JP2645966B2 - Electrode - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode suitable as an electrode of a primary or secondary battery or an electrode of a display element.

[0002]

2. Description of the Related Art In general, a conductive polymer compound can be electrochemically doped / dedoped or oxidized / reduced, and utilizing this phenomenon, it has begun to be used as an electrode material of a secondary battery. Further, since a color change is caused by doping / undoping or oxidation / reduction, the possibility of application as a display material constituting a display element is increasing. Furthermore, the use of a solid electrolyte has the potential of an all-solid-state secondary battery and a display material, and many studies on them have been made.

[0003] When they are formed of secondary batteries or display elements, in particular, of all solid type, a large problem is that the resistance at the interface between the conductive polymer and the electrolyte is large. Alternatively, when a conductive polymer film is formed on a conductive substrate by casting or the like, the movement of ions within the conductive polymer as well as the interface between the conductive polymer and the electrolyte is extremely slow, which is a major problem. there were. In addition, the size of the conductive polymer changes, though slightly, due to the ingress and egress of the dopant (doping / undoping or oxidation / reduction). Therefore, the film on the conductive substrate becomes brittle, and the cycle life is shortened.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems in the prior art. That is, an object of the present invention is to provide an electrode capable of forming a secondary battery having excellent charge / discharge cycle life and stability, or a display element having excellent coloring and decoloring cycle life and stability. Things.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventor has found that a film-like or plate-like conductive substrate has a crosslinked chain or side chain having a polyether structure on its surface. The inventor has found that the doping / dedoping (oxidation / reduction) cycle becomes very stable by providing an electrode active material layer containing a conductive polymer, thereby completing the present invention.

[0006] The plate-like or film-like conductive substrate used for the electrode of the present invention is not particularly limited as long as it has conductivity, but is usually a metal plate, a metal foil, a metal fiber paper,
Examples thereof include those obtained by depositing a metal or metal oxide on paper, a film, a glass plate, a sintered glass, or the like. As the metal, a simple substance such as gold, platinum, silver, copper, nickel, tin, and aluminum, and an alloy such as stainless steel and gold-tin are usually used. As the metal oxide, indium oxide, tin oxide and the like can be used. As the deposition method, an arbitrary method can be appropriately selected from known methods, for example, a vacuum deposition method, a sputtering method, an ion plating method, a CVD method, or the like. However, when the electrode of the present invention is used as a display element, the conductive substrate to be used preferably has an inactive color tone such as glass or a film on which platinum or a metal oxide is deposited.

The conductive polymer having a crosslinked chain having a polyether structure used for the electrode of the present invention is represented by the following formula (I):

Embedded image [Wherein, m and n are integers of 0 or more, and m / (n + m) = 0 to 0]
1, m + n = 10 to 5000], and a polyaniline having a number average molecular weight of 2,000 to 500,000 as a main chain, and the main chain forms a crosslinked structure represented by the following formula (II). The number of nitrogen atoms participating in the structure is 0.01 to 50 of the nitrogen atoms of the main chain polyaniline.
% Polyaniline derivative is preferred.

Embedded image [Wherein RP represents a polyether chain having oxygen atoms at both ends with an average molecular weight of 100 to 100,000, A ¹ represents a linking group selected from the following formula, and -C (= X) -RC (= X)-, -C (= X) -R
-, -C (= X) NH-R-NHC (= X)-, -C
(= X) NH-R-, -SOp-R-SOp-, SOp
_{-R -, - CH 2 CH (} YH) -R -, - (B) P (=
X) -R -, - R - , - RP 1 -OCO-RP 2 -CO
−

