JPS60264052A - Organic polymer system electrode - Google Patents

Abstract

PURPOSE:To form a light weight battery which shoes high energy density and maximum output density and provides no public hazard by utilizing the material obtained by thermally backing the linear polymer novolak resin or reaction material between said resin and hardening agent as the electrode material. CONSTITUTION:The linear polymer novolak resin is obtained by polycondensation, under the acidic catalyst, between the monosubstitution phenor (inducated by the expression I or II and X indicates a substitution group) having the substitution group such as alkyl group and chlorine group of methyl group, nonly group at the position of rotho and para and the aldehyte compound. Otherwise, this resin is caused to react with the hardening agent such as aldehyde compound. This novolak resin or product by reaction of such resin and hardening agent is formed like a film and it is then baked. Thereby, the electrode material can be obtained. A battery having excellent charge efficient can be provided by forming the electrode with such electrode material.

Description

DETAILED DESCRIPTION OF THE INVENTION (Objectives) The present invention relates to an electrode using a polymeric material that is lightweight, has high energy density, high maximum output density, and can form a non-polluting battery.

(Prior Art) In recent years, there has been a rapid movement in research and development aimed at improving the performance of batteries. Among these, there is also a great deal of interest in the development of rechargeable secondary batteries that utilize electrochemical doping using conjugated polymers such as polyacetylene and polyvaraphenylene as electrodes. For example, JP-A-57-121168 proposes a battery using an acetylene polymer.

However, polyacetylene is unstable due to oxidative deterioration in the air, and deteriorates when it reacts with trace amounts of moisture and air contained in the electrolyte or solvent, resulting in poor stability as an electrode. Furthermore, polyacetylene is difficult to mold, and polyacetylene films are only synthesized experimentally under special polymerization conditions, which poses many problems in industrial production.

Also, JaernaA of ChemicatSoc
iety, Chemicat community cat
ion (1982) p 361 and below, Boripa, 7
Batteries using phenylene have been proposed, but polyparaphenylene is insoluble and infusible and difficult to mold, and batteries using polyparaphenylene have a high cell voltage, making it difficult to select a solvent that can withstand this.

On the other hand, it is stable against oxidative deterioration in air and has a specific surface area of 10
0-2 saan? JP-A-58-35881 proposes a battery using activated carbon molded bodies with a large diameter /f for both electrodes. However, as proposed in Japanese Patent Laid-Open No. 55-99714, an electric double layer capacitor using activated carbon fibers as both electrodes, positive and negative charges are placed at the interface between the activated carbon electrode and the solution, facing each other across a very short distance. It stores and releases electric charge using the electric double layer distributed in the electric field, and has several important issues such as being prone to self-discharge, not being able to withstand long-term discharge, and not being able to achieve voltage flatness. It has some problems.

(Summary of the Invention) In view of these current circumstances, the present inventors have developed a device that is lightweight, has excellent energy density and maximum output density, and is capable of long-time discharge.
Efforts have been made to develop electrodes that can form batteries with stable battery performance. As a result, a material obtained by producing a linear high molecular weight novolac resin by a specific method as it is or by reacting it with a curing agent and then thermally firing it under appropriate conditions can be electrochemically ionized. The present invention was achieved by discovering that it can be efficiently doped and dedoped, and that a battery using this as an electrode has stable and good battery performance.

That is, the present invention provides an organic polymer electrode containing an electrode material obtained by thermally firing the reaction products of (a) to (b) below.

What) A linear high molecular weight novolak resin obtained by polycondensing a monosubstituted phenol having a substituent at the ortho or para position and an aldehyde compound in the presence of an acidic catalyst (b) Curing agent (specific description) The present invention It is obtained by thermally firing a linear high molecular weight novosic resin or a reaction product of the novolak resin and a curing agent.

Linear novolac resins can be prepared by using monosubstituted phenols having substituents in the ortho or para position.

A monosubstituted phenol having a substituent at the ortho or para position is a compound represented by the following formula (1).

