JP2003217642A - Direct alcohol fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell whose size and weight are securely reduced, having safety electromotive force and output property greater than a direct methanol fuel cell by using a specific electrode material for an anode with respect to a fuel cell of such a type as to directly feed isopropyl alcohol as a fuel to a fuel electrode. <P>SOLUTION: The miniaturized or microminiaturized fuel cell, having safety and electromotive force and output larger than a direct methanol fuel cell can be provided by using an isopropyl alcohol aqueous solution as the fuel and using a platinum - ruthenium alloy with a specific composition or an alloy material based on the alloy for the material of the anode. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell for directly supplying an alcohol fuel to an anode, and more specifically, it is characterized in that a fuel containing isopropyl alcohol (2-propanol) or ethanol as a main component is directly supplied to the anode. Further, the present invention relates to a direct alcohol fuel cell suitable for reduction in size and weight, which uses an anode material that effectively anodizes the fuel.

[0002]

2. Description of the Related Art Direct methanol fuel cell (DMFC)
Is a power generator that operates at a relatively low temperature (normal temperature to 120 ° C.). Since this fuel cell has been researched for a long time, it supplies methanol fuel directly to the anode, so that a reformer for taking out hydrogen from alcohol is not required, and the device itself can be miniaturized and inexpensive, as well as the entire device. The driving means can also be simplified. Although the direct methanol fuel cell has many advantages as described above, it has a drawback that the anodic oxidation reaction of methanol has a large overvoltage. In an oxygen-hydrogen fuel cell that uses hydrogen as a fuel, the oxidation rate of hydrogen is high, and the oxygen reduction at the air electrode (oxygen electrode) is rate-determining, but in the direct methanol fuel cell, methanol oxidation is far more likely than oxygen reduction. It became the rate-control, and I could not avoid avoiding the output reduction. Further, the toxicity of methanol not only harms the health of the human body but also threatens the life. Furthermore, in a direct methanol fuel cell, it is known that formic acid and formaldehyde are produced as reaction intermediates for methanol oxidation, and both have been reported to be toxic.

On the other hand, the liquid fuel is expected to have a large amount of safety as a combustible substance and is easily miniaturized as compared with the case where hydrogen gas is used as a fuel. From such a point of view, a fuel cell using dimethyl ether instead of methanol fuel has been proposed, but at present, output characteristics higher than those using methanol are not obtained. For this reason, it has been desired to develop a safe fuel cell that has output characteristics superior to those of the direct methanol fuel cell even though the fuel cell directly supplies the liquid fuel to the anode.

[0004]

The electrode reaction of a fuel cell consists of an anode reaction and a cathode reaction. Since the cathode reaction is usually oxygen reduction and cannot be avoided, the anode reaction is required to be a faster reaction (higher reaction rate). That is, it is desired that the anode reaction does not rate-control the whole. When hydrogen is used as a fuel, this requirement is satisfied, but as described above, the requirement for handling a hydrogen fuel cell is complicated, and it is suitable for personal use for the purpose of power supply for small power supplies, especially portable devices. Is not suitable for. Liquid fuel is the most promising alternative, and methanol is the first candidate. However, when methanol is used alone in addition to being mixed with water, the overvoltage of anodic oxidation is large and the current value that can be taken out is lower than hydrogen. Other than this, dimethyl ether is listed as a promising candidate, but in reality, it does not actually exhibit anodic oxidation characteristics superior to those of methanol. The reason why the oxidation of methanol is rate-determined is that carbon monoxide generated in the process of undergoing electrode oxidation is adsorbed on the electrode and poisons the electrode catalyst such as platinum. In order to solve this, development of various electrocatalysts has been studied. Above all, Pt-
It is known that when Ru alloy is used, CO poisoning is reduced, but in this case as well, the fuel electrode reaction is still rate-controlling as compared with oxygen reduction, and liquid fuel oxidation is performed while using liquid fuel. There has been a long-awaited development of a technique for reducing the reaction overvoltage and increasing the electromotive force and output current density of the fuel cell.

