JP2006164832A - Fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell which can improve output characteristics by preventing a carbon dioxide etc. produced as by-products from interfering with the continuous diffusion supply of fuel. <P>SOLUTION: A fuel electrode 12 and an oxygen electrode 13 are arranged so as to face each other via an electrolyte film 11. The angle that the perpendicular line perpendicular to the surface of the fuel electrode 12 makes with a gravity direction is within the range of not lower than 30 to 90°C. When a fuel chamber 14 adjacent to the fuel electrode 12 is located on the gravity direction side with respect to the fuel electrode 12, high output characteristics are obtained. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel cell in which a fuel electrode and an oxygen electrode are arranged to face each other through an electrolyte membrane.

  In recent years, with the reduction in size and weight of portable electronic devices, further improvement in capacity has been demanded. In nickel hydride secondary batteries and lithium ion secondary batteries that are widely used at present, the energy density is approaching the theoretical limit, and therefore, it is strongly desired to put into practical use a new power generation device that exhibits a high energy density.

  As such a new power generation device, a polymer electrolyte fuel cell using hydrogen ions has attracted attention. Polymer electrolyte fuel cells are classified into several types according to the supply system of hydrogen ions. Among them, in recent years, research and development on direct methanol fuel cells that directly oxidize methanol have been energetically studied. This is because it is relatively easy to handle both fuel handling and high energy density.

On the other hand, the conventional direct methanol fuel cell has a problem that the output characteristics tend to be unstable. Therefore, various devices relating to the constituent members or the internal configuration of the fuel cell have been proposed as methods for stabilizing the output characteristics. For example, Patent Document 1 discloses a device for sealing for preventing leakage of fuel from a fuel tank. Patent Document 2 discloses a device such as a method of connecting single cells in series and measures against fuel leakage. Furthermore, Patent Document 3 discloses a system that enables fuel concentration adjustment in a fuel cell.
JP-A-2001-283888 JP-A-2002-280016 Japanese Patent Laid-Open No. 2003-346836

  By the way, in order to stabilize the output characteristics of the fuel cell, it is considered important to increase the efficiency of the catalytic reaction that controls the power generation reaction. In particular, it is indispensable that the fuel material is continuously diffused and supplied to the catalyst surface of the fuel electrode. However, in a direct methanol fuel cell, a reaction in which carbon dioxide is by-produced also proceeds in parallel with a reaction in which liquid fuel is converted to hydrogen ions on the catalyst surface, and this carbon dioxide is a contact interface between the catalyst and liquid fuel. As a result, there is a problem that the continuous supply of fuel is hindered.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a fuel cell capable of suppressing the inhibition of continuous diffusion supply of fuel due to by-produced carbon dioxide and the like and improving the output characteristics. There is to do.

  The fuel cell according to the present invention has a power generation unit in which a fuel electrode and an oxygen electrode are arranged to face each other through an electrolyte membrane, and an angle formed between an orthogonal line perpendicular to the surface of the fuel electrode and the direction of gravity is 30 °. It is within the range of 90 ° or less.

  According to the fuel cell of the present invention, the angle formed by the orthogonal line orthogonal to the surface of the fuel electrode and the direction of gravity is within the range of 30 ° or more and 90 ° or less. Inhibition of continuous diffusion and supply of fuel due to fuel can be suppressed, and output characteristics can be improved.

  Hereinafter, embodiments of the present invention will be described in detail.

(First embodiment)
FIG. 1 shows the configuration of a fuel cell according to an embodiment of the present invention. The fuel cell includes a power generation unit 10 capable of generating energy and a support member 20 that supports the power generation unit 10 as necessary.

  FIG. 2 shows a cross-sectional structure taken along line II of the fuel cell shown in FIG. The power generation unit 10 includes a fuel electrode 12 and an oxygen electrode 13 that are disposed to face each other with an electrolyte membrane 11 interposed therebetween. A fuel chamber 14 is provided adjacent to the fuel electrode 12, and an oxygen chamber 15 is provided adjacent to the oxygen electrode 13. For example, the fuel chamber 14 can seal liquid fuel, and the liquid fuel is supplied to the fuel electrode 12 by natural convection. Further, for example, a fuel supply port (not shown) is provided in the fuel chamber 14 and is closed during power generation. Further, the oxygen chamber 15 is provided with a flow hole 15A so as to communicate with the outside, and air, that is, oxygen is supplied to the oxygen electrode 13 from the flow hole 15A by natural ventilation. The fuel chamber 14 and the oxygen chamber 15 are fixed by, for example, screws 16.

