JPS6183611A - carbon thin plate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is made by immersing it in an electrolyte solution as an electrode material.
It is suitable for applying an external voltage to dope into p' type and n type, and then discharging, so that the electromotive force generated in the discharge process can be used as a battery, or by combining a metal element as a counter electrode (cathode). The present invention relates to a carbon thin plate which is doped with p-type to serve as an anode and which is then suitable for utilizing the electromotive force generated by discharging. More specifically, it is used as an electrode material for secondary batteries, characterized in that it is obtained by blending a heat-resistant fibrous reinforcing material with a carbon precursor, forming it into a thin plate, and then subjecting it to infusibility treatment and carbonization treatment. Regarding carbon thin plates suitable for.

(Prior Art) In recent years, various conductive polymers including polyacetylene have been actively developed, and their application to polymer batteries using them as electrode materials is being considered. However, practical application has been delayed due to the instability of the polymer and the difficulty in synthesizing and molding the polymer.

(Summary of the Invention) Therefore, the present inventors have developed a material that does not have such drawbacks, can be manufactured at low cost in terms of engineering, has large electromotive force and voltage flatness required as an electrode material, and has mechanical properties. After conducting extensive research in order to obtain a food material with excellent strength, the inventors discovered that a carbon thin plate obtained by a specific method could achieve this objective, and thus completed the present invention.

That is, the carbon thin plate according to the present invention is characterized in that it is obtained by blending a heat-resistant fibrous reinforcing material with a carbon precursor, forming it into a thin plate shape, and then subjecting it to infusibility treatment and carbonization treatment.

(Specific Description of the Present Invention) Carbon precursors used in the present invention include petroleum pinch, which is a residual carbonaceous material obtained from distillation of crude oil or catalytic cracking of petroleum distillate, and coal tar obtained from distillation of coal. Pitch, various pitches such as acenaphthylene pitch obtained by thermally decomposing acenaphthylene polymer, or regenerated cellulose, likunin, divinylbenzene polymer, polyacrylonitrile, polyvinyl alcohol, holj [vinyl chloride, furfuryl alcohol] resin, phenol/formaldehyde resin, acetone/
A pitch-like substance obtained by heat-treating polyols such as furfural resin, furfuryl alcohol/phenol cocondensation resin, or these polymers at a temperature of 50 to 300° C. in air or inert gas is used.

In particular, petroleum pitch, coal pitch, divinylbenzene polymers, or the above resins are added in an amount of 5 weight percent or more, preferably 1 weight percent.
Preference is given to pitch-like materials that have been heat treated until the zero weight plate weight is reduced.

As the heat-resistant fibrous reinforcing material, one is selected that does not lose its reinforcing function due to melting, volatilization, decomposition, etc. during the infusibility and carbonization steps. Specifically, natural, artificial, inorganic ljH, or organic fibrous substances such as asbestos, coal wool, carbon fiber, and cellulose fiber are used. These materials must maintain their reinforcing effect without changing their chemical composition or form throughout the process of infusibility and carbonization of the thin plate, or they must eventually carbonize and maintain their reinforcing effect. .

The carbon precursor is composited with a heat-resistant fibrous reinforcing material and formed into a film. Molding can be done by kneading a carbon precursor and a heat-resistant #lI fibrous reinforcement material to form a thin plate using a method normally applied to sheet molding or film molding of thermoplastic resins, or by kneading both components in a compression molding machine. It is also possible to make it into a thin plate shape. When carbon paper (made from carbon fibers) is used as the fibrous reinforcing material, or when it is necessary to maintain the length of the fibrous reinforcing material as long as possible, compression molding is preferably used.

The heat-resistant fibrous reinforcement has a weight ratio of 0.1 to the carbon precursor.
-20%, preferably 0.5-10%, more preferably 1-5'%. If it exceeds the above range, a sufficient reinforcing effect will not be obtained, and the carbon precursor thin plate will easily break. Exceeding the above range is not a problem in terms of strength, but it is not preferable in terms of the presence of a large amount of inert parts when used as an electrode material, and is disadvantageous in terms of economy.

The thickness of the carbon precursor thin plate is several tens of microns to 100 µm thick.