A ² represents a linking group selected from the following formula: -C (= X) -RC (= X)-, -RC (= X)
-, -C (= X) NH-R-NHC (= X)-, -R-
NHC (= X)-, -SOp-R-SOp-, -RS
Op -, - R-CH ( YH) CH 2 -, - R- (B) P
(= X) -, - R -, - CO-RP 2 -COO-RP 1
- (wherein, R is a direct bond, a divalent hydrocarbon group having 1 to 30 carbon atoms or a halogen or -COOM substituents, (M; represents an H, Li, Na, K, Cs, Rb, NH 4 ), X represents O or S, Y represents O, S, or NH, B represents a hydrocarbon group or an alkoxy group having 1 to 30 carbon atoms, and p represents an integer of 0 to 2. .)
Represents a group selected from the group consisting of: ]

The conductive polymer having a side chain having a polyether structure used for the electrode of the present invention is represented by the following formula (II)
A polymer compound comprising the structural units represented by I), (IV) and (V), wherein the number i of each of the structural units constituting the polymer compound [formula (III)], j [formula (IV) ], K [Formula (V)] is: k + 2i + j = 10 to 5000, k / (k + 2i + j) = 0.01 to 0.5, i / (j + k) = 0 to 1, (where i and j are 0 or more) , And k is an integer of 1 or more).

[0011]

Embedded image

[In the formula, Alk represents a polyether chain having an oxygen atom at both terminals and having an average molecular weight of 100 to 100,000, Z represents a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms,
R ¹ C (＝ O) — group or R ¹ OC (＝ O) CH ₂ — group (where R ¹ is a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, an alkenyl group, a benzyl group, an aryl group or a group thereof) Represents a substituent), and A represents a linking group selected from the following formula. -C (= X) NH-R-, -SOp-R-SOp-,-
_{CH 2 CH (YH) -R -} , - PB (= X) -, - C
(= X) -RC (= X)-, -C (= X) NH-R-
NHC (= X)-, -C (= X) -R-, -SOp-R
-, -C (= O) -C (= O)-(wherein, R is a divalent hydrocarbon group having 1 to 30 carbon atoms, or a halogen or COOM substituent thereof (where M is a hydrogen atom, Li , Na, K, Ca, Rb or NH ₄ ); X represents an oxygen atom or a sulfur atom;
Represents a sulfur atom or NH, B represents a hydrocarbon group having 1 to 30 carbon atoms or an alkoxy group, and p represents an integer of 0 to 2). ]

The polyaniline derivative having a polyether structure in a crosslinked chain or a side chain contained in the electrode active material layer facilitates migration of a dopant in the electrode active material layer due to the polyether structure of the derivative. It has the function of reducing the resistance of the movement of ions at the electrolyte interface. As a similar idea, there is a method of blending a polyether-based polymer in the electrode active material layer.However, in this method, the compatibility between the polyether and the electrode active material is low, and the function as an electrode is impaired by layer separation, Alternatively, there is a problem that the polyether is eluted in the electrolytic solution or diffuses into the solid electrolyte layer, thereby similarly impairing the function as an electrode. On the other hand, the polyaniline derivative having a polyether structure in a crosslinked chain or a side chain according to the present invention can facilitate migration of a dopant without causing such a problem.

The cross-linked or side chain polyether structure may be formed by forming at least one of alkylene oxides such as methylene oxide, ethylene oxide, trimethylene oxide, tetramethylene oxide, propylene oxide and 3-methyltetramethylene oxide. It has as a unit. In addition, these polyaniline derivatives having a polyether structure in a crosslinked chain or a side chain are obtained by reacting the N-position of polyaniline obtained by oxidative polymerization of aniline with a polyether having a functional group that reacts with an amino group at a terminal,
It can be obtained by performing crosslinking or grafting.

