JPS6355861A - Secondary battery - Google Patents

Abstract

PURPOSE:To be able to attain all of a high energy density, a low self-discharge, high charge and discharge efficiencies and a long cycle life by complexing an undoped polyaniline type compound with proton acid in non-aqueous system. CONSTITUTION:Polyaniline type compound used for a positive electrode is formed by complexation of undoped polyaniline type compound with proton acid in non-aqueous system. The undoped polyaniline compound is allowable to form a complex compound directly by proton acid, but preferably to remove components which are soluble in electrolyte used for secondary battery before complexation by proton acid. Suitable complexation processes of polyaniline compound by proton acid in non-aqueous system are: complexation in atmosphere of proton acid gas such as HCl, complexation in non-aqueous solution of proton acid such as acetonitrile solution of p-toluene sulfonic acid, and complexation of HF in an eutectic of NH4F.nHF.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention has a high energy density, small self-discharge,
υRegarding a non-aqueous secondary battery with a long cycle life and good charging and discharging efficiency (Coulombic efficiency).

[Conventional technology]

A so-called polymer battery, in which a polymer compound having a conjugated double bond in its main chain is used as an electrode, is expected to be a high energy density secondary battery. Many reports have already been made regarding polymer batteries, such as B.G.
Nigrey et al., Journal of the Chemical Society, Chemical Communication, 1979, p. 594 (P, J, Nigrey et al., J, C, S
,,Chem,Commun,, 1979 Engineering 594
), Journal Electrochemical Society, 1981, p. 1651 (J, EIectroc
hcn+.

Sac,, 19811651), Japanese Patent Publication No. 56-13
No. 6469, No. 57-121168, No. 59-387
No. 0, No. 59-3872, No. 59-3873, No. 59-3872, No. 59-3873, No.
No. 59-196566, No. 59-196573, No. 5
No. 9-203368, No. 59-203369, etc. can be mentioned as some of them.

In addition, there has already been a proposal to use polyanine obtained by electrolytic oxidation polymerization of aniline as an electrode for aqueous or non-aqueous batteries [A.G. Matsuku Diarmid et al., Polymer Preprints, Vol. 25] , Number 2. Page 248 (i984) (A, G, Ha
cOiarr6id et al, Polyoerρr
eprints, 25 N(i2,248(i984
) ), Sasaki et al., Abstracts of the 51st Conference of the Electrochemical Society,
123 (i983), Proceedings of the 51st Conference of the Electrochemical Society, 228 (i984)').

[Problem that the invention seeks to solve]

However, in polymer batteries using conventionally known polymers as electrodes, (i) high energy density, 0] low self-discharge, 0
Nothing has been obtained that simultaneously satisfies high charging, discharging efficiency, and (g) long cycle life.

The present inventors have conducted various studies to obtain a secondary battery that satisfies the above four battery characteristics at the same time, and have discovered that battery performance can be improved by selecting a polyaniline compound for the positive electrode.

The present invention was made based on the above-mentioned discovery, and
The purpose of the present invention is to provide a secondary battery that simultaneously satisfies two battery characteristics.

Means for Solving Problem C] The present invention has been made to achieve the above object, and its gist is that a polyaniline compound is used for the positive electrode, and (
i) Total alkali, (it) Alkali metal alloy, (to)
In a secondary battery using a conductive polymer, a composite of an alkali metal or an alkali metal alloy and a conductive polymer, or (v) an intercalation compound, the polyaniline compound in which the polyaniline compound is undoped is used in a non-aqueous system. It is found in secondary batteries that are complexed with protonic acid.

[Specific structure and operation of the invention]

The present invention will be explained in detail below.

The polyaniline compound used in the positive electrode of the secondary battery of the present invention is an oxidized polymer of an aniline compound represented by the following general formula (i) or (2). Whether it is a homopolymer or a copolymer of aniline-based compounds (in the formula, R1 to R6 are hydrogen atoms, alkyl bases or alkoxy groups having 1 to 5 carbon atoms, and X and Y are hydrogen atoms. or) is a 1-nyl group. ) Examples of aniline compounds represented by formulas (i) and (2) include aniline, 2-methyl-aniline, 2,
5-dimethyl-aniline, 2-methoxy-aniline, 2
-5-dimethoxy-aniline, 0-phenylenediamine, 3-methyl-1,2-diamino-benzene, diphenylamine, ]-liphenylamine and the like. Among these, preferred are aniline, 0-phenylenediamine, and triphenylamine, and particularly preferred is aniline.