As the substituent in the above formula, an alkyl group such as a methyl group or a nonyl group, or a halogen such as chlorine is usually used.

Examples of the aldehyde compounds used in the present invention include formaldehyde, paraformaldehyde, trioxane, acetaldehyde, furfural, and acrolein. Especially formaldehyde, rose formaldehyde,
Trioxane is preferred.

As the acidic catalyst used for polycondensation of the monosubstituted phenol and aldehyde compound, mineral acids such as hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, and perchloric acid, and organic acids such as p-toluenesulfonic acid and oxalic acid are used. .

In order to obtain a high-molecular-weight linear novolac resin using the above-mentioned monosubstituted phenol and aldehyde compound using an acidic catalyst, it is necessary to further select production conditions in each case.

Known methods for polymerizing high molecular weight linear novolak resins include, for example, Jaurna! , of Po4mer
W in 5science+20.75-88 (1956)
, J., Burke.

S, H, Ruteman! % reported that a high molecular weight novolak type p-chlorophenol resin with a number average molecular weight of 1,600 to 3,300 or more was obtained by polycondensing p-chlorophenol and formaldehyde, and also, Industrial Chemistry Magazine 95 ~99 (1963), Hideo Matsuzaki polycondensed nonylphenol and paraformaldehyde in benzene or toluene with P-)luenesulfone e to produce novolak types each having a number average molecular weight of 1555.2735. It has been reported that resin can be obtained.

Furthermore, high molecular weight ortho-cresol novolac resins and their production methods are described in Japanese Patent Application Laid-Open No. 113-1983. That is, by reacting an ortho-cresol novolac resin with a number average molecular weight of 550 with 37% formalin in the presence of nitric acid in a toluene solvent under pressure at 175°C, a linear high molecular weight polymer soluble in dimethylacetamide with a number average molecular weight of 2010 is obtained. A cresol novolac resin is obtained.

In addition, regarding high molecular weight ortho, baracresol copolymerized novolac resin and its manufacturing method, JP-A-56-9290
It is described in Publication No. 8. That is, the number average molecular weight is 55
0 ortho-cresol novolac resin with 2,6-dimethylol-p-cresol in the presence of nitric acid in an ortho-dichlorobenzene solvent at 175°C to obtain a linear high molecular weight ortho-cresol soluble in dimethylacetamide having a number average molecular weight of 1930. A para-cresol copolymer resin is obtained.

A more preferable linear high molecular weight ortho-cresol novolac resin or a random copolymerized novolak resin of ortho- and halacresol can be produced by using the following novel manufacturing method. That is, a linear high molecular weight ortho-cresol can be obtained by acid-catalyzed polymerization of ortho-cresol or a mixture of ortho-cresol and northo-cresol with formaldehyde, paraformaldehyde or trioxane in an alkyl alcohol or alkyl carboxylic acid in a polar organic solvent. A cresol novolac resin or a random copolymerized novolac resin of ortho- and vala-cresol is obtained.

The novolac resin produced by this method has a number average molecular weight of 210.
0 to 5000) can be obtained.

The linear high molecular weight novolak resin in the present invention is prepared by the method described above to have a number average molecular weight of 6 and 10 by vpo.
It is used as a polymer having a molecular weight of 00 or more, preferably 1200 or more, more preferably 1500 or more, particularly preferably 2000 or more.

In addition, the linear polymer in the present invention refers to a novolak resin in which the polymeric novolac resin is soluble in any of the solvents dimethylacetamide, tetrahydrofuran, and dioxane, and has no residual gel content. means. Therefore, even those having some branching or network structure can be used as long as they are soluble in the above-mentioned solvents.

Novolac-type phenolic resin obtained by polycondensing an unsubstituted phenol with an aldehyde in the presence of an acidic catalyst instead of a monosubstituted phenol having a substituent at the ortho or para position has a high molecular weight for gelation. Even if a material produced by thermal sintering is used for electrodes, good battery performance cannot be obtained.

