JPS6020467A - Secondary battery - Google Patents

Abstract

PURPOSE:To increase the cycle life of a secondary battery by using a crystalline 2,5-thienylene high polymer formed by repeatedly connecting the 2,5-thienylene group for at least one of the positive and the negative electrodes. CONSTITUTION:2,5-Dihalogenothiophene or its derivative is caused to react with metallic magnesium in an inactive atmosphere and in an aliphatic ether system solvent to make an active organic monomagnesium compound. Next, after the aliphatic ether system solvent is removed, the organic monomagnesium compound is polymerized in an inactive atmosphere, in the presence of a nickel complex catalyst and in an aromatic ether system solvent to obtain a crystalline linear 2,5-thienylene high polymer formed by repeatedly connecting the 2,5- thienylene group represented by the general formula. Such a high polymer is used for at least one of the positive and the negative electrodes of a secondary battery.

Description

Detailed Description of the Invention The present invention is characterized in that a crystalline 2,5-thennylene polymer having a 2,5-thennylene group as a repeating unit is used for at least one of the positive electrode and the negative electrode.
This relates to secondary batteries.

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 the Journal of Polymer Science, Bart A-1, Vol. 5, p. 1527 (1967), there is a report by M. Armor et al. that when thiophene is polymerized using trifluoroacetic acid as a catalyst, a yellow-brown color is produced. Although a polymer is obtained, it is described that this polymer has about 4 repeating units and 1 mole, and is a low polymer that is soluble in solvents such as benzene and chloroform. Additionally, in Journal of Chemical Society (C), Vol. 1971, p. 234, there is a report by R.F. Tartius et al. that several types of low polymers can be obtained by polymerizing thiophene in polyphosphoric acid. It is stated that the main product is a non-conjugated compound consisting of 2,4-di-2-chenyltetrahydrothiophene.

On the other hand, Yamamoto et al. reported in the Journal of Polymer Science Polymer Letters Edition Vol. It is stated that when an active organomagnesium compound is prepared by reacting it with metallic magnesium in an ether solvent such as butyl ether, and a nickel complex catalyst is added to this, polymerization easily occurs to obtain poly(2,5-chenylene). . Yamamoto et al. further discuss Chemistry Letters No. 10.
P. 79 (i981) states 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 by 9 to 9 orders of magnitude compared to that of the undoped polymer. F"" 10-28 /
It is stated that it becomes a semiconductor having an electrical conductivity of about cm. - However, as mentioned above, poly(2,5-thennylene) obtained by this method is amorphous, and the yield of the hot chloroform-insoluble part is low.
In Publication No. 21, the average molecular weight was 173 from the elemental analysis results.
0 (average degree of polymerization of about 19), 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 found that in an aliphatic ether solvent under an inert atmosphere,
2,5-dihalogenothiophene or a derivative thereof is reacted with metallic magnesium to form a substantially active organic monomagnesium compound, and after removing the aliphatic ether solvent, in the presence of a nickel complex catalyst under an inert atmosphere. By polymerizing the organic monomagnesium compound in an aromatic ether solvent, a 2,5-thhenylene polymer bonded at the 2,5-position can be obtained in extremely high yield and with a high molecular weight. We have already proposed that it is crystalline.

It has not been previously known that the 2,5-thennylene polymer thus obtained has crystallinity. Furthermore, as a result of various studies to use the crystalline 2,5-thennylene polymer obtained by the above method as a battery electrode, the present inventors found that the crystalline 2,5-thennylene polymer obtained by the above method could be used as a battery electrode. The secondary battery used was amorphous Bo'J (2,5
- Chenylene) was found to have a better cycle life than a secondary battery using as an electrode, and the present invention was achieved.

That is, the present invention involves reacting 2,5-dihalogenothiophene or a derivative thereof with metal magnesium in an aliphatic ether solvent under an inert atmosphere to form a substantially active organic monomagnesium compound, and After removing the group 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 to obtain the general formula (I) (
However, in the formula, R is an alkyl group having 5 or less carbon atoms, and n is 0.
1 or 2. The present invention relates to a secondary battery characterized in that a crystalline linear 2,5-chenylene polymer having a 2,5-chenylene group as a repeating unit represented by the following formula is used for at least one of a positive electrode and a negative electrode.

The crystalline linear 2,5-thennylene polymer used in the present invention is first prepared under an inert atmosphere as a first step.
2,5-dihalogenothiophene or its derivative and metallic magnesium are reacted in an aliphatic ether solvent to form a substantially active organomagnesium compound, and the aliphatic ether solvent is reacted with the metal magnesium at normal pressure and/or reduced pressure. After most of it is removed, the organic monomagnesium compound is polymerized in a second stage in an aromatic ether solvent in the presence of a nickel complex catalyst under an inert atmosphere.