As described above, the fuel cell of the type that directly supplies the liquid fuel to the anode is extremely useful as a small and ultra-small power source for portable devices and the like. In view of such requirements, in the present invention, the electromotive force and the output which are higher than those of the direct methanol fuel cell are obtained through the technique of reducing the overvoltage of the reaction and increasing the current density as compared with methanol while using the liquid fuel. An object of the present invention is to provide a fuel cell having the same.

[0006]

Means for Solving the Problems As a result of intensive studies conducted by the present inventors in order to achieve the above object, surprisingly, when isopropyl alcohol (2-propanol) was used as a fuel, high electromotive force and high output were obtained. It was found that a fuel cell having The present inventors have also found that by using ethanol as a fuel and supplying this to an anode heated to a predetermined temperature, a fuel cell having high electromotive force and high output can be obtained.

The present invention has been made on the basis of the above findings, and in a fuel cell comprising at least an anode, a cathode, a portion for accommodating an electrolyte and a liquid fuel interposed therebetween, and a casing for accommodating these, The object is achieved by providing a direct alcohol fuel cell in which a fuel containing isopropyl alcohol as a main component is directly supplied to the anode.

Further, the present invention provides a fuel cell comprising at least an anode, a cathode, an electrolyte interposed between them, a portion for containing a liquid fuel, a heating means for the anode, and a casing for containing them, wherein By providing a fuel containing ethanol as a main component directly to the anode heated to 40 ° C. to 100 ° C. by a means, a direct alcohol fuel cell is provided. It has been achieved.

Further, according to the present invention, in a fuel cell having at least an anode, a cathode and an electrolyte interposed between the anode and the cathode, a fuel containing ethanol as a main component is supplied to the anode at a temperature of 40 ° C. to 100 ° C. The above object is achieved by providing a power generation method characterized in that the power is directly supplied under a heated state.

In this specification, "direct supply" means
It means supplying alcohol to the fuel cell as it is without reforming alcohol into hydrogen gas or other gas.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described based on its preferred embodiments with reference to the drawings. FIG. 1 is a conceptual diagram showing a single cell structure of a direct alcohol fuel cell according to the present invention, which has an ion exchange membrane 2, a cathode 3 and an anode 4 sandwiching the ion exchange membrane 2 in housings 1a and 1b. An oxidant flow path 5 and a liquid fuel storage portion 6 are provided outside the.

The ion exchange membrane 2 may be of either anion or cation ion conduction type, but a proton conduction type is preferably used. As the ion exchange membrane 2, all known materials including polymer membranes typified by perfluoroalkyl sulfonic acid polymers can be used.

The cathode 3 and the anode 4 are often porous carbon paper coated with a predetermined catalyst. An electrolyte membrane 2 is provided between the cathode 3 and the anode 4.
Are sandwiched by interposing them, or the three members are joined together by hot pressing, cast film formation, or the like to form a membrane-electrode structure (Membrane Electrode Assembly). If necessary, a water repellent typified by polytetrafluoroethylene can be added to or laminated on the porous carbon paper.

In many cases, the anode 4 is constituted by thoroughly mixing carbon carrying platinum or a platinum-based alloy with an ion conductive material and then bringing the carbon into contact with the ion exchange membrane 2. A preferable result is obtained when the ion conductive material is the same material as the ion exchange membrane 2. As a method of bringing the anode 4 into contact with the ion exchange membrane 2, hot pressing,
Known methods including cast film formation can be used.
In addition to carbon supporting platinum or a platinum-based alloy, a known material such as a noble metal or a material supporting them (electrode catalyst), an organometallic complex or a material obtained by firing the same can be used as the anode 4. A noble metal or a noble metal thin film or a laminate thereof as disclosed in US Pat. No. 5,759,712 can also be used as the anode 4. Of these materials, platinum or platinum-based alloys give good results.