That is, an aniphosphorylated polymer obtained by oxidative polymerization of aniline at a low temperature, for example, at a temperature in the range of -20 to 50 ° C. using ammonium persulfate or the like as an oxidizing agent is first treated with ammonia to obtain a soluble polyaniline. Get. Then, this is treated with an excess of hydrazine to give a number average molecular weight of 2000 to 500000 [GPC (N-methyl-
(Measured with 2-pyrrolidone solvent) to obtain a reduced polyaniline having a number average molecular weight in terms of polystyrene]. In the hydrazine treatment, a soluble polyaniline is dispersed in water or methanol, and an equivalent or more to a nitrogen atom in the polyaniline is used.
Preferably, hydrazine is added three times or more under a nitrogen atmosphere, and the mixture is stirred at 0 to 30 ° C. for 24 hours or more. The obtained reduced polyaniline is N-methyl-2-
It is soluble in pyrrolidone or N, N-dimethylacetamide, but is almost insoluble in other general-purpose organic solvents such as chloroform and tetrahydrofuran.

In order to introduce the crosslinked chain or side chain into the reduced polyaniline, a polyether compound having a functional group which reacts with an aromatic secondary amine at the terminal is used. The main point of the present invention is to use a polyaniline derivative having a crosslinked or side chain composed of an appropriate polyether with polyaniline as the main chain, and the crosslinked or side chain is connected to the polyaniline main chain by any linking group. It does not matter. Specific examples of the terminal functional group include a halogen atom, a carboxyl group, a haloformyl group, an isocyanate group, an isothiocyanate group, a sulfenyl halide, a sulfinyl halide, a sulfonyl halide, an oxirane ring, an aziridine ring, a thiirane ring, and a phosphinyl halide. Thiophosphinyl halide, intramolecular cyclic carboxylic anhydride, and the like.

The reaction between the reduced polyaniline and the compound having a terminal functional group is carried out by adding a polyether compound having a functional group capable of reacting with an aromatic secondary amine at both terminals or a polyether compound having the functional group at both ends to a reduced polyaniline amide solution. The solution is added and stirring is continued under a nitrogen stream for 1 to 48 hours at a temperature ranging from -10 to 80C. If necessary, the reaction may be carried out by adding a tertiary amine catalyst such as pyridine or triethylamine or diethylaniline. The reaction mixture is poured into alcohol or water to precipitate the polymer formed. By further treating this polymer with aqueous ammonia, the polyaniline derivative of the present invention can be produced.

The conductive polymer having a crosslinked or side chain having a polyether structure contained in the electrode active material layer may have a weight ratio of 5 to 100 with respect to the total weight of the electrode active material layer.
%. At this time, the weight of the conductive polymer compound is the weight in the undoped state containing no dopant. If this amount is less than 5%, it is difficult to move the dopant in the electrode active material layer or the ions at the interface with the electrolyte, and it is impossible to draw a stable cycle. Also, this substance (polyether structure
The conductive polymer having a crosslinked chain or a side chain has sufficient ability as an electrode active material, and it is possible to form an electrode active material layer using only this material.

[0019] As a method for producing an electrode of the present invention, port <br/> Rieteru tether or a conductive polymer having a side chain and another electrode active material having a structure (e.g., polyaniline) and a 5:95 The electrode active material layer can be formed on the conductive substrate by a method of dissolving or gelling in a solvent at a weight ratio of 100: 0, and casting or coating the conductive substrate.
Alternatively, if a conductive polymer having a crosslinked chain or a side chain having a polyether structure or another electrode active material can be melted, a melt is applied to form an electrode active material layer on a conductive substrate. Can be.

[0020]

The present invention will be described below with reference to examples. Example 1 4.1 g of aniline and 21.9 g of concentrated hydrochloric acid were dissolved in water to obtain 1
Make up to 00 ml and cool to 0 ° C. 21.9 g of concentrated hydrochloric acid and 6.28 g of ammonium persulfate are dissolved in water to make 100 ml, and the solution is slowly added dropwise to the aniline solution at -10 ° C.
For 1 hour. The generated solid was separated by filtration, washed sufficiently with water, and further de-dope with aqueous ammonia. A polyaniline having a number average molecular weight of 12,000 (GPC, measured in N-methyl-2-pyrrolidone solvent, number average molecular weight in terms of polystyrene) was obtained. This was further reduced with hydrazine to obtain a reduced polyaniline, which was used for the next derivative synthesis.