The above polyaniline compound can be produced by electrochemical oxidation polymerization method,
It can be produced by either a chemical oxidative polymerization method or a Grignard method.

When electrochemical method 1 is used, polymerization of aniline compounds is positive If! , by oxidation, for which current densities of, for example, 2-20 mA/ci are used, and voltages of often 5-3 (iv) volts are applied. The polymerization is preferably carried out in the presence of an auxiliary liquid in which the aniline compound is soluble, for which water or a polar organic solvent can be used. When using a water-miscible solvent, a small amount of water may be added.

Preferred organic solvents are alcohols, ethers such as dioxane, tetrahydrofuran, acetone, acetonitrile, benzonitrile, dimethylbormamide, N-methylpyrrolidone.

Polymerization is carried out in the presence of a compounding agent. This is C1-, B'-+ i-+ F-+BF as anions.
a −+Δ5Fa−, ASF6−. 5bFs-.

5bCJ-+PF6-, CJOa-, H3O4-.

and a salt containing a SO2-4 group. The resulting polyaniline compound is doped (complex compound) with the corresponding anion.

These salts contain, for example, quaternary ammonium, lithium, sodium or potassium cations as cations.

The use of compounds of this type is known and is not the subject of the present invention.

When producing a polyaniline compound by a chemical oxidative polymerization method, for example, the aniline compound can be polymerized in a strong acid aqueous solution with an inorganic peroxide. According to this method, a polyaniline compound is obtained in the form of a fine powder, but since an anion is also present in this method, the polyaniline compound is doped (complex compound) with the corresponding anion.

The inorganic peroxide used in the production of polyaniline compounds by the chemical oxidation polymerization method is not particularly limited as long as it is soluble in a strong acid aqueous solution, and examples include ammonium persulfate, potassium persulfate, hydrogen peroxide, and ammonium persulfate. -Fe(II) ion redox system, 'iAm hydrogenide-
Examples of Fe ('l) ion redox systems include potassium monochromate, potassium permanganate, and sodium chlorate, but from the viewpoint of obtaining a secondary battery with good battery performance, ammonium persulfate, ammonium persulfate-Fe I
I) Ion redox system and hydrogen peroxide-Fe(If) ion redox system are preferred.

'IJ Ti' polyaniline compound by Grignard method
In this case, it may be carried out according to the polymerization of triphenylamine as described in JP-A-60-212420. According to this method, the polyaniline compound is obtained in an undoped state.

In the present invention, first, a doped polyaniline compound is brought into an undoped state.

Methods for undoping a doped polyaniline compound include (i) a method of compensating a doped polyaniline compound obtained by a chemical oxidative polymerization method or an electrochemical oxidative polymerization method with an alkali, and Oi) a chemical method. A method of electrochemically undoping a doped polyaniline compound obtained by a chemical oxidative polymerization method or an electrochemical oxidative polymerization method, 0. Examples include a method of undoping a polyaniline compound by heat treating it in a temperature range of 1(iv) to 3(iv)°C.

Since the polyaniline compound obtained by the Grignard method is in an undoped state, it can be complexed with a protonic acid as it is.

Among the above methods (D, (ii) and (g)), method (+) is preferred.As the alkali used in method (i), ammonia water, sodium carbonate, Examples include inorganic bases such as potassium and sodium hydroxide, and organic bases such as lower aliphatic amines such as triethylamine. Among these, aqueous ammonia is preferred.

Even if the thus obtained undoped polyaniline compound is used as it is in the positive electrode of the secondary battery of the present invention, the remarkable effects of the present invention cannot be obtained.

Therefore, in the present invention, an undoped polyaniline compound is complexed with a protonic acid in a nonaqueous system.

The undoped polyaniline compound may be complexed with a protic acid as it is, but it is preferable to remove components that dissolve in the electrolyte used in the secondary battery of the present invention before complexing with a protic acid. It's better.

There are no particular restrictions on the method for removing components dissolved in the electrolyte used in the secondary battery of the present invention, but usually a method of cleaning with an electrolyte, a method of cleaning with an organic solvent, a method of extraction with an organic solvent etc. are used.

In the method of washing with an electrolytic solution or an organic solvent, there are no restrictions on the presence or absence of stirring, the number of times of washing, the time, etc., as long as the washing is carried out until the electrolytic solution or solvent for washing is no longer colored.

