JPH0855620A - Electrode for organic electrolytic battery and organic electrolytic battery using the electrode - Google Patents

Abstract

PURPOSE:To provide a battery with high cycle characteristic and high Coulomb efficiency by using a base material obtained by heating a polycarbodiimide resin in an inert atmosphere at 350-900 deg.C. CONSTITUTION:A polycarbodiimide resin solution is prepared by reacting a mixture of 2,4-tolylenediisocyanate and 2,6-tolylenediioscyanate in tetrachloroethylene under a carbodiimidizing catalyst. A carbodiimid resin molding is heated to form a base material to be used. The heat treatment is conducted in vacuum or an inert atmosphere such as helium at 350-900 deg.C. The polycarbodiimide resin molding is not baked in this temperature range, but at less than 350 deg.C, conductivity is not obtained, and at higher than 900 deg.C, the molding does not act as an electrode. The base material is used as either one electrode of positive and negative electrodes together with an organic electrolyte in which an electrolyte is dissolved to constitute an organic electrolytic battery.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode for an organic electrolyte battery which functions as a secondary battery and an organic electrolyte battery using the electrode.

[0002]

2. Description of the Related Art In recent years,
A secondary battery using polyacetylene as an electrode has been closed as an organic electrolyte battery (see Japanese Patent Application Laid-Open No. 56-186469), and research on secondary organic electrolyte batteries has been actively conducted. Conductive polymer compounds used as electrodes, such as polyacetylene, polyaniline, polyparaphenylene, polyvinylcarbazole, etc., are generally easily oxidized and have the drawbacks of being severely deteriorated when used as electrodes for secondary batteries.

Recently, secondary batteries using organic fibers such as polyacrylonitrile and rayon as electrodes have been developed. Such organic fibers are charged and discharged as electrodes for organic electrolyte secondary batteries. The cloning efficiency was low and the cycle characteristics were not good, which was insufficient.

An object of the present invention is to solve the above problems of the prior art and to provide an electrode for an organic electrolyte battery which does not deteriorate even after long-term use and an organic electrolyte battery using the electrode. It was

[0005]

In order to achieve the above object, the structure of the electrode for an organic electrolyte battery adopted by the present invention is such that the polycarbodiimide resin is 350 to 9 in an inert atmosphere.
The organic electrolyte battery is characterized by comprising a base material obtained by heating to 00 ° C. Further, the structure of the organic electrolyte battery adopted by the present invention to achieve the above-mentioned object is an organic electrolyte comprising an electrode and an organic electrolyte. In the battery, the base material obtained by heating the polycarbodiimide resin to 350 to 900 ° C. in an inert atmosphere is used as at least one electrode.

That is, the inventors of the present invention have made earnest studies on the application of a heat-treated resin of a heat-resistant resin to an organic electrolyte electrode, and as a result, the heat-treated product of a polycarbodiimide resin has excellent stability as an electrode. The inventors have found that they exhibit excellent performance as an electrode of an organic electrolyte secondary battery, and have completed the present invention.

The present invention will be described in detail below.

The polycarbodiimide resin for obtaining the base material used in the present invention is not necessarily required to have strength when it is heated to be used as a base material for an electrode. It can be used, "having at least two carbodiimide groups in the molecule and having a molecular weight of 200 to 1,000,000, preferably 5,000.
0 to 500,000, and more preferably 50,000 to 150,000 ”. Such a polycarbodiimide resin is disclosed in, for example, Japanese Patent Application Laid-Open No. 51-
It can be produced by the method disclosed in Japanese Patent No. 61599, or the method disclosed in Japanese Patent Laid-Open No. 2-292316, and can be easily prepared, for example, by a condensation reaction involving decarbonization of organic diisocyanate. Can be manufactured.

The organic diisocyanate used for producing the above polycarbodiimide resin may be any type of aliphatic, alicyclic, aromatic or aromatic-aliphatic type. , Even if used alone,
Alternatively, two or more kinds may be combined and used as a copolymer.

More specifically, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,
A mixture of 4-tolylene diisocyanate and 2,6-tolylene diisocyanate, crude tolylene diisocyanate,
Xylene diisocyanate, m-phenyl diisocyanate, naphthylene-1,5-diisocyanate, 4,
4'-biphenyl diisocyanate, 3,3'-dimethoxy-4,4 'biphenyl diisocyanate, or a mixture thereof can be exemplified as the organic diisocyanate.

Therefore, the polycarbodiimide resin used in the present invention includes a homopolymer or a copolymer having at least one repeating unit represented by the formula -RN = C = N-. The above-mentioned organic diisocyanate residue R, which is the remaining part of the organic diisocyanate molecule excluding the two isocyanate groups (NCO), is preferably an aromatic diisocyanate residue.

