JPS61271744A - Battery - Google Patents

Abstract

PURPOSE:To obtain the high coulomb efficiency, energy density, and long-term cycle life of a battery by comprising the battery with an optimum combination of active material, electrolyte, and solvent. CONSTITUTION:This battery uses a deposit obtained by anode-oxidizing aniline, pyrrole, and azulene in an electrolytic solution that contains phosphate hexafluoride as the supporting salt, or polypyrrole and aniline black as the active material of an electrode. The battery also uses phosphatehexafluoride as the electrolyte and a mixture of propylenecarbonate and dimethoxyethane as the solvent of the electrolyte. In this case, for example, lithium phosphate hexafluoride and the like can be used as the phosphate hexafluoride in the anode oxidation of pyrrole and azulene. Propylenecarbonate and the like or a hexafluoride phospheric solution can be used as the solvent in this oxidation. In addition, when aniline is anode-oxidized, the hexafluoride phospheric solution should be used.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a battery using an organic material such as volivyl as an electrode active material.

[Conventional technology and its problems]

In recent years, organic materials such as polyacetylene and polyvarapehenicin that exhibit excellent properties as electrode active materials have been discovered, and their practical application is expected.

However, these organic materials have problems such as being easily degraded and having to be doped with unstable electron acceptors or electron donors to increase conductivity.

On the other hand, so-called electrolytically oxidized polymers of aromatic organic compounds such as virole, aniline, azulene, and thiophene, or polypyrrole and polyethylene synthesized by chemical methods, contain perchlorate ions, hexafluorophosphate ions, tetrafluorophosphate ions, etc. It has recently been known that by doping with borate ions or the like, its electrical conductivity can be increased and, moreover, it is stable. For this reason, one electrode is composed of such an electrode active material of an organic material, and one of the electrolytes described later or a mixture thereof is used as the electrolytic solution, and one of the solvents described later is dissolved in the mixture. It is theoretically possible to create a secondary battery. However, in reality, the optimal combination of active material, electrolyte, and solvent that constitutes a battery that can be put to practical use is completely unknown. These are lithium hexafluorophosphate, lithium arsenic hexafluoride, tetraalkylammonium perchlorate, tetraalkylammonium tetrafluoroborate, and tetraalkylammonium arsenic hexabutide. Solvents include polypylene carbide, dimethoxyethane, tetrahedral sigma plan,
They are acetonitrile, r-butyrolactone, nitromethane, nitrobenzene, N,N-dimethylformamide, hexamethyltriamide phosphate, dimethylsulfoxide, dimethylsulfide, sulfolane, and 1,3-dioxolane.

The present invention has been made in view of these points.
The company has developed a battery with coulombic efficiency, energy density, and long cycle life.

[Means for solving problems]

In the present invention, aniline is used as the active material of at least one electrode.
A precipitate obtained by anodizing pyrrole or azulene in an electrolytic solution containing hexafluorophosphate as a supporting salt, or a precipitate obtained by anodizing pyrrole or azulene in an electrolyte containing hexafluorophosphate as a supporting salt, or using polypyrrole or aniline black and using a hexafluorophosphate as the electrolyte. The battery is characterized in that the solvent is a mixture of propylene carbonate and inmethoxychetane.

Here, as the hexafluorophosphate in the anodic oxidation of pyrrole and azulene in the present invention, for example, lithium hexafluorophosphate, tetraalkylammonium hexafluorophosphate, etc. can be used. Further, as a solvent for this oxidation, propylene carbonate, dimethoxyethane, acetonitrile, nitromethane, etc. or an aqueous hexafluorophosphoric acid solution can be used.

Further, in the present invention, when aniline is anodically oxidized, it is preferable to use an aqueous hexafluorophosphoric acid solution. Further, the concentration of the supporting salt during oxidation is preferably 0.1 mol/j to 10 mol/no, and the concentration of the 7-mer (pyrrole, aniline, azulene) is 0.01 mol/l to 10 mol/l. l is preferred.

Further, the composition of the electrolytic solution is such that the proportion of propylene carbonate in the total solvent is preferably in the range of 0.2 to 0.8 in terms of volume ratio, particularly preferably in the range of 0.2 to 0.6. The concentration of the hexagonal phosphate is preferably in the range of 0.1 mol/l to 1 mol/l.

[Action/effect of the invention]

According to the battery according to the present invention, since the battery is constituted by an optimal combination of active material, electrolyte, and solvent, high coulombic efficiency, energy density, and long cycle life can be obtained.

[Examples of real rights, comparative examples]

Hereinafter, practical examples of the present invention and comparative examples conducted for comparison thereto will be explained.

Practical Example 1 Lithium hexafluorophosphate and pyrrole were dissolved in propylene carbonate at concentrations of 0-5 mol/11 and 0.5 mol/j, respectively. A platinum plate with a size of 1 scratch x 1 scratch was installed as an anode, and after 7,000 cycles of current was applied at a constant current of 1 mA, the plate was washed with a platinum surface made of aluminum carbide and dried. As a result, black precipitates appeared on the surface of the platinum plate.
I got it. The thus obtained platinum plate was placed as an electrode in an electrolytic solution obtained by dissolving the platinum plate in a mixed solvent of propylene carbonate: dimethoxyethane = 1:1 containing lithium hexafluorophosphate at a concentration of 1 mol/j, A lithium plate embedded in nickel expanded metal was placed as a counter electrode, a vol-a-pyrene separator was sandwiched between the two electrodes, and the whole was sealed in a glass scale to prepare a battery.

