JPH0381269B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a secondary battery characterized in that a crystalline 2,5-thienylene polymer having a 2,5-thienylene group as a repeating unit is used for at least one of a positive electrode and a negative electrode. Conventionally, polythiophene, which has a thiophene ring as a repeating unit, has a conjugated structure similar to cis-type polyacetylene and also contains a sulfur atom, so it has been expected to have a unique electronic structure as a conductive material, and has been used in various ways. Synthetic examples have been reported. For example, in Journal of Polymer Science, Part A-1, Vol. 5, p. 1527 (1967), there is a report by M. Armor et al. that when thiophene is polymerized using tofluoroacetic acid as a catalyst, a yellow-brown polymer is produced. is obtained, but it is described that this polymer has about 4 repeating units/mol and is a low polymer that is soluble in solvents such as benzene and chloroform. Also, in Journal of Chemical Society (C), Vol. 1971, p. 234, R.F.
There is a report by Curteius et al. that several types of low polymers are obtained when thiophene is polymerized in polyphosphoric acid, and that the main product is a nonconjugated compound consisting of 2,4-di-2-thienyltetrahydrothiophene. Are listed. On the other hand, Yamamoto et al.
No. 47421 discloses that 2,5-dibromothiophene is reacted with metallic magnesium in an ether solvent such as tetrahydrofuran or dibutyl ether to produce an active organomagnesium compound, and when a nickel complex catalyst is added to this, polymerization easily occurs. It is stated that poly(2,5-thienylene) can be obtained. Yamamoto et al. further state in Chemistry Letters, p. 1079 (1981) that the polymer obtained by this method is amorphous, and that when this polymer is doped with iodine or sulfuric anhydride, its electrical conductivity increases compared to that of the undoped polymer. 7-9 digit increase, 10 ^-4
It is stated that it becomes a semiconductor with an electrical conductivity of about 10 ^-2 S/cm. However, the poly(2,
5-thienylene) is amorphous as mentioned above,
In addition, the yield of thermal chloroform-insoluble parts is low, and furthermore, in JP-A-56-47421, it is stated that the average molecular weight is 1730 (average degree of polymerization about 19) based on the elemental analysis results, and the degree of polymerization is not very high. . As a result of intensive research in view of the various drawbacks mentioned above, some of the present inventors have discovered that 2,5-dihalogenothiophene or its derivatives are reacted with metallic magnesium in an aliphatic ether solvent under an inert atmosphere. After at least substantially forming an active organic monomagnesium compound and removing the aliphatic ether solvent,
By polymerizing the organic monomagnesium compound in an aromatic ether solvent in the presence of a nickel complex catalyst under an inert atmosphere, a 2,5-thienylene high polymer bonded at the 2,5-position can be produced in extremely high yield. We have already proposed the discovery that it is not only obtainable with high molecular weight and high molecular weight, but also crystalline. It has not been previously known that the 2,5-thienylene polymer thus obtained has crystallinity. Furthermore, as a result of various studies to use the crystalline 2,5-thienylene polymer obtained by the above method as a battery electrode, the present inventors found that the crystalline 2,5-thienylene polymer obtained by the above method could be used as a battery electrode. The secondary battery used for the electrode is made of amorphous poly(2,5-
The present invention was achieved based on the discovery that the battery has a better cycle life than a secondary battery using thienylene as an electrode. That is, the present invention involves reacting 2,5-dihalogenothiophene or a derivative thereof with metallic magnesium in an aliphatic ether solvent under an inert atmosphere to substantially form an active organic monomagnesium compound; After removing the aliphatic ether solvent, the organic monomagnesium compound is polymerized in an aromatic ether solvent in the presence of a nickel complex catalyst under an inert atmosphere, resulting in the general formula () (However, in the formula, R is an alkyl group having 5 or less carbon atoms,
n is 0, 1 or 2. The present invention relates to a secondary battery characterized in that a crystalline linear 2,5-thienylene polymer having a 2,5-thienylene group as a repeating unit represented by the following formula is used for at least one of a positive electrode and a negative electrode. Crystalline linear 2,5 used in the present invention
- As a first step, the thienylene polymer is prepared in an aliphatic ether solvent under an inert atmosphere.