Examples of the 2,5-dihalogenothiophene used in the present invention include 2,5-dichlorothiophene, 2,5-dibromothiophene, 2,5-shortthiophene, 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 have as high a purity as possible in order to prevent side reactions. The amount of magnesium metal used is 0.8 per mole of 2,5-dihalogenothiophene or its derivative.
~1.2 mol, preferably as close to 1 mol as possible in order to produce a monomagnesium compound and obtain a high polymer. The inert atmosphere here refers to moisture,
This refers to an atmosphere in which carbon dioxide gas, oxygen, etc. are not present, because these react with the active organic magnesium 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 by normal pressure and/or reduced pressure. The nickel complex catalyst used in the second stage includes dichloro(2,2'-bipyridine)nickel,
Examples include dibromo(2,2'-bipyridine)nickel, dichlorobis(triphenylphosphine)nickel, dibromobis(triphenylphosphine)nickel, l,5-cyclooctadienebis(triphenylphosphine)nickel, nickel acetylacetonate, etc. The amount used is 0.05 to 10 mol%, preferably 0.05 to 10 mol%, based on 2,5-dihalogenothiophene or its derivative.
It is 1 to 5 zil%.

Examples of aromatic ether solvents include anisole, trimethyl ether, and diphenyl ether. As the reaction humidity, a wide range of temperatures from room temperature to 250°C can be used. The reaction time is preferably 1 to 20 hours.

The 2,5-thennylene polymer obtained by the present invention is characterized by being crystalline, whereas known poly(2,5-thennylene) is amorphous, and X-ray diffraction reveals clear crystals. Show a pattern. Moreover, the average molecular weight is 3.000 or more by elemental analysis, and the degree of polymerization is high.

The secondary batteries of the present invention include those in which the crystalline 2,5-thennylene polymer obtained by the method of the present invention is used only in (1) the positive electrode, (11) only in the negative electrode, and (iii) Any battery used for both the positive and negative electrodes may be used. In the case of the secondary battery of the type (1), other conjugated polymer compounds, alkali metals such as Li and Na, Kurofune, carbon fiber, T i S 2, etc. are used as the counter negative electrode. In the case of the type (II) type of secondary battery, another conjugated polymer compound is used as the counter positive electrode.

Among the above-mentioned types, (1) or (
It is an m+ type secondary battery, and particularly preferred is a type (1) in which another conjugated polymer compound is used as a counter electrode.

Other conjugated polymer compounds mentioned here include acetylene polymers (polyacetylene), poly(p-phenylene), poly(m-phenylene), polypyrrole, poly(phenylene sulfide), and phenol (phenylacetate). , poly(arylene quinone), poly(azophenylene), poly(Schiff base), poly(amituquinone),
Poly(benzimidazoles), polyacenequinones,
and JP-A-57-195731, EP-67,44
Examples thereof include electroactive polymers described in 4, polyimide, polyacrylonitrile, thermal decomposition products of poly-α-cyanoacryl, etc., but are not necessarily limited to these. Among the above-mentioned conjugated polymer compounds, specific examples of poly(arylene quinones), poly(azophenylene), poly(Schiff base), poly(aminoquinone), and poly(benzimidazole) can be found in J.
E.

It is described in pages 87 to 112 of "Polymer Organic Semiconductors" edited by KATON, translated by Hidetoshi Tsuchida, published by Shokodo, 1972).

Among the above conjugated polymers, preferred are acetylene polymers, polyparaphenylene, and polypyrrole, and more preferred are acetylene polymers, particularly preferably highly crystalline acetylene polymers. This will produce a polymer.

The method for producing the acetylene polymer preferably used in the present invention is not particularly limited, and any method can be used. -129404,
No. 55-128419, No. 55-142012, No. 56-10428, No. 56-133133, Tra
ns Farady, Soc., 64.823 (196
8), J. Polymer Sci, A-1, 7, 34
19 (1969), Makromol.

Chem, Rapid Comm, 621 (
1980).

J, Chem, Phys, 69(1), 106 (1
978).

5ynthetic Matals, 4. 81 (1
981), but the method is not necessarily limited to these.

The crystalline linear 2,5-thhenylene polymer used in the present invention and the conjugated polymer compound used as the counter electrode (hereinafter, both will be abbreviated as conjugated polymer compound) are film-like, Any form such as powder, short fiber, etc. can be used. In addition, other suitable conductive materials such as graphite, carbon black, acetylene black, metal powder, carbon tam
There is no problem at all with mixing these materials, or using a metal net or the like as a current collector. Also, polyethylene,
It may be reinforced with a thermoplastic resin such as modified polyethylene or poly(tetrafluoroethylene).