Next, this battery was charged and discharged in a voltage range of 3.5 to 2.0 volts with the platinum plate side as the positive electrode and the lithium side as the negative electrode, resulting in a capacity of 0.12Ah/7 and a coulombic efficiency of 1.
00% was obtained. Next, when charging and discharging cycles were repeated in the above electrode range, the decrease in capacity remained at 10% or less even after 1000 cycles or more. Also,
When the battery was charged at 0.12Ah/I, left for 30 days, and then discharged, the discharge capacity was 0.11Ah/7, and the self-discharge rate was 8.3%.

Example 2゜Lithium hexafluorophosphate and azulene in propylene carbonate are each 0.5 mol/1,0.5 mol/! It was dissolved at a concentration of A platinum plate with a size of lcs<X1cm was installed on this as an anode, and a constant current of 1mA was applied to
c After energization, the platinum surface was washed with propylene carbonate and dried. As a result, about 4.5 square meters of black precipitate was obtained on the surface of the platinum plate. The thus obtained platinum plate was mixed with lithium hexafluorophosphate at a concentration of 1 mol/l and pyrene carbonate:
An electrode was placed in an electrolytic solution obtained by dissolving it in a mixed solvent of dimethoxyethane = 1:1, a lithium plate embedded in nickel extract band metal was placed as a counter electrode, and a polypropylene separator was sandwiched between the two electrodes. , the whole was sealed inside a glass scale to create a battery.

Next, when this battery was charged and discharged in a voltage range of 4.0 to 2.5 volts with the platinum plate side as the positive electrode and the lithium side as the negative electrode, a capacity of 0.14 Ah/El and a coulombic efficiency of 100% were obtained. Ta. Next, when charging and discharging cycles were repeated in the electrode range mentioned above, the decrease in capacity remained below 10% even after 1000 cycles or more. Further, when the battery was charged at 0.14 person h/g, left for 30 days, and then discharged, the discharge capacity was 0.12 Ah/11, and the self-discharge rate was 14.3%.

Practical Example 3: 0.0.0.0% in an aqueous hexafluoroboric acid solution with a concentration of 0.5 mol/l.
Aniline is dissolved at a concentration of 1 mol/l, and this
A platinum plate with a size of m x 1 cs was installed as an anode, a nickel mesh of 1.5CIIX2CII was installed as a counter electrode, and a constant voltage of 1.2 volts was applied to the platinum plate with respect to the nickel mesh side. Electrolytic synthesis was performed. 3
After a period of time, electrolysis was stopped, and the platinum plate was washed with water and dried. As a result, 6.5* deep green precipitates were obtained on the surface of the platinum plate.

A battery was prepared in the same manner as in Example 1 using the platinum plate thus obtained as one electrode.

Next, when this battery was charged and discharged in a voltage range of 4.0 to 2.6 volts with the platinum plate side as the positive electrode and the lithium side as the negative electrode, it had a capacity of 0.14 Ah, J, and a coulombic efficiency of 1.
00% was obtained. Next, when charging and discharging cycles were repeated in the above-mentioned electrode range, the decrease in capacity remained below 10% even after 1000 cycles or more. Also,
When the battery was left to stand for 30 days after being charged for 0.14 h/2 and then discharged, the discharge capacity was 0.121 h/11, and the self-discharge rate was 14.3%.

Comparative Examples 1 to 5 Five types of batteries were prepared in the same manner as in Practical Example 1, except that lithium perchlorate was used as the supporting electrolyte during electrolytic synthesis, and the composition shown in Table 1 below was used as the electrolyte. Created.

When these five types of batteries were subjected to the same battery test as in Example 1, the results were shown in Table 2 below.

As is clear from the results in Table 2, the battery according to the present invention has high coulombic efficiency, high energy density, and long cycle life.

Table 1■ PC: Propylene carbonate DME: Dimethoxyethane PC+DME: 1:1 (body ratio) of PC and DME
As is clear from the above-mentioned examples, the battery of the present invention has a high Coulombic efficiency, a double energy density, and a long cycle life, and its practical value is extremely great.

Applicant's agent Patent attorney Takehiko Suzue Procedural amendment February 21, 1949 Director General of the Patent Office Michibe Uga 1, Indication of the case Patent application No. 113675 1988 2, Name of the invention Battery 3, Amendment Relationship with the case of a person who does and page 7 no. 16
Line VCrf Rascale" is "Glass case"
I am corrected.

(2) ``Electrode range'' on page 6, line 16 is corrected to ``voltage range.''

(3) Same, page 10, table 1, r LicJQ4 J is corrected to [LiCl0* J.

Claims (1)

[Claims] The active material of at least one electrode is a precipitate obtained by anodic oxidation of aniline, pyrrole, or azulene in an electrolytic solution containing hexafluorophosphate as a supporting salt, or polypyrrole or aniline black, and the electrolyte is 1. A battery characterized in that the electrolyte is made of hexafluorophosphate and the solvent of the electrolyte is a mixture of propylene carbonate and dimethoxyethane.