JPS60221973A - Secondary battery - Google Patents

Abstract

PURPOSE:To obtain a secondary battery having high power and light weight by forming a positive electrode with electric conductive high polymer and a negative electrode with carbon containing graphite structure. CONSTITUTION:A secondary battery is fabricated by using electric conductive high polymer as a positive electrode, carbon containing graphite structure as a negative electrode, and electrolyte prepared by dissolving a compound capable of electrolytically producing an ion which can be doped into the positive and negative electrodes in a nonaqueous solvent. Performance, espetially energy density, of the secondary battery is substantially increased compared with a secondary battery using conventional electric conductive high polymer. Artificial carbon prepared by carbonizing a substance at a temperature of above 1,000 deg.C and less than 2,500 deg.C, or artificial graphite prepared by graphitizing a substace at 2,500 deg.C or more, or natural graphite is preferable as the carbon containing graphite structure.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a secondary battery using a conductive polymer material, and more specifically, a positive electrode formed of a conductive polymer material,
A negative electrode is formed using a carbon material containing a U3 black structure, and a compound capable of generating ions that can be doped into these iE electrodes or negative electrodes through electrolysis is dissolved in a non-aqueous solvent. Relates to high-output secondary batteries that use a solution as an electrolyte.

In recent years, it has been revealed that conductive polymer substances such as polyacetylene are excellent as electrode materials for batteries, and are attracting attention as extremely promising materials for increasing the output and reducing the weight of secondary batteries. Therefore, these conductive polymer materials can be used as electrodes! , various secondary batteries have been proposed (Japanese Unexamined Patent Publication No. 136469/1983, etc.).

However, secondary batteries using conventional conductive polymer materials as electrodes have the following problems and have not yet been put into practical use.

That is, (1) when a conductive polymer substance is used as the tE electrode, it exhibits relatively excellent electrode properties, but when -C is used as the negative electrode, the electrode properties are poor; (ii) how Even if a standard electrolyte is used, it is extremely sensitive to impurities such as water, and in order to improve and maintain battery performance, the electrolyte needs to be highly purified.
) It has also been proposed to use lithium metal as the negative electrode instead of the Cs-conductive polymer material, but
This method has the disadvantage that a so-called Puntorai 1 phenomenon occurs in the lithium metal that is the negative electrode, making it impossible to provide a practical battery.
(1v) Also, an electrode using graphite for both the positive and negative electrodes has been proposed (Japanese Patent Application Laid-Open No. 11158-192266).
However, there are problems with this battery (such as the output is not high),
In order to create a practical battery, it is desirable to solve these problems.

In view of the above circumstances, the inventors of the present invention have conducted intensive studies on an appropriate negative electrode monthly rate that will exhibit excellent performance when combined with a conductive polymer substance as a positive electrode material.As a result, graphite M4 It has been found that the above object can be achieved by using a carbonaceous material as a negative electrode.

That is, a conductive polymer material is used as a positive electrode, a graphite structure-containing carbon material is used as a negative electrode, and a compound capable of generating ions that can be doped into the positive and negative electrodes by electrolysis is used as a non-aqueous solvent. When constructing a battery using a dissolved solution as an electrolyte, (a) it must have high output and maintain this characteristic for a long period of time; ~Advantages such as no light phenomenon, (c) small effect of impurities such as water on battery performance, and therefore no special purification or sealing technology for the electrolyte is required. When a graphite structure-containing carbon material is used as a negative electrode for a positive electrode made of a conductive polymer material, the combination of these positive and negative electrodes is very suitable and effective. We discovered that it is possible to effectively demonstrate the characteristics of
This has led to the present invention.

The present invention will be explained in more detail below.

As described above, the secondary battery according to the present invention has a conductive polymer material as a positive electrode, a carbon-containing material with an Ei black structure as a negative electrode, and ions that can be doped into the positive electrode and the negative electrode, respectively, through electrolysis. The electrolyte is a solution prepared by dissolving a compound capable of producing and covering t'b in a non-aqueous solvent, and this improves the performance of the secondary battery, especially the energy density, compared to conventional conductive t'b molecular substances as electrodes. This is an amazing improvement in C compared to the covered secondary battery.