- Reacting dihalogenothiophene or its derivative with metallic magnesium to substantially form an active organomagnesium compound, removing most of the aliphatic ether solvent at normal pressure and/or reduced pressure, and then The second step is obtained by polymerizing the organic monomagnesium compound in an aromatic ether solvent under an inert atmosphere in the presence of a nickel complex catalyst. Examples of the 2,5-dihalogenothiophene used in the present invention include 2,5-dichlorothiophene, 2,5-dibromothiophene, and 2,5-diiodothiophene, and derivatives thereof include 3-Methyl-2,5-dichlorothiophene, 3
-Methyl-2,5-dibromothiophene and the like. These may be used alone or as a mixture. Although commercially available magnesium metals are sufficient, it is desirable to use one with as high a purity as possible in order to prevent side reactions from occurring. The amount of metallic magnesium used is 0.8 to 1.2 mol per 1 mol of 2,5-dihalogenothiophene or its derivative, preferably as close to 1 mol as possible, especially in order to produce a monomagnesium compound and obtain a high polymer. This is desirable. The inert atmosphere here refers to an atmosphere in which moisture, carbon dioxide, oxygen, etc. are not present, because these react with the active organomagnesium compound and hinder the progress of the polymerization reaction. Examples of the aliphatic ether solvent used in the first stage include diethyl ether, dibutyl ether, tetrahydrofuran, dioxane, diethylene glycol dimethyl ether, and the like.
In order to obtain a high polymer, these solvents are preferably dried. The reaction temperature can be varied over a wide range from 0°C to the boiling point of the solvent. The reaction time is preferably 1 to 20 hours, but it is preferable to substantially convert the active organomagnesium compound into a monomagnesium compound in order to obtain a high polymer, and a longer reaction time gives better results. The solvent used in the first stage is removed under normal pressure and/or reduced pressure. The nickel complex catalysts used in the second stage include dichloro(2,2'-bipyridine)nickel, dibromo(2,2'-bipyridine)nickel, dichlorobis(triphenylphosphine)nickel, and dibromobis(triphenylphosphine)nickel. Nickel, 1,5-cyclooctadienebis(triphenylphosphine)nickel,
Examples include nickel acetylacetonate, and the amount used is 0.05 to 10 mol%, preferably 0.1 to 5 mol%, based on 2,5-dihalogenothiophene or its derivative. Examples of aromatic ether solvents include anisole, tomethyl ether, diphenyl ether, and the like. As the reaction temperature, a wide range of temperatures from room temperature to 250°C can be used. Reaction time is 1 to 20
Time is preferably used. The 2,5-thienylene polymer obtained in the present invention is characterized by being crystalline, whereas known poly(2,5-thienylene) is amorphous.
Linear diffraction shows a clear crystal pattern. Furthermore, the average molecular weight is 3000 or more according to elemental analysis, and the degree of polymerization is high. The secondary batteries of the present invention include those in which the crystalline 2,5-thienylene polymer obtained by the method of the present invention is used only in (i) the positive electrode, (ii) only in the negative electrode, and (iii) Any battery used for both the positive and negative electrodes may be used. In the case of (i) type of secondary battery,
Other conjugated polymer compounds, Li,
Alkali metals such as Na, graphite, carbon fiber, TiS ₂ , etc. are used. In the case of the secondary battery of type (ii), another conjugated polymer compound is used as the counter positive electrode. Among the above-mentioned types, the types of secondary batteries that can maximize the characteristics of the secondary battery of the present invention are:
The secondary battery is of the type (i) or (iii), and the type (i) in which another conjugated polymer compound is used as the counter electrode is particularly preferred. Other conjugated polymer compounds mentioned here include:
Acetylene high polymer (polyacetylene), poly(p-phenylene), poly(m-phenylene), polypyrrole, poly(phenylene sulfide),