The linear high molecular weight novolac resin used in the present invention is preferably cured to various degrees using a curing agent, and then thermally baked to form a polymer, from the viewpoint of maintaining the strength of the shaped product to a certain level. Generate a conjugated system. As the curing agent used for curing the linear high molecular weight novolak resin of the present invention, known crosslinking agents such as aldehyde compounds such as formaldehyde, paraformaldehyde, acetaldehyde, and furfural, hexamethylenetetramine, and trimethylolphosphine oxide may be used. can.

The linear high molecular weight novolac resin used in the present invention has a crosslinking position only at the meta position, which is relatively less reactive compared to the ortho and para positions of the phenol group, so the curing reaction conditions are different from those of ordinary phenolic resins. It is necessary to set conditions that make it easier for people to react.

It is also possible to react a resol obtained by reacting phenol with an aldehyde compound in the presence of an alkali catalyst and cure it with a linear high molecular weight novolak resin.

Furthermore, compounds having epoxy groups, such as epoxy resins, can also be used as curing agents.

The amount of curing agent added varies depending on the type of crosslinking agent.

For example, when using an aldehyde compound or epoxy compound as a curing agent, the amount of the aldehyde compound or epoxy group to be added is selected in the range of 0 to 2.5 moles per mole of phenolic OH group of the linear high molecular weight novolac resin. .

Further, when hexamethylenetetramine or resol is used as a curing agent, the amount added is selected in the range of 0 to 60% by weight based on the linear high molecular weight novolak resin.

At this time, curing accelerators such as benzyldimethylamine, imidazoles, trisdimethylaminomethylphenol, BFa-piperidine salt, or various fillers may be added as necessary.

The linear high-molecular-weight novolac resin of the present invention is used as it is, or preferably, it is reacted with a curing agent as described above to be shaped into a desired shape, and then thermally fired to obtain an electrode material. That is, inert gas (nitrogen,
under a stream of oxidizing gas (air, water vapor, etc.) or oxidizing gas (air, water vapor, etc.)
It is thermally fired under a flowing stream of carbon dioxide (carbon dioxide, etc.) or a mixture of both.

Thermal firing temperature is related to the degree of growth of the polymer conjugated system to be generated, and is determined by the balance of ease of doping with electrolyte ions, stability of doped charges, and electrical conductivity of the polymer conjugated system before doping. Preferably 300℃~20
A temperature of 00°C, more preferably 400°C to 1500°C is usually selected.

Thermal firing time is generally 5 minutes or more, preferably 10 minutes to 20 minutes.
A time period, more preferably a range of 20 minutes to 10 hours, is used.

By increasing the specific surface area of the produced electrode material, the maximum output density of a battery using this material as an electrode can be increased. Therefore, when it is desired to increase the maximum output density of the battery, the specific surface area of the molded body made of the electrode material to be produced or the molded body containing the electrode material to be produced is preferably 10 m'/P or more, more preferably 50 m'/P or more, Particularly preferably, it is 100 m'/f or more.In this case, when performing thermal firing, the thermal firing is performed under a flow of oxidizing gas (steam, air, carbon dioxide, etc.) or under a mixed flow of oxidizing gas and inert gas. By doing so, the specific surface area can be increased.Furthermore, the specific surface area can be increased by performing thermal calcination under an inert gas flow and then further thermal calcination under an oxidizing gas flow or a mixed flow of an oxidizing gas and an inert gas. You can also make it bigger.

Further, the specific surface area can also be increased by molding a porous molded body from a reaction product of a linear high molecular weight novolak resin and a curing agent and then thermally baking the molded body.

The linear high molecular weight novolak resin or the reaction product of the novolak resin and a curing agent before being fired is used after being formed into various shapes such as fibrous, powder, granular, film, and felt. In particular, when a large specific surface area is desired, fiber-like, felt-like, and honeycomb-like forms are preferable in terms of strength and ease of handling. When a film-like polymer conjugated system is obtained by thermally baking a reaction product of a linear high-molecular-weight novolac resin in a film-like form and a curing agent, it can be used as it is as an electrode for a battery.