The temperature is usually in the range of above the freezing point and below the boiling point of the organic solvent or the organic solvent in the electrolytic solution.

As a method for extraction with an organic solvent, a method such as Waxley extraction is employed. In this case as well, there are no particular limitations as long as the conditions do not cause the extract to become colored, but it is usually desirable to carry out the process in an inert gas atmosphere such as nitrogen or argon.

There is no particular restriction on the type of electrolytic solution used for cleaning the polyaniline compound, and for example, the electrolytic solution used in the secondary battery of the present invention described later can be used.

Furthermore, there is no restriction on the type of organic solvent used for washing or extracting the polyaniline compound, and any organic solvent may be used as long as it can remove components that dissolve in the electrolyte of the secondary battery of the present invention. . That is, the right used in the electrolyte of the secondary battery of the present invention! ¥! ! Washing or extraction may be carried out with the solvent itself, or organic solvents with similar solubility parameters to the polyaniline compound, such as carbonyl compounds such as acetone, nitrile compounds such as acetonitrile, chlorine compounds such as dichloroethane, acetic acid, etc. There is no problem in washing or extraction with a carboxylic acid compound, an amide compound such as dimethylformamide, etc.

As a method for complexing a polyaniline compound with a protonic acid in a non-aqueous system, (i) an undoped polyaniline compound is complexed with H
(Method of complexing in a proton acid gas atmosphere such as J) (i)
A method for complexing an undoped polyaniline compound in a non-aqueous proton solution such as an acetonitrile solution of P-toluenesulfonic acid.
6 years.

Page 127 (J, EIectrochem, 5oc6.
Eutectic NH4F reported in 1986.127) etc.
- A method of complexing IF in nHF is mentioned.

(An example of the protonic acid gas used in D is 1-1
cfo4.1-IBF4, HPFs, H(J,
Examples include hydrogen halides such as HBr, and H2804.

Examples of protic acids used in (i) include para.

Examples include sulfonic acids such as meta-, ortho-toluenesulfonic acid, methanesulfonic acid, and trifluoromethanesulfonic acid. The nonaqueous solvent is not particularly limited as long as it can dissolve these, and polar solvents such as nitriles and alcohols are generally used.

Among these protonic acids, (i
), HCj, (n), bara-toluenesulfonic acid, and 0 HF is also preferred.

The shape of the polyaniline compound when a doped polyaniline compound is made into an undoped state and the shape of the polyaniline compound when an undoped polyaniline compound is complexed with a protonic acid may be powder-like or film-like. Alternatively, it may be formed into an electrode.

Molded bodies that can be used as electrodes can be obtained by various methods. For example, when the polyaniline compound is in powder form, a molded body can be produced by press-molding the powder by a known method.

Often at temperatures between room temperature and 3 (iv) °C and between 10 and 1
A pressure of 0.0OOK9/lri is used.

The negative electrode used in the secondary battery of the present invention includes (+) an alkali metal, (5) an alkali metal alloy, an OiD conductive polymer,
(f) A complex of an alkali metal or alkaline earth alloy and a conductive polymer, or (v) an intercalation compound.

Examples of the alkali metal (+) include Li, Na, etc., and examples of the alkaline earth alloy (ii) include Ll/
M alloy, Li/Hg alloy, Li/Zn alloy, Ll/
3 including Cd alloy, Li/3n alloy, Li/Pb alloy and alkali metals used in these alloys.
Metals (7) Alloys, W4 Eva LI/N/M C
J, Ll/#/S n.

Examples include Ll/A#/Pb, Li/M/Zn, and L+/V/Hg. These alloys may be manufactured by either an electrochemical method or a chemical method, but those alloyed by an electrochemical method are preferable. Further, examples of the zero conductive polymer include polypyrrole, polypyrrole derivatives, polythiophene, polydiophene derivatives, polyquinoline, boriacene, polyparaphenylene, polyparaphenylene derivatives, polyacetylene, and the like. Furthermore, (g) composites of alkali metals or alkali metal alloys and conductive polymers include Li/M
Examples include composites of alloys and the various conductive polymers mentioned above, such as polyparaphenylene or polyacetylene. Among these, preferred are polyacetylene, polyparaphenylene, L/M alloy, Ll/AJ/MO alloy, and Li/AJ gold alloy complex with polyparaphenylene. The composite referred to here is a homogeneous mixture of an alkali metal or alkali metal alloy and a conductive polymer.
It refers to a modified product in which the components forming the laminate and the base are modified with other components.

