvent, using a shaker, an ultrasonic oscillator, or the like, or without stirring. The immersion temperature may be higher than or equal to the freezing point of the solvent and lower than or equal to the boiling point. However, if the temperature is too high, unfavorable reactions such as side reactions occur, and thus the temperature is preferably 50 ° C. or lower.

The immersion time is determined depending on the conditions such as the presence or absence of stirring and the temperature, but it is usually in the range of 12 hours to 30 days.

[0037]

INDUSTRIAL APPLICABILITY In this way, the anions in polypyrrole are ion-exchanged by anions having a smaller ion size. Since the diffusion of large anions in the polymer is forcibly repeated many times due to the rise and fall of the potential during polymerization, the ion migration path (channel) corresponding to the size of the anion has a thickness of the molded body. Formed throughout. Furthermore, it is considered that the above-mentioned ion channel is expanded by swelling the polymer by immersing in a polar organic solvent having a high affinity for polypyrrole before and / or after the ion exchange. Therefore, this expanded channel makes migration and diffusion of small anions in the polypyrrole very easy after ion exchange. Therefore, by using the polypyrrole molded article of the present invention as an electrode of a polymer secondary battery, it is possible to charge and discharge at a high current density and obtain a high charge and discharge capacity.

The battery characteristics of the polypyrrole molded article obtained as described above were evaluated as follows. That is,
The obtained polypyrrole molded body was used as a positive electrode, the platinum foil was used as a negative electrode, the Ag / AgCl electrode was used as a reference electrode to form a three-electrode electrolytic cell, and a liquid prepared by dissolving 1M LiCl ₄ in propylene carbonate was used as an electrolytic solution. A constant current discharge at a current density and a constant potential charge at 0.6 V (vs. Ag / AgCl) were performed. The potentials shown in the following examples are all potentials with respect to the Ag / AgCl reference electrode.

[0039]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

[0040]

Example 1 0.2M pyrrole monomer and 0.2M
P-toluenesulfonic acid tetraethylammonium salt of ((Et) ₄ N.TsO) was dissolved in propylene carbonate containing 1% by volume of water to prepare an electrolytic solution. The large anion incorporated into polypyrrole during polymerization is p-
It is a toluene sulfonate ion (TsO ion). A 200 mesh stainless steel net was used as an anode and a stainless steel plate was used as a counter electrode in this electrolytic solution to form a polymerization cell.

Next, a current density of 10 mA / cm ² was applied between both electrodes.
Positive current for 300 seconds to electropolymerize polypyrrole on the stainless steel surface of the anode, then reverse the current and apply a negative current with a current density of 5 mA / cm ² for 200 seconds to trap TaO ions in the polypyrrole. Was undoped. Polypyrrole was polymerized up to 20 cycles with the above positive current and negative current as one cycle. The polymerization was kept in a nitrogen atmosphere and the polymerization temperature was kept at 25 ° C.
The film thickness of polypyrrole polymerized on the stainless steel net of the anode was about 10 μm per cycle, and the film thickness after 20 cycles was about 200 μm. After the second cycle, the polypyrrole is polymerized when a positive current is applied, and the TsO ions undoped in the immediately preceding cycle are doped again.

Then, the polypyrrole polymerized on the stainless steel net was immersed in dimethylacetamide in which 1M lithium perchlorate (LiClO ₄ ) was dissolved for 5 days at room temperature without stirring.

Then, the obtained polypyrrole was subjected to ion exchange treatment by the following method. Polypyrrole with stainless steel mesh as anode, platinum foil as counter electrode, Ag
A three-electrode electrolytic cell was constructed using the / AgCl electrode as a reference electrode. As the electrolytic solution, a solution prepared by dissolving 1M lithium perchlorate in dimethylacetamide was used. Next, the potential applied to the anode was repeatedly raised and lowered on the fifth floor at a potential scanning speed of 5 mV / sec within a potential range of an upper limit potential of 1.0 V and a lower limit potential of −1.5 V. In this way, the TsO ion doped in the polypyrrole at the time of polymerization was exchanged for perchlorate ion (ClO ₄ ion).

The polypyrrole thus obtained was cut into a circular shape having a diameter of 1 cm together with a stainless steel mesh electrode and incorporated into an electrolytic cell for battery characteristic evaluation. In the electrolytic cell for battery evaluation, polypyrrole was used as the positive electrode, platinum foil was used as the negative electrode, an Ag / AgCl electrode was used as the reference electrode, and a propylene carbonate solution in which 1M lithium perchlorate was dissolved was used as the electrolytic solution. The battery characteristics are 3 at a constant potential of positive electrode potential of 0.6V.
After charging for 0 minutes, the battery was subsequently discharged at a constant current with a current density of 1 to 20 mA / cm ² , and the constant current discharge capacity was measured when the discharge end potential was set to -1.0V. Discharge current density 1mA / cm ²
Then 66 Ah / k in volume density per dry polymer weight
g, capacity density 70 Ah at discharge current density 10 mA / cm ²
/ Kg, and the capacity density was 69 Ah / kg even at a discharge current density of 20 mA / cm ^{2, and} even when discharging a large current, almost no decrease in discharge capacity was observed and a high capacity density was maintained.