  The power generation unit 10 may include control means (not shown) for controlling the maximum surface temperature within a range of 10 ° C. or more and 80 ° C. or less during power generation. This is because high output characteristics can be obtained if the maximum value is within this range. Examples of such control means include a mechanical cooling device such as an electric fan, or a device that arranges a plate having excellent heat conductivity for heat dissipation.

  The electrolyte membrane 11 is made of, for example, a proton conductor. The proton conductor may have ionic conductivity. For example, a sulfonic acid group is introduced into perfluorosulfonic acid polymer, polybenzimidazole, polyimide, polyether ether ketone, polyphenylene sulfide, polystyrene, fullerene. And derivatives containing these in the basic skeleton. Moreover, what carried the normal temperature molten salt on the support body is also mentioned.

  The thickness of the electrolyte membrane 11 is preferably in the range of 5 μm to 200 μm. If the thickness is smaller than this, the output characteristics are deteriorated due to the crossover phenomenon, and if the thickness is larger than this, the resistance is increased in the reaction between the catalyst and the liquid fuel and the output characteristics are decreased.

  The fuel electrode 12 has a configuration in which a catalyst layer 12B is formed on a current collector 12A. As the current collector 12A, a material having high corrosion resistance and electrical conductivity can be used. For example, the current collector 12A is made of nickel (Ni), stainless steel, gold (Au), platinum (Pt), or silver (Ag) noble metal. Examples include expanded metal or carbon fiber.

  FIG. 3 schematically shows an enlarged part of the catalyst layer 12B. The catalyst layer 12B includes, for example, a conductive auxiliary agent 12C and a binder 12D that binds the conductive auxiliary agent 12C to the current collector 12A. The surface of the conductive auxiliary agent 12C has a structure as shown in FIG. A catalyst 12E is supported.

  As the conductive auxiliary agent 12C, one having a large surface area such as activated carbon or carbon black is preferable. This is because high output characteristics can be obtained.

  The binder 12D only needs to have proton conductivity, and examples thereof include a polymer compound having a sulfonic acid group such as a perfluorosulfonic acid polymer.

  The content of the binder 12D is preferably in the range of 5% by mass to 80% by mass with respect to the total of the conductive auxiliary agent 12C, the binder 12D, and the catalyst 12E. This is because high output characteristics can be obtained within this range.

The catalyst 12E is not particularly limited as long as it has catalytic activity for liquid fuel, but platinum or ruthenium (Ru) is preferable. This is because catalyst poisoning can be mitigated. When ruthenium is used as the catalyst 12E, it is preferably contained in the range of 5% by mass or more and 60% by mass or less with respect to the total catalyst. When platinum is used as the catalyst 12E, it is preferably supported on the catalyst layer 12B within a range of 0.5 mg · cm ^{−2 to} 10 mg · cm ⁻² . This is because high output characteristics can be obtained within these ranges.

  The diameter of the catalyst 12E is preferably as small as possible, and specifically, about 1 nm is preferable. This is because a sufficient reaction amount can be obtained while suppressing the amount used.

  The angle formed by the orthogonal line T orthogonal to the surface of the fuel electrode 12 and gravity is preferably in the range of 30 ° or more and 90 ° or less. This is because inhibition of continuous diffusion and supply of fuel due to carbon dioxide generated as a by-product can be suppressed, and output characteristics can be improved. However, it is preferable that the fuel chamber 14 is located on the gravity direction side with respect to the fuel electrode 12. This is because a high effect can be obtained.

  Specifically, the orthogonal line T orthogonal to the surface of the fuel electrode 12 is orthogonal to a plane obtained when a smooth and non-warped metal plate is pressed against the catalyst layer 12B, as shown in FIG. Say a line. The direction of gravity is the direction from the measurement point toward the true center of the earth.

  Such an angle can be controlled by appropriately changing the mode of the support member 20.

  Examples of the fuel supplied to the fuel electrode 12 include organic substances such as methanol, ethanol and dimethyl ether, or solutions obtained by diluting these with pure water. When the organic substance is diluted with pure water, the concentration of the organic substance is preferably in the range of 5% by mass to 60% by mass. This is because if the value is low, the increase in polarization due to the material diffusion rate limit increases, and the output characteristics are deteriorated.

  The oxygen electrode 13 has, for example, a configuration in which a catalyst layer 13B is formed on a current collector 13A, similarly to the fuel electrode 12. Similarly to the catalyst layer 12B, the catalyst layer 13B includes a conductive auxiliary agent that supports the catalyst and a binder that binds the conductive assistant to the current collector. Examples of the catalyst, conductive additive, and binder used for the current collector 13A and the catalyst layer 13B include the same materials used for the fuel electrode 12.

  The material constituting the fuel chamber 14 is preferably a material having corrosion resistance to liquid fuel, and examples thereof include a polymer compound such as tetrafluoroethylene, polycarbonate or acrylic, a metal such as stainless steel or aluminum, or glass. It is done.

  The material constituting the oxygen chamber 15 is the same as the material constituting the fuel chamber 14, for example.

  This fuel cell can be manufactured, for example, as follows.

  First, for example, the conductive assistant 12C carrying the catalyst 12E, the binder 12D, and water are mixed to form a slurry, which is applied to the current collector 12A, and then naturally dried to produce the fuel electrode 12. To do.

  In the same manner as the fuel electrode 12, a conductive additive carrying a catalyst, a binder, and water are mixed to form a slurry, which is applied to the current collector 13A and then naturally dried to be an oxygen electrode. 13 is produced.

  Next, the fuel electrode 12, the electrolyte membrane 11, and the oxygen electrode 13 are laminated in this order to form a laminate, which is sandwiched between, for example, metal flat plates, and heated and pressurized to thereby form the fuel electrode 12 and the oxygen electrode. 13 and the electrolyte membrane 11 are interface-bonded. In that case, it is preferable that heating temperature exists in the range of 100 degreeC or more and 180 degrees C or less. This is because if it is low, sufficient bonding strength cannot be obtained, and if it is high, the electrolyte membrane 11 is thermally decomposed.

  Subsequently, the fuel chamber 14 is attached so as to be adjacent to the fuel electrode 12 side of the laminated body, and the oxygen chamber 15 is attached so as to be adjacent to the oxygen electrode 13 side, and these are fixed by, for example, screws 16. After that, the angle formed by the orthogonal line T and gravity is adjusted by the support member 20. Thereby, the fuel cell shown in FIG. 1 is completed.

  In this fuel cell, fuel is supplied to the fuel electrode 12, and hydrogen ions and electrons are generated by the reaction. Hydrogen ions move to the oxygen electrode 13 through the electrolyte membrane 11 and react with electrons and oxygen to generate water. At that time, carbon dioxide is by-produced, but since the angle formed by the orthogonal line T and gravity is in the range of 30 ° or more and 90 ° or less, the carbon dioxide stays at the contact interface between the catalyst and the liquid fuel. This prevents the liquid fuel from being continuously diffused and supplied.

  As described above, according to the present embodiment, the angle formed between the orthogonal line T orthogonal to the surface of the fuel electrode 12 and the direction of gravity is in the range of 30 ° or more and 90 ° or less. Inhibition of continuous diffusion and supply of fuel due to carbon dioxide or the like can be suppressed, and output characteristics can be improved.

(Second Embodiment)
FIG. 6 shows the configuration of a fuel cell according to the second embodiment of the present invention. The fuel cell includes a power generation unit 30 capable of generating energy and a support member 40 that supports the power generation unit 30.

  The power generation unit 30 includes a fuel electrode 32 and an oxygen electrode 33 that are disposed to face each other with an electrolyte membrane 31 interposed therebetween. The fuel electrode 32 has a configuration in which a catalyst layer 32B is formed on a current collector 32A. The current collector 32A is provided with a fuel flow path 32C. The flow path 32C is connected to a fuel supply unit (not shown) so that fuel is continuously supplied by, for example, a pump. The oxygen electrode 33 has a configuration in which a catalyst layer 33B is formed on a current collector 33A. The current collector 33A is provided with a flow path 33C. The flow path 33C communicates with the outside and is supplied with air, that is, oxygen by natural ventilation. The configurations of the electrolyte membrane 31, current collectors 32A and 33A, and catalyst layers 32B and 33B are the same as those of the electrolyte membrane 11, current collectors 12A and 13A, and catalyst layers 12B and 13B described above.

  This fuel cell can be manufactured, for example, as follows.

  First, the catalyst layer 32B, the electrolyte membrane 31, and the catalyst layer 33B are laminated in this order and interface bonded to form a laminate. Subsequently, the current collector 32A is attached so as to be adjacent to the catalyst layer 32B side of the laminate, and the current collector 33A is attached so as to be adjacent to the catalyst layer 33B side. After that, the angle formed by the orthogonal line T and the gravity is adjusted by the support member 40. Thereby, the fuel cell shown in FIG. 6 is completed.

  This fuel cell has the same operation and effect as the fuel cell of the first embodiment.

  Furthermore, specific examples of the present invention will be described.

(Examples 1-1 to 1-7, 2-1 to 2-7, 3-1 to 3-7)
The fuel cell shown in FIG. 1 was produced. First, carbon in which the conductive auxiliary agent 12C is supported with platinum and ruthenium metal fine powders that are the catalyst 12E, and a solution (Nafion, DuPont) in which the perfluorosulfonic acid polymer that is the binder 12D is diluted. The mixture was mixed to form a slurry, which was applied to the carbon fiber as the current collector 12A, and then naturally dried for 24 hours to produce the fuel electrode 12. At that time, ruthenium was adjusted to 50 mass% with respect to the whole catalyst. The supported amount of platinum was 3.0 mg · cm ⁻² . Furthermore, the amount of the perfluorosulfonic acid polymer was 60% by mass with respect to the total of the conductive assistant 12C, the binder 12D, and the catalyst 12E.

  In addition, a catalyst in which platinum as a catalyst is supported on carbon as a conductive auxiliary agent and a solution in which a perfluorosulfonic acid polymer as a binder is diluted are mixed to form a slurry, and this is collected by a current collector 13A. After being applied to a certain carbon fiber, it was naturally dried for 24 hours to produce an oxygen electrode 13. The amount of platinum supported on the oxygen electrode 13 was 60% by mass.

  Next, a perfluorosulfonic acid polymer (Nafion, DuPont Co., Ltd.) is prepared as the electrolyte membrane 11, and the fuel electrode 12, the electrolyte membrane 11 and the oxygen electrode 13 are laminated in this order to form a laminate, which is a metal. These interfaces were joined with a flat plate made of metal and heated and pressed. At that time, the fuel electrode 12 and the oxygen electrode 13 were used as a rectangular parallelepiped having a length and width of 2.5 cm, and the electrolyte membrane 11 was used as a rectangular solid having a length and width of 3 cm. Subsequently, a fuel chamber 14 into which 5.5 ml of liquid fuel is injected is attached so as to be adjacent to the fuel electrode 12 side of the laminated body, and an oxygen chamber 15 is attached so as to be adjacent to the oxygen electrode 13 side. The power generation unit 10 was manufactured by fixing. The liquid fuel was a methanol solution obtained by diluting methanol with pure water, and the concentration of methanol was 20% by mass.

  Subsequently, the power generation unit 10 was supported by the support member 20 to produce a fuel cell. At that time, as shown in FIG. 7, the angle formed between the orthogonal line T and the direction of gravity was changed within a range of 30 ° to 90 ° by appropriately adjusting the support member 20. Further, the fuel chamber 14 is positioned on the gravity direction side with respect to the fuel electrode 12.

  Comparative Examples 1-1 to 1-3, 2-1 to 2-3, 3-1 to 3-3- for Examples 1-1 to 1-7, 2-1 to 2-7, and 3-1 to 3-7 3 except that the angle between the orthogonal line T and the direction of gravity is 20 °, 10 °, or 0 °, and the other examples 1-1 to 1-7, 2-1 to 2-7, 3 Fuel cells were produced in the same manner as in -1 to 3-7.

  Examples 1-1 to 1-7, 2-1 to 2-7, 3-1 to 3-7 and Comparative Examples 1-1 to 1-3, 2-1 to 2-3, 3-1 to 3- Regarding 3, the output characteristics were examined. The results are shown in Tables 1-3. The output characteristics were examined as follows.

First, a continuous power generation test was conducted with a current density of 50 mA · cm ⁻² , 100 mA · cm ⁻² or 200 mA · cm ⁻² , and when the voltage between terminals reached 0 V, the total power generation based on the constant current method was completed. Asked. During power generation, the temperature around the power generation unit 10 was controlled to be within a range of about 10 ° C. to 80 ° C. so that the maximum temperature at a predetermined position of the oxygen electrode 13 was 30 ° C. The output characteristic was a relative ratio of the total power generation amount when the total power generation amount when the angle between the orthogonal line T and the direction of gravity was 90 ° was 100.

  As can be seen from Tables 1 to 3, the relative ratio of the total power generation gradually decreased as the angle formed between the orthogonal line T and the direction of gravity became smaller than 90 °, but rapidly decreased from less than 30 °.

  That is, it was found that the angle formed between the orthogonal line T orthogonal to the surface of the fuel electrode 12 and the direction of gravity is preferably within a range of 30 ° or more and 90 ° or less.

(Examples 4-1 to 4-6)
As shown in FIG. 8, the angle formed between the orthogonal line T and the direction of gravity is within the range of 30 ° or more and less than 90 ° so that the fuel chamber 14 is positioned in the direction opposite to the gravity with respect to the fuel electrode 12. A fuel cell was fabricated in the same manner as in Examples 1-1 to 1-7, except that the above was changed.

  As Comparative Examples 4-1 to 4-3 with respect to Examples 4-1 to 4-6, except that the angle formed by the orthogonal line T and the direction of gravity is set to 20 °, 10 °, or 0 °, the others are implemented. Fuel cells were fabricated in the same manner as in Examples 4-1 to 4-6.

  The output characteristics of Examples 4-1 to 4-6 and Comparative Examples 4-1 to 4-3 were examined in the same manner as in Examples 1-1 to 1-7. The results are shown in Table 4. In addition, the output characteristic was made into the relative ratio of the total power generation amount when the total power generation amount of Example 1-1 was set to 100.

  As can be seen from Table 4, the same results as in Examples 1-1 to 1-7 were obtained. However, higher output characteristics were obtained when the fuel chamber 14 was positioned on the gravity direction side with respect to the fuel electrode 12.

(Examples 5-1 to 5-3)
A fuel cell was fabricated in the same manner as in Example 2-7, except that the fuel electrode 12 was fabricated with the ruthenium content in the catalyst 12E being 5 mass%, 40 mass%, or 60 mass%. For the obtained fuel cells of Examples 5-1 to 5-3, the output characteristics were examined in the same manner as in Examples 2-1 to 2-7. The results are shown in Table 5. In addition, the output characteristic was made into the relative ratio of the total power generation amount when the total power generation amount of Example 2-1 was set to 100.

  As can be seen from Table 5, a high total power generation ratio was obtained when the ruthenium content in the catalyst 12E was in the range of 5 mass% to 60 mass%, and a maximum point was observed in the vicinity of 40 mass%.

  That is, it was found that the content of ruthenium in the catalyst 12E is preferably in the range of 5% by mass to 60% by mass.

(Examples 6-1 to 6-5)
The amount of supported platinum is a catalyst 12E except that to produce a fuel electrode 12 is varied in the range 0. 5 mg · cm ^-2 or more 10 mg · cm ^-2 less as shown in Table 6, the other is carried out A fuel cell was produced in the same manner as in Example 2-7. For the obtained fuel cells of Examples 6-1 to 6-5, the output characteristics were examined in the same manner as in Examples 2-1 to 2-7. The results are shown in Table 6. In addition, the output characteristic was made into the relative ratio of the total power generation amount when the total power generation amount of Example 2-1 was set to 100.

As can be seen from Table 6, the amount of supported platinum is high total power generation ratio in the range of less than 0. 5 mg · cm ^-2 or more 10 mg · cm ^-2 was obtained, 4. 0mg · cm ^-2 maximum point in the vicinity of Was observed.

That is, the amount of supported platinum in the catalyst layer 12B has been found that it is preferably in the range of 0. 5 mg · cm ^-2 or more 10 mg · cm ^-2.

(Examples 7-1 to 7-4)
As shown in Table 7, the amount of the perfluorosulfonic acid polymer as the binder 12C is within the range of 5% by mass to 80% by mass with respect to the total of the conductive auxiliary agent 12C, the binder 12D, and the catalyst 12E. A fuel cell was fabricated in the same manner as in Example 2-7, except that the fuel electrode 12 was fabricated by changing. For the obtained fuel cells of Examples 7-1 to 7-4, the output characteristics were examined in the same manner as in Examples 2-1 to 2-7. The results are shown in Table 7. In addition, the output characteristic was made into the relative ratio of the total power generation amount when the total power generation amount of Example 2-1 was set to 100.

