JPH03147261A - Electrode for organic electrolyte battery - Google Patents

Abstract

PURPOSE:To speed up the impregnating speed of the electrolyte by applying the water soluble high polymer, in which carbon group powder is distributed, to a compact made of the insoluble and infusible substrate powder including polyacen group skeletal structure. CONSTITUTION:The water soluble high polymer solution, in which the carbon group powder is distributed, is applied to the surface of electrodes, which is obtained by forming the insoluble and infusible substrate powder including the polyacen group skeletal structure, by coating or the like to be dried. The electrode obtained in this way can speed up the impregnating speed of the electrolyte, and the productivity equal or more than other electrode using MnO2 produced generally and industrially as the active material can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a mechanical electrolyte electrode, and more particularly, the present invention relates to an electric rod for a mechanical electrolyte, and more particularly, to This invention relates to an electrode for an organic electrolyte in which a water-soluble polymer in which carbon-based powder is dispersed is applied.

(Prior Art) The present inventors used an insoluble and infusible substrate containing a polyacene skeleton structure, which is a type of organic semiconductor, doped with an electron-donating substance or an electron-accepting substance as an electrode active material. proposed a secondary battery (Japanese Patent Application Laid-Open No. 1986-17)
No. 0163), this battery has high performance, has the possibility of being thinner and lighter, has a high oxidation stability of the electrode active material, and is easy to mold, making it a promising secondary battery. It is.

Although not yet disclosed, the present inventors have achieved high performance by pulverizing the insoluble and infusible substrate having the polyacene skeleton structure into powder, and molding the substrate powder.
We have developed an organic electrolyte battery using high-strength electrodes.

However, an electrode made of an insoluble and infusible base powder containing a polyacene skeleton structure, which is an electrode active material, is inferior to a battery electrode made of an active material such as MnOz, which is generally produced industrially. However, the problem remained that the impregnation rate of the electrolyte was slow.

(Problems to be Solved by the Invention) The present inventors have solved the above problem by applying a water-soluble polymer in which carbon-based powder is dispersed to the surface of an insoluble and infusible base powder compact having a polyacene-based skeleton structure. The present invention has been completed by discovering that all of the above problems can be solved.

An object of the present invention is to provide an electrode with excellent liquid absorption properties and a fast electrolyte impregnation rate.

Another object of the present invention is to provide an electrode for an organic electrolyte battery that is easy to manufacture and economical.

Further objects and advantages of the invention will become apparent from the description below.

[Means to solve the problem]

According to the present invention, such objects and advantages of the present invention are provided in an electrode comprising a molded body of an insoluble and infusible base powder containing a polyacene skeleton structure, in which water-soluble progeny molecules having carbon-based powder dispersed on the surface of the electrode are provided. This is achieved by an organic electrolyte battery electrode characterized in that it is coated with.

In the present invention, the insoluble and infusible substrate containing a polyacene skeleton structure (hereinafter referred to as polyacene) is an aromatic condensation polymer described in, for example, JP-A-593806 filed by the applicant of the present application. Obtained by heat treatment and processing under certain conditions.

Specifically, the aromatic condensation polymer used in the present invention is (
a) Condensates of aromatic hydrocarbon compounds with phenolic hydroxyl groups and aldehydes, such as phenol/formaldehyde resins; (b) xylene-modified phenol/formaldehyde resins (where phenol is partially replaced with xylene); , an aromatic hydrocarbon compound having a phenolic hydroxyl group, a condensation product of an aromatic hydrocarbon compound having no phenolic hydroxyl group, and an aldehyde, and (C
I-furan resins are preferred.

The insoluble and infusible substrate in the present invention is a heat-treated product of the aromatic condensation polymer as described above, and can be produced, for example, as follows.

An inorganic salt such as zinc chloride or sodium phosphate is mixed with the aromatic condensation polymer described above. Thereby, porosity can be imparted to the insoluble and infusible substrate. The amount to be mixed is
Although it varies depending on the type of inorganic salt and the shape and performance of the target Ti, a weight ratio of 1071 to 1/7 is preferable.Also, when obtaining a porous substrate with communicating pores, the inorganic salt may be aromatic. It is preferable to use it in an amount of 2.5 to 10 times the weight of the group-based condensation polymer. The mixture of inorganic salt and aromatic condensation polymer thus obtained is shaped into a desired shape such as a film or a plate, and is cured by heating at a temperature of 7.50 to 180°C for 2 to 90 minutes. Shape.

The thus obtained cured product is then heated in a non-oxidizing atmosphere at a temperature of 400 to 800°C, preferably 450 to 750°C.
, particularly preferably to a temperature of 500 to 700°C. Through this heat treatment, the aromatic condensation polymer becomes
Dehydrogenation and dehydration reactions occur, and the condensation reaction of aromatic rings results in
A polyacene skeleton structure is formed.

