JPS6290878A - Secondary cell - Google Patents

Abstract

PURPOSE:To obtain a cell having high charge-and-discharge efficiency in a secondary cell in which a compound of polyaniline series is used for a positive electrode while using an alkaline metal for a negative electrode by using a chemical polymer oxide of the compound of aniline series as the compound of polyaniline series of the positive electrode while removing a component soluble in an electrolyte in advance. CONSTITUTION:A negative electrode 3, a diaphragm 4 made of porous polypropylene having thickness to be fully impregnated with an electrolyte and a positive electrode 5 all of which are in a disk-shape are tightened with a platinum net collector 6 used for the positive electrode and a platinum net collector 2 used for the negative electrode for constituting a secondary cell. And this is housed in a container 8 made of Teflon. Thereafter, a platinum lead wire 1 used for the negative electrode is drawn out from the collector 2 while drawing out a positive electrode lead wire 7 from the collector 6 respectively. In said constitution a liquid, in which LiPF6 is dis-solved in fully distilled and dehydrated propylene carbonate-1,2-dimethyoxyethane, is used as an electrolyte. Further, a compound of polyaniline series made free, in advance, from a component soluble in the electrolyte by means of an organic solvent is used for the collector 6.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention has high energy density, low self-discharge,
The present invention relates to a secondary battery that has a long cycle life and good charge/discharge efficiency (Coulomb 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, for example, B.J.
Nigrey et al., Journal of the Chemical Society, Chemical Communication, 1979, p. 594 CP, J, Nigrey et al., J, C, S.
, , Chem, Commun, .

1979.594), Journal Electrochemical Society, 1981, p. 1651 [J, El
electrochem, Soc, 1981, 1
651 ] , ] JP-A-56-136469 No. 57-
No. 121168, No. 59-3870, No. 59-387
No. 2, No. 59-3873, No. 59-196566,
No. 59-196573, No. 59-203368, No. 59-203369, etc. can be mentioned as some of them.

In addition, there have already been proposals to use polyaniline, which is obtained by electrolytic oxidation polymerization of aniline, which is a type of conjugated polymer, as an electrode for aqueous or non-aqueous batteries [A.No. Polymer Prederins, Volume 25.

Number 2. Page 248 (i984) (A, G.

MacDiarmid etc., Polymer Prepr
ints, 25, A2゜248 (i984)
L. Sasaki et al., Proceedings of the 50th Conference of the Electrochemical Society, 123.
(i983), Abstracts of the 51st Conference of the Electrochemical Society, 2
28 (i984)].

[Problem that the invention seeks to solve]

However, in polymer batteries using conventionally known polymers as electrodes, (i) high energy density, 01) low self-discharge,
It has not been possible to obtain anything that simultaneously satisfies (iij) high charge/discharge efficiency and (i) long cycle life.

In addition, the polyaniline used in conventionally known documents is obtained by electrolytic oxidation polymerization, but industrially it is possible to use polyaniline obtained by chemical oxidation polymerization, which is more economical. Although considered preferable, the electrode performance of polyaniline obtained by chemical oxidative polymerization was inferior to that of polyaniline obtained by electrolytic oxidative polymerization.

[Failure to solve the problem]

The present inventors investigated various types of electrode materials that simultaneously satisfy the above-mentioned four battery performance requirements and are more economical. As a result, the inventors of the present invention discovered that an aniline-based compound from which components that dissolve in the electrolyte of a secondary battery have been removed in advance for the positive electrode. The inventors have discovered that by using a chemically oxidized polymer, it is possible to obtain a secondary battery that can simultaneously satisfy the above four properties, and have arrived at the present invention.

That is, the present invention uses a polyaniline compound for the positive electrode,
In a secondary battery using a negative electrode of (i) an alkali metal, (ii) an alkaline earth metal alloy, (Iil) a conductive polymer, or (iv) a composite of an alkali metal or an alkaline earth metal alloy and a conductive polymer. , the polyaniline compound of the positive electrode is a chemically oxidized polymer of an IJ compound, and the components contained in the chemically oxidized polymer that dissolve in the electrolyte of the secondary battery have been removed in advance. The present invention relates to a secondary battery characterized by the following.

