JPH0582032B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a secondary battery that has high energy density, high charge/discharge efficiency, long cycle life, low self-discharge, and good voltage flatness during discharge. consisting of a transition metal compound and an organometallic compound,
Acetylene polymers obtained by polymerizing acetylene using so-called Ziegler and Natsuta catalysts are
Because the electrical conductivity is in the semiconductor region,
It is already known that organic semiconductor materials are useful as electrical and electronic devices. Methods for producing practical molded products of acetylene high polymers include (a) pressure molding of powdered acetylene high polymers, and (b) molding into a membrane at the same time as polymerization under special polymerization conditions. A method for obtaining a membranous acetylene polymer having a fibrous microcrystalline (fibril) structure and high mechanical strength (Japanese Patent Publication No. 32581/1983) is known. The powdered acetylene polymer molded product obtained by the method (a) above is mixed with BF ₃ , BCl ₃ , HCl, Cl ₂ , SO ₂ ,
Chemical treatment with electron-accepting compounds (acceptors) such as NO ₂ , HCN, O ₂ , and NO increases electrical conductivity by up to three orders of magnitude, and conversely, chemical treatment with electron-donating compounds (donors) such as ammonia and methylamine It is already known that the electrical conductivity decreases by up to four orders of magnitude when treated with . In addition, I ₂ , Cl ₂ , Br ₂ , ICl, IBr, AsF ₅ , SbF ₅ ,
Electron-accepting compounds such as PF ₆ or Na, K,
It is also possible to freely control the electrical conductivity of acetylene polymers over a wide range of 10 ^-8 to ^{10 3} Ω ^-1 cm ^-1 by chemically doping them with electron-donating compounds such as Li. Already known. The idea of using this doped film-like acetylene polymer as a material for the positive electrode of a primary battery has already been proposed. On the other hand, in addition to the above chemical doping method, electrochemical doping methods such as ClO ₄ ^- , PF ₆ ^- , AsF ₆ ^- ,
An acetylene polymer is doped with anions such as AsF ₄ ^- , CF ₃ SO ₃ ^- , BF ₄ ^-, etc. and a cation such as R′ ₄ N ⁺ (R′ is an alkyl group, and they are also the same group). A method for producing p-type and n-type conductive acetylene polymers has also been developed. A rechargeable battery using electrochemical doping using a film-like acetylene polymer obtained by the method (b) has been reported. For example, this battery is made by using two 0.1 mm thick acetylene polymer films obtained by method (b) as positive and negative electrodes, and soaking them in a tetrahydrofuran solution containing lithium iodide to generate a voltage of 9V. When connected to a DC power source, lithium iodide is electrolyzed, and the acetylene polymer film at the positive electrode is doped with iodine, and the acetylene polymer film at the negative electrode is doped with lithium. This electrolytic doping corresponds to the charging process. When a load is connected to the two doped electrodes, lithium ions and iodine ions react to generate electricity. in this case,
Open circuit voltage (V _OC ) is 2.8V, short circuit current density is 5m
A/cm ² , and when a tetrahydrofuran solution of lithium perchlorate was used as the electrolyte, the open circuit voltage was 2.5 V and the short circuit current density was about 3 mA/cm ² . In addition, two sheets of acetylene high polymer film with a thickness of 0.1 mm obtained by the method (b) above were each wrapped in a platinum mesh from which the lead wires were taken out separately.
Immersion in an acetonitrile solution containing mol/equivalent of tetrabutylammonium perchlorate,
When charged for a certain period of time at a constant current of mA/cm ² , tetrabutylammonium ions are doped into the acetylene high polymer film of the negative electrode, and perchlorate ions are doped into the acetylene high polymer film of the positive electrode. In this case, the open circuit voltage (V _OC ) of the battery was 2.5V. This battery is 1mA/cm ²
If the battery is discharged until the voltage drops to 1.0V, the amount of discharged electricity can be extracted with an efficiency of 81% compared to the amount of charged electricity. These batteries use acetylene polymer as the electrode material, which is easy to reduce weight and size, so they are attracting attention as batteries that have high energy density, are easy to reduce weight and size, and are inexpensive. . However, most of the electrolytes used as dopants used in these known documents have low solubility in solvents with a relatively wide stable potential range, and have low electrical conductivity as electrolytes.
