JP2000200619A - Redox battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a redox battery improved in contact resistance between a porous carbon electrode and a current collector, and simplified in assembly of battery components. by developing a current collector excellent in balance between conductivity and brittleness. SOLUTION: This redox battery is a circulating-liquid battery to be charged/ discharged by oxidizing/reducing reaction with a positive-electrode liquid and a negative-electrode liquid passed through a positive-electrode chamber and a negative-electrode chamber, respectively, separated from each other by a diaphragm and each having a liquid-permeable porous carbon electrode disposed therein. This redox battery is characterized in that the porous carbon electrode integrally fused with a collector plate made of a conductive resin and the conductive resin is essentially made up of carbon of 10 to 50 wt.% and a polyolefinic resin of 50 to 90 wt.% containing at least two kinds of olefine copolymers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid circulation type battery. More specifically, the present invention relates to a liquid circulation type all-vanadium redox battery.

[Background of the Invention] At present, the concentration of carbon dioxide in the atmosphere is remarkably increased due to the large use of fossil fuels, and global warming is a major problem. For this reason, solar cells, which are clean energy sources, are being actively developed. However, since solar cells cannot generate power at night or in rainy weather, the development of high-performance secondary cells combined with solar cells is awaited. ing.

On the other hand, even in the conventional power generation equipment, the difference in power demand between night and day is large, and the power generation capacity must be provided in accordance with the peak of the demand, so that the load factor of the power generation equipment is reduced. For this reason, it is necessary to store power at night with a large power storage battery and use it during the day to smooth the operating load and raise the load factor of the power generation equipment for efficient operation. The development of power storage batteries is awaited. Further, development of a secondary battery having a high output density suitable for a mobile power source such as an electric vehicle is also awaited.

A redox flow battery is characterized as being capable of being charged in accordance with the output voltage of a solar cell by tapping, and having a relatively simple structure and being easily enlarged, as a new type of secondary battery suitable for the above applications. Promising.

[0005]

2. Description of the Related Art A redox flow type secondary battery is a battery in which a battery active material is in a liquid state, positive and negative electrode battery active materials are passed through a liquid-permeable electrolytic cell, and charge and discharge are performed using an oxidation-reduction reaction. The redox flow type secondary battery has the following advantages as compared with the conventional secondary battery. (1) In order to increase the storage capacity, it is only necessary to increase the capacity of the storage container and increase the amount of active material, and the electrolytic cell itself may be used as long as the output is not increased. (2) Since the positive and negative electrode active materials can be completely separated and stored in the container, unlike batteries where the active material is in contact with the electrodes,
The possibility of self-discharge is small. (3) In the liquid permeable carbon porous electrode used in the present battery, the charge / discharge reaction of the active material ions (electrode reaction) is simply performed by exchanging electrons on the electrode surface, and in the zinc-bromine battery, The reaction of the battery is simple because it does not deposit on the electrode as zinc ions do.

However, iron-chromium-based batteries, which have been conventionally developed even in redox flow type secondary batteries, have low energy densities and have drawbacks such as mixing of iron and chromium via an ion exchange membrane. It has not been converted. Therefore, all vanadium redox flow batteries (JE
Electrochem. Soc., 133 1057 (1986), 62-186473) has been proposed, and this battery has a higher electromotive force, a higher capacity density, and a single electrolyte element as compared with an iron-chromium battery. Even if the positive and negative electrode solutions are mixed with each other via the stagnation membrane, it can be easily regenerated by charging, the battery capacity does not decrease, and the electrolyte solution can be completely closed. ing.

However, even in this all-vanadium redox flow battery, a liquid-permeable porous electrode, a current collector made of a carbon plate, an outer frame of a current collector made of a vinyl chloride resin, and an electrolytic solution are supplied to the positive electrode chamber and the negative electrode chamber. There are many parts constituting a battery such as a PVC resin separator to be distributed and introduced, and the assembly is complicated and the productivity is poor. Further, the contact resistance between the porous electrode and the current collector plate is high, and improvement from this viewpoint has been required. In addition, the carbon plate used as the current collector plate is also brittle, and when broken, there is a problem that the positive electrode and negative electrode electrolytes are mixed to generate heat, and from this viewpoint, improvement is necessary.

The present inventors have proposed various proposals for an all-vanadium redox flow battery (Japanese Patent Application Laid-Open No.
No. 223513, Japanese Patent Application Laid-Open No. 10-12261, Japanese Patent Application No. 1
No. 0-53722), but these proposals are intended to be further improved.