The chemically oxidized polymer of aniline compound used in the positive electrode of the secondary battery of the present invention has the following general formulas (i) and (2),
and chemical oxidative polymerization or chemical oxidative copolymerization of at least one aniline compound selected from structural formula (3).

[However, in the formula, R1 and R2 are an alkyl group having 5 or less carbon atoms or an alkoxy group having 5 or less carbon atoms, and X.

Y is 0, 1 or 2. ] Specific 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, 0-7 enylenenoamine, 3-methyl-1,2-diamino-benzene and the like. Among the aniline compounds represented by formulas (i) to (3), aniline,
Examples include 0-phenylenediamine and triphenylamine, with aniline being particularly preferred.

Chemically oxidized polymers or chemically oxidized copolymers of aniline compounds (hereinafter both are collectively referred to as oxidized polymers)
Any conventionally known chemical oxidative polymerization method can be used.

A specific example of producing an oxidized polymer of an aniline compound by a chemical method is a method in which an aniline compound is polymerized in an aqueous solution with a strong acid such as hydrochloric acid and an inorganic peroxide such as potassium persulfate. be able to. According to this method, the oxidized polymer is obtained in the form of a fine powder. Due to the presence of a salt in this method, the oxidized polymer is a complex compound with the corresponding anion.

Molded bodies that can be used as electrodes can be obtained by various methods. For example, a molded article can be produced by compression molding a fine powder of an oxidized polymer of an aniline compound under pressure and heat using a known method. Often temperatures between room temperature and 300°C and 10-10. OO0kg7c
A pressure of m2 is used.

The oxidized polymer obtained by forming a complex compound with an anion may be used as it is as the positive electrode of the secondary battery of the present invention, or the complexed anion may be chemically or electrochemically removed before use as the positive electrode. It's okay.

There are no particular restrictions on the method for removing in advance components that dissolve in the electrolyte of the secondary battery from the oxidized polymer of the aniline compound.
Usually, methods such as washing or extraction with an organic solvent are used. The shape of the oxidized polymer of the aniline compound when washed or extracted with an organic solvent may be a fine powder obtained by oxidative polymerization, or it may be formed into an electrode. good. Furthermore, it may be either one complexed with an anion or one from which the complexed anion has been removed in advance.

The method of washing with an organic solvent is not particularly limited in terms of the presence or absence of stirring, the number of times of washing, the time, etc., as long as it is a method of washing until the organic solvent for washing is no longer colored.

The temperature is usually in the range from the freezing point to the boiling point of the organic solvent.

As a method for extraction with an organic solvent, a method such as Soxhlet extraction, which is well known among those skilled in the art, is usually 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 are no particular restrictions on the type of organic solvent used to wash or extract the oxidized polymer of the aniline 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. You may. That is, washing or extraction may be performed with the organic solvent itself used in the electrolyte of the secondary battery of the present invention, or an organic solvent with solubility and parameters similar to those of the oxidized polymer of the aniline compound. For example, there is no problem in washing or extracting with a carbonyl compound such as acetone, a nitrile compound such as acetonitrile, a chlorine compound such as dichloroethane, a carboxylic acid compound such as acetic acid, an amide compound such as dimethylformamide, etc.

The negative electrode used in the secondary battery of the present invention is (i) an alkali metal, (i1) an alkali metal alloy, (mountain) a conductive polymer, or (iv) a composite of an alkali metal or an alkali metal alloy and a conductive polymer. It is the body.