Alternatively, since the electrolyte itself or its electrolyzed product has reactivity with a solvent having a relatively wide stable potential range, it has the disadvantage that it cannot be used with a solvent having a relatively wide stable potential range. For example, lithium metal is reactive with nitrile solvents, which are considered to be solvents with a relatively wide stable potential range, and it is difficult to use lithium salts containing lithium metal as a cation component as electrolytes. In addition, the above-mentioned tetrabutylammonium salt dissolves relatively well in nitrile solvents,
When used as an electrolyte, it is possible to obtain high charge/discharge efficiency, but the energy density is not sufficiently satisfactory. Furthermore, when using tetraethylammonium salt, which is one of the same alkylammonium salts, as an electrolyte, the solubility of tetraethylammonium salt is low in benzonitrile, which has a wide stable potential range, and the saturated solubility at room temperature is 1 mol/mol. Therefore, an electrolytic solution prepared by dissolving a tetraethylammonium salt in benzonitrile is very disadvantageous in terms of energy density, and is difficult to be applied as an electrolytic solution for batteries having a high energy density. Therefore, when using an organic solvent with a relatively wide stable potential range, it has high solubility in the organic solvent, has a molar molecular weight as low as possible, and provides high electrical conductivity.
There is a strong demand among the industry to obtain an electrolyte, that is, a dopant, which has good electrochemical stability itself and has low reactivity with the polymer compound having a conjugated double bond in the main chain used as an electrode. Ta. In view of the above points, the present inventors have discovered that the present invention has high energy density, high charge/discharge efficiency, long cycle life, good voltage flatness, low self-discharge rate, light weight, and small size. As a result of various studies to obtain a battery that is easy to produce and inexpensive, an ammonium salt whose cation component is a quaternary ammonium ion satisfies the above requirements, and by using this as an electrolyte, it has been found that it has good performance. They discovered that a secondary battery could be obtained and completed the present invention. That is, the present invention provides a battery in which a polymer compound having a conjugated double bond in its main chain, or a conductive polymer compound obtained by doping the polymer compound with a dopant, is used for the negative electrode or both the positive and negative electrodes. A secondary battery characterized in that an ammonium salt consisting of a quaternary ammonium ion whose cation component is represented by the following general formula is used as the electrolyte of the electrolytic solution, and an aromatic nitrile compound is used as the solvent of the electrolytic solution. It is related to.

[Formula] [In the formula, R ₁ , R ₂ , R ₃ and R ₄ have 1 to 16 carbon atoms
is an alkyl group or an aryl group. however,
All R ₁ , R ₂ , R ₃ and R ₄ are never the same group. ] The secondary battery using the ammonium salt of the present invention as an electrolyte of the electrolytic solution is a quaternary battery represented by the conventionally known R′ ₄ N ⁺ (R′ is an alkyl group and is also the same group). Compared to secondary batteries that use ammonium salts containing ammonium ions as cation components or lithium salts as electrolytes, they have () higher energy density, () better voltage flatness,
It has the advantages of () low self-discharge and () long repeated life. Specific examples of polymer compounds having a conjugated double bond in the main chain (hereinafter referred to as conjugated polymer compounds) used in the present invention include acetylene polymers (polyacetylene), polyparaphenylene, and polymethaphenylene. Nylene, poly(2,5-thienylene), polypyrrole, polyimide, polyphenylacetylene, polyacene, polyacenequinone radical polymer, quinazoline polymer with Schiff base structure, polyarylenequinones, thermal decomposition products of polyacrylonitrile and polyimide, etc. Examples thereof include, but are not necessarily limited to, and any polymer compound having a conjugated double bond in its main chain may be used. Further, there is no problem with either homopolymers or copolymers. Among the above-mentioned polymers, preferred are acetylene polymers, polyparaphenylene, poly(2,5-thienylene), and polypyrrole, and particularly preferred are acetylene polymers. be able to. The method for producing the acetylene polymer preferably used in the present invention is not particularly limited, and any method can be used.