[0009]

In view of this situation, the present inventors have developed a current collector having an excellent balance between conductivity and brittleness, improved the contact resistance between the porous carbon electrode and the current collector, As a result of intensive studies on simplification of the assembling process of battery components, the present invention has been achieved.

[0010]

According to the present invention, a positive electrode solution and a negative electrode solution are passed through a positive electrode chamber and a negative electrode chamber provided with a liquid-permeable porous carbon electrode separated by a diaphragm. In a liquid-circulating battery that performs an oxidation-reduction reaction and charges and discharges, the porous carbon electrode is fused and integrated with a conductive resin current collector plate, wherein the conductive resin contains 10% by weight of carbon or less. 50
% By weight and a polyolefin-based resin containing a copolymer of at least two olefins, from 50% by weight to 90% by weight.
And a redox battery characterized by consisting essentially of:

According to a preferred embodiment of the present invention, there is provided a redox battery, wherein the copolymer is a random copolymer.

According to a preferred aspect of the present invention, there is further provided a redox battery in which the conductive resin current collector plate is fused and integrated with an insulating outer frame made of an olefin polymer.

According to another preferred embodiment of the present invention, there is provided an insulating member having the conductive resin current collector plate, the insulating outer frame, and an inlet for introducing a positive electrode solution and a negative electrode solution into a positive electrode chamber and a negative electrode chamber. The present invention provides a redox battery in which a liquid separating plate is fused and integrated, and in this case, the separating plate is made of an olefin-based polymer.

According to another preferred embodiment of the present invention, the inlet for introducing the positive electrode solution and the negative electrode solution into the positive electrode chamber and the negative electrode chamber comprises a plurality of slits, and the manifold for supplying the electrolytic solution is connected to the slits. Redox batteries are provided.

According to another preferred embodiment of the present invention, a redox outlet for discharging the positive electrode solution and the negative electrode solution from the positive electrode chamber and the negative electrode chamber is constituted by a plurality of slits and connected to a subsequent manifold. A battery is provided.

According to another preferred aspect of the present invention, the fusion bonding of the porous carbon electrode and the current collector is performed by a process of melting and forming the current collector. A redox battery is provided, which is performed by pressing a porous carbon electrode at a temperature equal to or higher than a softening point at which a conductive resin is not completely solidified.

According to another preferred embodiment of the present invention, the fusion bonding of the porous carbon electrode and the current collector plate is performed at a temperature above the softening point at which the conductive resin constituting the current collector plate is not completely solidified. There is provided a redox battery performed by pressure bonding at a temperature.

According to another preferred aspect of the present invention, the fusion bonding of the porous carbon electrode and the current collector plate is performed by heating the conductive resin current collector plate to a softening temperature or higher. A redox battery is provided which is performed by crimping the porous carbon electrode.

According to another preferred embodiment of the present invention, the conductive resin current collector plate and the insulating outer frame are integrated by fusion by locally irradiating ultrasonic energy to the fusion portion. A redox battery is provided.

According to another preferred embodiment of the present invention, the conductive resin current collector plate and the porous carbon electrode fused and integrated are inserted into a mold, and then the insulating outer frame is formed. In addition, by injection molding the resin composition constituting the liquid separating plate, a redox battery in which the insulating outer frame and the liquid separating plate are integrally formed together with the porous carbon electrode is provided.

According to another preferred embodiment of the present invention, the positive electrode solution and the negative electrode solution have a vanadium ion concentration of 0.5 to 8.0.
Redox batteries are provided that are moles / liter.

According to another preferred embodiment of the present invention, the positive electrode solution and the negative electrode solution are aqueous solutions of vanadium in sulfuric acid, and the concentration of sulfate in the electrolyte is 0.5 to 9.0 mol / l. A battery is provided.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (1) Porous carbon electrode The electrode used in the redox battery of the present invention is a liquid-permeable porous carbon electrode. The electrodes are preferably 0.0
1 to 1.0 g / cc, more preferably 0.08 to 0.80
g / cc, most preferably from 0.12 to 0.50 g / cc.

(2) Current collecting plate The current collecting plate used in the redox battery of the present invention is made of a conductive resin, and it is required that this and the porous carbon electrode are fused and integrated. It is a feature.