Furthermore, when a fibrous, powder, or granular electrode material is obtained, it can be shaped into a vapor, sheet, or film by a known method and used as a battery electrode.

In addition to forming the electrode material obtained by firing a linear polymeric novolac resin alone, the electrode of the present invention can also be formed by adding a conductive material such as carbon fiber, a reinforcing material, etc. to the electrode material. can. In this case, the content of the electrode material of the present invention contained in the molded body is preferably 50% by weight or more, and more preferably 70% by weight or more.

When manufacturing a battery using the organic polymer-based electrode of the present invention, there are cases in which the electrode of the present invention is used as both electrodes, and cases in which the electrode of the present invention is used as one electrode and a metal such as lithium, aluminum-lithium alloy, or fusible metal is used. In some cases, the electrode of the present invention is used as one electrode and a conjugated compound other than the electrode of the present invention is used as the counter electrode. From the viewpoints of light weight, low cost, and safety, it is preferable to use the electrodes of the present invention for both poles. In addition, especially when voltage flatness is required or when a high electromotive force is desired, it is possible to use the electrode of the present invention for one electrode and use a metal such as lithium, aluminum-lithium alloy, or fusible metal for the counter electrode. is preferred.

As an electrolyte, Li ClO4, L, i(n, LiPF
a.KCNS.

NaPF5, LiBF4, N(Bu)4Ct04,
Known salts such as alkali metal salts such as N(Bu)4CA, alkaline earth metal salts, and tetraalkylammonium salts are combined with propylene carbonate, ethylene carbonate, acetonitrile, γ-butyrolactone, dimethylformamide, dimethyl sulfoxide, and ethyl ether. ,
Usually, a solvent dissolved in one or a mixture of two or more organic solvents commonly used in batteries, such as tetrahydrofuran and glyme, is used.

From the viewpoint of using a solvent with a high decomposition voltage, propylene carbonate, ethylene carbonate, etc. are preferable as the organic solvent. Furthermore, in order to obtain a compact battery that does not leak, it is preferable to use an electrolyte that is solid at room temperature (or the operating temperature of the battery).

A battery using the electrode of the present invention is used, for example, in the following manner. When the electrode of the present invention is used as both electrodes and charged by applying a constant voltage or regulating the voltage so that a constant current flows, the electrode material of the electrode is doped with electrolyte ions,
They become a p-type electrode and an n-type electrode, respectively, and can be used as a battery by utilizing the electromotive force generated at these two electrodes. Due to the discharge, electrolyte ions are dedoped from each electrode, allowing current to be extracted. By repeating such charging and discharging cycles, it can be used as a secondary battery.

In addition, P! with different doping amounts! ! ! ! Although an electromotive force is generated even if both electrodes or n-type electrodes are used, the electromotive force is lower than when p-type and n-type electrodes are used for both poles.

Also, when one electrode uses a metal such as lithium, aluminum-lithium alloy, or fusible metal as the counter electrode, it is possible to charge by applying a constant voltage to both electrodes or regulating the voltage so that a constant current flows. Electrolyte ions are doped into the polymer conjugated system of one electrode to generate an electromotive force, and a current is extracted by the action of dedoping due to discharge, so that it can be used as a battery.

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

Example 1 (1) Synthesis of linear high molecular weight novolac resin 108f of orthocresol, 32ml of paraformaldehyde, and 10t of ethyl cellosolve 240F total sulfuric acid were placed in a reactor and reacted at 115°C for 4 hours with stirring. 17 after completion of reaction
After neutralization by adding f NaHCOa and water 3 f) IF,
While stirring at high speed, the reaction solution was poured into water 2, and the precipitated resin was separated and dried to form resin 115? I got it. This resin is soluble in methanol, ethanol, butanol, octatool, methyl cellosolve, ethyl cellosolve, tetrahydrofuran, dioxane, acetone, methyl ethyl ketone, and ethyl acetate, and has no gel content. It was insoluble in benzene, toluene, xylene, chloroform, and carbon tetrachloride. Steam method (40℃ in methyl ethyl ketone)
) The number average molecular weight was 2600, and the softening point of the resin determined by microscopy was 155°C. From infrared absorption spectrum and nuclear magnetic resonance measurements, it was confirmed that this resin is a linear novolac resin in which cresol is linked through methylene groups.