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.

As a dopant to be electrochemically doped, (i
) halide anions of elements of group Va such as PF, SbF;, AsF;, 5bC1; halide anions of elements of lUam such as BF;
), B1', halogen anions such as C6-, ClO''
Anion dopants such as perchlorate anions such as No. 4 (both are effective as dopants that provide a P-type conductive conjugated polymer compound) and (ii) Li +, Na +
, cation dopants such as alkali metal ions such as K'', quaternary ammonium ions such as R4N+ (R: hydrocarbon group having 1 to 20 carbon atoms) (all dopants that provide an n-type conductive conjugated polymer compound) (effective as an effective method), but is not necessarily limited to these.

Specific examples of compounds providing the above-mentioned anionic dopants and cationic dopants include LiPF, Li5
bF,, LiAsF,, LiC10,, NaI N N
aPF6, Na5bF, , NaAsF, , NaClO4
,KI,KPF,,KSbF,,KAsF,,KCl
O4, ((n Bu), N]'-(AsFa)-1[
(n-Bu), N]+・(PF,)'-1[(n=Bu
)4N)” -CllO4, LiAlCJ, , LiBF
,, No -BF XN0- BF,, NO□・A
Examples include, but are not limited to, sF6, No.424AsFa, N02.ClO4, and No-CIO. These dopants may be used alone or in combination of two or more.

Examples of anion dopants other than the above include HEi''; anion, and examples of anion dopants other than the above include pyrylium or pyridinium cations represented by the following formula (I): (wherein, X is an oxygen atom or a nitrogen atom, k 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 a halogen atom or an alkyl group having 1 to 10 carbon atoms, and 6 carbon atoms; ~15 aryl groups, m is O when X is an oxygen atom, and l when X is a nitrogen atom. n is 0 or 1 to 5. Carbonium cation represented: R3/ and R' C+Ql [In the above formula, R1, R2, R3 are hydrogen atoms (RI, R2,
R3 is not a hydrogen atom at the same time), carbon number 1 ~
15 alkyl groups, allyl group, carbon number 6
~15 aryl groups or 10R5 groups, where R5 is an alkyl group having 1 to 10 carbon atoms or 6 carbon atoms
-15 aryl group, R4 is a hydrogen atom, an alkyl group having 1 to 15 carbon atoms, or an aryl group having 6 to 15 carbon atoms. ] It is.

The HF used; the anion usually has the following general formula % formula %
(): ) () [However, in the above formula, R, R// are hydrogen atoms or carbon atoms are 1
~15 alkyl group, aryl having 6 to 15 carbon atoms (ar
yl) group, 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 O or a positive integer of 5 or less. . M is an alkali metal] is obtained by dissolving the compound (hydrogen fluoride salt) in a suitable organic solvent using as a supporting electrolyte. Specific examples of H, N
-HF2, Bu4N・HF2, Na-HF2,
K-HF, , Li-HF2 and the pyrylium or binodinium cation represented by the above formula (I) are dissolved in an appropriate organic solvent using a salt of the cation represented by the formula (I) with an anion as a supporting electrolyte. Obtained by dissolving. Specific examples of such salts include .

Specific examples of the carbonium cation represented by the above formula (6) or the formula (C6H6)3C+, (CH3)
3 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', AlCd;
, A11Br3Cl-1FeCIJ, -1Sn C73
, PF;, PC1, 5bCl′6, SbF″6, C
IO'4, CF35o; etc. can be mentioned, and
Specific examples of carbonium salts include (C6H5)
3c-BF, , (CH3)3C-BF4, HCO-A
Examples include lCl4, HCO-BF, and CHCo.5nC15.

5. As the electrolytic solution of the secondary battery of the present invention, either an aqueous solution or a non-aqueous solution can be used, but it is preferably one in which the above-mentioned dot 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. Examples include 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, phosphite ester compounds, borate ester compounds, chlorinated hydrocarbons , carbonates are preferred. Representative examples of these include tetrahydrofuran, 2-methyltetrahydrofuran,
4-dioxane, monoglyme, acetonitrile, propionitrile, 4-methyl-2-pentanone, butyronitrile, valeronitrile, benzonitrile, 1,2-dichloroethane, γ-butyrolactone, noflerolaftone,
Dimethoxyethane, methylformate, propylene carbonate, ethylene carbonate, dimethylformamide, dimethylsulfoxide, dimethylthioformamide, ethyl phosphate, methyl phosphate, ethyl phosphite, methyl phosphite, sulforane 3-methylsulfolane, etc. I can do it. 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, 1. Oxygen, water, protic solvents, etc. in these solvents may deteriorate the characteristics of the battery. 9. In that case, purify according to the usual method. It is preferable.