No. 32581, JP 56-45365, JP 55-129404
No. 55-128419, No. 55-142012, No. 56-
No. 10428, No. 56-133133, Trans. Farady Soc.
64, 823 (1968), J. Polymer Sci., A-1, 7 ,
3419 (1969), Makromol.Chem., Rapid
Comm., 1 , 621 (1980), J.Chem.Phys., 69(1),
106 (1978), Synthetic Metals, 4 , 81 (1981)
The following methods can be mentioned. In the present invention, a conductive material such as graphite, carbon black, acetylene black, metal powder, carbon fiber, etc. may be mixed with the conjugated polymer compound, and it is absolutely prohibited to insert a metal net or the like as a current collector. do not have. In the present invention, not only conjugated polymer compounds but also
A conductive polymer compound obtained by doping the polymer compound with a dopant can also be used as an electrode. The method for doping the conjugated polymer compound with a dopant may be either chemical doping or electrochemical doping. As dopants to be chemically doped into the conjugated polymer compound, there are various conventionally known electron-accepting compounds and electron-donating compounds, i.e.,
() Halogens such as iodine, bromine and bromine iodide, () Arsenic pentafluoride, Antimony pentafluoride, Silicon tetrafluoride, Phosphorus pentafluoride, Phosphorus pentafluoride, Ammonium chloride, Aluminum bromide and Aluminum fluoride. metal halides such as
() Protic acids such as sulfuric acid, nitric acid, fluorosulfuric acid, trifluoromethanesulfuric acid and chlorosulfuric acid; () Oxidizing agents such as sulfur trioxide, nitrogen dioxide, difluorosulfonyl peroxide; ()
AgClO ₄ , ()tetracyanoethylene, tetracyanoquinodimethane, chloranil, 2,3-dichloro-5,6-dicyanoparabenzoquinone,
Examples include 2,3-dibromo-5,6-dicyanoparabenzoquinone. On the other hand, dopants to be electrochemically doped into a conjugated polymer compound include ()PF ₆ ,
Halide anions of group a elements such as SbF ₆ ^- , AsF ₆ ^- , SbCl ₆ ^-, halide anions of group a elements such as BF ₄ ^{- , -} ( ₃ ^- ), Br ^- ,
Anion dopants such as halogen anions such as Cl ^- , perchlorate anions such as ClO ₄ ^- (both are effective as dopants that provide a P-type conductive conjugated polymer compound), and ()Li ⁺ , Na ⁺ ,
Alkali metal ions such as K ⁺ , cations and dopants such as quaternary ammonium ions such as _R4N ⁺ (R: hydrocarbon group having 1 to 20 carbon atoms) (both of which provide n-type conductive conjugated polymer compounds) (effective as a dopant), but are not necessarily limited to these. However, when a conductive polymer compound obtained by doping a conjugated polymer compound with a dopant in advance is used for the electrode, the dopant pre-doped into the negative electrode is a quaternary ammonium cation used in the battery electrolyte in the present invention. It is desirable to have the same one. Furthermore, the amount of doping in the battery of the present invention can be freely controlled by measuring the amount of electricity flowing during electrolysis. Doping can be carried out either under constant current, constant voltage, or varying current and voltage conditions. The current value, voltage value, doping time, etc. during doping vary depending on the type of conjugated polymer compound used, bulk density, area, type of dopant, type of electrolyte, and required electrical conductivity. cannot be specified. The amount of dopant doped into the conjugated polymer compound is 2 to 40 mol%, preferably 4 to 30 mol%, particularly preferably 5 to 20 mol%, based on 1 mol of repeating units of the conjugated polymer compound. be. Even if the amount of the doped dopant is less than 2 mol % or more than 40 mol %, a secondary battery with a sufficiently large discharge capacity cannot be obtained. The electrical conductivity of the conjugated polymer compound is 10 ^-5 Ω ^-1 cm ^-1 or less before doping, and the electrical conductivity of the conductive conjugated polymer compound obtained by doping with a dopant is about 10 ^-10 ~ It is in the range of 10 ⁴ Ω ^-1 cm ^-1 . The electrolyte of the battery used in the present invention is an