(I) Conductive resin: The conductive resin constituting the current collector plate contains 10 to 50% by weight, preferably 20 to 45% by weight, more preferably 25 to 40% by weight of carbon (a),
And 50 to 90% by weight, preferably 55 to 80% by weight,
More preferably, it consists essentially of a polyolefin-based resin (b) containing 60 to 75% by weight of a copolymer of at least two olefins.

(A) Carbon Examples of carbon suitable for use in the present invention include carbon black, carbon fiber, natural graphite, artificial graphite, and the like. As carbon black, acetylene black, furnace black, thermal black, channel black and the like are used. As the carbon fibers, polyacrylonitrile-based carbon fibers and pitch-based carbon fibers are used. In order to maintain a good balance between the dispersibility with the resin and the conductivity, a mixture of carbon black and graphite can be used.

(B) Polyolefin resin Another essential component of the conductive resin together with the carbon is a polyolefin resin containing a copolymer of at least two olefins. The polyolefin-based resin includes a mixture of the copolymer and an olefin homopolymer and a copolymer in addition to a case where the polyolefin-based resin is composed of only the copolymer.

The above-mentioned copolymer of at least two olefins may be any copolymer such as a binary copolymer or a terpolymer obtained by copolymerizing at least two types of olefins such as ethylene, propylene, butene, pentene and hexene. It may be something. Preferably, mainly propylene,
For example, propylene 60 to 99.5 weight, preferably 80
９９99.0% by weight, more preferably 94-98% by weight
And other olefins, for example ethylene, 0.5 to 40% by weight, preferably 1.0 to 20% by weight, more preferably 2 to 40% by weight.
To 6% by weight. As the copolymer,
Although a random copolymer, a block copolymer, etc. can be mentioned, a random copolymer is preferred in the present invention.

As described above, the polyolefin resin must contain a copolymer of at least two types of olefins as an essential component, but the olefin resin may contain an optional component in addition to the copolymer. Examples of the coalescence include homopolymers and copolymers of olefins such as ethylene, propylene, butene, and hexene (excluding the copolymer as an essential component).
These optional components (when used) are 5 to 80% by weight, preferably 10 to 60% by weight, based on the polyolefin resin.
%, Most preferably from 20 to 50% by weight.

(3) Integration of porous carbon electrode and current collector plate The battery of the present invention is characterized in that the porous carbon electrode is fused and integrated with the above-mentioned conductive resin current collector plate. I do. The fusion bonding of the conductive resin current collector and the porous carbon electrode is performed at a temperature equal to or higher than the softening temperature of the conductive resin current collector with the conductive resin current collector and the porous carbon electrode pressed. , And can be fused and integrated. After the conductive resin current collector plate is heated to a softening temperature or higher, a liquid-permeable porous carbon electrode can be integrated by pressure bonding. 150 ~
A fusion temperature of 300C is preferred, and a fusion temperature of 160-290C is more preferred. Such a method is preferable for mass production since an integrated product of the current collector / porous carbon electrode can be directly produced from the conductive resin material.

The fusion bonding of the conductive resin current collector plate and the porous carbon electrode is performed by melting the conductive resin current collector plate in a process of melting and forming the resin current collector plate at a softening point temperature at which the resin current collector plate is not completely solidified. As described above, the porous carbon electrode can be pressed and fused and integrated.

(4) Outer frame of current collector plate The current collector plate according to the present invention has an insulating outer frame on its outer periphery. This outer frame is made of olefin polymer 1
A species or a mixture of two or more species.

Examples of the olefin polymer that can be used here include homopolymers and copolymers of olefins such as ethylene, propylene, butene, and hexene. Non-limiting examples of the olefin-based polymer include a propylene homopolymer, a copolymer of propylene and ethylene, a homopolymer of ethylene, a copolymer of ethylene with propylene or butene, and hexene. There are hard materials that are relatively rigid. Further, soft materials such as a copolymer elastomer of ethylene and propylene, a copolymer elastomer of ethylene and propylene with a diene such as ethylidene norbornene, and a copolymer elastomer of ethylene with propylene or butene, hexene and the like can be given. Further, a thermoplastic elastomer composed of a mixture of the above-mentioned hard material and soft material can also be used. In this case, the content of the hard material is 20 per elastomer.
% By weight or more, more preferably from 30 to 95% by weight, and particularly preferably from 35 to 90% by weight.

The current collector used in the present invention has a thickness of preferably 0.1 to 1.5 mm, more preferably 0.3 to 1.3.
mm, most preferably 0.5-1.2 mm.