This reaction is a type of thermal condensation polymerization, and the degree of reactivity is expressed by the atomic ratio of hydrogen atoms/carbon atoms (hereinafter referred to as 1/C) in the final product. H/ of insoluble and infusible substrate
The bond of C is 0.05-0.5.

If the H/C value of the insoluble and infusible substrate is greater than 0.5, the polyacene skeleton structure is underdeveloped and the electric type conductivity is low, which is undesirable. On the other hand, if the H/C value is greater than 0.05 If it is small, carbonization has progressed too much and the performance as an electrode constituent material is low.

The obtained heat-treated body is sufficiently washed with water or dilute hydrochloric acid to remove inorganic salts contained in the heat-treated body. Thereafter, this is dried to obtain an insoluble and infusible substrate.

Next, the insoluble and infusible substrate powder of the present invention can be obtained by pulverizing the insoluble and infusible substrate.

There are generally various methods of pulverization, such as ball milling and vibration milling, but a pulverization method with a small impact force is preferable so that the specific surface area value after pulverization does not become less than 600 m 7 g. By changing the amount of balls and the number of rotations, or by adding a solvent, the impact can be weakened to achieve pulverization.

More preferably, pulverization is performed using a nylon ball mill. For example, when pulverization is performed using a nylon ball mill, the appropriate pulverization time is from several minutes to 100 hours, but the time should be determined depending on what is to be obtained.9 Important points are:
The objective is to obtain powder with fine particle size without reducing the specific surface value under conditions of weak impact force.

Next, the insoluble and infusible base powder is formed into a film, and by adding a conductive material and a binder to the insoluble and infusible base powder, film formation becomes easy. Conductive materials are added to provide the appropriate electrical conductivity to the poles of the manufactured battery.

The electrical conductivity suitable for the battery electrode is io-'s/c.
m or more, preferably 10-"37 cm or more.'
If the g1 gas conductivity is less than 0-'S/cm, the internal resistance due to the electrodes increases, which is undesirable as it causes a decrease in charging and discharging efficiency.

Although tllll on the conductive side is not particularly limited, carbon-based materials such as activated carbon, carbon blank, and graphite are preferable, and the smaller the particle size, the more effective it is. It is also possible to use a conductive polymer as the conductive material. The proportion of the conductive material varies depending on the electrical conductivity of the insoluble and infusible base powder, the type of binder, and the conditions of the molding method, but it is required to be 40 to 2 wt% based on the total amount.

The type of binder is a solvent that dissolves the electrolyte used when assembling the battery, such as ethylene carbonate, propylene carbonate, γ-butyrolactone, dimethylformamide, dimethylacetamide, dithymer sulfoxide, acetonitrile, dimethoxyethane, tetrahydrofuran, dioxolane, sulfolane, etc. There is no particular limitation as long as it is insoluble in organic solvents.For example, SBR etc.
Thermoplastic resins such as polypropylene and polyethylene are preferred, and polytetrafluoroethylene is particularly preferred.The mixing ratio varies depending on the type, but based on the total amount. A mixing ratio of 20 WL% or less is desirable; if the mixing ratio exceeds 20 wt%, the electrolyte will not be able to enter the inside of the electrode sufficiently;
This is not preferable because the capacity decreases.

The above-mentioned insoluble and infusible base powder, conductive material, and binder are thoroughly kneaded and molded to form an electrode.

The molding method may be pressure molding, roller molding, or roller molding.

1. A water-soluble polymer aqueous solution in which carbon-based powder is dispersed is applied to the surface of the obtained electrode by coating or the like and dried. The desired electrode for organic electrolyte is obtained.

The type of water-soluble polymer is preferably a cellulose-based water-soluble polymer such as carboxymethyl cellulose (hereinafter referred to as CMC), methyl cellulose, or hydroxypropyl cellulose, and CMC is particularly preferable among them.
The concentration of the CMC aqueous solution in which C is applied to the electrode is 0.01~
1 wt% is desirable; if it is less than 0.01 wt%, the effect of accelerating the rate of impregnation of the electrolyte into the electrode is low;
If it exceeds this, it is difficult to handle due to its high viscosity, and it also forms a film on the electrode surface, which slows down the impregnation rate.

The carbon-based powder is preferably activated carbon, graphite, carbon black, etc. The amount of carbon-based powder added to the CMC aqueous solution is preferably 0.01w to 30% by weight of the carbon-based powder and the CMC aqueous solution.
If the amount is less than t%, the amount of carbon-based powder will be small and it will be difficult to achieve a significant effect, and if it exceeds 30wt%, the powder will easily peel off after application and drying, making it difficult to achieve good effects. Furthermore, the finer the particle size of the carbon-based powder, the more effective it is.