(v) Metal oxides such as Fe2O2 are used as N intercompounds.

Examples include metal chalcogenides such as TLS2.

The polyaniline compound and conductive polymer used as the electrode of the secondary battery of the present invention may include other suitable conductive materials such as carbon black, acetylene black, metal powder, etc., as is well known to those skilled in the art. , metal fiber, and carbon mM layer may be combined. In addition, polyethylene, modified polyethylene, polypropylene, polytetrafluoroethylene, ethylene-brobylene-dieneter polymer ((
EPDM), sulfonated EPDM, or other thermoplastic resin may be used for reinforcement.

The supporting electrolyte of the electrolytic solution of the secondary battery of the present invention is an alkali metal salt. Examples of the alkali metal of the alkali metal salt include Li, Na and K metals, with L1 metal being particularly preferred.

Typical anion components of the supporting electrolyte include, for example, C
IO<-, PF6-, ASFs-.

Examples include ΔSF4'', 'SO3CF3-, BF4, and BR4- (wherein R is an alkyl group having 1 to 10 carbon atoms or an aryl group).

Examples of the alkali gold F4 salt as a supporting Nwl substance include LiPF6, LISbFs, LICfO4°LI
ASFa, CF3803Ll, LiBF4.

LIB (BLI)4 , LIB (Et)z (B
uz2゜NaPF6. NaB'F< , NaASFs
.

NaB (BLI)4, KB (BLJ)4, KA
Examples include SFs, but are not necessarily limited to these. These alkali metal salts may be used alone or in combination of two or more.

Alkaline gold fiPA? 1 degree cannot be unconditionally defined as it varies depending on the type of polyaniline compound used for the positive electrode, the type of cathode, charging conditions, production temperature, type of supporting electrolyte, type of organic solvent, etc., but it is generally 0. It is preferably within the range of .5 to 10 mol/J.

The electrolyte may be homogeneous or heterogeneous.

Examples of organic solvents that can be used alone or in combination as a solvent for the electrolyte of the secondary battery of the present invention include the following.

Alkylene nitrile: e.g., crotonitrile (liquid range, -51.1°C to 120°C) trialkyl borate:
Examples, trimethyl borate, (CH30>3 B (liquid range, -29,3°C to 67°C) two tetraalkyl silicates, tetramethyl silicate, (Chh O)4 S
i (boiling point, 121 °C) di-1~roalkanes: e.g., nitromethane, Ct-h NO2 (liquid range, -17 °C to 1
(iv). 8°C) Alkyl nitrile: e.g., acetonitrile, CI-hCN (liquid range, -45°C to 81.6°C)
.

Dialkylamide: e.g. dimethylformamide, 1-I
CON (CH3)2 (liquid range, -60,48℃~149℃) (liquid range,
-16℃～202℃) Two monocarboxylic acid esters, ethyl acetate (liquid range,
-83,6°C to 77,06°C) Orthoesters: e.g., trimedel orthoformate, IC(OCH3)3 (boiling point, 103°C) two lactones, γ-butyrolactone CH2-CH2-CH2-0-G .