(i) Alkali metals include Li, Na, K
(i1) As the alkali metal alloy, L
i/At alloy, Li/Hg alloy, Li/2n alloy,
Examples include Li/Cd alloy, Li/Sn alloy, Li/Pb alloy, and alloys of three types of metals containing alkali metals used in these alloys. Also, (i11)
Examples of the conductive polymer include polypyrrole and polypyrrole derivatives, polythiophene and polythiophene derivatives, polyquinoline, polyacene, polyparaphenylene and polyparaphenylene derivatives, polyacetylene, and the like. Furthermore, as (i■) a complex of an alkali metal or an alkali metal alloy and a conductive polymer, Li
/At alloy and the above-mentioned various conductive polymers, such as borino-9-raphenylene or polyacetylene. Among these, preferred are polyacetylene, polynographenylene, Lr/AA alloy, Li
/AA alloy and polygraphhenylene composite. The complex herein refers to a homogeneous mixture of an alkali metal or an alkali metal alloy and a conductive polymer, a laminate, and a modified product in which a base component is modified with another component.

As well known to those skilled in the art, other suitable conductive materials such as carbon blank, acetylene black, Metal powder, metal fiber, carbon fiber, etc. may be mixed.

Further, it may be reinforced with a thermoplastic resin such as polyethylene, modified polyethylene, polypropylene, poly(tetrafluoroethylene), engineered ethylene-propylene-dieneter polymer (EPDM), or sulfonated EPDM.

The supporting electrolyte of the electrolytic solution of the secondary battery of the present invention is an alkali metal salt. As the alkali metal of the alkali metal salt,
Examples include metals Li, Na and K, preferably Li metal.

Typical anion components of the supporting electrolyte include, for example, C
lO4-, PF6-, AsF6-, AsF4-
, 5O5CF3-.

BF4-, and BR4 (however, R has 1 to 1 carbon atoms
0 alkyl group or aryl group).

Specific examples of alkali metal salts as supporting electrolytes include:
LrPFb + Li5bFb +L+CAO4r L
IASF6 yCF3SO3Li, LiBF4.
LiB(Bu)4. LiB(Et)2(Bu)2゜Na
PF6. NaBF4. NaAsF6. NaB(B
u)4. )G3(Bu)4°KAsF6, but is not necessarily limited to these. These alkali metal salts may be used alone or in combination of two or more.

The concentration of the alkali metal salt cannot be specified unconditionally as it varies depending on the type of oxidized polymer of the aniline compound used in the positive electrode, the type of cathode, charging conditions, operating temperature, type of supporting electrolyte, type of organic solvent, etc. However, it is generally preferable that the amount is within the range of 0.5 to 10 mol/l. The electrolyte may be homogeneous or heterogeneous.

Examples of organic solvents that can be used alone or in combination as a solvent for the electrolytic solution 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, trimethyl borate, (CH30)3B (liquid range, -29.3°C to 67°C) tetraalkyl siligate Bi-side, tetramethyl silicate, (CHsO)4si (boiling point, 121 °C) Nitroalkane di-side, nitromethane, CH3N02 (liquid range, -17 °C to 1oo, 8 °C) Alkyl nitrile: e.g., acetonitrile, CH3CN (
Liquid range, -45°C to 81.6°C) Noalkylamides, dimethylformamide, HCON(CH3)2 (Liquid range, -60,48°C to 149°C) Lactams: e.g., N
-Methylpyrrolidone CH2-C) I2-CH2-Co-N-CH.