1 g of the reduced polyaniline and PEO acid # 1000 (manufactured by Kawaken Fine Chemical Co., Ltd., molecular weight of about 10
00, carboxylic acid type polyethylene oxide at both ends)
After acid chloride of 1.10 g, it was reacted in 30 ml of N-methyl-2-pyrrolidone to obtain a polyaniline derivative having a crosslinked chain. The number of nitrogen atoms involved in crosslinking is 20% of the total nitrogen atoms in polyaniline, m / (m + n) =
^{0.46, A 1 = -CO-CH} 2 -, A 2 = -CH 2 -
CO-. 1 g of this polyaniline derivative was added to N-methyl-2
-Swelled and dissolved with 10 ml of pyrrolidone, and cast into a film on a platinum plate. A secondary battery was constructed by combining this electrode, lithium metal and a 0.1 M solution of lithium perchlorate in propylene carbonate. FIG. 1 shows the quantity of discharged electricity and the number of cycles. The numbers in the figure indicate the example numbers, and R1 indicates the comparative example 1.
A stable amount of discharged electricity was obtained even when the number of repetitions was larger than that in the comparative example.

Example 2 0.05 g of the polyaniline derivative of Example 1 was added to 5 ml of N
-Methyl-2-pyrrolidone was dissolved and cast into a film on ITO glass. Lithium perchlorate is put on this film for 10 minutes.
A film of polyethylene glycol containing 200% by weight was formed at a thickness of 200 μm, and the film was sandwiched between ITO glasses to form an electrochromic device. When a voltage of 2.0 V was applied between the electrode of the present invention and the ITO glass electrode and oxidized, the color quickly changed to blue. Next, it was almost colorless when reduced at a voltage of -2.0 V. FIG. 2 shows the change in absorbance at 620 nm during color development when this oxidation / reduction was repeated, and FIG. 3 shows the change in absorbance at 620 nm when color was erased. Even if it is repeated many times, the decrease in the absorbance at the time of color development is small and the increase of the absorbance at the time of color erasure is also small as compared with the comparative example.

Example 3 0.05 g of the polyaniline derivative of Example 1 and 0.95 g of polyaniline were swollen and dissolved in 10 ml of N-methyl-2-pyrrolidone and cast into a film on a platinum plate. Using this, a secondary battery was formed according to Example 1. FIG. 1 shows the quantity of discharged electricity and the number of cycles. A stable amount of discharged electricity was obtained even when the number of repetitions was larger than that in the comparative example.

Example 4 0.05 g of the polyaniline derivative of Example 1 and 0.95 g of polyaniline were dissolved in 10 ml of N-methyl-2-pyrrolidone and cast into a film on ITO glass. Polyethylene glycol containing 10% by weight of lithium perchlorate was formed on this film to a thickness of 200 μm, and then the film was subjected to IT
An electrochromic element was formed by sandwiching between O glasses.
When a voltage of 2.0 V was applied between the electrode of the present invention and the ITO glass electrode and oxidized, the color quickly changed to blue. Then-
When reduced at a voltage of 2.0 V, it became almost colorless. When coloration and decoloring are repeated when this oxidation / reduction is repeated, 62
Changes in absorbance at 0 nm are shown in FIGS. Even if it is repeated many times, the decrease in the absorbance at the time of color development is small and the increase of the absorbance at the time of color erasure is also small as compared with the comparative example.

Example 5 1 g of reduced polyaniline and 1.13 g of monoethyl ester of PEO acid # 1000 (manufactured by Kawaken Fine Chemical Co., Ltd., molecular weight: about 1,000, carboxylic acid type polyethylene oxide at both ends) were acid chlorided, and then 30 ml. N
The reaction was carried out in -methyl-2-pyrrolidone to obtain a polyaniline derivative having a side chain. k + 2i + j = 130, k /
(K + 2i + j) = 0.2, i / (j + i) = 0.4
_{6, A = -CO-CH 2} -, Z = -CH 2 -CO-OC
₂ H _5. Using this, a secondary battery was formed according to Example 1. FIG. 1 shows the quantity of discharged electricity and the number of cycles. A stable amount of discharged electricity was obtained even when the number of repetitions was larger than that in the comparative example.