(Liquid range, -42°C to 206°C) Dialkyl carbonate, dimethyl carbonate, QC(OCH3)z (Liquid range, 2°C to 90°C) Alkylene carbonate: e.g., propylene carbonate, (Liquid range, -48°C ~242°C) two monoethers, diethyl ether (liquid range, -116°C to 34.5°C) polyether:
Example, 1.1- and 1,2-dimethoxyethane (liquid range, -113,2°C to 64,5°C and -58°C, respectively)
-83℃) Cyclic ethers: e.g. detrahydrofuran (liquid range, -
65°C to 67°C): 1,3-dioxolane (liquid range,
-95°C to 78°C) 2 nitroaromatics, nitrobenzene (liquid range, 5.7°C to 210.8°C) Aromatic carboxylic acid halides: e.g., benzoyl chloride (liquid range, 0°C
~197°C), benzoyl bromide (liquid range, -24°C ~
218°C) aromatic sulfonic acid halide, benzenesulfonyl chloride (liquid range, 14°5°C to 2
51°C) Aromatic phosphonic acid dihalide: e.g., benzenephosphonyl dichloride (boiling point, 258°C) Aromatic thiophosphonic acid dihalide: e.g., benzene diiophosphonyl dichloride (boiling point, 124°C at pressure 5 #llj) Cyclic sulfone Two, sulfolane, (melting point, 22°C) 3-methylsulfolane (melting point, -1°C) Two alkyl sulfonic acid halides, methane sulfonyl chloride (boiling point, 161°C) Two alkyl carboxylic acid halides, acetyl chloride ( liquid range, -112°C to 50.9°C), acetyl bromide (liquid range, -96°C to 76°C), propionyl chloride (
liquid range, -94°C to 80°C) saturated heterocyclic compound, tetrahydrofuranene (liquid range, -96°C to 12°C)
1°C): 3-methyl-2-oxazolidone (melting point, 15
．． 9℃) Two dialkyl sulfamic acid halides, dimethyl sulfamyl chloride (boiling point, 880℃ at a pressure of 16ml ()) Two alkyl halosulfonates, ethyl chlorosulfonate (boiling point, 1
51°C) Unsaturated polycyclic carboxylic acid halogen compounds: e.g., 2-chloride
Furoyl (liquid range, -2°C to 173°C) five-membered unsaturated heterocyclic compounds: e.g., 1-methylvirol (boiling point, 114
℃), 2,4-dimethyldeazole (boiling point, 144℃)
, furan (liquid range, -85,65℃~31.36℃)
, two esters and/or halides of dibasic carboxylic acids, ■ del oxalyl chloride (boiling point, 135°C) mixed alkylsulfonic acid halide/carboxylic acid halide, chlorosulfonylaredel chloride (boiling point, pressure 10 mmHg) 98°C) Two dialkyl sulfoxides, dimethyl sulfoxide (liquid range, 18.4°C to 189°C) Dialkyl sulfate: e.g., dimethyl sulfate (liquid range, -3
1,75℃～188.5℃) 2 dialkyl sulfites, dimethyl sulfide (ijli point, 126℃
) Alkylene sulfide: e.g., ethylene glycol
Zulfite (liquid range, -11°C to 173°C) halogenated alkane, methylene chloride (liquid range, -173°C)
95°C to 40°C) 1,3-dichloropropane (liquid range, -99.5°C to 120.4°C) Among the above, preferred solvents include sulfolane, crotonitrile, nitrobenzene, tetrahydrofuran, methyl-substituted tetrahydrofuran, 1,3-dioxolane, 3-methyl-2-oxazolidone, propylene or ethylene carbonate, sulfolane, γ-butyrolactone, ethylene glycol
Reelphite, dimethyl sulfide, dimethyl sulfoxide, and 1,1- and 1,2-dimethoxyethane, particularly preferred are propylene carbonate and 1,2-dimethoxyethane, and sulfolane and 1,2-dimethoxyethane.
, 2-dimethoxyethane. This is because they are believed to be the most chemically inert towards battery components and have a wide liquid range, and in particular they allow for highly and efficient use of cathode active materials. Because it does.

In the secondary battery of the present invention, the amount of dopant doped into the polyaniline compound is 0.2 to 1.0 mol per N atom in the polyaniline compound,
Preferably it is 0.2 to 0.8 mol.

The dope ε can be freely controlled by measuring the amount of electricity flowing during electrolysis. - Doping may be carried out either under constant current, constant voltage, or under conditions of varying current and voltage.

In the present invention, it is preferred that cell experiments begin with a discharge to electrochemically remove the anions in the complexed protic acid.

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 the diaphragm.

In addition, some of the electrodes used in the secondary battery of the present invention may react with MS or water and degrade the performance of the battery, so the battery should be sealed and substantially oxygen-free and water-free. It is desirable that the condition is as follows.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Example 1 <Production of undoped polyaniline> Pre-deoxidized distilled water 4 (iv) 1fd! and 42wt%HB F4
Put 1 (iv) ml of aqueous solution into a three-necked flask,
Nitrogen gas was bubbled through the mixture for about 1 hour while stirring. After that, the inside of the system was placed under a nitrogen gas atmosphere, a thermometer and a condenser were attached, and then the flask was cooled with water and ice to bring the solution temperature to 15°C.

To this was added aniline 2(iv). After the aniline was dissolved, 22q of ammonium persulfate was gradually added, and the mixture was reacted for 5 hours while stirring and keeping the internal temperature at 25°C or lower. After the reaction was completed, the greenish-brown reaction solution was filtered and dried under vacuum to obtain a dark green product 15G. The dark green product obtained was soaked in 30 OId of 10% aqueous ammonia and filtered (after stirring overnight at room temperature).