As the platinum-based alloy, an alloy of platinum and one or more elements selected from the group consisting of ruthenium, iridium, osmium, iron, nickel, gold, cobalt, palladium, tungsten, molybdenum and tin. Is preferable because a fuel cell having high electromotive force and high output can be obtained. Especially when a platinum ruthenium alloy is used, extremely good electromotive force and output can be obtained. From this viewpoint, the element ratio of platinum to ruthenium in the platinum-ruthenium alloy (the former: the latter) is 65:35 to 1
It is preferably 0:90, particularly 60:40 to 20:80.

In many cases, the cathode 3 is also formed by mixing platinum-carrying carbon with an ion-conducting material well and then bringing the carbon into contact with the ion-exchange membrane 2. A preferable result is obtained when the ion conductive material is the same material as the ion exchange membrane 2. As a method of bringing the cathode 3 into contact with the ion exchange membrane 2, known methods such as hot pressing and cast membrane formation can be used. In addition to platinum-carrying carbon, as the cathode 3, a known material such as a noble metal or one carrying them (electrode catalyst), an organometallic complex or one obtained by firing it can be used.

On the cathode 3 side, an oxidant introducing hole (not shown) for introducing an oxidant (in most cases, air) upwards.
On the other hand, an oxidant discharge hole (not shown) for discharging unreacted air and products (often water) is provided below. In this case, forced intake and / or forced exhaust means may be attached. Moreover, you may provide the natural convection hole of air in the housing | casing 1a.

On the outside of the anode 4, a liquid fuel storage section 6 is provided.
Is provided. The liquid fuel storage portion 6 may be a portion for storing alcohol fuel, or may be a flow passage with an external fuel storage portion (not shown). At this time, the fuel is agitated by natural convection and / or forced convection. When forced convection is required, forced convection means may be attached.

The inventors of the present invention have found that good fuel cell electromotive force and output can be obtained when the fuel directly supplied to the anode 4 contains isopropyl alcohol as a main component. It was also found that when the fuel was a mixture of isopropyl alcohol and water, crossover was effectively prevented, and more favorable cell electromotive force and output were obtained. The fuel cell having high output performance and high electromotive force has a molar ratio of propyl alcohol and water (the former: the latter) of 1:60 to 1: 0.1, particularly 1: 7 to 1: 0.5. Is preferred from the standpoint of obtaining Further, even when the fuel contains a mixture of isopropyl alcohol and methanol as a main component, good cell electromotive force and output can be obtained.
In this case, the molar ratio of isopropyl alcohol and methanol (the former: the latter) is 10: 0.5 to 1: 9, and particularly 9: 1 to 7: 3. It is preferable because it can be obtained.

Anode 4 heated to a predetermined temperature using ethanol as a fuel instead of isopropyl alcohol.
It was found by the study of the present inventors that a fuel cell having a high electromotive force and a high output can be obtained by directly supplying a fuel containing ethanol as a main component. It has been considered that ethanol has an extremely slow electrode reaction rate as compared with methanol. However, the present inventors have found that by raising the temperature of the anode to a temperature within a predetermined range, a reaction rate comparable to that of methanol electrode oxidation, that is, a high current density can be obtained. The electrode reaction of ethanol is further promoted by mixing water with ethanol, controlling the mixing ratio thereof, and optimizing the anode electrode material.

The anode 4 is 40 ° C. to 100 ° C., especially 4
It is preferable to directly supply ethanol under the condition of being heated from 5 ° C to 90 ° C because a fuel cell having higher electromotive force and higher output can be obtained. When ethanol is used as the fuel, it is necessary to additionally provide a heating means (not shown) for the anode 4 in the housing. As this heating means, for example, known heating means such as resistance heating element, PTC heating element, infrared ray, high frequency wave, and Bertier element can be used. The heating means may be arranged at any part capable of heating the anode 4,
It is desirable to prevent contact between the anode 4 and the fuel as much as possible. For example, the heating means may be arranged in the liquid fuel storage portion 6, or the entire housing may be heated. It is necessary to heat the anode 4 by the heating means mainly at the start of operation of the fuel cell. In steady operation, the anode 4 is heated by self-heating caused by the reaction,
It is not necessary to heat the anode 4 by heating means.