(5) Fusing and integrating the current collecting plate and the insulating outer frame The fusing and integrating the conductive resin current collecting plate and the insulating outer frame is performed by insulating the current collecting plate made of the conductive resin with the insulating resin. By heating the conductive resin current collector plate and the insulating outer frame to a temperature equal to or higher than the softening temperature of the insulating outer frame in a state where the insulating outer frame is press-bonded, fusion and integration can be performed. 100-3
A fusion temperature of 00C is preferred, and a fusion temperature of 130-280C is more preferred. Heating can be performed by a method of heating the welded portion with far infrared rays, or by locally heating only the welded portion with an impulse sealer or the like.
Heating is preferably performed by locally irradiating energy such as ultrasonic waves to the fusion bonding portion.

The thickness of the insulating outer frame used in the present invention is preferably 0.1 to 1.5 mm, more preferably 0.4 to 1.5 mm.
1.3 mm, most preferably 0.6-1.2 mm.

(6) Fusing and integrating a current collector, a porous carbon electrode, and a liquid separating plate Further, the present invention provides a current collector made of a conductive resin, a porous carbon electrode, a positive electrode chamber and a negative electrode chamber. A battery characterized in that a positive electrode solution and an insulating separator having an inlet for introducing a negative electrode solution are fused and integrated. This insulating distribution plate is made of one or a mixture of two or more olefin polymers. Non-limiting examples of the olefin polymer that can be used here include those exemplified in the above section (4) as the olefin polymer that can be used for the outer frame of the current collector plate.

In order to fuse and integrate an insulating separator having an inlet for introducing a positive electrode solution and a negative electrode solution into a positive electrode chamber and a negative electrode chamber, an insulating outer frame, and a conductive resin current collector plate. Can be integrated by pressing each other at a softening point temperature or higher. For example, a conductive resin current collector plate and a porous carbon electrode fused and integrated are inserted into a mold, and the materials of the insulating outer frame and the liquid separating plate are integrated at once by injection molding. Can also be formed. In such a case, it is preferable to select an olefin polymer having the same composition for both the insulating outer frame and the liquid separating plate.

(7) Manifold A discharge port for discharging the positive electrode solution and the negative electrode solution from the positive electrode chamber and the negative electrode chamber is installed on the liquid separating plate so as to face the inlet, and a manifold for supplying an electrolytic solution is connected to the outlet. It is composed. Further, the present invention is a battery in which an inlet and an outlet for discharging the positive electrode solution and the negative electrode solution from the positive electrode chamber and the negative electrode chamber are formed of a plurality of slits and connected to a subsequent manifold.

(8) Ion Exchange Membrane (Diaphragm) As the ion exchange membrane that can be used in the redox battery of the present invention, it is preferable to use an ion exchange membrane made of an organic polymer. Either a cation exchange membrane or an ion exchange membrane can be used. Examples of the cation exchange membrane include a cation exchange membrane obtained by sulfonating a styrene divinylbenzene copolymer, and a cation exchange membrane in which a sulfonic acid group is introduced based on a copolymer of tetrafluoroethylene and perfluorosulfonylethoxyvinyl ether. A cation exchange membrane composed of a copolymer of tetrafluoroethylene and a perfluorovinyl ether having a carboxyl group in a side chain, a cation exchange membrane in which a sulfonic acid group is introduced based on an aromatic polysulfone copolymer, or the like can be used. . Examples of the anion exchange membrane include an anion exchange membrane obtained by introducing and aminating chloromethyl groups based on a styrene divinylbenzene copolymer, an anion exchange membrane obtained by quaternizing a vinylpyridine divinylbenzene copolymer, and an aromatic polysulfone. A chloromethyl group-introduced and aminated anion exchange membrane based on the copolymer can be used.

(9) Electrolyte solution The electrolyte solution that can be used for the electrode of the present invention is an aqueous solution of vanadium for both the positive electrode solution and the negative electrode solution, and the vanadium ion concentration is 0.5 to 8 mol / l, preferably 1.0-4.5 mol / l, most preferably 1.5-1.5 mol / l
3.5 mol / l. When the concentration of vanadium is
If it is less than 5 mol / l, the energy density of the battery will be low, and if it exceeds 8.0 mol / l, the viscosity of the electrolyte will increase, the resistance of the battery cell will increase, and the power efficiency will decrease. Further, as the electrolytic solution, an aqueous solution of vanadium in sulfuric acid is preferably used, and the concentration of sulfate in the electrolytic solution is preferably 0.5 to 9.0 mol / liter, more preferably 1.0 to 8.0 mol. / Liter, particularly preferably 1.5 to 6.0 mol / liter or less.

