JPS6262817A - Polyaniline - Google Patents

Abstract

PURPOSE:To provide a polyaniline consisting of a DMF-insoluble component and having excellent electronic properties such as electrochemical activity and excellent durability as an electronic material applicable to cell, photocell, electrochromic display, various modified electrodes, etc. CONSTITUTION:The objective polyaniline can be produced by preparing a polyaniline by electrolytic polymerization or oxidizing polymerization and removing DMF-soluble component from the polyaniline in dedoped state. The electrolytic polymerization is carried out preferably by using hydrochloric acid.

Description

DETAILED DESCRIPTION OF THE INVENTION [1] The present invention is directed to polyaniline which has excellent durability and can be suitably used as an electronic material such as batteries and photovoltaic cells.

In recent years, polyaniline has been used as a new electronic material in batteries, photovoltaic cells,
Polyaniline synthesized in an alkaline solution has attracted attention in application fields such as electrochromic displays and various modified Wa electrodes, and as a result of active research and development in electrochromic properties such as interconnectivity and electrochemical activity. is electric 9z
Polyaniline, which is electrochemically inert and electrochemically active, is
In this case, among the small oxidation methods, it is one of the most advantageous in terms of energy density (discharge current and discharge voltage), productivity as various electrode materials, etc. Electrolytic oxidation (electropolymerization) methods have been found to be superior to chemical oxidation methods using chemical oxidants such as sulfates.

As one of the results of such research on polyaniline, the present invention proposes that when polyaniline electrolytically synthesized in a hydrochloric acid solution is used as an active material of a battery,
We have already proposed a secondary battery containing polyaniline as an active VlJ material, having found that the capacitance increases (
(Japanese Patent Application No. 59-78260) 9゜But currently, conductivity? There have been various proposals for polyaniline that has excellent initial performance in terms of electrochemical activity, but there have been few studies on polyaniline that combines these electronic properties with the same durability. When used as an electronic material, durability is a practical bottleneck in its application in the above application fields.

The present invention was made in view of the above circumstances, and it not only has first-to-one performance such as conductivity and electrochemical activity, but also has the durability of these electronic properties, and is suitable for batteries, photovoltaic cells, etc. The purpose is to provide polyaniline that can be used and does not easily deteriorate.

Means and Function for Determining I11ν'- Prior to the present invention, intensive studies were conducted with the aim of obtaining polyaniline with excellent durability such as I-U conductivity and electrochemical activity. ■ After the binding, polyaniline was soaked in dimethylformamide and the C dimethylformamide soluble portion was eluted and removed -4
Due to these factors, polyaniline consisting of dimethyl filmamide-insoluble parts has excellent durability as an electronic material. For example, when dimethyl formamide-insoluble polyaniline is used as the electrode plate material of a secondary 1 hour pond, the cycle life is short. , -1 (voltage characteristics are significantly reduced, and the above objective can be effectively achieved), which led to the present invention.

The present invention will be explained in more detail below.

The polyaniline of the present invention consists of a dimethylformamide-insoluble portion, and such dimethylformamide-insoluble polyaniline is preferably prepared by eluating the dimethylformamide-soluble portion from conventional polyaniline and separating the dimethylfilmamide-insoluble portion. 1 by doing 1! '7
It is something that was given. In this case, the dimethylformamide soluble part is removed as polyaniline, and then υ1
There is no limit, and commonly used ones can be used. For example, aniline can be electrolytically combined with IQ using an acidic aqueous solution such as hydrochloric acid, sulfuric acid, nitric acid, perchloric acid, boric acid, hydrofluoric acid, or hydrobromic acid, or an organic solvent such as acetonitrile, pyridine, or benzonitrile. However, those obtained by oxidative polymerization using ferric chloride or the like having an oxidation potential slightly higher than that of aniline as a gold catalyst can be obtained.