When ethanol is used as the fuel, ethanol may be used alone, but from the viewpoint of promoting the electrode reaction of ethanol, preventing crossover, etc., ethanol is the main component and other components are added. Is preferably used as fuel. For example, a fuel containing ethanol and water can be used. The molar ratio of ethanol to water (the former: the latter) is preferably 1:60 to 1: 2, and particularly preferably 1:10 to 1: 3 from the viewpoint of obtaining a fuel cell with high electromotive force and high output. . For the same reason, it is preferable to use a fuel containing ethanol and methanol and to set the molar ratio of ethanol and methanol (the former: the latter) to 1: 9 to 9: 1, particularly 3: 7 to 7: 3. preferable.

It is believed that acetic acid, acetaldehyde, carbon dioxide and the like are produced when the electrode oxidation of ethanol alone or with water is performed. Since these substances have a low environmental load, it is advantageous to use ethanol as a fuel also from this point. On the other hand, it is known that formic acid, formaldehyde, and the like are generated when the electrode oxidation of methanol alone or with water is performed. All of these substances adversely affect the living body. Since it is virtually impossible for methanol to undergo complete six-electron oxidation to become carbon dioxide alone, the use of methanol as a fuel inevitably causes some environmental load.

The conceptual diagram of the direct alcohol fuel cell shown in FIG. 1 shows only a single cell, but in the present invention, this single cell may be used as it is, or a plurality of cells may be connected in series and / or. Alternatively, they can be connected in parallel to form a mounted fuel cell. As a method of connecting cells, a conventional connection method using a bipolar plate may be adopted.
The flat connection method described in 000 Fuel Cell Seminar Abstracts ", pages 791 to 812 may be adopted. Of course, it is also useful to adopt other known connection methods.

FIG. 2 is a schematic view showing another embodiment of the direct alcohol fuel cell of the present invention. The fuel cell shown in FIG. 2 has the shape of a flat rectangular parallelepiped with a little thickness. In the fuel cell, a fuel supply path 6 that divides the fuel cell into upper and lower
Are formed. Further, the fuel cell has a storage portion for the liquid fuel which is composed of a cylindrical container 7. Container 7
Is removable from the fuel cell. A small hole 7a is formed on the side surface of the container 7. The fuel contained in the container 7 is supplied through the small holes 7a. The small hole 7a is sealed by a predetermined sealing means (not shown) before the container 7 is mounted in the housing, and the fuel can be hermetically contained in the container 7. The small hole 7a is formed at a position where the small hole 7a communicates with the above-described fuel supply passage 6 when the container 7 is mounted in the fuel cell.

The fuel cell of this embodiment has two or more cells. More specifically, the first cell group including four cells is arranged above the fuel supply path 6. On the other hand, a second cell group including four cells is also arranged below the fuel supply passage 6. Each of the cells is composed of an anode 4, a cathode 3 and an electrolyte membrane 2 arranged between them, and is independent of each other. The cells in each cell group are arranged in a plane and are connected in series. The cells of the first cell group and the cells of the second cell group are arranged so that their anodes 4 face each other with the fuel supply passage 6 interposed therebetween. Along with this, the cells of the first cell group and the cells of the second cell group are arranged such that their cathodes 3 face outward. By arranging the cells in this way, the fuel cell can be easily downsized, and the fuel cell is suitable as a small power source, particularly as a power source for portable devices.
Further, since the container 7 containing the fuel is detachable, the fuel can be easily replenished, which also makes the fuel cell of the present invention suitable as a power source for portable equipment.
When using the above-mentioned ethanol as fuel,
It is necessary to additionally install a heating means for the anode 4 in the housing.

The fuel may be supplied from the container 7 to the fuel supply passage 6 in the liquid state or in the gas state. In any case, from the viewpoint of smooth fuel supply, it is composed of, for example, a porous body obtained by sintering SiO ₂ or Al ₂ O _3, etc., a polymer fiber, a polymer porous membrane, etc. It is preferable. When polymer fibers or polymer porous membranes are used, it is necessary that they do not deform even if they are exposed to fuel.

In FIG. 2, it is desirable to dispose a member having a fuel shut-off function between cells that are laterally adjacent to each other in order to prevent the fuel from reaching the cathode 3 (a kind of crossover). (Not shown). For example, polymeric materials typified by polyethylene and polypropylene,
It is possible to block the fuel from reaching the cathode 3 by filling the space between adjacent cells with an inorganic oxide such as glass and aluminum oxide.

The cathodes 3 in the cells of each cell group face outward as described above. That is, the cathode 3 faces the housing. A space is provided between the cathode 3 and the housing. Further, the housing is provided with a vent hole (not shown) for communicating the space with the outside. Therefore, cathode 3
Air circulates in the space between the housing and the housing by natural convection. As a result, oxygen is supplied to the cathode 3. When it is desired to control the supply of air to the cathode 3, a forced convection means such as a fan may be attached to a predetermined portion of the housing.

The fuel contained in the container 7 is consumed by the oxidation reaction at the anode 4. In this case, depending on the type of fuel, the oxidation reaction may be hindered by the reaction intermediate and / or the reaction product. However, in the present embodiment, these substances can be removed from the reaction system by a simple operation of replacing the container 7. Therefore, power generation can be continued easily. In this case, since the reaction intermediate and / or the reaction product is contained in the container 7,
There is also an advantage that the environmental load can be reduced by collecting the entire container 7.

According to the fuel cell of this embodiment, it is easy to reduce the size as described above. Therefore, the fuel cell of the present embodiment can have a small volume of 100 cm ³ or less, particularly 20 cm ³ or less. The smaller this volume is, the more preferable, but the minimum volume that can be reached at present is about 10 cm ³ .

The present invention is not limited to the above embodiment. For example, the above-described embodiments shown in FIGS. 1 and 2 are merely examples for explaining the present invention, and it is perfectly possible to use a known method other than the illustrated method for the arrangement, arrangement, connection, etc. of each cell. There is no.

When isopropyl alcohol is used as the fuel, high electromotive force and high output can be obtained without heating the anode, but power generation can be performed while the anode is heated.

[0034]

The present invention will be described in detail with reference to examples.
However, it is needless to say that the present invention is not limited to these examples, since the examples are for explaining the present invention in detail.

(Example 1 and Comparative Examples 1 to 3) Diameter 6 mm
A gold wire of 0.2 mm was welded to the gold foil of No. 2 using a welding machine to form a lead portion. A platinum layer having a thickness of about 0.1 μm was provided on both surfaces of this gold foil portion by a sputtering film forming method. Isopropyl alcohol (Example 1), ethanol (Comparative Example 1), methanol (Comparative Example 2), 1-propanol (Comparative Example 3), so that the amount of 0.5 mol / liter was obtained in a 1N aqueous solution of perchloric acid.
Was added to make a test solution. Using the gold electrode provided with the platinum layer as a working electrode, a platinum wire as a counter electrode, and a standard hydrogen electrode as a reference electrode, these electrodes were immersed in each test liquid, and an electrochemical measurement was performed at room temperature. . The results are shown in Fig. 3. From the current-potential curve (cyclic voltammogram) of FIG. 3, isopropyl alcohol (Example 1) was found to be more active than methanol (Comparative Example 2), which was considered to be the most active alcohol.
It can be seen that in the case of, the absolute value of the current is larger, and the potential at which the current begins to flow is in the base direction, which is higher than that of methanol as fuel. In addition, ethanol (Comparative Example 1) and 1-propanol (Comparative Example 3) are shown in FIG.
From the results, it is clear that, in comparison between the absolute value of the current and the potential at which the current starts to flow, it does not exhibit a characteristic exceeding that of methanol.

(Example 2 and Comparative Examples 4 to 6) Instead of the electrodes used in Example 1 and Comparative Examples 1 to 3, platinum ruthenium alloy was formed on a gold foil, and the element ratio of both metals was 5: 5. The same measurement as in Example 1 and Comparative Examples 1 to 3 was performed except that the electrode provided by the sputtering method was used. The results are shown in Fig. 4. The order of electrode oxidation of each alcohol is the same as in the case of the platinum electrode (see FIG. 3), but especially in the case of isopropyl alcohol (Example 2) and methanol (Comparative Example 5), the platinum ruthenium alloy It was found that the absolute value of the electric current was large and the electric potential at which the electric current started to flow was shifted to the base, and it is clear that this has a beneficial effect on the electrode oxidation of alcohol.

(Examples 3 and 4 and Comparative Examples 7 to 9) Each alcohol shown in Table 1 was adjusted to 0.5 mol / liter with respect to pure water, and a commercially available fuel cell (H-TEC) was used.
It was put into the fuel electrode of the model PEM Power 1-DMFC manufactured by the same company. The cathode side of the fuel cell supplies oxygen by natural convection of air. A platinum-ruthenium alloy in which the element ratio of platinum and ruthenium is 1: 1 is used for the anode. Open circuit voltage (electromotive force) of the fuel cell at room temperature when using each fuel
Table 1 shows the maximum output (current x voltage) when the current is taken out.

[0038]

[Table 1]

As described above, the direct alcohol fuel cell using isopropyl alcohol or a mixed alcohol of isopropyl alcohol and methanol is a fuel cell (DM) in which methanol is the best conventional liquid fuel.
It can be seen that FC) is exceeded by the combined characteristics of circuit voltage and maximum output. Further, from the above results, it was found that platinum and platinum ruthenium alloy are suitable as the anode material.

(Examples 5 and 6 and Comparative Examples 10 and 1)
1) Using the electrodes and test liquids used in Example 1 and Comparative Examples 1 to 3, the anode was heated to the temperatures shown in Table 2 to measure current-potential curves similar to those in Example 1 and Comparative Examples 3 to 3. I went. The measurement results are shown in Table 2.

[0041]

[Table 2]

As is clear from the comparison between Example 6 and Comparative Example 10 in Table 2, at high temperatures (40 ° C. or higher), ethanol and methanol have almost the same current density values. . Therefore, from the viewpoint of the safety of substances generated by the anode electrode reaction, it is understood that ethanol is more advantageous than methanol when operating the fuel cell at high temperature.

(Examples 7 and 8 and Comparative Examples 12 and 1)
3) Using the electrodes and test liquids used in Example 2 and Comparative Examples 4 to 6, the anode was heated to the temperature shown in Table 3 to obtain a current-potential curve similar to that of Example 2 and Comparative Examples 4 to 6. The measurement was performed. The measurement results are shown in Table 3.

[0044]

[Table 3]

(Example 9 and Comparative Examples 14 and 15) In Example 3 and Comparative Examples 7 and 8, operation was performed at room temperature for 24 hours at maximum power density, and the aqueous solution of the fuel electrode was analyzed by gas chromatography. As a result, when isopropyl alcohol (Example 9) was used as the fuel, acetone was detected as an electrolytic product together with isopropyl alcohol. In the case of methanol (Comparative Example 14), formic acid, formaldehyde and methyl formate were detected as products. In the case of ethanol (Comparative Example 15), acetic acid was detected.

(Examples 10 and 11 and Comparative Examples 16 and 17) Similar to Example 3 and Comparative Examples 7 to 9 except that the anode was heated to the temperature shown in Table 4 in Example 3 and Comparative Examples 7 to 9. Various current-potential curves were measured. The measurement results are shown in Table 4.