Further, the polycarbodiimide resin may be one whose molecular weight is lowered by stopping the polycondensation with one or more monoisocyanates. Thus, as the monoisocyanate for sealing the end of the polycarbodiimide and controlling the molecular weight thereof, phenylisocyanate, (ortho, methan, para) -tolylisocyanate, dimethylphenylisocyanate is used. Examples thereof include cyclohexyl isocyanate and methyl isocyanate.

The above-mentioned polycarbodiimide resin is then formed into a film, fiber, powder, sheet, or any other suitable molded article, which is not stretched,
It may be uniaxially stretched or biaxially stretched.

The above-mentioned polycarbodiimide resin molded article is finally heated to become a base material used in the present invention, and this heat treatment is carried out at 350 ° C. in an inert atmosphere such as vacuum, nitrogen, argon or helium. It is carried out between ℃ and 900 ℃. In addition, the heat treatment in this temperature range does not completely burn the polycarbodiimide resin molded article, and when the heating temperature is lower than 350 ° C., sufficient conductivity cannot be obtained, so that it does not act as an electrode. No, and the heating temperature is 900
When the temperature becomes higher than 0 ° C, the reason is not clear, but the organic electrolyte battery using this as an electrode does not work.

The obtained base material is insoluble in the solvent of the electrolyte used in the organic electrolyte battery, and is infusible under the temperature condition of −100 to 350 ° C. used as the battery. That is, it has preferable characteristics as an electrode for an organic electrolyte battery. When the base material requires some strength, it is preferable to use a polycarbodiimide resin as a raw material having a molecular weight of 10,000 or more.

Then, the organic electrolyte battery of the present invention can be obtained by using the above-mentioned base material together with an electrolytic solution in which an organic electrolyte is dissolved as an electrode for both positive and negative electrodes or one of a positive electrode and a negative electrode.

When the above base material is used as the positive electrode, the negative electrode may be an alkali metal such as Li, Na or K, Mg or Ca.
Alkaline earth metals such as, active metals such as Zn, Pb,
A metal or alloy that forms an alloy with Li, such as Al,
A conjugated polymer such as polyacetylene can be used, but is not limited thereto.

When the insoluble and infusible base material of the present invention is used as a negative electrode, a metal oxide such as WO ₃ , MgO ₃ , V ₂ O ₅ or a metal sulfide such as TiS ₂ , NbS ₂ is used as a positive electrode. ,
Other conjugated polymers such as metal selenides, polyacetylene, and polyaniline can be used, but are not limited to these.

Further, the solvent for the electrolyte is preferably an aprotic organic solvent, such as propylene carbonate,
Examples thereof include γ-butyl lactone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, ethylene carbonate, dimethoxyethane, tetrahydrofuran, methylene chloride, and mixtures of two or more thereof. In addition, it is preferable that these solvents are subjected to dehydration or deoxidation treatment before use.

In order to obtain an electrolytic solution, a compound which produces ions may be dissolved in the above-mentioned solvent. The compounds which produce ions are LiI, NaI, NH ₄ I and LiC.
lO ₄ , LiAsF ₆ , LiBF ₄ , KPF ₄ , NaP
_{F 6, (n-C 4} H 9) 4 NClO 4, (n-C 4 H 9) 4 NA
sF _6, may be mentioned _{(n-C 4 H 9)} 4 NPF 6 or the like.

The concentration of the electrolyte in the electrolytic solution at this time is not particularly limited and may be determined depending on the type of the electrolyte used, but is preferably in the range of 0.001 to 10 mol / l.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0023]

【Example】

Example 1 A mixture of 2,4-tolylene diisocyanate / 2,6-tolylene diisocyanate (80:20) [TDI].
54 g was reacted with 500 g of tetrachloroethylene together with 0.12 g of a carbodiation catalyst (1-phenyl-3-methylphosphorene oxide) at 120 ° C. for 5 hours to give a polycarbodiimide resin (molecular weight: 60,00).
0) A solution was obtained. Pour the reaction solution into a glass petri dish, 60
After drying at 5 ° C. for 5 hours and 120 ° C. for 10 hours, it was heated to 200 ° C. at a temperature rising rate of 1 ° C./hour to obtain a cured film.

The obtained film was heated in nitrogen gas at a temperature rising rate of 2 ° C./min to 400, 500, 600, 700, 75.
The temperature was raised to 0,850 ° C. to obtain an insoluble and infusible base material, and a small piece of 10 × 10 mm was cut out from this insoluble and infusible base material to obtain a positive electrode. LiCl ₄ is used for the negative electrode, and 1 LiClO ₄ is used.
Propylene Carbonate containing mol / l was used as electrolyte solution,
A secondary battery was formed using a beaker.