[0042]

The present invention will be specifically described below based on examples and comparative examples. Example 1 A sheet of a conductive resin composed of 30% by weight of carbon black and 70% by weight of a polyolefin resin composition (an ethylene / propylene random copolymer having an ethylene content of 4.5% by weight) was formed into a sheet having a thickness of 1 mm. This is width 1010
It was punched into a conductive resin current collector plate having a length of 420 mm and a width of 420 mm. As a porous carbon electrode, a bulk density of 0.35 g /
A cc cellulosic carbon fiber felt was used. As the insulating outer frame, a 1.2 mm thick molded from an olefin polymer composition comprising a thermoplastic elastomer composed of 40% by weight of polypropylene and 60% by weight of a crosslinked product of a copolymer elastomer of ethylene, propylene and ethylidene norbornene. Was used. The outer width is 1120 mm, the outer height is 720 mm, and the inner width is 1010.
mm and an inner diameter vertical width of 420 mm.

The conductive resin current collector, the porous carbon electrode, and the insulating outer frame were placed inside the upper and lower molds made of aluminum as shown in FIG. And further evacuated the interior. The mold was placed in an infrared heating furnace and heated to a temperature of 190 ° C. for 3 minutes.
After taking out the mold and cooling, the current collector plate made of conductive resin,
A structural component in which the porous carbon electrode and the insulating outer frame were integrated was obtained (see FIG. 1). A liquid separating plate made of a polypropylene resin was arranged on the obtained structural component, packing and an ion-exchange membrane were arranged outside the liquid separating plate to form a stack of 21 cells.

The liquid separating plate has four inlets for introducing the positive and negative electrode solutions into the positive and negative electrode chambers and four outlets for discharging the positive and negative electrode solutions from the positive and negative electrode chambers. ) And the inlet are four slits and a manifold (18 mm square) for supplying an electrolytic solution to the slits, and the slits have a width of 2.4.
mm, a depth of 1 mm, and a length of 14.5 mm (see FIG. 3), and the outlet is composed of four slits followed by a manifold.

The battery cell stack is assembled using the conductive resin current collector plate, the porous carbon electrode, the insulating outer frame and the separator plate thus manufactured, and the positive electrode solution and the negative electrode solution are combined. It is a sulfuric acid aqueous solution with a vanadium ion concentration of 2 mol / l, and the concentration of sulfate in the electrolyte is 4 mol / l.
A charge / discharge experiment was conducted in which a liter of electrolyte was introduced from the inlet of the battery, discharged from the outlet, charged to a battery cell voltage of 1.65 V, and discharged to a battery cell voltage of 1.16 V. The results are shown in Table 1. In addition, although the test which repeatedly bent the structural article obtained above was performed,
No change for 5 or more bends.

Example 2 A liquid separating plate made of polypropylene was fused and integrated to a conductive resin current collecting plate, a porous electrode, and an insulating outer frame in the same manner as in Example 1, and the obtained integrated product was obtained. A stack of battery cells was configured using the same, and a charge / discharge experiment was repeated in the same manner.
The results are shown in Table 1.

Example 3 In the process of forming a conductive resin current collector sheet into a sheet, the same procedure as in Example 1 was carried out except that the porous electrode was pressed and fused and integrated at 145 ° C., which was not yet solidified by cooling. A charge / discharge experiment was performed. The results are shown in Table 1.

Example 4 Fusion and integration and charge and discharge were performed in the same manner as in Example 1 except that the interface between the conductive resin current collector plate and the insulating outer frame was locally irradiated with ultrasonic waves to perform fusion and integration. An experiment was performed. The results are shown in Table 1.

Comparative Example 1 The procedure of Example 1 was repeated except that a carbon plate was used in place of the conductive resin current collector plate, and the carbon plate, the porous electrode, and the insulating outer frame were all used as independently separated parts. Similarly, a stack of battery cells was formed, and a charge / discharge experiment was repeated in the same manner. The results are shown in Table 1.

Comparative Example 2 A charge / discharge experiment was carried out by fusing and integrating in the same manner as in Example 1 except that a propylene homopolymer was used as the polyolefin resin. The results are shown in Table 1.