Example 6 An electrochromic device was constructed according to Example 2 using the polyaniline derivative of Example 5 and polypropylene glycol (diol type, average molecular weight 3000, manufactured by Wako Pure Chemical Industries, Ltd.) instead of polyethylene glycol. . 2.0 V between the electrode of the present invention and the ITO glass electrode
When the battery was oxidized, the color quickly changed to blue. Next, it was almost colorless when reduced at a voltage of -2.0 V. FIGS. 2 and 3 show changes in absorbance at 620 nm at the time of coloring and decoloring when the oxidation and reduction are repeated. Even if it is repeated many times, the decrease in the absorbance at the time of color development is small and the increase of the absorbance at the time of color erasure is also small as compared with the comparative example.

Example 7 1 g of reduced polyaniline and polyethylene glycol monomethyl ether (manufactured by Aldrich, having a molecular weight of about 20)
Glycidyl etherification of 11.00 g of (00, terminal hydroxyl group type) was reacted in 30 ml of N-methyl-2-pyrrolidone to obtain a polyaniline derivative having a side chain. k + 2i + j = 130, k / (k + 2i + j) =
0.5, i / (j + i ) = 0.40, A = -CH 2 CH
_{(OH) CH 2 -, Z} = -CH 3. Using this, a secondary battery was formed according to Example 1. The figure shows the amount of discharged electricity and the number of cycles. A stable amount of discharged electricity was obtained even when the number of repetitions was larger than that in the comparative example.

Example 8 Using the polyaniline derivative of Example 7, an electrochromic device was constructed according to Example 2. When a voltage of 2.0 V was applied between the electrode of the present invention and the ITO glass electrode and oxidized, the color quickly changed to blue. Next, it was almost colorless when reduced at a voltage of -2.0 V. FIGS. 2 and 3 show changes in absorbance at 620 nm at the time of coloring and decoloring when the oxidation and reduction are repeated. Even if it is repeated many times, the decrease in the absorbance at the time of color development is small and the increase of the absorbance at the time of color erasure is also small as compared with the comparative example.

Comparative Example 1 0.1 g of the polyaniline of Example 1 was dissolved in 5 ml of N-methyl-2-pyrrolidone and cast into a film on a platinum plate. This electrode, lithium metal and lithium perchlorate 0.1
A secondary battery was constructed by combining M propylene carbonate solutions. FIG. 1 shows the quantity of discharged electricity and the number of cycles.

Comparative Example 2 0.05 g of the polyaniline of Example 1 was dissolved in 5 ml of N-methyl-2-pyrrolidone and cast on ITO glass to form a film. 10% by weight of lithium perchlorate on this film
Polyethylene glycol was formed into a film having a thickness of 200 μm, and the film was sandwiched between ITO glasses to form an electrochromic device.

[0031]

According to the present invention, an electrode containing a conductive polymer compound having a side chain or a cross-linked chain having a polyether structure on the surface of a conductive substrate on a film or a plate in the electrode active material layer is doped. -The undoping (oxidation / reduction) cycle is very stable, and is very useful as an electrode for a secondary battery or a display element.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the amount of discharge electricity and the number of cycles.

FIG. 2 is a graph showing a change in absorbance at 620 nm during color development.

FIG. 3 is a graph showing a change in absorbance at 620 nm when decoloring.