This secondary battery is used as a charging / discharging device H manufactured by Hokuto Denko.
Connect to J-201B, charge at 0.1mA for 60 minutes,
Then, a cycle of discharging to a terminal voltage of 1 V at 0.1 mA was repeated 1000 times. Table 1 shows the results.
Shown in

Comparative Example 1 The film obtained in Example 1 was heated to 300, 950, and 1100 ° C. at a heating rate of 2 ° C./min in nitrogen gas to obtain an insoluble and infusible substrate. 10 x 10 from fusible substrate
A small piece of mm was cut out and used as a positive electrode. A Li metal piece was used for the negative electrode, and a propylene carbonate containing 1 mol / l of LiClO ₄ was used as an electrolytic solution, and a beaker was used to form a secondary battery. This secondary battery is a charging / discharging device HJ manufactured by Hokuto Denko.
It was connected to -201B and the same charging / discharging cycle as the example was repeated. Table 1 shows the results.

[0027]

[Table 1]

Example 2 50 g of methylene diphenyl diisocyanate (MDI)
Was reacted with 0.12 g of a carbodiimidization catalyst (1-phenyl-3-methylphosphorene oxide) in tetrahydrofuran 880 ml at 68 ° C. for 15 hours to give a polycarbodiimide resin (molecular weight: 110,00).
0) A solution was obtained. Spread the reaction solution on a glass dish and 4
After drying at 0 ° C for 10 hours and 120 ° C for 5 hours, 1 ° C /
A cured film was obtained by heating to 200 ° C. at a heating rate of time.

The obtained film was heated to 400, 500, 600, 700, 750, 850 ° C. at a heating rate of 2 ° C./min to obtain an insoluble and infusible substrate. From this insoluble and infusible substrate A 10 × 10 mm piece was cut out to obtain a positive electrode. For the negative electrode, the 750 ° C. heat-treated product prepared in Example 1 was used.
Using γ-butyl lactone containing 1 mol / l of F ₄ as an electrolytic solution, a beaker was used to form a secondary battery.

This secondary battery is used as a charging / discharging device H manufactured by Hokuto Denko.
A cycle of connecting to J-201B, charging at 0.1 mA for 60 minutes, and then discharging at 0.1 mA to a terminal voltage of 1 V was repeated 1000 times. The results are shown in Table 2.

Comparative Example 2 The film obtained in Example 2 was heated to 300, 950 and 1100 ° C. at a heating rate of 2 ° C./min in nitrogen gas to obtain an insoluble and infusible substrate. 10 x 10 from fusible substrate
A small piece of mm was cut out and used as a positive electrode. The 750 ° C. heat-treated product prepared in Example 1 was used as the negative electrode, and γ-butyl lactone containing 1 mol / l of LiBF ₄ was used as an electrolytic solution to form a secondary battery using a beaker. This secondary battery was connected to a charging / discharging device HJ-201B manufactured by Hokuto Denko, and the same charging / discharging cycle as in the example was repeated. The results are shown in Table 2.

[0032]

[Table 2]

Example 3 50 g of diphenyl ether diisocyanate was added to 850 ml of tetrahydrofuran to prepare a carbodiimidization catalyst (1-phenyl-3-methylphosphorene oxide).
It was made to react with 0.12 g at 68 ° C. for 15 hours to obtain a polycarbodiimide resin (molecular weight: 80,000) solution. Using this solution, a polycarbodiimide resin fiber having a diameter of 20 micrometers was prepared by a dry method.

The obtained fiber was heated to 40 ° C. at a heating rate of 2 ° C./min.
The temperature was raised to 0, 500, 600, 700, 750, 850 ° C. to obtain a fibrous insoluble infusible base material, and 1 g of this fibrous insoluble infusible base material was used as a positive electrode. The negative electrode using the Al-Li alloy, the LiAsF _6, dimethyl sulfoxide containing 1 mole / l and the electrolyte solution, to form a secondary battery using a beaker.

This secondary battery was connected to a charging / discharging device HJ-201B manufactured by Hokuto Denko and charged at 0.1 mA for 60 minutes,
Then, a cycle of discharging to a terminal voltage of 1 V at 0.1 mA was repeated 1000 times. The results are shown in Table 3.
Shown in

COMPARATIVE EXAMPLE 3 The fiber obtained in Example 3 was heated to 30 ° C. at a heating rate of 2 ° C./min.
The temperature was raised to 0, 950, 1100 ° C. to obtain a fibrous insoluble infusible substrate, and 1 g of this fibrous insoluble infusible substrate was used as a positive electrode. Al-Li alloy is used for the negative electrode, and LiAsF is used.
₆ was used as an electrolytic solution of dimethyl sulfoxide containing 1 mol / l, and a secondary battery was formed using a beaker. This secondary battery was connected to a charging / discharging device HJ-201B manufactured by Hokuto Denko, and the same charging / discharging cycle as in the example was repeated. The results are shown in Table 3.