Poly(phenylacetylene), poly(arylenequinone), poly(azophenylene), poly(Schiff base), poly(aminoquinone), poly(benzimidazole), polyacenequinone, and JP-A-57-195731 , EP-67.444, thermal decomposition products of polyimide, polyacrunitrile, poly-α-cyanoacryl, etc., but are not necessarily limited to these. Among the above-mentioned conjugated polymer compounds, poly(arylenequinone), poly(azophenylene), poly(Schiff base), poly(aminoquinone), poly(benzimidazole)
For specific examples of this type, see "Polymer Organic Semiconductors" edited by JEKATON, translated by Hidetoshi Doyo, Shokodo. (published in 1972)
It is described on P.87 to P.112. Among the above conjugated polymer compounds, preferred are acetylene high polymer, polyparaphenylene, and polypyrrole, and more preferred are acetylene high polymer,
Particularly preferred are highly crystalline acetylene polymers. 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 Matals, 4 , 81 (1981)
Methods such as the following can be mentioned, but the method is not necessarily limited to these. Crystalline linear 2,5 used in the present invention
- The thienylene polymer and the conjugated polymer compound used as the counter electrode (hereinafter both are collectively referred to as the conjugated polymer compound) can be in any form such as film, powder, short fiber length, etc. can also be used. In addition, other suitable conductive materials such as graphite, carbon black, acetylene black, metal powder, carbon fiber, etc. may be mixed with the conjugated polymer compound, or a metal net or the like may be inserted as a current collector. There is absolutely no problem. Further, it may be reinforced with thermoplastic resin such as polyethylene, modified polyethylene, poly(tetrafluoroethylene), etc. As the positive electrode or negative electrode of the secondary battery of the present invention, not only a conjugated polymer compound but also a conductive conjugated polymer compound obtained by doping the conjugated polymer compound with a dopant can be used. The method for doping the conjugated polymer compound with a dopant may be either chemical doping or electrochemical doping. Charging and discharging of the secondary battery of the present invention correspond to electrochemical doping and undoping of cations and anions to the electrodes, respectively. Dopants to be electrochemically doped include (i) halide anions of group a elements such as PF ^- ₆ , SbF ^- ₆ , AsF ^- ₆ , SbCl ^- ₆ , a halide anions such as BF ^- ₄ ;
Halide anions of elements of the group I ^- (I ^- ₃ ), Br ^- ,
Anion dopants such as halogen anions such as Cl ^- and perchlorate anions such as ClO ^- ₄ (both are effective as dopants that provide P-type conductive conjugated polymer compounds); and (ii) Li ⁺ , Na ⁺ , Alkali metal ions such as K ⁺ , R ₄ N ⁺ (R: 1 to 20 carbon atoms)
Cation dopants such as quaternary ammonium ions (hydrocarbon groups) (all of which are effective as dopants that provide n-type conductive conjugated polymer compounds), but are not necessarily limited to these. It's not a thing. The above-mentioned anion/dopant and cation/dopant
Specific examples of compounds that provide dopants include
LiPF ₆ , LiSbF ₆ , LiAsF ₆ , LiClO ₄ , NaI,
_NaPF6 , _NaSbF6 , _NaAsF6 , _NaClO4 , KI,
KPF ₆ , KSbF ₆ , KAsF ₆ , KClO ₄ , [(n-
Bu) ₄ N] ⁺・[AsF ₆ ) ^- , [(n-Bu) ₄ N] ⁺・(PF ₆ ) ^-
,
[(n-Bu) ₄ N] ⁺・ClO ^- ₄ , LiAlCl ₄ , LiBF ₄ ,
NO ₂・BF ₄ , NO・BF ₄ , NO ₂・AsF ₆ , NO・
Examples include AsF ₆ , NO ₂ .ClO ₄ , and NO.ClO ₄ , but are not necessarily limited to these. These dopants may be used alone or in combination of two or more. As anion dopants other than those mentioned above,
HF ^- ₂ anion, and other anion dopants include pyrylium or pyridinium cations represented by the following formula (): (In the formula, ~10 alkyl group, aryl group having 6 to 15 carbon atoms, m is 0 when X is an oxygen atom, and 1 when X is a nitrogen atom. n is 0 or 1 to 5. ) or a carbonium cation represented by the following formula () or (): and [In the above formula, R ¹ , R ² , R ³ are hydrogen atoms (R ¹ , R ² , R ³
is not a hydrogen atom at the same time), carbon number is 1
-15 alkyl group, allyl group, aryl group having 6 to 15 carbon atoms or -OR ⁵ group, provided that R ⁵ is an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 15 carbon atoms (aryl) group, R ⁴ is a hydrogen atom, an alkyl group having 1 to 15 carbon atoms, and 6 to 15 carbon atoms.