[Explanation of symbols]

 1 Example 1 2 Example 2 3 Example 3 4 Example 4 5 Example 5 6 Example 6 7 Example 7 8 Example 8 R1 Comparative Example 1 R2 Comparative Example 1

Claims (5)

(57) [Claims] 1. An electrode active material layer provided on the surface of a film-shaped or plate-shaped conductive substrate, wherein a conductive polymer having a crosslinked chain or a side chain having a polyether structure is contained. Electrode. 2. A conductive polymer having a crosslinked chain having a polyether structure is represented by the following formula (I): [Wherein, m and n are integers of 0 or more, and m / (n + m) = 0 to 0]
1, m + n = 10-5000], having a main chain of polyaniline having a number average molecular weight of 2,000 to 500,000, wherein the main chain forms a crosslinked structure represented by the following formula (II). The number of nitrogen atoms participating in the structure is 0.01 to 50% of the nitrogen atoms of the main chain polyaniline.
The electrode according to claim 1, wherein the polyaniline derivative is: Embedded image [Wherein RP represents a polyether chain having oxygen atoms at both ends with an average molecular weight of 100 to 100,000, A ¹ represents a linking group selected from the following formula, and -C (= X) -RC (= X)-, -C (= X) -R
-, -C (= X) NH-R-NHC (= X)-, -C
(= X) NH-R-, -SOp-R-SOp-, -SO
_{p-R -, - CH 2} CH (YH) -R -, - (B) P
(= X) -R -, - R -, - RP 1 -OCO-RP 2 -
CO-A ² represents a linking group selected from the following formula: -C (= X) -RC (= X)-, -RC (= X)
-, -C (= X) NH-R-NHC (= X)-, -R-
NHC (= X)-, -SOp-R-SOp-, -RS
Op -, - R-CH ( YH) CH 2 -, - R- (B) P
(= X) -, - R -, - CO-RP 2 -COO-RP 1
- (wherein, R is a direct bond, a divalent hydrocarbon group having 1 to 30 carbon atoms or a halogen or -COOM substituents, (M; represents an H, Li, Na, K, Cs, Rb, NH 4 ), X represents O or S, Y represents O, S or NH, B represents a hydrocarbon group or an alkoxy group having 1 to 30 carbon atoms, and p represents an integer of 0 to 2. )]. 3. The polymer according to claim 1, wherein the conductive polymer having a side chain having a polyether structure is a polymer compound comprising structural units represented by the following formulas (III), (IV) and (V): The number i of each structural unit constituting the compound (formula (III)), j
[Expression (IV)] and k [Expression (V)] are as follows: k + 2i + j = 10 to 5000, k / (k + 2i + j) = 0.01 to 0.5, i / (j + i) = 0 to 1, (where i , J is an integer of 0 or more, and k is an integer of 1 or more) The electrode according to claim 1, wherein the polyaniline derivative satisfies the following three relational expressions. Embedded image [In the formula, AlK represents a polyether chain having an oxygen atom at both terminals and having an average molecular weight of 100 to 100,000, Z represents a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms, and R ¹ C (=
O) — group or R ¹ OC (＝ O) CH ₂ — group (provided that
R ¹ represents a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, an alkenyl group, a benzyl group, an aryl group or a substituent thereof), and A is selected from the following formula: -C (= X) NH-R-, -SOp-R-SOp-,-representing a linking group
_{CH 2 CH (YH) -R -} , - PB (= X) -, - C
(= X) -RC (= X)-, -C (= X) NH-R-
NHC (= X)-, -C (= X) -R-, -SOp-R
-, -C (= O) -C (= O)-(wherein, R is a divalent hydrocarbon group having 1 to 30 carbon atoms, or a halogen or COOM substituent thereof (where M is a hydrogen atom, Li , Na, K, Ca, Rb or NH ₄ ); X represents an oxygen atom or a sulfur atom;
Represents a sulfur atom or NH, B represents a hydrocarbon group having 1 to 30 carbon atoms or an alkoxy group, and p represents an integer of 0 to 2). ] 4. The weight ratio of the conductive polymer having a crosslinked or side chain having a polyether structure contained in the electrode active material layer is 5 to 100 with respect to the total weight of the electrode active material layer.
%. The electrode according to claim 1, wherein 5. The electrode according to claim 1, which is used as an electrode of a display element, a primary battery, or a secondary battery.