ammonium salt whose cation component is a quaternary ammonium ion represented by the above general formula. Specific examples of the cation component of the ammonium salt include trimethylpropylammonium, trimethylbutylammonium, trimethylhexylammonium, trimethyloctylammonium, trimethylisobutylammonium, trimethyltertiarybutylammonium, trimethylisopropylammonium, trimethylhexadecyl ammonium, trimethylpentylammonium, Trimethylphenylammonium, triethylbutylammonium, triethylpropylammonium, triethylmethylammonium, triethylhexylammonium, triethylphenylammonium, tripropylbutylammonium, tributylmethylammonium, tributylethylammonium, dipropyldiethylammonium, dibutyldiethylammonium, dibutyldimethyl ammonium, dimethyldiphenylammonium, diethyldiphenylammonium,
Examples include dibutylethylmethylammonium, dipropylethylmethylammonium, butylpropylethylmethylammonium, and the like. Specific examples of these cationic components and anionic components constituting the ammonium salt include HF ₂ ^- ,
ClO ₄ ^- , AlCl ₄ ^- , BF ₄ ^- , FeCl ^{4 -} , SnCl ₅ ^- , PF ₆ ^- ,
Examples include PCl ₆ ⁻ , SiF ₄ ⁻ , SbF ₆ ⁻ , AsF ₆ ⁻ , CF ₃ SO ₃ ⁻ and the like. Specific examples of ammonium salts include triethylbutylammonium tetrafluoroborate, triethylbutylammonium perchlorate, triethylbutylammonium hexafluorophosphate, trimethylbutylammonium trifluoromethanesulfonate, trimethylethylammonium tetrafluoroborate, and trimethylethylammonium hexafluoroborate. Examples include fluorophosphate, dibutyldiethylammonium perchlorate, tributylethylammonium tetrafluoroborate, butylpropylethylmethylammonium hexachlorophosphate, trimethylphenyltetrafluoroborate, triethylphenyltetrafluoroborate, etc. It is not limited to. These ammonium salts may be used alone or in combination of two or more. The ammonium salts of the present invention may also be used as mixed electrolytes with other alkylammonium salts, such as tetrabutylammonium salts and tetraethylammonium salts, or with alkali metal salts, such as lithium salts, sodium salts, and potassium salts. It can also be used as a mixed electrolyte. Furthermore, the ammonium salt of the present invention has the following formula ()
Pyrylium or pyridium cation represented by:

[Formula, X is an oxygen atom or a nitrogen atom, R' is a hydrogen atom or an alkyl group having 1 to 15 carbon atoms, or an aryl group having 6 to 15 carbon atoms, and R'' is a halogen atom or a carbon number 1 ~10 alkyl groups, 6 to 15 carbon atoms
In the aryl group, m is 0 when X is a carbon atom, and 1 when X is a nitrogen atom. n is 0 or 1-5. ] Or a carbonium cation represented by the following formula () or ():

【formula】 or

[Formula] [In the formula, R ¹ , R ² , and R ³ are hydrogen atoms (R ¹ , R ² , and R ³ are never hydrogen at the same time), an alkyl group having 1 to 15 carbon atoms, allyl ) group, carbon number 6-15
aryl group or -OR ⁵ group, provided that R ⁵ represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 15 carbon atoms, and R 4 is a hydrogen atom, and R ⁴ is a hydrogen atom, and
are an alkyl group and an aryl group having 6 to 15 carbon atoms. ] may be used in combination with an electrolyte having as a cationic component. However, when the cationic component of the present invention is a mixture of an ammonium salt consisting of quaternary ammonium ions and another electrolyte, it is preferable to use the ammonium salt in a form containing equal moles or more of the ammonium salt. The organic solvent of the electrolyte used in the present invention is an aromatic nitrile compound. Specific examples of this organic solvent include benzonitrile, o-tolnitrile, m-tolnitrile, p-
Examples include tolnitrile. There is no problem in using these solvents as a mixed solvent. The concentration of the electrolyte used in the secondary battery of the present invention cannot be unconditionally defined because it varies depending on the type of positive electrode or negative electrode used, charge/discharge conditions, operating temperature, type of electrolyte, type of organic solvent, etc. , usually in the range of 0.5 to 10 mol/.