[0051]

[Table 1]

From the above results, the redox battery of the present invention has a simplified cell assembling process as compared with the battery of the comparative example, and has a low cell resistance, high power efficiency, and excellent strength. You can see that there is.

[0053]

The redox flow battery of the above embodiment has a simpler assembly process than the battery of the comparative example, has a low cell resistance, and has high power efficiency. Also, it has excellent impact resistance. Further, according to the present invention, there is provided a novel redox flow battery having a low cell resistance, high power efficiency, and excellent long-term charge / discharge cycle characteristics.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of a structural component of the present invention in which a conductive resin current collector, a porous carbon electrode, and an insulating outer frame are integrated.

FIG. 2 is a schematic explanatory view related to the molding of a structural component in which a conductive resin current collector, a porous carbon electrode, and an insulating outer frame are integrated according to the present invention.

FIG. 3 is a schematic explanatory view showing a manifold of the present invention.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Toshihiko Tanimoto 16 Towada, Kasu-gun, Kashima-gun, Ibaraki Prefecture V Battery Development Room, Kashima-Kita Co., Ltd. Kashimakita Joint Power Generation Co., Ltd. V Battery Development Room F-term (reference) 5H018 AA08 EE05 5H026 AA10 BB00 BB01 BB02 CC08 EE05 EE18 HH05 HH08 RR01

Claims (13)

[Claims] 1. A liquid circulation system in which a positive electrode solution and a negative electrode solution are passed through a positive electrode chamber and a negative electrode chamber provided with a liquid-permeable porous carbon electrode separated by a diaphragm and charged and discharged by performing an oxidation-reduction reaction. In the type battery, the porous carbon electrode is fused and integrated with a conductive resin current collector plate, in which case the conductive resin is
Polyolefin resin containing 10% to 50% by weight of carbon and a copolymer of at least two olefins
A redox battery, consisting essentially of 50% to 90% by weight. 2. The redox battery according to claim 1, wherein the copolymer is a random copolymer. 3. The redox battery according to claim 1, wherein the conductive resin current collector plate is fused and integrated with an insulating outer frame made of an olefin polymer. 4. The fusion-bonding of the conductive resin current collector plate, the insulating outer frame, and an insulating separator plate having inlets for introducing a positive electrode solution and a negative electrode solution into a positive electrode chamber and a negative electrode chamber. The redox battery according to claim 1, wherein the liquid separation plate is made of an olefin-based polymer. 5. The redox according to claim 1, wherein an inlet for introducing a positive electrode solution and a negative electrode solution into the positive electrode chamber and the negative electrode chamber comprises a plurality of slits, and a manifold for supplying an electrolyte is connected to the slits. battery. 6. The redox battery according to claim 1, wherein a discharge port for discharging the positive electrode solution and the negative electrode solution from the positive electrode chamber and the negative electrode chamber comprises a plurality of slits and is connected to a subsequent manifold. 7. The fusion bonding of the porous carbon electrode and the current collector plate is performed during the process of melt-forming the current collector plate so that the conductive resin constituting the current collector plate is not completely solidified. The redox battery according to claim 1, which is performed by pressing a porous carbon electrode at a temperature equal to or higher than a point. 8. The fusion bonding of the porous carbon electrode and the current collector plate is performed by pressure bonding at a temperature higher than a softening point at which a conductive resin constituting the current collector plate is not completely solidified. The redox battery according to claim 1. 9. The fusion bonding of the porous carbon electrode and the current collector plate is performed by heating the conductive resin current collector plate to a softening temperature or higher and then pressing the porous carbon electrode. The redox battery according to claim 1, which is performed. 10. The fusion bonding of the conductive resin current collector plate and the insulating outer frame is performed by locally irradiating ultrasonic energy to a fusion portion and heating the fusion portion. 2
A redox battery as described. 11. A fusion-bonding of the conductive resin current collector plate and the porous carbon electrode is inserted into a mold, and then a weight constituting the insulating outer frame and the liquid separating plate is formed. The redox battery according to claim 2, wherein the insulative outer frame and the liquid separating plate are integrally formed together with a porous carbon electrode by injection molding the united body. 12. The redox battery according to claim 1, wherein the concentration of vanadium ions in the positive electrode solution and the negative electrode solution is 0.5 to 8.0 mol / L. 13. The redox battery according to claim 1, wherein the cathode solution and the anode solution are aqueous solutions of vanadium in sulfuric acid, and the concentration of sulfate in the electrolyte is 0.5 to 9.0 mol / l.