Here, what is used for the negative electrode of the secondary battery of the present invention? 5 Ink structure-containing carbon material, C is a carbonaceous material or graphite material, carbonized bt, < is a person who carbonized a graphitized +'F substance at a temperature of 1000°C or more and less than 2500°C. I;/J-bond or graphitized at a temperature of 2500° C. or higher, artificial graphite or natural graphite can be suitably used.

In this case, examples of substances that can be carbonized or graphitized include cellulose, bits, liquid crystal bits, polyacrylonitrile, polyvinyl chloride, phenol resins, and imides such as polybenzooxylylimide. Note that there is no particular restriction on the form of the graphite structure-containing carbon material used as the negative electrode, and it can be used in various forms such as fiber, cloth, nonwoven fabric, film, plate, powder, etc. Specifically, the material listed in -1- Calcined carbon fiber, carbon cloth, carbon foil, graphite fiber, graphite liss,
Graph 7? Itofoil, acetylene black, natural graphite, etc. may be used.

Next, examples of conductive polymer materials used for the positive electrode include polyaniline, polyphenylene, and polythenylene.

Polyacetylene, polyfuran, polypyrrole, poly(p
-phenylene vinylene), polyphenylene sulfide, and polyphenylene oxide. Among these, polyaniline and polyphenylene are preferred, and polyaniline is most preferably used.

Note that these IP conductive polymer substances can be obtained by electrochemical application methods, for example, by electrolytically synthesizing these conductive polymer substances directly on the electrode using a metal or carbon molded body as the electrode. It can be used as a positive electrode as it is, and by adopting such a method, the manufacturing process of the conductive polymer material can be shortened.

The compound used in the electrolytic solution constituting the secondary battery of the present invention and generating ions that can be doped into the positive and negative electrodes is a compound consisting of a combination of an anion and a cation, and examples of the anion include PF6-. 5bFs-, ASF
6-. A halide anion of a group VA element such as 3blJ6-.

BF4-, pigeonide anion of group IIIA element such as NIC9a-, I-(13-), Br-,
(Halogen anions such as J-, perchlorate anions such as CROa-, HF2-, CF3 SO3-, CN5
−.

Examples include Soa --, HSOa-, etc., but the anion is not necessarily limited to these anions. Examples of cations include noflukali metal ions such as li'', tJa'', and K'', and quaternary ammonium ions such as R4N'' (R represents hydrogen or a hydrocarbon residue). However, it is not necessarily limited to these cations. Specific examples of compounds containing these anions and cations include Li PFe and Li Sb F6.

Li As Fs, l-1cf04. Li 1. Li
Br.

Li CR, NaPF5, NbSb F6, NaA
SF6.

tbcRo 4 , , Na1. KPFa, KSbF
6゜KAS Fo, KCfo 4, I-i BF4
.

11 NCIa, Li HF2, Li CNS.

KSCN, Li SO3CF3.

(n Ct 4 F+7) 4 NAS l2. .

(n-04H7)4 NPFI+.

(n-C4Hy)4NCjO4.

(n-C4Hy)4NBF4.

(C21-1s>4 NCRO4.

(n -041-17>4 N 1 etc., but from the viewpoint of weight reduction and stabilization of the secondary battery, lithium salts, especially: Li CIO4, Li BF4 .

t I, l i[3r, LiCf is preferably used.

Note that the above-mentioned compound is usually used in a state dissolved in a solvent, and in this case, the solvent is not particularly limited, but a relatively highly polar solvent is preferably used. Specifically, propylene carbonate, ethylene carbonate, benzonitrile, acetonitrile, tetrahydrofuran, 2-
Methyltetrahydrofuran, γ-butyrolactone, dioxolane, methylene chloride, triethylphate A sulfate.

Triethylph A sphite, dimethyl sulfate, dimethylborumamide. Dimethylacetamide, dimethylsulfoxide, dioxane, dimethoxyethane, polyethylene glycol, sulforane.

Mention may be made of dichloroethane, chlorobenzene, nitrobenzene, water, etc. or a mixture of two or more thereof. Among these, nonaqueous solvents are preferred, and when a nonaqueous solvent is used as the solvent, the electromotive force of the battery increases.