15 aryl groups. ] It is. The HF ^- ₂ anion used usually has the following general formula (), () or (): R′ ₄ N・HF ₂ () M ・HF ₂ () [However, in the above formula, R', R'' is a hydrogen atom or an alkyl group having 1 to 15 carbon atoms, an aryl group having 6 to 15 carbon atoms, R is an alkyl group having 1 to 10 carbon atoms,
An aryl group having 6 to 15 carbon atoms, X is an oxygen atom or a nitrogen atom, and n is 0 or a positive integer of 5 or less. M is an alkali metal] by dissolving a compound (hydrogen fluoride salt) in a suitable organic solvent using as a supporting electrolyte. Specific examples of compounds represented by the above formulas (), (), and () include H ₄ N・HF ₂ , Bu ₄ N・
HF ₂ , Na・HF ₂ , K・HF ₂ , Li・HF ₂ and

[Formula] can be given. The pyrylium or pyridinium cation represented by the above formula () is a combination of the cation represented by the formula () and ClO ^- ₄ , BF ^- ₄ , AlCl ^- ₄ , FeCl ^- ₄ , SnCl ^- ₅ ,
Obtained by dissolving in a suitable organic solvent using a salt with an anion such as PF ^- ₆ , PCl ^- ₆ , SbF ^- ₆ , AsF ^- ₆ , CF ₃ SO ^- ₃ , HF ^- ₂ as a supporting electrolyte . Examples of such salts include

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

[Formula] etc. can be given. Specific examples of carbonium cations represented by the above formula () or () are (C ₆ H ₅ ) ₃ C ⁺ ,
( _CH3 ) _3C ⁺ ,

【formula】

[Formula] can be given. These carbonium cations can be obtained by dissolving salts of them and anions (carbonium salts) in a suitable organic solvent as a supporting electrolyte. Representative examples of anions used here include BF ^- ₄ , AlCl ^- ₄ , AlBr ₃ Cl ^- , FeCl ^- ₄ , SnCl ^- ₃ ,
Examples include PF ^- ₆ , PCl ^- ₆ , SbCl ^- ₆ , SbF ^- ₆ , ClO ^- ₄ , CF ₃ SO ^- ₃ , and specific examples of carbonium salts include (C ₆ H ₅ ) ₃ C・BF ₄ ,
(CH ₃ ) ₃ C・BF ₄ , HCO・AlCl ₄ , HCO・BF ₄ ,
Examples include C ₆ H ₅ CO and SnCl ₅ . As the electrolyte of the secondary battery of the present invention, either an aqueous solution or a non-aqueous solution can be used.
Preferably, the dopant is dissolved in a non-aqueous organic solvent. The organic solvent mentioned here is preferably one that is aprotic and has a high dielectric constant. For example, ethers, ketones, nitriles,
Amines, amides, sulfur compounds, phosphate ester compounds, phosphite ester compounds, borate ester compounds, chlorinated hydrocarbons, esters, carbonates, nitro compounds, etc. can be used, but Among these, ethers, ketones, nitriles, phosphate ester compounds,
Preferred are phosphite ester compounds, borate ester compounds, chlorinated hydrocarbons, and carbonates. Representative examples of these include tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-
Dioxane, monoglyme, acetonitrile, propionitrile, 4-methyl-2-pentanone, butyronitrile, valeronitrile, benzonitrile, 1,2-dichloroethane, γ-butyrolactone, valeroluftone, dimethoxyethane, methylformate, propylene carbonate, ethylene Examples include carbonate, dimethylformamide, dimethylsulfoxide, dimethylthioformamide, ethyl phosphate, methyl phosphate, ethyl phosphite, methyl phosphite, sulfolane 3-methylsulfolane, and the like. Among these, nitriles are particularly preferred. These organic solvents may be used alone or as a mixed solvent of two or more. Depending on the type of battery used or the type of electrode used, oxygen, water, protic solvents, etc. in these solvents may deteriorate the battery characteristics.
