JPH0628170B2 - Battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is a high-performance compound obtained by electrolytic polymerization of an organic compound such as pyrrole, aniline, thiophene, azulene, indole, furan, iminostilbene, toluidine, carbazole and benzofuran. The present invention relates to a battery using a molecular substance as an electrode material.

[Prior art and its problems]

Electropolymerizing an organic compound such as pyrrole on a conductive substrate,
It is known that a secondary battery having a high energy density can be easily manufactured by using this as an electrode. However, because the adhesion strength of the polymer to the conductive substrate and the strength of the polymer are not sufficient, the polymer peels from the substrate or the shape of the film collapses during repeated charge and discharge cycles. , A sufficient cycle life cannot be obtained.

The present invention has been made in view of the above points, and developed a battery in which the strength of an electrically active high molecular weight polymer is increased, and the adhesion strength to a substrate is increased to prolong the charge / discharge cycle life. It is a thing.

[Means for solving problems]

In a battery in which a polymer obtained by synthesizing an electrically active polymer substance on a conductive substrate by an electrolytic polymerization method is used as an electrode, the polymer substance is synthesized on the conductive substrate by anodic oxidation, and the surface of the electrode is A battery characterized by being coated with polystyrene or polyvinyl chloride by being immersed in a solution of either polystyrene or polyvinyl chloride.

The electrically active polymer obtained by electropolymerization in the present invention means an aromatic compound such as aniline, aniline black, pyrrole, thiophene, indole, azulene, furan, carbazole, benzofuran, toluidine, methylthiophene and methylpyrrole. A substance obtained by introducing a compound and its derivative or a phenol derivative such as 1-naphthol, 5-hydroxy-1,4-naphthoquinone, etc. into an appropriate electrolyte solution and anodic oxidation on a conductive substrate installed as an anode. . Particularly preferred as the aromatic compound and its derivative are aniline, aniline black and pyrrole.

The conductive substrate in the present invention may be any one as long as it does not dissolve at the electropolymerization potential of an electrically active organic compound and a deposit of a polymer can be attached thereto. The material of the conductive substrate is, for example, a metal plate such as nickel, platinum, stainless steel, or copper, or a mesh thereof, graphite, amorphous carbon, activated carbon,
Carbon fiber may be used.

Examples of the method for electrolytic polymerization on these conductive substrates include anodic oxidation by repeating constant voltage or constant current or potential scanning.

In order to coat the electrically active polymer deposited on the conductive substrate in the form of a film, a method of immersing the electrode in a resin prepared by dissolving the resin used in the coating material in a suitable solvent and then drying it is adopted. can do.

It is particularly preferable to use polystyrene or polyvinyl chloride as the resin used for coating. When coating the electrode surface with these resins, the resin concentration must be large enough to cause overlap between the resin molecules in the solution when immersed in the solution. Also, in the case of coating by vapor deposition, the coating material is placed on the bottom of a container that can be evacuated, the electrode is hung on the top, and the bottom of the container is heated to evacuate, or inside the plasma polymerization reactor. A method of installing an electrode plate and synthesizing and vapor-depositing benzene, acetonitrile and the like on the electrode plate by plasma polymerization can be mentioned.

[Operation of the invention]

According to the battery of the present invention, the electrically conductive high molecular weight polymer is attached to the conductive substrate in the form of a film, which is coated with an electrically inactive thin film of polystyrene or polyvinyl chloride. To increase the adhesion of the active high molecular weight polymer to the conductive substrate, and to bond the high molecular weight polymers together to prevent the capacity from decreasing under a large number of charge / discharge cycles and to have a long life. You can

〔The invention's effect〕

In the battery according to the present invention, the electrically active high molecular weight polymer composed of an organic compound does not easily peel off from the conductive substrate constituting the electrode even after a large number of charge / discharge cycles, and prevents a decrease in capacity. , Which has a long life.

Hereinafter, the present invention will be described in more detail with reference to examples.