It does not matter whether the electrolyte is homogeneous or heterogeneous. In the present invention, the conjugated polymer compound or the conductive conjugated polymer compound obtained by doping the conjugated polymer compound with a dopant can be used as an active material for the () negative electrode or () both the positive and negative electrodes of a battery. However, in order to maximize the effects of the present invention, batteries of the type () are preferred. For example, in the case of a secondary battery using an acetylene polymer as a conjugated polymer compound, as an example of (),
If the acetylene polymer is (CH) _x , graphite (positive electrode) / (Et ₃ BuN) ⁺・(ClO ₄ ) ^- (electrolyte) / ( _CH ) CH) ^+0.024 (ClO ₄ ) ^- _0.024 ] _x (positive electrode)/
(Me ₃ BuN) ⁺・(ClO ₄ ) ^- (electrolyte)/[(Me ₃ BuN)
^+0.024 (CH) _-0.024 ] _x (negative electrode), [(CH) ^+0.06
(PF ₆ ) ^- _0.06 ] _x (positive electrode) / (Bu ₃ EtN) ⁺・(PF ₆ ) ^- (electrolyte) / [(Bu ₃ EtN) ^+0.06 (CH) ^-0.06 ] _x (negative electrode),
[(Et ₃ BuN) ^+0.02 (CH) ^-0.02 ] _x (positive electrode)/
(Et ₃ BuN) ⁺・(ClO ₄ ) ^- (electrolyte)/[Et ₃ BuN) ^+0.0
7 ) (CH) ^-0.07 ] _x (negative electrode). In the case of polyparaphenylene, the above (CH) _x
(C ₆ H ₄ ) _x instead of (C 6 H 4 ) x, and (C ₄ H ₂ S) _x instead of (CH) _x in the case of poly(2,5-thienylene).
In the case of polypyrrole, it is used as (C ₄ H ₂ N) _x in the same type of secondary battery as above. Further, in the present invention, different conjugated polymer compounds can be used for the positive electrode and the negative electrode, and a specific example thereof is (CH) _x /Et ₃ BuN・ClO ₄ /
(C ₆ H ₄ ) _x , (CH) _x ／Me ₃ BuN・BF ₄ ／(C ₄ H ₂ S) _x ,
Examples include (C ₆ H ₄ ) _x /Et ₂ Bu ₂ N, PF ₆ , (C ₄ H ₂ S) _x , and the like. In the present invention, if necessary, a porous membrane made of synthetic resin such as polyethylene or polypropylene or natural fiber paper may be used as a diaphragm. In addition, some of the conjugated polymer compounds used in the present invention undergo a gradual oxidation reaction with oxygen,
The battery must be sealed and substantially oxygen-free, as this may reduce the performance of the battery. The secondary battery of the present invention has high energy density, high charge/discharge efficiency, long cycle life,
The self-discharge rate is low and the voltage flatness during discharge is good. Furthermore, the secondary battery of the present invention is lightweight, compact, and has a high energy density, so it is suitable for use in portable devices, electric vehicles, gasoline vehicles, and power storage batteries. Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples. Example 1 [Production of film-like acetylene polymer] 1.7 ml of titanium tetrabutoxide was added to a glass reaction vessel with an internal volume of 500 ml under a nitrogen atmosphere, 30 ml of anisole was dissolved, and then 2.7 ml of triethylaluminum was stirred. A catalyst solution was prepared in parallel. This reaction vessel was cooled with liquid nitrogen, and the nitrogen gas in the system was evacuated using a vacuum pump. The reaction vessel was then cooled to −78° C. and purified acetylene gas at a pressure of 1 atmosphere was bubbled through while the catalyst solution remained stationary. Polymerization immediately occurred on the surface of the catalyst solution, producing a film-like acetylene high polymer. Thirty minutes after the introduction of acetylene, the acetylene gas in the reaction vessel system was exhausted to stop the polymerization. After the catalyst solution was removed with a syringe under a nitrogen atmosphere, it was washed five times with 100 ml of purified toluene while keeping the temperature at -78°C. The film-like acetylene polymer swollen with toluene was a uniform film-like swollen product in which fibrils were tightly entangled.