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 dope can be freely controlled by measuring the amount of electricity that flows during electrolysis. The doping can be carried out either under constant current, constant voltage or under varying conditions of 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.

A paste obtained by simply mixing a dopant and an organic solvent can also be used.

In addition, the concentration of the electrolyte (dopant) used in the secondary battery of the present invention is determined by the type of positive electrode or negative electrode used, charging and
It cannot be unconditionally defined because it varies depending on discharge conditions, operating temperature, type of electrolyte, type of organic solvent, etc. The electrolytic solution may be homogeneous or heterogeneous, but it is usually in the range of 0.001 to 10 mol/l.

Glass or polyethylene if necessary in the present invention.

There is no problem in using a porous membrane made of synthetic resin such as polypropylene or natural fiber paper as the diaphragm.

In addition, some of the conjugated polymer compounds used in the present invention undergo a gradual oxidation reaction with oxygen,
It is preferred that the battery be sealed and substantially oxygen-free, as some may degrade the performance of the battery.

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. Further, the secondary battery of the present invention is lightweight,
Because it is small and has high energy density, it is ideal for portable devices, electric vehicles, gasoline vehicles, and power storage batteries.

The present invention will be explained in more detail below by way of examples.

Example 1 [Production of crystalline 2,5-thennylene polymer] Commercially available metallic magnesium 2 for Grignard reagent, Olg (827
mmol) was placed in a 10ml 3-mL flask equipped with a temperature control tube, a reflux condenser, and a dropping funnel, and the inside of the flask was sufficiently purged with dry nitrogen gas. Add 60 ml of dry purified tetrahydrofuran to this, and while stirring with a magnetic cooler, 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 dropping, add water at reflux temperature of tetrahydrofuran on an oil bath for 9 hours.
Allowed time to react. At this time, the product was decomposed with acid, extracted with ether, and analyzed by gas chromatography.
It was confirmed that 2-bromochenyl-5-magnesium bromide was produced. After that, the oil bath temperature was set to 120
The temperature was raised to .degree. C., and tetrahydrofuran was distilled off under normal pressure and then reduced pressure to obtain a reddish brown oily residue.

To this oily residue was added 60 ml of dry purified anisole, 1 S dichloro(2,2-bipyridine) nickel 80 mg (0,28
mmol) and reacted at 152°C for 2 hours.
It was washed by pouring it into 00ml of hydrochloric acid and methanol. 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 amount insoluble in hot chloroform was 6.02.
g of blackish brown fine powder, and the heat chloroform soluble part is 0.
．． It was 4.9.

The elemental analysis result of this thermal chloroform insoluble part is carbon 560.
8%, hydrogen 2.61%, ash 109%, NNi 200p
p, Mg was 60 ppm. The average molecular weight calculated from the results of elemental analysis of carbon was 3,880, and the average degree of polymerization was about 45. In addition, the infrared analysis results (Japan Bunko JA
Figure 1 shows that the absorption based on C-Br stretching vibration near 960cITL-1 is extremely small, while the absorption at 785cm-1
The absorption, which is thought to be based on the nearby 2,5-chenylene group, is extremely large, indicating that it is a high polymer. Furthermore, the X-ray diffraction diagram is shown in Figure 2 (using a Rigaku Rotaflex RU-200 X-ray diffractometer).
Crystalline peaks were present at 8=19.8°, 232°, and 28.2°, indicating that this polymer was clearly crystalline.

When the crystalline 2,5-chenylene 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]

ll glass auto with vane-type mechanical stirrer
Linear low density polyethylene (LLDPE) powder (density = 0.9:
l/CC, M, 1. =8.2) lg, carbon black powder (electrical conductivity 2. IXlO'Q-
'・cm-' Ketjenblack) 2,17. ) 200ml of toluene 1°tetrabutoxytitanium 2ml (
5,9 mmol) and 2 ml of triethylaluminum
(14.6 mmol), acetylene partial pressure 0.9
One polymerization was carried out at a polymerization temperature of -20° C. and stirring for 2 hours.

After completion of the polymerization, the resulting mixture of short fibrous acetylene polymer with an average length of about 1 mm, carbon black, and polyethylene was placed on a glass filter and thoroughly washed with about 11 toluene solvent to remove the catalyst. After that, the short fibrous acetylene high polymer content was reduced to 83 by vacuum degassing.
% (by weight), a mixture with a carbon black content of 113% and a polyethylene content of 56% was obtained. This mixture was then placed on a ferro plate and pressed at 100°C with a pressure of 300 kg/c/L, and then degassed under vacuum to obtain a composite with acetylene high polymer, carbon black, and polyethylene. . The surface of the composite had metallic luster.