(2) Reaction with curing agent The above linear high molecular weight novolak resin 2.17? , 0.33 f of hexamine was dissolved in ethanol and then cast onto a glass plate. Thereafter, the ethanol was removed by air drying. Thereafter, a curing reaction was carried out at a temperature of 120°C.

(3) Thermal firing The cured film was heated to 600°C at a rate of 5°C/min under nitrogen flow. The temperature was further maintained at 600°C for 30 minutes. In this way, a black film-like electrode material with a thickness of 10 μm was obtained.

(4) 10m9 of film-like electrode material with a thickness of 10μm on the battery using the above electrode material
It was wrapped in a mesh platinum wire mesh and used as an electrode and an auxiliary electrode.

The above electrode and two sets of auxiliary electrodes were immersed in a 1.0 mol/l LiC604 propylene carbonate solution. Glass fiber F paper with a thickness of 0.5 wax was placed between both electrodes as a diaphragm. A platinum wire was connected as a lead wire between both auxiliary electrodes, and connected to a potentiostat/galvanostat (HA-501 manufactured by Hokuto Denko Co., Ltd.). 3 between both electrodes.
It was charged by applying a constant voltage of 5V. Charging was completed when a charge of 0.5 coulombs was charged as indicated by the coulomb meter.

(5) Battery performance The open circuit voltage of the battery after the above charging was measured and was found to be 1.7V.

Immediately after the above charging, constant resistance discharge was performed by connecting a 50Ω resistor between the two electrodes, and the amount of charge discharged until the open circuit voltage reached 0.1 V was 0.35 coulombs.

After the above charging, after leaving it for 3 days, a constant resistance discharge was performed by connecting a 50Ω resistor between the two electrodes, and the open circuit voltage was 0.
．． The amount of charge discharged until it reached 1V was 0.28 coulombs.

Comparative Example 1 (1) A novolac resin with a number average molecular weight of 600 produced by an acid-catalyzed reaction of phenol and formaldehyde (formaldehyde/phenol = Q, IJ molar ratio) was added to the linear high molecular weight novolac resin of Example 1. (2) Curing reaction using the above Novolac resin was carried out in the same manner as in Example 1 except that the above novolac resin was used.

(3) Thermal baking A polymer conjugated film having a thickness of 10 μm was obtained by thermal baking in the same manner as in Example 1 except that the above-mentioned cured film was used.

(4) Battery using the above polymer conjugated system A battery was constructed in the same manner as in Example 1 except that the above 10 μm thick polymer conjugated film 10cm was used,
Charging was carried out in the same manner as in Example 1.

Charging was completed when a charge of 0.5 coulombs was charged as indicated by the coulomb meter.

(5) Battery Performance The open circuit voltage of the battery after the above charging was measured and was found to be 1.2V.

Immediately after the above charging, constant resistance discharge was carried out by connecting a 50Ω resistor between the two electrodes, and the amount of charge discharged until the open circuit voltage reached 0.1V was 0.29 coulombs.

After the above charging, after leaving it for 3 days, a constant resistance discharge was performed by connecting a 50Ω resistor between the two electrodes, and the open circuit voltage was 0.
．． The amount of charge discharged until reaching jv was 0.19 coulombs.

Comparison of Example 1 and Comparative Example 1 The battery of Example 1 has a higher charge efficiency (discharge amount of charge It can be seen that the ratio of the amount of charge to the amount of charge is large, making it an excellent battery.

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

Claims (1)

[Claims] 1. An organic polymer-based electrode characterized by containing an electrode material obtained by thermally sintering the reaction product of the following (() or (support) and (b). ) A linear high molecular weight novolak resin obtained by polycondensing a monosubstituted phenol having an ortho- or para-trap substituent and an aldehyde compound in the presence of an acidic catalyst (b) Curing agent