In this case, the polyaniline processed by these depolymerization methods or oxidative polymerization methods has no problems in the initial state of conductivity, electrochemical activity, etc., but their durability is poor. However, such polyaniline J: Polyaniline obtained by removing the lydimethylformamide soluble portion and collecting the dimethyl filmamide insoluble portion is highly durable. In addition, the polyaniline produced by the manufacturing method (;7) is doped with negative ions, and when removing the dimethyl formamide filtrate from the polyaniline in this doped state, it must be done in an undoped state. is effective in further increasing durability.The method for removing the dimethylformamide soluble portion in this lli-doped state is to first perform a negative ion dedoping operation n', and then remove the dimethylformamide soluble portion. It is preferable to remove.

Further, the type of acid used in polymerization in the present invention is not necessarily limited to &l+, but it is particularly preferable to perform electrolytic reaction using hydrochloric acid.
Polyaniline with Rm and iQ has excellent electronic properties such as IS applied to batteries, which increases the discharge capacity of batteries as described above. A product from which the r=T soluble portion is removed, which is further subjected to a dedoping operation, and then from which the dimethylformamide soluble portion is removed is particularly suitable as a durable crushed electronic material.

As described in detail of the invention, the polyaniline comprising the dimethylformamide-insoluble portion according to the present invention is susceptible to electronic properties such as conductivity and electrochemical activity, but is not suitable for use in batteries, photovoltaic cells, electrochromic displays, etc. It has excellent durability as an electronic material used in scale repair sieve electrodes, etc.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

[Example, comparative example]

A polymerization solution consisting of 5 cc of aniline, 1 to 115 cc of i2N salt, and 3 Q cc of ion-exchanged water was placed in an electrolytic cell with a working electrode and a counter electrode each composed of a platinum plate with an area of 4 ad, and heated at a constant current of 20 IIA for 1.4 hours. Turn on the power and turn on the power
? After mixing, apply 4 mA to remove negative ions in the mixture.
i! Dedoping treatment was performed during lightning current I1. The thus prepared small compound was washed with water, vacuum dried, and heated to about 40'l.
Wg polyaniline II+! I crushed it. This polyaniline was immersed in 53 cc of dimethylformamide to remove the dimethylformamide soluble portion, the insoluble portion was separated, and this was vacuum dried to obtain 34 cm of polyaniline insoluble in dimethylformamide.

Next, the above dimethylformamide-insoluble polyaniline was used as a battery ff1m&, and a lithium counter electrode, Li
A battery was constructed using an electrolyte of BF4/propylene carbonate 11QJ/J.

Using this battery, the polyaniline electrode plate was fixed at 4V relative to Li, and the discharge electric capacity It% was measured every 24 hours to examine the oxidation deterioration characteristics, and the results shown in the drawings were obtained.

Furthermore, for comparison, aniline was combined with polyaniline (comparative example) which was not subjected to the dimethylformamide treatment in the same manner as in the example. This polyaniline? A battery was constructed using the same method as in Example 1 and the oxidative deterioration characteristics were investigated using the same method as in Example. The results are shown in the drawing.

From the results shown in the drawings, it was found that the 7tf battery using polyaniline insoluble in dimethylformamide of the present invention has superior durability compared to a battery using polyaniline that is not treated with dimethylformamide. It was determined that polyaniline, which is insoluble in amides, is a highly durable electronic material.

[Brief explanation of the drawing]

The drawings show the charge/discharge cycles when the polyanilines of Examples and Comparative Examples are used as battery electrodes.
151ffi shows the capacitance change.

Claims (1)

[Scope of Claims] 1. A polyaniline characterized by comprising a dimethylformamide insoluble portion. 2. The polyaniline according to claim 1, which is obtained by removing the dimethylformamide soluble portion in a dedoped state from polyaniline obtained by electrolytic polymerization or oxidative polymerization. 3. The polyaniline according to claim 2, wherein the electrolytic polymerization is carried out using hydrochloric acid.