[0037]

[Table 3]

Example 4 1 mol / l HClO ₄ containing 0.5 mol / l of aniline
Polyaniline was synthesized from an aqueous solution on a platinum electrode by the potential scanning method. Using this polyaniline as a positive electrode, 400, 500, 600, 700, 75 prepared according to Example 1
A secondary battery was constructed by using an insoluble and infusible substrate treated at 0,850 ° C. as a negative electrode, and using propylene carbonate containing 0.7 mol / l of (nC ₄ H ₉ ) ₄ NClO ₄ as an electrolytic solution. .

This secondary battery is used as a charging / discharging device H manufactured by Hokuto Denko.
A cycle of connecting to J-201B, charging at 0.1 mA for 60 minutes, and then discharging at 0.1 mA to a terminal voltage of 1 V was repeated 100 cycles. Table 4 shows the results.

Comparative Example 4 1 mol / l HClO ₄ containing 0.5 mol / l of aniline
Polyaniline was synthesized from an aqueous solution on a platinum electrode by the potential scanning method. Using this polyaniline as the positive electrode and the insoluble and infusible base material prepared in Comparative Example 1 and treated at 300, 950 and 1100 ° C. as the negative electrode, (n-C ₄ H ₉ ) ₄ N
A secondary battery was constructed using propylene carbonate containing 0.7 mol / l of ClO ₄ as an electrolytic solution. This secondary battery was connected to a charging / discharging device HJ-201B manufactured by Hokuto Denko, and the same charging / discharging cycle as in the example was repeated. The results are shown in Table 4.
Shown in

[0041]

[Table 4]

Comparative Example 5 4 g of p-xylylenebisdiethylsulfonium bromide
Was dissolved in 200 ml of ion-exchanged water and then cooled to 0 ° C. Strongly basic ion exchange resin (Amberlite IR) exchanged with OH ^- type in twice the amount of sulfonium salt
A-401) was gradually added, and the mixture was stirred at 0-2 ° C. After this treatment, the ion exchange resin was taken out by filtration. The reaction solution was subjected to dialysis treatment for 1 day, and then the solution was spread on a glass shearer and the solvent was dried to obtain a polymer sulfonium salt film. After fixing both ends of this film and heating to 100 ° C, remove the film fixing jig and
After the temperature was raised to 300C, the film was stretched 3 times while heating at 300C to obtain a poly-P-phenylenevinylene film.

The obtained film was heated in nitrogen gas at a heating rate of 2 ° C./min to 300, 400, 500, 600, 70.
The temperature is raised to 0, 750, 850, 950, 1100 ° C. to make an insoluble and infusible substrate, and 10 × 1 from this insoluble and infusible substrate
A 0 mm piece was cut out and used as a positive electrode. A Li metal piece was used for the negative electrode, propylene carbonate containing 1 mol / l of LiClO ₄ was used as an electrolytic solution, and a beaker was used to form a secondary battery.

This secondary battery is used as a charging / discharging device H manufactured by Hokuto Denko.
The cycle of connecting to J-201B, charging at 0.1 mA for 60 minutes, and then discharging at 0.1 mA to a terminal voltage of 1 V was repeated 1000 times. The results are shown in Table 5.

[Table 5]

[0045]

As is clear from Tables 1 to 5, the organic electrolyte batteries of the examples of the present invention show almost no deterioration due to cycling, and operate as batteries having good cycle characteristics and Coulombic efficiency. I understand.

Claims (4)

[Claims] 1. An electrode for an organic electrolyte battery comprising a base material obtained by heating a polycarbodiimide resin at 350 to 900 ° C. in an inert atmosphere. 2. A polycarbodiimide resin has at least two carbodiimide groups in the molecule and has a molecular weight of 200.
The electrode for an organic electrolyte battery according to claim 1, which is from 1 to 1,000,000. 3. An organic electrolyte battery comprising an electrode and an organic electrolyte, wherein a substrate obtained by heating a polycarbodiimide resin to 350 to 900 ° C. in an inert atmosphere is used as at least one electrode. Electrolyte battery. 4. The polycarbodiimide resin has at least two carbodiimide groups in the molecule and has a molecular weight of 200.
4. The organic electrolyte battery according to claim 3, which is from 1 to 1,000,000.