It is preferable to purify it according to a conventional method. The amount of dopant doped into the conjugated polymer compound during charging is 2 to 40 mol %, preferably 4 to 30 mol %, based on 1 mol of repeating units in the conjugated polymer compound. The amount of doping can be freely controlled by measuring the amount of electricity flowing during electrolysis. The doping may be carried out either under constant current, constant voltage or under conditions of varying current and voltage. The current value, voltage value, doping time, etc. during doping cannot be unconditionally defined because they vary depending on the bulk density and area of the conjugated polymer compound used, the type of dopant, and the type of electrolyte. In addition, in the secondary battery of the present invention, polyethylene oxide and NaI are used in addition to the electrolyte described above.
A highly ionic conductive organic solid electrolyte such as NaSCN or a paste obtained by simply mixing an electrolyte (dopant) and an organic solvent can also be used. Furthermore, the concentration of the electrolyte (dopant) used in the secondary battery of the present invention 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., so it is not generally specified. I can't. The electrolyte may be homogeneous or heterogeneous, but usually
It is in the range of 0.001 to 10 mol/. In the present invention, if necessary, a porous membrane made of synthetic resin such as glass, polyethylene, or polypropylene or natural fiber paper may be used as the diaphragm. Furthermore, some of the conjugated polymer compounds used in the present invention undergo gradual oxidation reactions due to oxygen, reducing the performance of the battery. Preferably, the condition is oxygen-free. The secondary battery of the present invention has a long cycle life, high energy density, and good self-discharge rate, voltage flatness, and charge/discharge efficiency. Furthermore, since the secondary battery of the present invention is lightweight, compact, and has high energy density, it can be used in portable devices, electric vehicles, etc.
Ideal for gasoline-powered vehicles and power storage batteries. The present invention will be explained in more detail below using examples. Example 1 [Production of crystalline 2,5-thienylene polymer] Commercially available metallic magnesium for Grignard reagent
2.01 g (82.7 mmol) into a thermometer, reflux condenser,
The mixture was placed in a 100 ml three-necked flask equipped with a dropping funnel, and the inside of the flask was sufficiently purged with dry nitrogen gas. Add 60ml of dry purified tetrahydrofuran to this and stir with a magnetic stirrer.
20 g (82.7 mmol) of 2,5-dibromothiophene was added dropwise at room temperature. A reaction started simultaneously with the dropwise addition, and an organomagnesium compound was produced. After the dropwise addition was completed, the mixture was reacted on an oil bath at the reflux temperature of tetrahydrofuran for 9 hours. At this time, by acid decomposition of the product, ether extraction, and gas chromatography analysis,
It was observed that 2-bromothienyl-5-magnesium bromide was produced at 86.4 mol%. Thereafter, the oil bath temperature was raised to 120°C, and tetrahydrofuran was distilled off under normal pressure and then reduced pressure to obtain a reddish brown oily residue. Add to this oily residue 60 ml of dry purified anisole and 80 mg of dichloro(2,2'-bipyridine)nickel.