(L-form range, -16°C to 202°C) Monocarboxylic acid ester diside, ethyl acetate (liquid range,
-836~77.06℃) Orthoester: e.g., trimethyl orthopormate, HC(OCH3)3 (
Boiling point, 103 °C) Lactones: e.g., γ-butyrolactone CH2-CH2-CH2-O-C0 (l-form range, -42 to 206 °C) Noalkyl carbonate diside, trimethyl carbonate, QC(OCH3)2 (liquid range, 2-90℃) Alkylene carbonate: e.g., Solovylene carbonate
- (liquid range, -48 to 242°C) Monoethers: e.g., diethyl ether (liquid range, -116 to 34.5°C) Polyethers: e.g., 1.1- and 1,2-dimethoxyethane (liquid range, -116 to 34.5°C) Range, respectively -113,2~64,5℃
and -58-83°C) cyclic ether, tetrahydrofuran (liquid range, -
65-67℃): 1,3-dioxolane (liquid range, -
95-78℃) Nitroaromatic di-side, nitrobenzene (liquid range, 5.7-210.8℃) Aromatic carboxylic acid halide di-side, benzoyl chloride (
Liquid range, 0-197°C), benzoyl bromide (liquid range -24-218°C), two examples of aromatic sulfonic acid halides, benzenesulfonyl chloride (liquid range, 14.5-251°C), aromatic phosphonic acid dihalogen Compounds: Examples, benzenephosphonyl dichloride (boiling point, 258°C) aromatic thiophosphonic acid dino-rhodanide, benzene thiophosphonyl dichloride (boiling point, 124°C at 5s+) cyclic sulfoxide, sulfolane, (melting point, 22°C) 3- Methyl sulfolane (melting point, -1°C) 2 examples of alkyl sulfonic acid halide, methane sulfonyl chloride (boiling point, 161°C) 2 examples of alkyl carboxylic acid halide, acetyl chloride (liquid range, -112 to 50.9°C), odor acetyl (
Liquid range, -96 to 76°C), Propionyl chloride (Liquid range, -94 to 80°C) Saturated heterocyclic compound diside, Tetrahydrothiophene (Liquid range, -96 to 121°C): 3-Methyl-2-oxazolidone (Melting point, 15.9°C) Dialkyl sulfamic acid halide: e.g. dimethyl sulfamyl
Chloride (boiling point, 80°C for 16 cod) Alkyl halosulfonate di-side, ethyl chlorosulfonate (boiling point, 151°C) Unsaturated heterocyclic caldenic acid halide di-side, 2-furoyl chloride (liquid range, -2 to 173°C ) Five-membered unsaturated heterocyclic compound diside, l-methylvirol (boiling point, 114°C)
, 2,4-trimethylthiazole (boiling point, 144 °C), furan (liquid range, -85,65 to 31,36 °C), esters and/or nologonides of dibasic carboxylic acids, ethyl oxalyl chloride (boiling point, 135°C) mixed alkyl sulfonic acid halide/cargonic acid halide 2-side, chlorosulfonylacetyl chloride (boiling point, 98°C at 10 m) dialkyl sulfoxide 2-side, dimethyl sulfoxide (liquid range, 18.4-18
9°C) Dialkyl sulfate: e.g., dimethyl sulfate (liquid range, -31.75~188.5°C) Dialkyl sulfide: e.g., dimethyl sulfide (boiling point, 126°C) Alkylene sulfite diside, ethylene glycol
Sulfide (liquid range, -11~173°C) Halogenated alkane diside, methylene chloride (liquid range, -
(95 to 40°C), 1,3-nochloropronogne (liquid range, -99.5 to 120.4°C) Among the above, preferred organic solvents are sulfolane, crotonitrile, nitrobenzene, tetrahydrofuran, and methyl-substituted tetrahydrofuran. , 1,3-sanooxolane, 3-methyl-2-oxolanzolidone, propylene or ethylene carbnate, sulfolane, γ-
butyrolactone, ethylene glycol sulfide,
dimethyl sulfide, trimethyl sulfoxide, and 1,1- and 1,2-dimethoxyethane, particularly preferably propylene carbonate and 1,2-dimethoxyethane)
- Examples include xyethane and a mixed solvent of sulfolane and 1.2-/methoxyethane. This is because they are believed to be the most chemically inert towards battery components and have a wide liquid range, especially since they make cathode materials highly and efficiently available. It is from.

In the secondary battery of the present invention, the amount of Do-Gund doped into the oxidized polymer of the aniline compound is 0.2 to 15 mol per N atom in the oxidized polymer; Preferably it is 0.2 to 1.0 mol.