Furthermore, the amount of travel is not particularly limited since it is applied by spraying, etc., but it is sufficient to cover at least the entire surface.There are some commercially available conductive adhesives such as CMC in which carbon is dispersed. There is a colloidal aqueous solution, but the same effect can be obtained by diluting it.

CMC with carbon-based powder dispersed in this way
The desired electrode can be obtained by drying the electrode applied with the aqueous solution, but the drying temperature is preferably 250°C or lower; if it exceeds 250°C, the polytetrafluoroethylene used as the binder will decompose. .

(Effects of the Invention) The electric rod for an electrolyte battery of the present invention includes applying a water-soluble polymer aqueous solution in which carbon-based powder is dispersed to a molded body of an insoluble and infusible base powder containing a polyacene-based skeleton structure. This significantly reduces the electrolyte impregnation rate.

In other words, even an electrode with a slow impregnation rate like this electrode can be made to be equivalent to or better than other industrially produced battery electrodes by combining it with a water-soluble polymer aqueous solution in which carbon-based powder is dispersed. The above productivity is obtained and the time required to manufacture batteries is greatly improved, so the industrial value is extremely large.

The present invention will be specifically explained below with reference to Examples.

〔Example〕

+11 An insoluble and infusible substrate having a polyacene skeleton structure was produced.

100ml of an aqueous solution of water-soluble resol (approximately 60% concentration)/zinc chloride/water mixed in a weight ratio of 10/24/4.
Pour into a mold of m x 100 mm x 2 mm and cover it with a glass plate to prevent moisture from evaporating, then heat to about 100°C.
It was cured by heating at a temperature of 1 hour.

The phenolic resin was placed in a siliconite electric furnace, heated at a rate of 40°C/hour under a nitrogen stream, and heat-treated to 500°C. Next, the heat-treated product was washed with dilute hydrochloric acid, then with water, and then By drying, a plate-shaped insoluble and infusible substrate was obtained.

(2) The obtained insoluble and infusible substrate was ground into powder using a ball mill. When the specific surface area of the powder was measured using the BET method, it was found to be 600 m''/g or more, and elemental analysis revealed that the atomic ratio of hydrogen atoms to carbon atoms was 0.24.

To 100 parts of the above powder, 5 parts of polytetrafluoroethylene as a binder and 10 parts of carbon blank were added, thoroughly kneaded with a mixer, and mixed with a biaxial roller to a thickness of 7.
A plate-shaped molded product with a diameter of 0.00 μm was obtained. The molded body has a diameter of 15 mm.
It was punched out into a disk shape (electrode A).

(31 parts MC was dissolved in distilled water to prepare a Q, l wt% CMC aqueous solution. Zero-order carbon black was ground in a ball mill so that the average particle size by centrifugal sedimentation method was about 1 μm. Weight ratio is Q, l w
The above-mentioned pulverized carbon blank was dispersed so as to have a concentration of t%. This CMC aqueous solution in which Q, l wt% carbon blank was dispersed was applied with a brush to the electrode obtained in (2) above, and thoroughly dried (electrode B).

(4) Next, dissolve LICjlO in sufficiently dehydrated propylene carbonate, and dissolve about 1. Q m o Il
/ A solution of 1 was prepared. A test was carried out by dropping 60 μl of this solution as an electrolyte onto electrode B, and the impregnation time was measured, and the impregnation time was very quick at 2 minutes.

[Example 2] A CMC aqueous solution was prepared so that the weight ratio of the crushed carbon blank to the CMC aqueous solution was 1 wt%, and electrolyzed on the t-electrode A prepared in (2) of Example 1 under the same conditions. When the liquid was dropped and the impregnation time was measured, it was 2 minutes.

[Example 3] As in Example 2, the weight ratio of the carbon blank to the CMC aqueous solution was set to 4 parts wt%, and the other conditions were similar to those in Example 2. , could not be applied easily.

[Comparative Example 1] The impregnation time was measured in the same manner as in Example 1 without dispersing the carbon blank in the CMC aqueous solution prepared in Example 1, and it was 3 minutes.

[Comparative Example 2] A drop test was conducted in the same manner as in Example 1 on electrode A, which was not coated with the CMC aqueous solution obtained in (2) of Example 1, and the impregnation time was 30 minutes.

Claims (1)

[Claims] For an organic electrolyte battery, characterized in that the electrode is made of a molded body of an insoluble and infusible base powder containing a polyacene skeleton structure, and a water-soluble polymer in which carbon-based powder is dispersed is applied to the surface of the electrode. electrode.