[0045]

Example 2 In the same manner as in Example 1, a polypyrrole having a film thickness of about 200 μm and containing TsO ⁻ ions as anions was polymerized on a stainless steel mesh electrode. Then, the obtained polypyrrole was subjected to an immersion treatment using dimethylformamide as an immersion solvent under the same conditions as in Example 1. Then, using dimethylformamide as an electrolyte solvent, the polypyrrole subjected to the immersion treatment was subjected to anion exchange treatment from TsO ⁻ ion to ClO ₄ ⁻ ion in the same manner as in Example 1.

The polypyrrole thus obtained was evaluated for battery characteristics in the same manner as in Example 1. When the discharge current density was 1 mA / cm ² , the capacity density was 61 Ah / kg, and a discharge capacity equivalent to that in Example 1 was obtained. Discharge current density 10mA /
In cm ² , the capacity density is 65 Ah / kg, and the discharge current density is 2
Even at 0 mA / cm ² , the capacity density was 60 Ah / kg, and a high capacity density was maintained with almost no decrease in discharge capacity observed in large current discharge.

[0047]

Example 3 In the same manner as in Example 1, polypyrrole having a film thickness of about 200 μm and containing TsO ⁻ ions as anions was polymerized on a stainless steel mesh electrode. Next, the obtained polypyrrole was immersed in N-methylpyrrolidone as an immersion solvent under the same conditions as in Example 1. Then, the polypyrrole subjected to the immersion treatment was subjected to anion exchange treatment from TsO ⁻ ion to ClO ₄ ⁻ ion in the same manner as in Example 1, using N-methylpyrrolidone as the electrolyte solvent.

The polypyrrole thus obtained was evaluated for battery characteristics in the same manner as in Example 1. When the discharge current density was 1 mA / cm ² , the capacity density was 67 Ah / kg, and a discharge capacity equivalent to that in Example 1 was obtained. Discharge current density 10mA /
In cm ² , the capacity density is 55 Ah / kg, and the discharge current density is 2
Even at 0 mA / cm ² , the capacity density was 47 Ah / kg, and there was little decrease in discharge capacity during high-current discharge, and high capacity density was maintained.

[0049]

Example 4 In the same manner as in Example 1, a polypyrrole having a film thickness of about 200 μm and containing TsO ⁻ ions as anions was polymerized on a stainless steel mesh electrode. Then, the obtained polypyrrole was immersed in propylene carbonate as an immersion solvent under the same conditions as in Example 1. Then, using propylene carbonate as an electrolytic solution solvent, the polypyrrole subjected to the immersion treatment was subjected to anion exchange treatment from TsO ⁻ ion to ClO ₄ ⁻ ion in the same manner as in Example 1.

The polypyrrole thus obtained was evaluated for battery characteristics in the same manner as in Example 1. When the discharge current density was 1 mA / cm ² , the capacity density was 61 Ah / kg, and a discharge capacity equivalent to that in Example 1 was obtained. Discharge current density 10mA /
In cm ² , the capacity density is 51 Ah / kg, and the discharge current density is 2
Even at 0 mA / cm ² , the capacity density was 40 Ah / kg, and there was little decrease in discharge capacity during high-current discharge, and high capacity density was maintained.

[0051]

Comparative Example 1 In the same manner as in Example 1, a polypyrrole containing TsO ⁻ ions as anions having a thickness of about 200 μm was polymerized on a stainless steel mesh electrode. Then, the obtained polypyrrole was treated with TsO ⁻ ion to ClO ₄ ^{− in} the same manner as in Example 1 in an electrolytic solution in which 1M lithium perchlorate was dissolved in propylene carbonate immediately after polymerization without adding a solvent dipping treatment. The ions were subjected to anion exchange treatment.

The polypyrrole thus obtained was cut into a circular shape having a diameter of 1 cm together with a stainless steel net, and Example 1
When the battery characteristics were evaluated in the same manner as in Example 1, the discharge current density was 1 mA / cm ² , and the capacity density was 61 Ah / kg.
The same discharge capacity was obtained, but the discharge current density was 10mA.
/ Cm ² , the capacity density was 37 Ah / kg, and the discharge current density was 20 mA / cm ² , the capacity density was 28 Ah / kg.

This result shows that when polypyrrole is not soaked in a solvent, the anions in polypyrrole do not diffuse sufficiently smoothly, so that the anions are not sufficiently undoped especially in a short time such as a large current discharge. It is shown that.