(0.28 mmol) was added and reacted at 152°C for 2 hours, then poured into 500 ml of methanol acidified with hydrochloric acid and washed. After repeating this operation twice, it was filtered, and the filtration residue was Soxhlet-extracted with hot methanol for 13 hours and then with hot chloroform for 50 hours.The hot chloroform-insoluble part was 6.02 g of blackish brown fine powder, and the hot chloroform-soluble part was 6.02 g. The weight was 0.4g. The elemental analysis results of this thermal chloroform insoluble part are 56.08% carbon, 2.61% hydrogen, 1.09% ash, 200ppm Ni,
Mg was 60ppm. The average molecular weight calculated from the results of elemental analysis of carbon was 3880, and the average degree of polymerization was about 45. In addition, infrared analysis results (manufactured by JASCO Corporation)
(using JASCO A-31R spectrum photometer)
is shown in Figure 1, while the absorption based on the C-Br stretching vibration near 960 cm ^-1 is extremely small, the absorption near 785 cm ^-1 that is thought to be based on the 2,5-thienylene group is extremely large, indicating that the high polymer It shows that it is becoming. Furthermore, the X-ray diffraction diagram is shown in Figure 2 (Rigaku Rotorflex RU-200 type
(using a line diffractometer) showed that crystal peaks were present at 2θ = 19.8°, 23.2°, and 28.2°, indicating that this polymer was clearly crystalline. When the crystalline 2,5-thienylene polymer thus obtained was compression-molded using a 1-ton press, a slightly flexible plate-shaped molded product was obtained.
This plate-shaped molded product could be easily cut with a knife without losing its shape. [Production of acetylene polymer] Linear low density polyethylene (LLDPE) powder (density = 0.93 g/cc, MI = 8.2) was placed in a glass autoclave equipped with a blade-type mechanical stirrer under a nitrogen atmosphere. ), 2 g of carbon black powder (Kettien black with electrical conductivity of 2.1×10 ³ Ω ^-1 cm ^-1 ), 200 ml of toluene, 2 ml (5.9 mmol) of tetrabutoxytitanium, and 2 ml (14.6 mmol) of triethylaluminum. Acetylene partial pressure 0.9Kg/cm ² , polymerization temperature -20
Polymerization was carried out with stirring at .degree. C. for 2 hours. After the polymerization is completed, the resulting mixture of short fibrous acetylene polymer with an average length of about 1 mm, carbon black, and polyethylene is placed on a glass filter and thoroughly washed with a toluene solvent of about 1 mm to remove the catalyst. After that, it was degassed under vacuum to obtain short fibrous acetylene polymer content of 83% (weight), carbon black content of 11.3%, and polyethylene content of 5.6%.
% mixture was obtained. This mixture was then placed on a ferro plate and pressed at 100° C. under a pressure of 300 kg/cm ² , and then degassed under vacuum to obtain a composite of acetylene high polymer, carbon black and polyethylene. The surface of the composite had metallic luster. The short fibrous acetylene polymer obtained by this polymerization method had a cis content of 76% and an electrical conductivity at room temperature (DC two terminal method) of 5.1×10 ^-6 Ω ^-1 .cm ^-1 . Furthermore, when the obtained short fibrous acetylene polymer was observed using a scanning electron microscope, it was found that the acetylene polymer had a structure consisting of fibrous microcrystals (fibrils) with a diameter of 300 to 400 Å. . [Battery Experiment] A battery was constructed using the crystalline 25-thienylene polymer obtained by the above method as a positive electrode and the acetylene polymer composite obtained by the above method as a negative electrode. FIG. 3 is a schematic cross-sectional view of a battery cell for measuring the characteristics of a button-type battery, which is a specific example of the present invention;
Ni-plated brass container, 2 is a circular negative electrode with a diameter of 20 mm, 3 is a circular porous polypropylene diaphragm with a diameter of 26 mm, 4 is a circular felt made of carbon fiber with a diameter of 26 mm, and 5 is a circular negative electrode with a diameter of 20 mm. Disk-shaped positive electrode, 6 is a Teflon sheet with holes with an average diameter of 2 μm (manufactured by Sumitomo Electric, Fluoropore FP-200), 7
numeral 8 indicates a Teflon container having a circular cross section, numeral 8 indicates a Teflon ring for fixing the positive electrode, and numeral 9 indicates a Ni lead wire. The positive electrode was placed in the recess at the bottom of the container 1, and a circular porous Teflon sheet 6 was placed over the positive electrode, and then tightened and fixed with a Teflon ring 8.
The felt 4 was placed in the recess at the top of the container 1, overlapped with the positive electrode, and impregnated with an electrolytic solution.The negative electrode 2 was placed on the felt 4 through the diaphragm 3, and then tightened with the container 7 to produce a battery. As the electrolytic solution, a 1 mol/solution of Bu ₄ N.BF ₄ dissolved in distilled and dehydrated benzonitrile was used. Charging was carried out for 12 minutes under constant DC (5 mA/cm ² ) (amount of electricity equivalent to 16 mol% doping amount).