The secondary battery of the present invention is usually constructed by interposing an electrolyte between the positive and negative electrodes, but in this case, a separator can be interposed between the positive and negative electrodes to prevent short circuiting of current due to contact between the two electrodes. As the separator, use a porous material that allows the electrolyte to pass through or contain it, such as nonwoven fabrics, woven fabrics, and nets made of synthetic resins such as polytetrafluoroethylene, polypropylene, and polyaniline.
can be done.

In the secondary battery of the present invention, the positive electrode is formed of a conductive polymer material and the negative electrode is formed of a graphite structure-containing carbon material, and since the combination of these positive and negative electrodes is very effective, it achieves high output and is lightweight. Therefore, it is suitable for use in a wide variety of applications such as automobiles, airplanes, portable machines, and electric vehicles.

Hereinafter, the present invention will be specifically explained by showing Examples and Comparative Examples.
However, the present invention is not limited to the following examples.

[Example] A perchloric acid aqueous solution containing aniline was used as an electrolytic solution, and platinum plates (2X 2C11
1> was immersed, and polyaniline was synthesized by constant potential electrolysis. The obtained polyaniline (weight: 41 m (+)) was thoroughly washed with distilled water and then thoroughly dried.

Next, this polyaniline was used as a positive electrode, and the negative electrode was Graph 7I-1- (GF20 manufactured by Nippon Carbon Co., Ltd.).
．． An NL net was attached as a collector electrode to a 38 m9 heavy hanging electrode, and the surrounding area was covered with 7 nanoparticles.The electrolyte was anhydrous sodium persalt wood acid in propylene carbonate treated with water. Using a solution in which 1 mol/i) of Fuchigourd was dissolved, the battery was heated to MIj. For the battery, the above-mentioned positive electrode, negative electrode, and electrolyte were assembled in a test tube type barrel, and the inside was evacuated to sufficiently degas it.

After assembling the battery -C, the voltage between both electrodes was OV,
When 2ml is charged with constant current C, the voltage between the two poles immediately becomes 2.8
When I applied 10'RL/ to V and continued charging 4 times, the voltage gradually increased by 1-V, and when the voltage reached 4.5V, I stopped charging. After that, with the same current of 2 ml, the voltage between the two electrodes was 2. It was discharged until it reached Ov. The charging/discharging efficiency at this time is 95%, and the energy density is 158Wb/
ka (average discharge voltage 3.5V).

[Comparative Example 1] A battery test was conducted under the same conditions as in the example except that the polyaniline produced in the example was used as both positive and negative electrodes.
Charge/discharge efficiency is 90%, energy density is 90Wl+/
ka (average number m'lH: 3, 0 V).

[Comparative Example 2] A battery test was conducted under the same conditions as in the example except that the graph II used in the example was used as the positive electrode and both electrodes.
i! i East, charging/discharging efficiency is 95%, energy density is 19
The energy density was 9 (average discharge voltage 1.5 V) in Wh/, and the energy density was rather small compared to the example.

From the above results, using a conductive polymer material as the positive electrode,
Secondary battery using carbon material containing Ishihaya structure as 11 poles (
It is found that Example) has a very high energy Wj degree.

Applicant: Stock Trial Brideston Agent: Patent Attorney Takashi Kojima

Claims (1)

[Claims] 1. It is possible to use an i# conductive molecular substance as a positive electrode and a graphite structure-containing carbon material as a negative electrode, and to generate ions that are doped into the positive tΦ and negative electrode respectively by electrolysis. 1. A secondary battery characterized in that the electrolyte is a solution obtained by dissolving a compound in a non-aqueous solvent. 2. Artificial carbon trade material obtained by carbonizing a substance that can be carbonized or graphitized at a temperature of 1000°C or more and less than 2500°C.
Graphitization at a temperature of 500'C or higher, in particular, the secondary N pond according to claim 1, which is graphite powder or natural graphite. 3. The secondary battery according to claim 1 or @2, wherein the conductive polymer material is polyaniline or polyphenylene.