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

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 oxygen or water and reduce 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.

〔Effect of the invention〕

The secondary battery of the present invention has high energy density, high charge/discharge efficiency, long cycle life, 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, so it is suitable for use in portable devices, electric vehicles, gasoline vehicles, and power storage batteries.

〔Example〕

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

Example 1 [Production of oxidized polymer] 400 ml of distilled water deoxygenated in advance and 42% HBF'4
100 Al of the aqueous solution was placed in an 11 three-necked flask, and nitrogen gas was bubbled through it for about 1 hour while stirring. after that,
The inside of the system was placed under a nitrogen 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 20.0 g of aniline.

After the monomer was dissolved, 22 g of ammonium persulfate was added at once, and the mixture was heated for 5 minutes while stirring and keeping the internal temperature below 25°C.
Allowed time to react. After the reaction was completed, the greenish-brown reaction liquid was filtered and dried under vacuum to obtain 15 g of a dark green product.

100 cc of acetone was added to 1 g of the product, and after stirring at room temperature for 3 hours, the slurry liquid was filtered to collect the solid content. Next, 100 cc of acetone was newly added and the same operation as above was repeated. When this operation was repeated three times, the coloring of the tear fluid almost disappeared. The amount of components dissolved in acetone in this operation was 18% by weight.

[Production of film-like acetylene polymer]

1.7 me of titanium tetrabutoxide was added to a glass reaction vessel with an internal volume of 500 mg under a nitrogen atmosphere.
A catalyst solution was prepared by dissolving in 30ml of anisole and then adding 2.7me of triethylaluminum with stirring.

This reaction vessel was cooled with liquid nitrogen, and the nitrogen gas in the system was exhausted using a vacuum pump. Next, this reaction vessel was
While cooling to 0.degree. C. and keeping the catalyst solution stationary, purified acetylene 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 with 100 ml of purified toluene five times by turning the edges while keeping the temperature 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 swollen product was vacuum-dried to obtain a reddish-purple film with a metallic luster, a thickness of 180 μm, and a cis content of 98%. In addition, the bulk density of this film-like acetylene polymer is 0.30 g/cc, and its electrical conductivity (DC four-probe method) is 3.2 x 10- at 20°C.
9Ω-1・crn-1 [Battery experiment] The oxidized aniline polymer powder obtained in the above method was
After removing the BF4 anion by impregnating it in a 4OH aqueous solution, it was pressure-molded into a disc shape with a diameter of 20 m by a known method, and a disc shape with a diameter of 20 m was cut out from the film-like acetylene polymer. A battery was constructed using the disk-shaped materials as active materials for the positive and negative electrodes, respectively.

The figure is a schematic cross-sectional view of a battery cell for measuring the characteristics of a secondary battery, which is a specific example of the present invention, and 1 is a platinum lead wire for the negative electrode;
2 is a platinum wire mesh current collector for the negative electrode with a diameter of 20 mm and 80 mesh;
3 is a disc-shaped negative electrode with a diameter of 20 mm, 4 is a circular porous polypropylene diaphragm with a diameter of 20 mm, and is thick enough to be sufficiently impregnated with the electrolyte, 5 is a disc-shaped positive electrode with a diameter of 20 mm,
6 is a platinum wire mesh current collector for the positive electrode with a diameter of 20 mm and 80 mesh;
7 is a positive electrode lead wire, and 8 is a screw-type Teflon container.

First, the platinum wire mesh current collector 6 for the positive electrode is placed in a Teflon container 8.
Further, the positive electrode 5 is placed on the platinum wire mesh current collector 6 for the positive electrode, the porous polypropylene diaphragm 4 is placed on top of it, and after sufficiently impregnated with the electrolyte, the negative electrode 3 is placed on top of the positive electrode 5.
Further, a platinum wire mesh current collector 2 for a negative electrode was placed on top of the current collector 2, and a Teflon container 8 was tightened to produce a battery.