[0054]

Comparative Example 2 In the same manner as in Example 1, a polypyrrole containing TsO ⁻ ions as anions having a film thickness of about 200 μm was polymerized on a stainless steel mesh electrode. Next, the obtained polypyrrole was immersed in acetonitrile as an immersion solvent under the same conditions as in Example 1. Then, using acetonitrile as an electrolytic solution solvent, polypyrrole subjected to the immersion treatment was treated with TsO ⁻ ions to ClO _{4 in} the same manner as in Example 1.
^- was the anion exchange process in ion.

The polypyrrole thus obtained was cut into a circle having a diameter of 1 cm together with a stainless steel net, and the battery characteristics were evaluated in the same manner as in Example 1. At a discharge current density of 1 mA / cm ² , the capacity density per dry polymer weight was measured. Discharge capacity decreased to 45 Ah / kg, discharge current density of 10 mA / cm ^{2 to} capacity density of 26 Ah / kg, and discharge current density of 20 mA / cm ^{2 to} capacity density of 18 Ah / kg.

The results show that when immersed in acetonitrile, which has a low affinity for polypyrrole, the diffusion of anions in polypyrrole is suppressed and the charge / discharge capacity becomes low.

Table 1 shows the discharge characteristics of Examples 1 to 4 and Comparative Examples 1 and 2. Before the ion exchange of polypyrrole, when the immersion treatment was carried out with any one of the solvents dimethylacetamide, dimethylformamide, N-methylpyrrolidone and propylene carbonate, compared with the case where the immersion treatment was not carried out (Comparative Example 1). , Discharge current density is 10
The result shows that the capacity decrease is small in the large current discharge of mA / cm ² to 20 mA / cm ² .

[0058]

[Table 1]

[0059]

Example 5 The ion-exchanged polypyrrole obtained in Comparative Example 1 was treated with 1M lithium perchlorate (LiCl).
It was immersed in dimethylacetamide in which O ₄ ) was dissolved for 7 days at room temperature without stirring.

The polypyrrole thus obtained was used in Examples
The battery characteristics were evaluated in the same manner as in 1.
Density 1mA / cm²With a capacity density of 74 Ah / kg,
Flow density 10mA / cm²Then capacity density 64Ah / kg,
Discharge current density of 20mA / cm ²But capacity density 57Ah /
kg was obtained. That is, the ion exchange treatment of Comparative Example 1
Compared to Mino polypyrrole, a large current discharge by immersion treatment
The discharge capacity does not decrease much and the high capacity density is maintained.
It was

The results show that the discharge characteristics are also improved by subjecting the polypyrrole to the solvent immersion treatment after the ion exchange.

[0062]

Example 6 The polypyrrole obtained in Comparative Example 1 after the ion exchange treatment was treated with 1M lithium perchlorate (LiCl).
It was immersed in propylene carbonate in which O ₄ ) was dissolved for 7 days at room temperature without stirring.

The polypyrrole thus obtained was used in Examples
The battery characteristics were evaluated in the same manner as in 1.
Density 1mA / cm²The capacity density is 65 Ah / kg,
Flow density 10mA / cm²Then, the capacity density is 52 Ah / kg,
Discharge current density of 20mA / cm ²But capacity density 44Ah /
kg was obtained. That is, the ion exchange treatment of Comparative Example 1
Compared to Mino polypyrrole, a large current discharge by immersion treatment
The discharge capacity does not decrease much and the high capacity density is maintained.
It was

The results show that the discharge characteristics are also improved by subjecting the polypyrrole to the solvent immersion treatment after the ion exchange.

[0065]

Example 7 After dipping in dimethylacetamide in the same manner as in Example 1, the ion-exchanged polypyrrole was treated with 1
M propylene carbonate in which lithium perchlorate (LiClO ₄ ) was dissolved for 7 days and 14 days at room temperature,
Immersion treatment was performed without stirring.

The thus-obtained polypyrrole was evaluated for battery characteristics in the same manner as in Example 1, and the results are shown in Table 2. By carrying out the solvent immersion treatment before and after the ion exchange, a high capacity density was maintained in which a decrease in discharge capacity was hardly observed in a large current discharge.

[0067]

[Table 2]

Claims (3)

[Claims] 1. A method for producing a polypyrrole molded article, which comprises exchanging anions contained in polypyrrole obtained by an electrolytic polymerization method with smaller anions.
A method for producing a polypyrrole molding, which comprises dipping treatment with a polar organic solvent before and / or after replacement. 2. The polypyrrole obtained by repeating electrolytic polymerization and undoping in an electrolytic solution containing pyrrole and a supporting salt composed of a cation and an anion having a molecular weight of 150 or more. A method for producing a polypyrrole molded article according to claim 1. 3. The polar organic solvent is one selected from dimethylacetamide, dimethylformamide, N-methylpyrrolidone, propylene carbonate, or a mixed solvent thereof, wherein the polar organic solvent is a mixed solvent thereof. A method for producing a polypyrrole molded article.