The carbon precursor thin plate containing the reinforcing material is subjected to an infusible treatment. This treatment is carried out to prevent the thin plate from melting and deforming during the subsequent carbonization process, and is usually carried out by exposing the thin plate to a temperature of 150 to 350°C in the air. This is a treatment to create crosslinks between body molecules. Although the details of the crosslinking reaction are unknown, it is thought that carbon-carbon, carbon-oxygen, oxygen-hydrogen bonds, etc. are newly generated. During this treatment, the weight of the precursor sheet decreases, decreases and then increases, or increases, and these behaviors are due to the volatilization of light-boiling components in the precursor or barge reinforcement, the volatilization of decomposition products, and oxidation reactions. Determined by the balance of oxygen absorption, etc.

Generally, this is done until the oxygen content in the sheet increases by at least 5 inches by weight, preferably by at least 10 inches.

The thin plate that has been subjected to the infusibility treatment is then subjected to a carbonization treatment. In the carbonization treatment, the infusible thin plate is heated at 800°C in an inert gas such as nitrogen or argon, preferably at Vi10.
A process that removes hydrogen atoms and other atoms from the carbon atoms, hydrogen atoms, oxygen atoms, etc. that make up the precursor in the form of various volatile compounds by heating to 00°C or higher. be.

The treatment time is several tens to hundreds of hours including temperature raising time.

Next, the present invention will be specifically explained with reference to Examples.

Example 1 Three times the volume of hexane was added to the distillation bottom (boiling point: 180° C. or higher) of cracked residual oil from ethylene production by naphtha cracking to precipitate a brown fine powder resinous component. After separating and drying this substance, the average molecular weight was determined by liquid chromatography to be approximately 3000°, and the average molecular weight to be determined by elemental analysis to be 92.
74, hydrogen atom 6.47, nitrogen atom 0.06 weight-1)%
It turned out to be.

This substance was removed under reduced pressure (5 m
*Hg), and the bottom fraction (carbon precursor) was recovered (recovery rate 70% by weight).

The mold was made by hollowing out a 9 cm x 10 α rectangle in a 300 μ thick copper plate, placing chrome-plated iron plates on the top and bottom, and placing about 500 q of the carbon precursor obtained earlier in the mold.
Then, insert carbon paper 5H-35 manufactured by Nippon Carbon Co., Ltd. (thickness 250 mm, weight 35 f/W?) cut into the same shape as the above mold, and use a press molder to heat it at 280°C.
, 50 kg/- for 3 minutes. After cooling the mold, a rectangular precursor thin plate was taken out. This thing weighed 485 capes.

Next, the thin plate was placed in an electric furnace and heated in air at a temperature of 240°C for 8
The weight of this 4, which was treated for 0 hours to obtain an infusible thin plate, was 1i.
509Tn9 and 9 (weight increase 5 inches).

The infusible thin plate was placed in a quartz tube electric furnace and heated in a stream of high-purity argon to perform carbonization treatment. The temperature conditions during this time were as follows. Temperature range Fi from 200 to 500℃
10℃/hour, temperature range from 500 to 1000℃Fi150
The temperature was raised at a rate of 0.degree. C./hour and maintained at 1000.degree. C. for 5 hours. Weight of carbon thin plate measured after cooling Fi37011
It was 9.

The obtained carbon thin plate was cut into middle pieces in the middle in the longitudinal direction, each piece was held between alligator clips, and placed in a solution of 0.90 mol of lithium perchlorate in propylene carbonate glyme (45155 volume 1)) in an argon atmosphere at room temperature. Soaked in. Both poles were connected to an external power source (manufactured by Hokuto Denko Co., Ltd.: battery charge/discharge measuring device), and a constant current IFFIA was applied for one hour. After that, the open circuit voltage (VOC>%) and short circuit current (Iac) between both poles were measured, and Voc=3.4Vx 1sc
==1 mA (7) Results were obtained.

Comparative Example 1 An attempt was made to prepare a carbon thin plate under the same conditions as in Example 1, except that carbonate <-3H-35 was not used as a reinforcing material, and a 7'C crab and carbon ifJ precursor were placed in a mold. After press forming, until it is removed from the mold, due to the compressive force due to the difference in shrinkage rate between the carbon precursor thin plate and the mold,
The thin plate was so finely cracked that it could not go through the subsequent treatment process.

Patent applicant: Mitsubishi Yuka Co., Ltd. Agent: Patent Attorney Hidetoshi Furukawa (1 other person)

Claims (1)

[Claims] 1. A carbon thin plate obtained by blending a carbon precursor with a heat-resistant fibrous reinforcing material, forming the mixture into a thin plate shape, and further performing infusibility treatment and carbonization treatment.