This swollen product was then vacuum-dried to obtain a reddish-purple film with a metallic luster, a thickness of 100 μm, and a cis content of 98%. In addition, the bulk density of this film-like acetylene high polymer is 0.30 g/cc,
Its electrical conductivity (DC four terminal method) is 3.2 at 20°C.
×10 ^-9 Ω ^-1・cm ^-1 . [Battery Experiment] Two disks with a diameter of 20 mm were cut out from the film-like acetylene polymer obtained by the above method, and a battery was constructed by using the disks as active materials for a positive electrode and a negative electrode, respectively. FIG. 1 is a schematic cross-sectional view of a battery cell for measuring the characteristics of a secondary battery, which is a specific example of the present invention, in which 1 is a platinum lead wire for the negative electrode, and 2 is a collection of platinum wire mesh for the negative electrode with a diameter of 20 mm and 80 meshes. Electric body, 3 is a disc-shaped negative electrode with a diameter of 20 mm, 4 is a circular porous polypropylene diaphragm with a diameter of 20 mm, and is thick enough to be sufficiently impregnated with electrolyte, 5 is a disc-shaped positive electrode with a diameter of 20 mm, 6 is 20mm in diameter,
80 mesh platinum wire mesh current collector for the positive electrode, 7 a positive electrode lead wire, and 8 a screw-in Teflon container. First, the platinum wire mesh current collector 6 for the positive electrode is placed in the lower part of the concave portion of the Teflon container 8, and then the positive electrode 5 is stacked on the platinum wire mesh current collector 6 for the positive electrode, and the porous polypropylene diaphragm 4 is placed on top of the platinum wire mesh current collector 6 for the positive electrode. After stacking them and sufficiently impregnating them with the electrolyte solution, the negative electrode 3 was stacked, and the platinum wire mesh current collector 2 for the negative electrode was further placed thereon, and the Teflon container 8 was tightened to produce a battery. The electrolyte was 1 mol/Et ₃ BuN・BF ₄ dissolved in distilled and dehydrated benzonitrile according to a conventional method.
A solution was used. Using the battery prepared in this way, the battery was heated at a constant current (4.0 mA/cm ² ) for 15 minutes in an argon atmosphere.
Charging was performed for minutes (amount of electricity corresponding to a doping amount of 5 mol %). Immediately after charging, the battery was discharged under a constant current (4.0mA/cm ² ), and when the battery voltage reached 1V, it was charged again under the same conditions as above. The number of charging and discharging cycles was recorded as 700 times before the discharge efficiency decreased to 50%. The relationship between discharge time and voltage at the fifth repetition in this repeated experiment was as shown by curve a in FIG. 2. Furthermore, the energy density at the fifth repetition was 140 W·hr/Kg, and the charge/discharge efficiency was 99%. Furthermore, when the battery was left for 48 hours after being charged, its self-discharge rate was 3.0%. Comparative Example 1 A battery was charged and discharged in exactly the same manner as in Example 1, except that Bu ₄ N BF ₄ was used instead of Et ₃ BuN BF ₄ used as the electrolyte in the electrolyte. After repeated experiments, the highest charging/discharging efficiency was 96%, and discharging became impossible after the 410th repetition. In this battery experiment, the relationship between discharge time and voltage for the fifth time was as shown by curve b in FIG. 2. Also, the energy density at the 5th repetition is 130W・hr/
kg, the charge/discharge efficiency was 96%. Furthermore, when the battery was left for 48 hours after being charged, its self-discharge rate was 5.2%. Comparative Example 2 In Example 2, an attempt was made to use equimolar amounts of Et ₄ N BF 4 instead of Et ₃ BuN BF ₄ used as the electrolyte in the electrolytic solution, and _it was found that Et ₄ N BF ₄ was benzonitrile. Et ₄ N・
The battery was repeatedly charged and discharged in the same manner as in Example 1 while BF ₄ remained precipitated. As a result, the maximum charging/discharging efficiency was 72%, and discharging became impossible after the 25th repetition. Comparative Example 3 In Example ₁ , an attempt was made to use an equimolar amount of LiBF 4 instead of Et ₃ BuN・BF ₄ used as the electrolyte in the electrolyte solution, but LiBF ₄ did not completely dissolve in benzonitrile and The battery was repeatedly charged and discharged in the same manner as in Example 1, with the remaining undissolved and precipitated. The result is that the highest charge/discharge efficiency is
24%, and discharge became impossible after the 12th repetition. In this battery experiment, the relationship between discharge time and voltage for the fifth time was as shown by curve c in FIG. 2. Further, at the energy density of 24 W·hr/Kg at the fifth repetition, the charging/discharging efficiency was 18%. Comparative Example 4 A 100-mesh mesh of stainless steel was placed in the glass reaction vessel 1 that was completely purged with nitrogen gas, and then 100 ml of toluene purified according to a conventional method was used as a polymerization solvent, and 4.41 mmol of tetrabutoxytitanium was used as a catalyst. and 11.01 mmol of triethylaluminum were sequentially charged at room temperature to prepare a catalyst solution. The catalyst solution was a homogeneous solution. Next, the reactor was cooled with liquid nitrogen, and the nitrogen gas in the system was exhausted using a vacuum pump. The reactor was cooled to −78° C., and purified acetylene gas at a pressure of 1 atmosphere was blown into the reactor while the catalyst solution was left standing. The polymerization reaction was continued for 10 hours while maintaining the pressure of the acetylene gas at 1 atm. The system was agar-like with a reddish-purple color. After polymerization, unreacted acetylene gas was removed and the system temperature was maintained at -78℃.
After repeated washing with 200ml of purified toluene four times, the stainless steel film was swollen with toluene and had a film thickness of about 0.5cm.
A sheet-like swollen acetylene polymer containing a steel mesh was obtained. This swollen acetylene polymer is
It was a swollen product in which fibrous microcrystals (fibrils) with a diameter of 300 to 500 Å were regularly intertwined, and no powder or lump-like polymer was produced. This sheet-like swollen acetylene polymer containing a stainless steel mesh was sandwiched between chromium-plated ferro plates and pre-pressed at room temperature at a pressure of 100 kg/cm ² and then pre-pressed at a pressure of 15 ton/cm ² to produce a reddish-brown color. A uniform and flexible composite with a metallic luster and a film thickness of 280 μm was obtained. This composite was vacuum dried for 5 hours at room temperature. This composite contained 43% by weight stainless steel mesh. [Battery experiment] Two disks with a diameter of 20 mm were cut out from the composite obtained by the above method and used as a positive electrode active material and a negative electrode active material, and the electrolyte was Me ₃ BuN.CuO ₄ dissolved in distilled and dehydrated acetonitrile. using 1 mol/solution of
A charging/discharging experiment was conducted using the same cell as in Example 1. Charging was carried out for 15 minutes at a charging current density of 5.0 mA/cm ² (doping amount equivalent to 5 mol %). Immediately after charging, the battery was discharged at a discharge current density of 5.0 mA/cm ² , and when the battery voltage reached 1 V, the battery was charged again under the same conditions as above. A repeated charge/discharge test was conducted to find out the charge/discharge efficiency. The number of charging/discharging cycles was recorded 420 times before the rate decreased to 50%. The energy density at the fifth repetition of this repeated experiment was 152 W·hr/Kg, and the charge/discharge efficiency was 98%. Furthermore, when the battery was left for 48 hours after being charged, its self-discharge rate was 9.5%. Example 2 Poly(paraphenylene) produced by the method described in Bull.Chem.Soc.Japan., 51 , 2091 (1978) was molded into a 20 mmφ disc shape at a pressure of 1 ton/cm ² and a positive electrode was used. [Battery experiment] was carried out in exactly the same manner as in Example 1 except that the voltage characteristics were almost the same as the first discharge up to 250 repeated charging/discharging tests. The number of repetitions until the charging/discharging efficiency decreased to 50% was recorded as 365 times.
The energy density of this battery was 162 W·hr/Kg, and the charging/discharging efficiency was 91%. Also, when I left it for 48 hours after charging, the self-discharge rate was
It was 4.5%. Comparative Example 5 In Example 3, instead of Et ₃ BuN・BF ₄ used as the electrolyte in the electrolyte solution, 1% benzonitrile was used as the electrolyte.
Pr ₄ .N.BF ₄ was used as a symmetric alkylammonium salt that dissolves in the vicinity of mol/molar and has a molecular weight as close as possible to Et ₃ BuN.BF ₄ . Hereinafter, in exactly the same manner as in Example 3 [Battery experiment]
I went there. As a result, repeated charging and discharging
I stopped at the 215th time. In addition, the energy density of this battery is 145w・hr/Kg, and the charging/discharging efficiency is
It was 88%. Furthermore, when the battery was discharged for 48 hours after being charged, the self-discharge rate was 18%. Examples 3 to 6 In Example 1, repeated charging/discharging experiments were conducted in exactly the same manner as in Example 1, except that the combinations of electrolytes and solvents were changed as shown in the table. The results were tabulated. In the table, the energy density indicates the 5th repetition, and the cycle life indicates the number of repetitions until the charge/discharge efficiency drops to 50%. In addition, the self-discharge amount is 48 hours after the end of charging.
Shown after being left open circuit.

【table】 [Brief explanation of drawings]

Fig. 1 is a schematic cross-sectional view of a battery cell for measuring the characteristics of a secondary battery, which is a specific example of the present invention, and Fig. 2 shows the discharge time of the battery in Example 1, Comparative Examples 1 and 3 of the present invention FIG. 3 is a diagram showing the relationship between voltages. 1... Platinum lead wire for negative electrode, 2... Platinum wire mesh current collector for negative electrode, 3... Negative electrode, 4... Porous polypropylene diaphragm, 5... Positive electrode, 6... Platinum wire mesh current collector for positive electrode, 7... Positive electrode lead wire, 8... Teflon container.

Claims (1)

[Scope of Claims] 1. A battery in which a polymer compound having a conjugated double bond in its main chain or a conductive polymer compound obtained by doping the polymer compound with a dopant is used as a negative electrode or both positive and negative electrodes. A secondary battery characterized in that an ammonium salt consisting of a quaternary ammonium ion whose cation component is represented by the following general formula is used as the electrolyte of the electrolytic solution, and an aromatic nitrile compound is used as the solvent of the electrolytic solution. . [Formula] [In the formula, R ₁ , R ₂ , R ₃ and R ₄ have 1 to 16 carbon atoms
is an alkyl group or an aryl group. however,
All R ₁ , R ₂ , R ₃ and R ₄ are never the same group. ]