Then, after washing with distilled water of 1(iv)0-, it was vacuum-dried at 80°C for 15 hours.

Then, further 1,2-dimethoxyethane 1(iv)0
Id, stirred at air temperature for 5 hours, filtered, further washed with 5(iv)-1,2-dimethoxyethane,
After vacuum drying at 0°C for 15 hours, it was further dried in vacuum at 220°C for 5 flashes. The elemental analysis value of the obtained purple powder is C+H
+N wt% 99.51%, its composition ratio C:l-1:
N=6. OO:4°51:0.99, indicating that it was an undoped polyaniline represented by the following formula.

(Complexation of J-ton acid to undoped polyaniline) After drying commercially available para-toluenesulfonic acid under vacuum at 80°C for 15 hours, it was dissolved in acetonitrile distilled to a water content of 10 ppm or less, and 0.5M of para-toluenesulfonic acid was prepared. An acetonitrile solution was prepared.To this solution 1(iv)d, the undoped polyaniline 5 was added and stirred in an argon atmosphere for about 15 hours.
v) Me's Ahito 2!・I'll wash it with Lil, 1 (
iv) 'Vacuum drying on CC for 15 hours yielded a dark green powder.

<Production of film-like acetylene polymer> 1.7rd titanium tetrabutoxide was added to a glass reaction vessel with an internal volume of 5 (iv) d under a nitrogen atmosphere,
A catalyst solution was prepared by dissolving in 30 rIdl of anisole and then adding 2.7-triethylaluminum with stirring.

This reaction vessel was cooled with liquid nitrogen, and the nitrogen gas in the system was energized using a vacuum pump. Next, this reaction vessel was
After cooling to 0.degree. C. and keeping the catalyst solution stationary, purified acetylene gas at a pressure of 1 atmosphere was bubbled through.

Immediately, polymerization 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 removing the catalyst solution with a syringe under nitrogen atmosphere, -78
It was washed repeatedly with purified toluene 1(iv)-5 times while being kept at °C. The film-like acetylene polymer swollen with toluene was a uniform film-like swollen product in which fibrils were tightly intertwined.

Next, this ll121 moist material was vacuum-dried to a reddish-purple color with a metallic luster and a thickness of 180 μm and a cis-containing ff of 198%.
A film-like acetylene copolymer was obtained. In addition, the bulk density of this film-like acetylene high polymer is 0.30 g/CG,
Its electrical conductivity (DC four terminal method) is 3.2X1 at 20℃
It was 0'Ω-1e crtt-1.

Battery experiment〉 The polyaniline powder obtained by complexing the undoped polyaniline with protonic acid was prepared by a known method.
Pressure molded into a disc shape with a diameter of 20 m, lithium foil (
A battery was constructed by using disk-shaped pieces with a diameter of 20 m cut from 2 (iv) μm thick as active materials for the positive and negative electrodes, respectively.

FIG. 1 is a schematic cross-sectional view of a battery cell for measuring the characteristics of a secondary battery, which is an example of the present invention, in which 1 is a platinum lead wire for the negative electrode, 2 is a negative electrode platinum wire mesh current collector with a diameter of 20M and 80 meshes. , 3 is a circular porous polypropylene diaphragm with a diameter of 20 m, and is thick enough to be sufficiently impregnated with electrolyte, 5 is a disk-shaped positive electrode with a diameter of 20 m, and 6 is a positive electrode platinum wire current collector with a diameter of 20 AW and 80 meshes. 7 is a positive electrode lead wire, and 8 is a screw-type polytetrafluoroethylene container.

First, the positive electrode platinum wire mesh current collector 6 is placed in the lower part of the concave portion of the container 8, and the positive electrode 5 is stacked on top of the positive electrode platinum wire mesh current collector 6, and a porous polypropylene diaphragm is placed on top of the positive electrode platinum wire mesh current collector 6. After sufficiently impregnating with the liquid, the negative electrode 3 was stacked, the negative electrode platinum wire mesh current collector 2 was further placed on top of the negative electrode 3, and the container 8 was tightened to produce a battery.

The electrolyte was propylene carbonate and 1,2-dimethoxyethane (volume ratio: 1), which had been distilled and dehydrated according to a conventional method.
A 2 mol/l solution of LI B F 4 dissolved in a mixed solvent of :1) was used.