As the electrolyte, zolopyrene carbonate-1,2-dimethoxyethane (volume ratio: 1
=1) 1 mol of L I PF 6 dissolved in mixed solvent/
l solution was used.

Using the battery prepared in this way, the battery was charged in an argon atmosphere under a constant current (3.0 m 17 cm) by flowing an amount of electricity corresponding to the doping amount of 50 moles and 6 moles into the positive and negative electrodes, respectively. did. After charging is finished,
Immediately discharge under a constant current (5.0mA/crn2), and when the battery voltage reached 0.15V, charge again under the same conditions as above.A repeated charging/discharging test was conducted, and it was found that the charging/discharging efficiency was The number of charging/discharging cycles was recorded as 872 times before the battery decreased to 70%.

Also, the energy density at the fifth repetition is 135
At IA/'hr/kg, the highest light/discharge efficiency was 100 cm. Furthermore, when the battery was left charged for 60 hours, its self-discharge rate was 1.9%.

Comparative Example 1 Electrode molding and [ battery experiment] was conducted.

As a result, the number of charge/discharge cycles was 425, the energy density was 133 W-hr/kg, and the highest light/discharge efficiency was 99 cm. When the battery was left charged for 60 hours, its self-discharge rate was 4.1 cm.

Examples 2 to 5 Example 2 except that the oxidized aniline polymer obtained in [Production of oxidized polymer] of Example 1 was washed using the organic solvent shown in Table 1 instead of washing with acetone. Electrode molding and [battery experiment] were carried out in exactly the same manner as in 1, and the results shown in Table 1 were obtained.

(Space below) Example 6 The oxidized polymer of aniline obtained in [Production of oxidized polymer] of Example 1 was subjected to Soxhlet extraction with 1,2-dimethoxyethane in a nitrogen atmosphere for 5 hours. Example 1
Electrode molding and battery experiments were carried out in exactly the same manner as described above. Note that the soluble content in this case was 19% by weight.

As a result, the number of charge/discharge cycles was 902, the energy density was 135 W'hr/kg, and the highest light/discharge efficiency was 100%. Furthermore, when the battery was left charged for 60 hours, its self-discharge rate was 1.8.・Society of Japan/4'n, Volume 51, Page 2091 (i978
) CBull, Chem, Soc, Japa
n.

51.2091 (i978) was molded into a disk shape of 20 mm diameter at a pressure of 1 tOn/crn2, and the same procedure as Example 1 was used. As a result of conducting a [battery experiment] using the same method, the number of repetitions until the charging/discharging efficiency decreased to 70 cm was recorded as 822 times.

The energy density of this battery is l 53 W-hr/Ii
), the highest light/discharge efficiency was 100chi. Also,
When the battery was left charged for 60 hours, its self-discharge rate was 2.0%.

Example 8 A battery was produced in exactly the same manner as in Example 1, except that a Li/At alloy (atomic ratio of 1=1) was used in the negative electrode instead of the acetylene polymer used in the negative electrode. experiment] was conducted. As a result, the number of repetitions until the light/discharge efficiency decreased to 70 was recorded as 1123 times. The energy density of this cell was 210 W'hr/9, and the highest light/discharge efficiency was 100 H. Furthermore, when the battery was left charged for 60 hours, its self-discharge rate was 1.1%.

[Brief explanation of drawings]

The figure 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. DESCRIPTION OF SYMBOLS 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... For positive electrode Platinum mesh current collector, 7
...Positive electrode lead wire, 8...Teflon container.

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, or (iv) a composite of an alkali metal or an alkali metal alloy and a conductive polymer is used for the negative electrode. In the secondary battery used, the polyaniline compound of the positive electrode is a chemically oxidized polymer of an aniline compound, and the components contained in the chemically oxidized polymer that dissolve in the electrolyte of the secondary battery are removed in advance. A secondary battery characterized by: