JP2008293762A - Alkaline fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem wherein an alkaline fuel cell using hydrazine as a fuel can generate power at room temperature and can be downsized, but the manufacture of a diaphragm separating an electrolyte is complicated, and the manufacturing cost of the fuel cell must be increased because a noble metal such as palladium is used for a catalyst of a negative electrode (action electrode), and the field using it is limited to special applications. <P>SOLUTION: An ion exchange membrane manufacturable by a simple operation from aqueous emulsion is used for a diaphragm, an inexpensive and easily obtainable metal catalyst selected from nickel, cobalt and copper is supported on graphite to form a negative electrode, and this alkaline fuel cell using hydrazine or sodium boron hydride for a fuel is assembled. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to an alkaline fuel cell using hydrated hydrazine or sodium borohydride as a direct fuel.

Fuel cells that operate at high temperatures have been developed for medium- and large-scale power generation from the viewpoint of energy saving and fuel diversification. On the other hand, fuel cells that can operate at a temperature close to room temperature have been attracting attention and developed for relatively small output power sources, particularly portable power sources.
A number of fuel cells using methanol as fuel have been proposed as attempts at room temperature operation, but noble metals such as platinum, palladium and ruthenium are used as essential catalysts for the working electrode (cathode). These noble metals are expensive because their production areas are limited and their production volume is small, and this increases the cost of manufacturing fuel cells.
On the other hand, hydrazine derivatives are more active than hydrogen and have been developed as advantageous because they are less polarized in large current discharge. (See Non-Patent Document 1)
For example, Patent Document 1 proposes nickel, cobalt, iron, copper, palladium, platinum, or alloy Raney nickel and Raney cobalt as a catalyst for generating hydrogen from a hydrazine aqueous solution. A fuel cell has been proposed in which the generated hydrogen is temporarily used as a hydrogen storage alloy to be used as a fuel.
In Patent Document 2, a fuel cell is proposed in which a cathode is made of a hydrogen storage alloy, sodium borohydride is used as a hydrogen generation source, and hydrogen is generated using a water-soluble hydrogen generation catalyst.
However, none of the proposals directly uses hydrazine or sodium borohydride as fuel, and hydrogen generated once is absorbed and used by the hydrogen storage alloy, so that battery production is complicated. The working electrode (cathode) is the same as a fuel cell using hydrogen as a fuel, and a precious metal such as platinum or palladium is used as a catalyst, so that the manufacturing cost is high.
On the other hand, a fuel cell using hydrazine as a direct fuel without using a hydrogen storage alloy has been proposed.
For example, in Patent Document 3, an electrode obtained by sintering nickel powder is impregnated with nickel ions and copper ions and then reduced to form a nickel copper alloy, and further has a cathode (working electrode) supported by palladium as a catalyst. Fuel cell proposals have been made. And as a diaphragm of an anode (air electrode) and an electrolyte solution, a proposal has been made to make a porous and hydrophobic film using fine tetrafluoroethylene powder as a water repellent component.
In Patent Document 4, asbestos is used for the diaphragm, and platinum is used as a catalyst for the cathode (working electrode). As a catalyst other than platinum, Raney nickel alloy, which is a hydrogen generation catalyst disclosed in Patent Document 1, can be used which is coated on a nickel wire mesh, but details are not disclosed at all.
Patent Document 5 proposes a hydrazine fuel cell in which a fluorine-based sulfonic acid polymer (Nafion) is used as an electrolyte membrane and a noble metal such as platinum, ruthenium, palladium, iridium, or rhodium is used as a catalyst.
As described above, in the conventional alkaline fuel cell using hydrazine as a fuel, an expensive noble metal such as platinum or palladium is used as an essential component for the working electrode as a catalyst while using an active reducing substance called hydrazine. .
In addition, when a porous organic polymer film or asbestos is used for the diaphragm that separates the electrolyte from the air electrode, diffusion of fuel to the air electrode is inevitable. As a material for the diaphragm, an ion exchange membrane is considered to be suitable, but a Nafion membrane is expensive, and a conventional ion exchange membrane is complicated because an ion exchange group is fixedly introduced after shaping into a film. However, the production cost of the fuel cell is increased, and no proposal has been made for use in a fuel cell using hydrazine as a fuel.
Battery Handbook 3rd Edition February 20, 2001 Maruzen Pages 481 to 486 Japanese Patent JP2004-244251 US Patent USP 5,599,640 US Patent USP 4,001,040 US Patent USP 3,960,598 International publication number WOA12003056649 US Patent USP 4,020,239 Japanese Patent JP-A-2005-230648

A fuel cell that does not require expensive precious metals such as palladium, platinum, ruthenium, etc. as a catalyst, does not contain a carcinogenic substance such as asbestos, and has a diaphragm that can be easily adjusted with general-purpose materials, and is easy to manufacture Propose.

It is known that reducing compounds such as hydrazine and boron hydride are more active than hydrogen and perform a catalytic reduction reaction using an inexpensive metal as a catalyst without using a catalyst such as palladium or platinum.
If a general-purpose metal such as nickel, copper, or cobalt, which was considered as a hydrogen generation catalyst for sodium borohydride or hydrazine, is changed to an active metal on the electrode, it can receive electrons directly and requires a noble metal. Working electrode (cathode) can be made.
In addition, an ion exchange membrane that can be produced simply by applying an aqueous emulsion and drying at a temperature equal to or higher than the film forming temperature is simple and has a high degree of freedom in shape.
A fine conductive powder such as graphite powder is used, and the cathode catalyst or anode catalyst is supported, and a binder resin is added to form a paste. Each is applied to both sides of the ion exchange membrane and dried, and the cathode (working electrode) ) And anode (air electrode), a fuel cell membrane integrated with the electrode can be formed.
Since the reaction product of hydrated hydrazine is only nitrogen and water, the electrolyte solution is not contaminated, the operation is easily maintained, and the structure of the fuel cell can be simplified.
It is preferable to use an ion exchange membrane prepared from an aqueous emulsion. Although an ion exchange membrane in which a sulfonic acid group is introduced into a polystyrene film or a fluorine ion exchange membrane can be used, it is expensive, limited in availability, inexpensive and easy to manufacture.
The ion exchange group concentration of the aqueous emulsion to be used can be determined by conductometric titration.
A higher ion exchange group concentration is advantageous. However, in the case of an aqueous emulsion in which the ion exchange group concentration is increased to 3 meq / g or more by increasing the emulsion resin composition or the degree of crosslinking, it may be difficult to form a membrane. In that case, an aqueous emulsion having a high film-forming ability is mixed and adjusted so that the ion exchange group concentration is 0.1 meq / g to 3 meq / g with respect to the resin weight. And if it apply | coats to release paper etc. and it dries above film-forming temperature, the target ion exchange membrane can be adjusted easily.
The aqueous emulsion can be used alone or mixed, but more preferably, the ion exchange group concentration of the aqueous emulsion is adjusted to 0.3 meq / g to 1.5 meq / g.
In order to improve the mechanical stability of the membrane, it is preferable to use a reinforcing material. It is preferable to impregnate a spunbonded nonwoven fabric such as polypropylene with an emulsion and dry it at a temperature equal to or higher than the film forming temperature to obtain an ion exchange membrane.
The thickness of the exchange membrane is not limited, but 40 to 800 microns can be recommended in consideration of the mechanical and chemical stability of the membrane.
As a support material for the electrode, a metal plate, a metal net, a porous sintered metal, or conductive carbon can be used. As the conductive carbon, natural or artificial graphite (graphite), fine powder carbon black, furnace black, acetylene black, carbon fiber and the like can be recommended.
The working electrode (cathode) catalyst is selected from nickel, cobalt and copper and used.
The method of adjusting the working electrode is as follows. Adjustment by electroless plating 2. Adjustment by electrolytic plating Three methods of preparation from an alloy containing a catalytic metal are simple and can be recommended.
When performing electroless plating, the total amount of target metal ion in the electroless plating solution, for adjusting an electroless solution so as to be 0.1mg / cm ² ~20mg / cm ² to the electrode area.
Alternatively, electroless plating may be performed after adding a target metal salt to conductive carbon powder, adding a resin binder, and shaping the electrode into an electrode shape. Also in this case, target metal is better to adjust so as to be 0.1mg / cm ² ~20mg / cm ² to the electrode area. As the reducing agent, reducing agents used for electroless plating such as hydrated hydrazine, sodium borohydride, hypophosphorous acid, etc. can be used. However, the performance of the working electrode varies depending on the processing conditions. There is a need.
When adjusting the working electrode (cathode) by electroplating, the optimum supported concentration of the metal catalyst varies depending on the composition of the plating solution, electrolysis conditions, and the type of the target metal, but 0.1 mg / cm for the electrode. ^{2 ~20mg} / cm ² flow to produce an electric current that can be carrying. If the amount is too small, the output of the fuel cell becomes unsatisfactory, and the performance of the electrode is remarkably reduced. Even if the electrode is increased beyond the range, no improvement in output can be expected.
The electrode material that supports the metal by electrolytic plating or electroless plating may be made on a metal surface such as stainless steel, but if an electrode that uses fine powder graphite and supports the metal on carbon is used, the fuel The battery output is stable and preferable.
As a method of supporting nickel on conductive carbon other than the above-mentioned electrolysis or electroless plating, a fine powder Raney nickel alloy and conductive carbon such as graphite are mixed well, and then a water-based binder is added to form a paste. There is a method in which nickel metal is supported on the graphite surface by directly applying to an ion exchange membrane and drying, and then treating with alkaline water to remove aluminum in the Raney alloy. It is simple and highly reproducible in electrode performance, so it can be recommended.
As for the air electrode (cathode), a method is known in which a porous nickel sintered body, carbon powder, and carbon fiber are used as electrode materials, silver is supported as a catalyst, and a fluorine-based water repellent treatment is performed. ing. There is also a proposal of an oxygen electrode using porphyrin such as phthalocyanine (see Patent Document 7), and it is possible to make an air electrode without using a noble metal. By doing so, an inexpensive air electrode can be adjusted.
In the case of a sintered metal treated with a catalyst or a carbon cloth containing a catalyst, if it is costly, in order to further reduce the manufacturing cost, carbon powder carrying the catalyst is used, and a binder is added to form a paste. It is recommended to apply it directly to the ion exchange membrane, then dry it and use it as an air electrode. In this case, since water is generated at the air electrode (anode) with power generation, it is preferable to perform water repellent treatment in order to efficiently vaporize it. For this purpose, fluorine polymer fine powder may be used by mixing 5 to 30% by weight with respect to graphite.
The active fuel is preferably a highly reducing active compound, and hydrated hydrazine, carbohydrazide, semicarbazide, methyl hydrazine, sodium borohydride, potassium borohydride, lithium borohydride, etc. can be used. In view of easy availability of raw materials and easy handling, hydrated hydrazine and sodium borohydride can be preferably used.
The electrolytic solution is alkaline, and an aqueous solution of sodium hydroxide or potassium hydroxide can be suitably used. The alkali concentration is preferably as high as possible, but if it is too high, there is a risk of handling, so 0.5-3 mol / l is preferred.

Compared to conventional power generation methods, the fuel cell has less difference in power generation efficiency due to the difference in power generation scale, and can be miniaturized. According to the present invention, it is possible to provide an energy efficient power generation device that is easy to carry.

Hereinafter, the present invention will be described with reference to examples.

An aqueous emulsion having the composition shown in Table 1 was used to prepare an ion exchange membrane. Emulsion resins can be made with various physical properties by changing the composition of the monomer components, the emulsifier added, the reaction method, etc., so it is possible to design an exchange membrane that suits the purpose. Various methods for thinning the film are also conceivable. Examples of the creation of the exchange membrane are given below, but the present invention is not limited to this.

{Manufacture of ion exchange membrane 1}
8 parts of emulsion (1) and 2 parts of emulsion (4) were mixed, neutralized with caustic soda to pH 7, impregnated with 10 cm square polypropylene spunbond nonwoven fabric, placed on release paper, 60 ° C After drying for 8 hours in a drier kept at a low temperature, heat treatment was performed using a household iron at an intermediate temperature (150 ° C.) for 5 minutes to obtain an ion exchange membrane reinforced with spunbond. An ion exchange membrane (1) was obtained. The film thickness was 200 microns.
The ion exchange group concentration is 0.71 meq / g.
{Production of ion exchange membrane 2}
A thin spunbond nonwoven fabric made of 10 cm square polypropylene is impregnated with the emulsion (2), placed on a release paper, dried in a drier kept at 60 ° C. for 8 hours, and then heated at a medium temperature (150 The ion exchange membrane reinforced with spunbond was obtained by heat treatment at 5 ° C. for 5 minutes. The film thickness was 150 microns. An ion exchange membrane (2) was obtained. The ion exchange group concentration is 0.37 meq / g.
Emulsion 3 was used in the same operation, and an ion exchange membrane (3) having a membrane thickness of 250 microns was obtained. The ion exchange group concentration is 0.59 meq / g.

{Anode; Air electrode adjustment 1}
A 5 cm square carbon fiber cloth was dipped in a 5% silver nitrate aqueous solution made alkaline with a concentrated aqueous ammonia solution and then dried in a dryer at 105 ° C. Then, it was immersed in distilled water, washed, and dried again at 105 ° C. to prepare an anode carrying silver ions.
{Cathode; Working electrode adjustment 1}
2 g of a metal salt shown in Table 2 was dissolved in 50 ml of 1 M sodium sulfate aqueous solution, and 28% ammonia water was added to make it ammonia / alkaline to prepare an electrolyte solution. 60 mesh 15 mm x 60 mm stainless steel mesh (hereinafter abbreviated as SUS) or copper mesh is immersed in a 4 cm electrolyte solution from the bottom, and electrolytic plating is performed under the conditions shown in Table 2 so that the target metal is supported on the electrode surface. It was. After electrolytic plating, it was quickly washed with distilled water and stored in a 2% aqueous hydrazine solution. The plating anode was a carbon rod made of graphite and having a diameter of 8 mm and a length of 6 cm. The concentration of the supported metal is a calculated value assuming that the current efficiency is 100% and all the metal ions are metal and are fixed on the wire mesh.

{Assembly and evaluation of evaluation cell}
As the ion exchange membrane, a cation exchange membrane CMI-7000 manufactured by MEMBRANES INTERNATONAL INC. Was cut into 5 cm square and used. The membrane thickness is 430 microns and the ion exchange group concentration is 1.30 meq / g.
The fuel cell for evaluation shown in FIG. 1 was assembled.
10 ml of 1 molar aqueous caustic potash solution and 0.5 ml of 60% strength hydrated hydrazine were added to the cell, and the voltage and current generated were measured to evaluate the performance of the electrode.
As a control, an electrode carrying 1.0 mg / cm ² of palladium on a 60 mesh stainless steel net was made and compared. A comparison result using the palladium-treated electrode and the electrodes 1, 2 and 3 is shown in FIG.
Similarly, 10 ml of a 1 molar aqueous caustic potash solution and 0.1 g of sodium borohydride were added to the cell, the voltage and current to be generated were measured, the performance of the electrodes was similarly compared, and the comparison results are shown in FIG. .
When hydrated hydrazine was used as the fuel, the cobalt-carrying electrode showed little electromotive force compared to palladium, but copper and nickel showed an electromotive force equivalent to or higher than palladium.
When sodium borohydride was used as the fuel, cobalt and copper had a lower electromotive force than palladium, but nickel exhibited performance superior to palladium.

The fuel cell for evaluation shown in FIG. 1 was assembled in the same manner as in Example 2 using the ion exchange membrane (2). Using the electrode 4, 10 ml of a 1 molar aqueous caustic potash solution and 0.1 g of carbohydrazide were added to the cell, the voltage and current to be generated were measured, and the performance of the electrode was evaluated. For comparison, hydrated hydrazine and sodium borohydride were used.
The result is shown in FIG.

{Cathode; Working electrode adjustment 2}
100 parts of graphite (manufactured by SCI Co., Ltd., artificial graphite powder, SPG-10; hereinafter abbreviated as SPG-10), emulsion (1), 36 parts, emulsion (4), 9 parts are put in a mortar and kneaded well with a pestle. Add water to make a paste. 60 mesh 15 mm × 60 mm nickel mesh was applied from the end to 4 cm and dried at 120 ° C. 0.50 g of graphite could be fixed.
In an aqueous solution of 10% sodium sulfate, 2 g of the metal salt shown in Table 3 was dissolved, and an electrolytic plating solution made ammonia / alkaline with 28% aqueous ammonia (about 3 ml) was prepared. The target metal was supported on the graphite by electrolytic plating under the conditions shown in FIG. After electrolytic plating, it was quickly washed with distilled water and stored in a 2% aqueous hydrazine solution.
The composition of the electrolytic plating solution is not limited to the above-described embodiment, and may be a mixture of citric acid, EDTA, ammonium sulfate, sulfamate, and the like. The anode for plating was made of graphite and a carbon rod having a diameter of 8 mm and a length of 6 cm was used. However, any material may be used as long as it is an alternative.

The concentration of the supported metal is a calculated value when the current efficiency is 100% and the metal ion becomes a metal and can be fixed on the graphite.
The synthetic membrane (3) was cut into 5 cm square and attached to the same fuel cell as in Example 1.
10 ml of 1 molar aqueous caustic potash solution and 0.5 ml of hydrazine 60% strength were added to the cell, a graphite electrode was attached to the cell, the voltage and current generated were measured, and the performance of the electrode was evaluated. The results are shown in FIG. 4 as nickel electroplating and cobalt electroplating.

Take SPG-10 (graphite), 100 parts, emulsion (2), 20 parts, nickel sulfate hexahydrate, 10 parts in a mortar, knead well with a pestle, adjust by adding a small amount of water, and paste. 60 mesh 15 mm × 60 mm nickel wire mesh was applied from the end to 4 cm and dried at 120 ° C. The weight increase of the nickel wire mesh is 0.23 g, and the nickel ion that can be fixed on the graphite electrode is 0.74 mg / cm ² from the blending ratio.
0.5 g of sodium borohydride was dissolved in 20 ml of distilled water, warmed to 80 ° C., a graphite electrode was immersed for 60 minutes, a reduction reaction was carried, and nickel metal was supported on the graphite. It was quickly washed with distilled water and stored in a 2% aqueous hydrazine solution.
The exchange membrane (1) was cut into 5 cm square and attached to the same fuel cell as in Example 1. 10 ml of 1 molar aqueous caustic potash solution and 0.5 ml of hydrazine 60% strength were added to the cell, a graphite electrode was attached to the cell, the voltage and current generated were measured, and the performance of the electrode was evaluated. The results are shown as nickel electroless plating in FIG.
The concentration of nickel catalyst is 0.74 mg / cm ^{2 when} all nickel ions are converted to metal by the reduction operation of sodium borohydride and all are present on the graphite.

{Adjustment of anode graphite}
Put 400 ml of distilled water in a 1 liter beaker, add 10 g of silver nitrate, and dissolve by stirring. 100 g of SPG-10 (graphite fine powder) is added to the above silver nitrate aqueous solution, and 60 ml of 1N sodium hydroxide aqueous solution is added dropwise with stirring. Stirring is continued for 15 minutes after completion of the dropwise addition, filtered off and washed with 100 ml distilled water. Take the wet graphite in a 1 liter flask, add emulsion (2), 23.3 g, 70 ml of distilled water, attach to a rotary vacuum dryer (rotary evaporator), heat in a 40 ° C water bath, Moisture is evaporated in vacuum and dried as it is.
When dried, 20 g of tetrafluoroethylene polymer powder (average particle size 10 microns) was added and mixed well, passed through a pulverizer, passed through a 60 mesh screen, and passed through and used for the anode electrode. (Contains 4.64% as silver ion)
{Adjustment of cathode paste}
Add 2 g of Raney nickel alloy fine powder to 10 g of SPG-10 (graphite fine powder) and mix well in a mortar. Add 3.1 g of Emulsion (1) and 1.3 g of Emulsion (4), knead well, and add a suitable amount of distilled water to make a paste. (Raney alloy content in solids is 14.5%)
{Creation of integral membrane}
A cathode paste is uniformly applied to a size of 30 mm in diameter (area 7.07 cm ² ) at the center of a 5 cm square ion exchange membrane (1) and dried at 80 ° C. The weight of the cathode fixed from the increase in weight is 0.27 g, and the nickel content in the alloy is 50%, so the supported concentration of nickel is 2.77 mg / cm ² .
After drying, a small amount of emulsion (2) is applied to the center of the opposite surface within a diameter of 30 mm, and 300 mg of anode graphite powder is sprinkled to form a uniform shape. After drying with an oven at 80 ° C., heat treatment was performed for 5 minutes with a domestic iron at medium temperature (150 ° C.), and the cathode and anode graphite electrodes were fixed to the ion exchange membrane. A fuel cell shown in FIG. 6 was assembled using ion exchange membranes with graphite electrodes on both sides with a silver ion concentration of 1.97 mg / cm ² at the anode. The cathode cell indicated by 14 has a cylindrical shape with an inner diameter of 28 mm and a height of 3 cm. Hold both sides of the ion-exchange membrane with a 30-mesh stainless steel wire mesh, attach it to the cell 14, sandwich it with the air electrode retainer plate 15 with a 28 mm diameter opening in the center, and fix it so that the electrolyte does not leak. Fixed.
{Activation of catalyst}
When 10 ml of 2N caustic soda is added to the cathode cell shown at 14, gas generation occurs within a few minutes. Gas generation stops in about 15 minutes. After 30 minutes, the caustic soda aqueous solution in the cell was emptied, washed quickly with distilled water, and 10 ml of 1N caustic potassium aqueous solution containing 5.00% hydrated hydrazine was added.
{Evaluation of fuel cell}
Ten minutes later, when the small DC motor was connected, the motor rotated at 0.6V, 15mA.
Every day, 0.53 g of 60% hydrated hydrazine was added to the cell, and the motor continued to rotate at 0.6 to 0.65 V and 15 mA. However, since the caustic potash concentration gradually decreased with the addition of hydrazine, the electrolyte in the cell was replaced with 10 ml of a 1N caustic potash aqueous solution containing new 5.00% hydrated hydrazine once a week. During operation, the temperature of the cell was kept at 19 ° C. to 22 ° C.
The results are shown in FIG. 6 as current-voltage characteristics of hydrazine.
The DC motor used moved at 0.3V or higher and was able to operate at a constant 15mA up to 1.5V with no load. Since the amount of hydrazine remaining in the cell can be easily quantified by titration, quantification was performed, and hydrazine was decomposed according to the reaction shown in Chemical Formula 1, and current efficiency was calculated assuming that electrons flow.

As a result of the analysis, the consumption rate of hydrated hydrazine was 0.012 g for 1 hour. The amount of hydrated hydrazine consumed is 0.24 mmol, and the theoretical amount of electricity that can be extracted is 0.24 × 4 × 96500 ÷ 1000 = 92.64 coulombs. Since the amount of electricity per hour at 15 mA was 54 coulombs, the current efficiency was 58.3%.

A fuel cell was assembled in the same manner as in Example 4 except that the same cell as in Example 4 was used and the ion exchange membrane (3) was used. After treatment with caustic soda water, the working electrode was activated and the inside of the cell was quickly washed, 10 ml of 1N KOH was added, and 0.1 g of sodium borohydride was added to the solution. Dissolved immediately.
Ten minutes later, when a small motor was connected, the motor rotated at 0.7V, 15mA. The cell temperature was 15 ° C. After 24 hours, the voltage dropped to 0.45 V, 15 mA. When 0.1 g of sodium borohydride was replenished, the voltage returned to 0.7 v, 15 mA again and the motor continued to rotate.
According to the reaction shown in Chemical Formula 2, it was decomposed and an estimated current efficiency was calculated assuming that 8 electrons flow.

The molecular weight of sodium borohydride is 37.85, the consumed sodium borohydride is 2.64 mmol, and the current that can be theoretically taken out is 2.64 × 8 × 96500 ÷ 1000 = 2039 coulombs. Since the current for 24 hours at 15 mA was 1296 coulombs, the current efficiency was 63.6%.

It is sectional drawing of the fuel battery cell used for electrode evaluation. The cell is 4 cm long, 3 cm wide, and 1 cm wide, and has a rectangular opening of 3 cm long and 2 cm wide as a liquid contact part of the ion exchange membrane at the center. When the cell fixing collar is included, it is a 5 cm square. An ion exchange membrane (synthetic membrane) cut into 5 cm square can be sandwiched. FIG. 3 is a current-voltage characteristic diagram of a plating electrode using the fuel cell of FIG. 1 and using hydrated hydrazine. FIG. 2 is a current-voltage characteristic diagram of a plating electrode using the fuel cell of FIG. 1 and using sodium borohydride. FIG. 2 is a current-voltage characteristic diagram when the fuel cell of FIG. 1 is used, an electrode plated with nickel on a copper wire mesh is used, and the fuel is changed. FIG. 6 is a current-voltage characteristic diagram when a graphite electrode is used. It is sectional drawing of a fuel battery cell. It is made of PVC and has an inner diameter of 28 mm and a height of 3 cm. Current-voltage characteristic diagram using the fuel cell of FIG.

Explanation of symbols

1 Anode terminal
2 Stainless steel wire mesh
3 Anode carbon cloth (air electrode)
4 Ion exchange membrane
5 Cathode (working electrode)
6 Cathode terminal
7 Cathode cell
8 Ion exchange membrane support plate 9 Cathode terminal using stainless steel wire mesh
10 Anode terminal using stainless steel wire mesh
11 Ion exchange membrane
12 Graphite cathode
13 Graphite anode
14 Fuel cell
15 Exchange membrane retainer plate (PVC plate)

Claims (7)

Using a working electrode (cathode) in which one or more metals selected from copper, nickel and cobalt are formed on the surface of the electrode material using an ion exchange membrane as a diaphragm, hydrazine and its derivatives or boron hydride derivatives as fuel A fuel cell using an alkaline aqueous solution as an electrolyte. The fuel cell according to claim 1, wherein the ion exchange membrane is prepared from an aqueous emulsion. The fuel cell according to claim 1 or 2, wherein a working electrode carrying a catalyst metal by electroplating is used. The fuel cell according to claim 1, wherein a working electrode carrying a catalyst metal by electroless plating is used. The fuel cell according to claim 1 or 2, wherein a working electrode in which Raney nickel alloy powder is mixed with conductive powder, shaped into an electrode, treated with an alkali to remove aluminum, and metal nickel is supported is used. The fuel cell according to claim 1, 2, 3, 4, or 5, wherein an anode and a cathode are formed on both surfaces of the ion exchange membrane, respectively, and adjusted as an integral membrane. The fuel cell according to claim 1, 2, 3, 4, 5, or 6, wherein the fuel is hydrated hydrazine or sodium borohydride.