The cis content of the short fibrous acetylene polymer obtained by this polymerization method is 76%, and the electrical conductivity at room temperature (DC two-terminal method)
is 5. I It had a structure consisting of fibrous microcrystals (fibrils).

[Battery experiment]

A battery was constructed using the crystalline 25-chenylene 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, where 1 is a Ni-plated brass container, 2 is a disc-shaped 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, 5 is a disk-shaped positive electrode with a diameter of 20 mm, and 6 is an average diameter of 2 μm
7 is a Teflon container with a circular cross section, 8 is a Teflon cylinder for fixing the positive electrode, 9 is N
The i lead wire is shown.

The positive electrode was placed in the lower four parts of the container 1, and a porous circular 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 upper four parts of the container and overlapped with the positive electrode, and after being impregnated with an electrolytic solution, the negative electrode 2 was placed through the diaphragm 3, and the felt was tightened with the container 7 to produce a battery. The electrolyte is Bu, N dissolved in distilled and dehydrated IJ.
A 1 mol/l solution of '-BF was used.

Charging was carried out for 2 minutes under a constant current (5 mA/i) (amount of electricity equivalent to a doping amount of 16 mol%), and immediately after charging was completed, discharging was carried out under a constant current (5.0 rnA/ff1) until the voltage reached 0. When the voltage reached .5 V, a repeated charging/discharging test was performed under the same conditions as above, and the charging/discharging efficiency fell below 50% at the 434th time.

In the same reaction sequence as in Example 1, 12.2'l (50.8 mmol) of 2,5-dibromothiophene, 1.23150.6 mmol of magnesium metal, 0 (2
, 2'-bipyridine) nickel 49.2 m9 (0,
17 mmol), 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 metal 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 thermal chloroform soluble portion of this polymer is 066g.
The amount of hot chloroform insoluble portion was 2.16 g, and the yield of hot chloroform insoluble portion was low. The X-ray diffraction diagram 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.

In place of the crystalline 2,5-thennylene polymer used for the positive electrode in Example 1, amorphous IJ (2,5-thienylene) obtained by the above method was used.
When a [battery experiment] was carried out in exactly the same manner as in Example 1, except for using the same battery as in Example 1, the charge/discharge efficiency fell below 50% at the 1'37th charge/discharge cycle.

Example 2 2,5-dibromothiophene used in Example 1 [Production of crystalline 2,5-thennylene polymer] was replaced with 2,5-dibromothiophene.
A crystalline 3-methyl-2,5-chenylene polymer was entirely prepared in the same manner as in Example 1, except that 5-dibutyl('8)-' 3-methyl-thiophene was used. [Battery experiment] was conducted in exactly the same manner as in Example I except that the obtained crystalline 3-methyl-2,5-thennylene polymer was used as the positive electrode, and the number of charge/discharge cycles was 420.
The charging/discharging efficiency fell below 50% in the second cycle.

Comparative Example 2 2,5-dibromothiophene used in Comparative Example 1 [Production of amorphous poly(2,5-thennylene]) was replaced with 2,5-dibromothiophene.
Amorphous poly(3-methyl-
2,5-chenisin) was produced. [Battery experiment] was conducted in exactly the same manner as in Comparative Example 1 except that the obtained amorphous poly(3-methyl-2,5-thennylene) was used as the positive electrode. At the 156th time, the charging/discharging efficiency fell below 50 units.

[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...
・till 4... Felt 5... Positive electrode 6... Porous Teflon sheet 7...
Teflon container 8...Teflon ring 9...Ni Lead wire patent applicant Showa Denko K.K. representative patent attorney Sei Kikuchi -

Claims (1)

[Claims] Under an inert atmosphere in an aliphatic ether solvent, 2.5-
Dihalogenothiophene or a derivative thereof is reacted with metallic magnesium to form a substantially active organic monomagnesium compound, and after removing the aliphatic ether solvent, an aromatic ether is prepared in the presence of a nickel complex catalyst under an inert atmosphere. General formula (I) obtained by polymerizing the organic monomagnesium compound in a system solvent (wherein R is an alkyl group having 5 or less carbon atoms, n is 0
, 1 or 2. ) A secondary battery characterized in that a crystalline linear 2,5-chenylene polymer having a 2,5-chenylene group as a repeating unit represented by the following formula is used for at least one of a positive electrode and a negative electrode.