[0047]

[Table 4]

(Examples 12 and 13 and Comparative Examples 18 and 19) In Example 2 and Comparative Examples 4 to 6, the composition (element ratio) of the platinum ruthenium alloy was changed as shown in Table 5,
Moreover, the current-potential curve was measured in the same manner as in Example 2 and Comparative Examples 4 to 6 except that the anode was heated to 50 ° C.
The measurement results are shown in Table 5.

[0049]

[Table 5]

(Examples 14 and 15 and Comparative Examples 20 and 21) In Example 2 and Comparative Examples 4 to 6, the composition (element ratio) of the platinum ruthenium alloy was changed as shown in Table 6,
Moreover, the current-potential curve was measured in the same manner as in Example 2 and Comparative Examples 4 to 6 except that the anode was heated to 100 ° C. The measurement results are shown in Table 6.

[0051]

[Table 6]

[0052]

According to the direct alcohol fuel cell of the present invention, it is possible to obtain electromotive force and output characteristics superior to those of the direct methanol fuel cell. In addition, the toxicity of the effluent produced as a result of the oxidation reaction is low and the environmental load is small.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing the configuration of an embodiment of a direct alcohol fuel cell of the present invention.

FIG. 2 is a schematic diagram showing the configuration of another embodiment of a direct alcohol fuel cell of the present invention.

FIG. 3 shows cyclic voltammograms of Example 1 of the present invention and Comparative Examples 1 to 3.

FIG. 4 shows cyclic voltammograms of Example 2 of the present invention and Comparative Examples 4-6.

[Explanation of symbols]

1a. Case 1b. Case 2. Ion exchange membrane 3. Cathode 4. anode 5. Oxidant channel 6. Liquid fuel storage 7. Fuel supply path

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiromasa Sugii             64-7 Sakai Sakaihara, Nakoso Town, Iwaki City, Fukushima Prefecture F-term (reference) 5H018 AA07 AS02 BB07 CC01 DD05                       EE03 EE05 EE10 EE18 EE19                       HH08                 5H026 AA08 CC03 EE08 HH02 HH08                 5H027 AA08 BA13 KK46 MM08

Claims (10)

[Claims] 1. A fuel cell comprising at least an anode, a cathode, a portion for accommodating an electrolyte and a liquid fuel interposed therebetween, and a casing for accommodating the electrolyte, wherein the fuel containing isopropyl alcohol as a main component is the anode. A direct alcohol fuel cell, which is characterized in that it is directly supplied to the fuel cell. 2. The direct alcohol fuel cell according to claim 1, wherein the fuel contains isopropyl alcohol and water. 3. The direct alcohol fuel cell according to claim 1, wherein the anode comprises platinum or a platinum-based alloy as an active ingredient. 4. The direct alcohol fuel cell according to claim 3, wherein the anode comprises a platinum ruthenium alloy as an active ingredient. 5. The container for accommodating the liquid fuel comprises a container attachable to and detachable from the housing.
4. The direct alcohol fuel cell according to any one of 4 to 4. 6. The direct alcohol fuel cell according to claim 1, wherein the housing has a volume of 100 cm ³ or less. 7. The fuel cell further comprises a supply passage for supplying the fuel contained in a portion containing the liquid fuel to the anode, and has two or more cells. 7. The direct alcohol fuel cell according to claim 1, wherein the anodes are arranged so as to face each other across the supply passage, and the cathodes in each cell are arranged so as to face outward. . 8. A fuel cell comprising at least an anode, a cathode, an electrolyte interposed between them, a portion for containing a liquid fuel, a heating means for the anode, and a housing for accommodating the anode, a cathode, and
A direct alcohol fuel cell characterized in that a fuel containing ethanol as a main component is directly supplied to the anode heated to 0 to 100 ° C. 9. The direct alcohol fuel cell according to claim 8, wherein the anode comprises a platinum ruthenium alloy as an active ingredient. 10. A fuel cell comprising at least an anode, a cathode and an electrolyte interposed therebetween, a fuel containing ethanol as a main component, the anode being heated from 40 ° C. to 100 ° C. A power generation method characterized in that the power is directly supplied under the condition.