Example 1 Aniline at a concentration of 0.1 mol / min was mixed in an aqueous perchloric acid solution at a concentration of 0.5 mol / min. A platinum plate of 1 cm x 1 cm and a nickel mesh plate of 1.5 cm x 2 cm are placed opposite to each other and immersed in the solution so that the platinum side is positive between both electrodes.
A voltage of 2 volts was applied. After a few minutes, dark green polyaniline was deposited and formed on the platinum plate. After standing for about 10 hours, this platinum plate was taken out, washed with water and dried.

The obtained polyaniline was adhered to the platinum plate in the form of a film, and the weight adhered to one side was about 6 mg.

Next, this platinum plate was immersed for 10 minutes in a solution in which polystyrene was dissolved in toluene at a ratio of 10 wt%, and then this was vacuum dried.

Next, this polystyrene-coated platinum plate was opposed to a lithium plate embedded in nickel expanded metal, and placed in an electrolyte solution in which lithium perchlorate was dissolved in propylene carbonate at a concentration of 1 l / l.

The lithium-polyaniline battery constructed as above showed an open circuit voltage of about 3.5V.

Next, at a constant current density of 1 mA / cm ² , 4.0 V to 2.6
Repeated charging / discharging in the range of volt, about 0.1A
A capacity of h / g was obtained, and even if this cycle was repeated 1000 times or more, the capacity decrease was only 10%.

Comparative Example 1 A battery was manufactured in the same manner as in Example 1 except that the platinum electrode coated with polyaniline of Example 1 was used as it was without being coated with polystyrene. When this battery was similarly tested, a clear decrease in capacity was observed after the 100th time, and the capacity decreased to about 60% of the initial value at the 400th time. Here, when the cycle test was stopped and the electric pole was taken out,
The polyaniline had changed to a powder form, and a considerable part had peeled off from the platinum plate.

[Example 2] The electrode to which polyaniline obtained in the same manner as in Example 1 was attached was immersed in a 10 wt% benzene solution of polyvinyl chloride for 10 minutes, and a battery was manufactured in the same manner as in Example 1 below, followed by a cycle test. Was done.

After the 1000-cycle test, the electrode was taken out and observed. As a result, polyaniline was well adhered to the platinum plate.

[Example 3] Pyrrole was mixed at a concentration of 0.1 mol / percent in an aqueous solution of perchloric acid at a concentration of 0.5 mol / min, and a film-like polypyrrole was formed on a platinum plate in the same manner as in Example 1. Synthesized. The weight of polypyrrole attached to one side of this platinum plate was about 4 mg. This electrode was immersed in a polystyrene solution in the same manner as in Example 1. Using the polystyrene-coated electrode thus obtained, a battery was manufactured in the same manner as in Example 1 below, showing an open circuit voltage of 3.2 V and charging at a potential electric field of 3.6 V to 2.0 V. When discharged, a capacity of 0.08 Ah / g was obtained. When the cycle test was conducted, the capacity reduction was only 10% even after repeating the cycle test 1000 times or more. After the completion of the cycle test, the electrode was taken out and observed. As a result, the polypyrrole film was still well attached to the platinum plate, and the shape did not change.

[Comparative Example 2] A battery was produced in the same manner as in Example 4 except that the polypyrrole-attached electrode was not coated with polystyrene and used as it was,
A cycle test was conducted. A clear decrease in capacity was observed after the 100th cycle, and the capacity decreased to about 60% of the initial value at the 200th cycle. After the test was completed, the electrode was taken out and observed. As a result, the polypyrrole had changed to a powder form, and a considerable part had fallen off from the platinum plate.

Claims (1)

[Claims] 1. In a battery using as an electrode, a polymer obtained by synthesizing an electrically active polymer substance on a conductive substrate by an electrolytic polymerization method, wherein the polymer substance is synthesized on the conductive substrate by anodic oxidation. A battery characterized in that the surface of the electrode is coated with polystyrene or polyvinyl chloride by immersing it in a solution of either polystyrene or polyvinyl chloride.