Using the battery thus prepared, the battery voltage was 2.5 mA under constant current (0.5 mA/Cl1) in an argon atmosphere. It was discharged until it reached Ov. After that, the battery was disassembled, the negative electrode lithium foil was replaced with a 20 m diameter disc cut out from the membrane acetylene polymer obtained in <Production of membrane acetylene copolymer>, and the battery was reassembled in an argon atmosphere. The battery was charged by flowing an electric conductor having a doping concentration of 65'nyl% and 6 mol% to the positive and negative electrodes, respectively, under a constant current (i, 0 mA/cd). Immediately after charging, under constant current (5,0mA/ci)
So, /15! When the battery voltage reached 1.5V, a repeated charge/discharge test was conducted in which the battery was charged again under the same conditions as above, and the charge/discharge efficiency was reduced to 80%. The number of times was recorded as 1020 times.

The energy density at the fifth repetition is 151W.
-hr//e, maximum charge/discharge efficiency is 1(iv)%
Met. When the battery was left charged for 70 hours, its self-discharge rate was 1.5%.

Comparative Example 1 Example M Except for using the polyaniline obtained in <Production of undoped polyaniline> in Example 1 without complexing it in an azetonitrile solution of para-toluenesulfonic acid.
A battery experiment was conducted in exactly the same manner as in Example 1.

As a result, the maximum charging/discharging efficiency was 90%, and the charging/discharging efficiency was 70% or less after 30 charging/discharging cycles.

Examples 2 to 6 and Comparative Example 2 <Processing to undoped polyaniline> of Example 1
・Protonic acid complexation> In place of the 0.5 M balatoluenesulfonic acid/acetonitrile solution used in Example 1, polyaniline complexed with protonic acid by various methods shown in Table 1 was used. A battery experiment was conducted in exactly the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 3 The same procedure as Example 1 was performed, except that in the <manufacture of undoped polyaniline> of Example 1, compensation with aqueous ammonia was not performed, and doped polyaniline in which Chigofu's HBF4 remained complexed was used. Battery experiments were conducted in exactly the same manner.

As a result, the highest charging/discharging efficiency was 96%, and the charging/discharging efficiency was less than 80% after 107 charging/discharging cycles.

Example 7 In Example 1, instead of the acetylene high polymer used for the negative electrode, Bulletin of Chemical Society of Japan, Vol. 51, p. 2091 (i978) was used.
(Bull, Chem, Soc, Japan,
Exactly the same method as in Example 1, except that polyparaphenylene produced by the method described in 51-2091 (i978)) was molded into a 208φ disc shape at a pressure of 1 ton/Ci and used as the negative electrode. I conducted a battery experiment.

As a result, the number of repetitions until the charging/discharging efficiency decreased to 80% was recorded as 822 times. The energy density of this battery was 153 W-hr/Kyte, and the maximum charge/discharge efficiency was 1 (iv)%. Also, if you leave it charged,
When left for 0 hours, the self-discharge rate was 1.5%.

Example 8 A battery experiment was conducted in exactly the same manner as in Example 1, except that Ll/fiJ alloy (atomic ratio: 1=1) was used as the negative electrode instead of the acetylene polymer used in the negative electrode. I did it. As a result, the number of repetitions until the charging/discharging efficiency decreased to 80% was recorded as 951 times. The energy density of this battery was 210 W-hr/Ky, and the maximum charge/discharge efficiency was 1(iv)%. When the battery was left charged for 80 hours, its self-discharge rate was 1.4%.

As described above, the secondary battery of the present invention has a high energy density, a low self-discharge rate, and good voltage flatness during discharge. Furthermore, the secondary battery of the present invention is lightweight, compact, and has a high energy density, making it ideal for use in portable devices, electric vehicles, gasoline vehicles, and power storage batteries.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of a battery cell for measuring characteristics of a secondary battery, which is a specific example of the present invention. 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 lead wire

Claims (1)

[Claims] A polyaniline compound is used for the positive electrode, and (i) an alkali metal, (ii) an alkali metal alloy, (iii) a conductive polymer, (iv) a composite of an alkali metal or an alkali metal alloy and a conductive polymer, for the negative electrode. Alternatively, (v) a secondary battery using an intercalation compound, wherein the polyaniline compound is a non-aqueous complex of an undoped polyaniline compound with a protonic acid.