Immediately after charging, the battery was discharged under a constant current (5.0mA/cm ² ), and when the voltage reached 0.5V, the same conditions as above were repeated. Charge/discharge efficiency fell below 50%. Comparative Example 1 [Production of amorphous poly(2,5-thienylene)] 12.29 g (50.8 mmol) of 2,5-dibromothiophene and 1.23 g (50.6 mmol) of metallic magnesium were prepared in the same reaction order as in Example 1. , dichloro(2,
2′-bipyridine) Nickel 49.2 mg (0.17 mmol)
was used, and diethylene glycol dimethyl ether was used as a solvent for both the first and second stage reactions. First, in the first stage, the reaction was carried out at 165°C for 3 hours to completely react the metallic magnesium, and then in the second stage, a catalyst was added and the reaction was carried out at 165°C for 3 hours to obtain a dark brown polymer. The heat chloroform soluble part of this polymer is 0.66g, and the heat chloroform insoluble part is 2.16g.
The yield of the heated chloroform insoluble portion was low. The X-ray diffraction pattern of this polymer showed no peaks and was completely amorphous. Further, the polymer was compression molded using a 1-ton press to obtain a plate-shaped molded product. Completely the same as Example 1 except that the amorphous poly(2,5-thienylene) obtained by the above method was used instead of the crystalline 2,5-thienylene polymer used for the positive electrode in Example 1. When we conducted a [battery experiment] using this method, the charging/discharging efficiency dropped below 50% at the 137th charge/discharge cycle. Example 2 Except that 2,5-dibromo-3-methyl-thiophene was used instead of 2,5-dibromothiophene used in Example 1 [Production of crystalline 2,5-thienylene polymer]. A crystalline 3-methyl-2,5-thienylene polymer was produced in exactly the same manner as in Example 1. The obtained crystalline 3-methyl-
[Battery experiment] was conducted in exactly the same manner as in Example 1 except that 2,5-thienylene polymer was used as the positive electrode, and the charge/discharge efficiency was 50 at the 420th charge/discharge cycle. %. Comparative Example 2 Except that 2,5-dibromo-3-methyl-thiophene was used instead of 2,5-dibromothiophene used in [manufacture of amorphous poly(2,5-thienylene)] in Comparative Example 1. produced amorphous poly(3-methyl-2,5-thienylene) in exactly the same manner as in Comparative Example 1. [Battery experiment] was conducted in exactly the same manner as in Comparative Example 1 except that the obtained amorphous poly(3-methyl-2,5-thienylene) was used as the positive electrode. However, at the 156th time, the charging/discharging efficiency fell below 50%.

[Brief explanation of drawings]

FIG. 1 is an infrared absorption spectrum diagram of the polymer obtained in Example 1, and FIG. 2 is an X-ray diffraction diagram of the polymer obtained in Example 1. FIG. 3 is a schematic cross-sectional view of a battery cell for measuring characteristics of a button-type battery, which is a specific example of the present invention. 1... Container, 2... Negative electrode, 3... Diaphragm, 4...
Felt, 5... Positive electrode, 6... Porous Teflon sheet, 7... Teflon container, 8... Teflon ring, 9... Ni lead wire.

Claims (1)

[Scope of Claims] 1. 2,5-dihalogenothiophene or a derivative thereof is reacted with metallic magnesium in an aliphatic ether solvent under an inert atmosphere to form a substantially active organic monomagnesium compound; After removing the aliphatic ether solvent, the organic monomagnesium compound is polymerized in an aromatic ether solvent under an inert atmosphere in the presence of a nickel complex catalyst to obtain the general formula () (However, in the formula, R is an alkyl group having 5 or less carbon atoms,
n is 0, 1 or 2. 1. A secondary battery characterized in that a crystalline linear 2,5-thienylene polymer having a 2,5-thienylene group as a repeating unit represented by the following formula is used for at least one of a positive electrode and a negative electrode.