  As can be seen from Table 7, a high total power generation ratio was obtained when the amount of perfluorosulfonic acid polymer was in the range of 5% by mass to 80% by mass, and a maximum point was observed in the vicinity of 60% by mass.

  That is, it was found that the amount of the binder 12C in the fuel electrode 12 is preferably in the range of 5% by mass to 80% by mass with respect to the total of the conductive auxiliary agent 12C, the binder 12D, and the catalyst 12E.

(Examples 8-1 to 8-5)
A fuel cell was fabricated in the same manner as in Example 2-7, except that the concentration of methanol was changed within the range of 5% by mass to 60% by mass. For the obtained fuel cells of Examples 8-1 to 8-5, the output characteristics were examined in the same manner as in Examples 2-1 to 2-7. The results are shown in Table 8. In addition, the output characteristic was made into the relative ratio of the total electric power generation amount when the total electric power generation amount of Example 2-1 was set to 100.

  As can be seen from Table 8, a high total power generation ratio was obtained when the concentration of methanol was in the range of 5 mass% to 60 mass%, and a maximum point was observed in the vicinity of 20 mass%.

  That is, it was found that the concentration of the organic substance in the liquid fuel is preferably in the range of 5% by mass to 60% by mass.

(Examples 9-1 to 9-4)
When examining the output characteristics of the fuel cell produced in Example 2-7, the maximum temperature at a predetermined position of the oxygen electrode 13 is within the range of 10 ° C. or higher and 80 ° C. or lower as shown in Table 9. The temperature environment was changed. Table 9 shows the relative ratio of the total power generation at this time. In addition, the output characteristic was made into the relative ratio of the total power generation amount when the total power generation amount of Example 2-1 was set to 100.

  As can be seen from Table 9, when the maximum temperature was in the range of 10 ° C. or more and 80 ° C. or less, a high total power generation ratio was obtained, and a maximum point was observed around 60 ° C.

  That is, it has been found that it is preferable to control the maximum surface temperature of the power generation unit 10 within a range of 10 ° C. or more and 80 ° C. or less during power generation.

(Examples 10-1 to 10-7)
The shape of the fuel cell was as shown in FIG. 6, and secondary batteries were fabricated in the same manner as in Examples 1-1 to 1-7, except that liquid fuel was circulated. Specifically, as shown in Table 10, the angle formed by the orthogonal line T and the direction of gravity was changed within a range of 30 ° to 90 °.

  As Comparative Examples 10-1 to 10-3 with respect to Examples 10-1 to 10-7, except that the angle formed by the orthogonal line T and the direction of gravity was set to 20 °, 10 °, or 0 °, the others were implemented. Fuel cells were fabricated in the same manner as in Examples 10-1 to 10-7.

  The output characteristics of Examples 10-1 to 10-7 and Comparative Examples 10-1 to 10-3 were examined in the same manner as in Examples 1-1 to 1-7. The results are shown in Table 10. The output characteristic was the relative ratio of the total power generation amount when the total power generation amount in Example 10-1 in which the angle between the orthogonal line T and the direction of gravity was 90 ° was 100.

  As can be seen from Table 10, the same results as in Examples 1-1 to 1-7 were obtained. That is, even when liquid fuel is circulated, it has been found that the angle formed by the orthogonal line T perpendicular to the surface of the fuel electrode 12 and the direction of gravity is preferably in the range of 30 ° to 90 °.

  The present invention has been described with reference to the embodiments and examples. However, the present invention is not limited to the above embodiments and examples, and various modifications can be made. For example, in the above-described embodiments and examples, the configurations of the electrolyte membrane 11, the fuel electrode 12, and the oxygen electrode 13 have been specifically described, but may be configured by other structures or other materials.

  Moreover, in the said embodiment and Example, although supply of the air to the oxygen electrode 13 was made into natural ventilation, you may make it supply forcibly using a pump etc. In that case, oxygen or a gas containing oxygen may be supplied instead of air.

  Furthermore, in the above-described embodiments and examples, the single cell type fuel cell has been described, but the present invention can also be applied to a stacked type in which a plurality of cells are stacked.

It is a perspective view showing the structure of the fuel cell which concerns on one embodiment of this invention. It is sectional drawing along the II line of the fuel cell shown in FIG. FIG. 2 is a schematic diagram illustrating an enlarged fuel electrode illustrated in FIG. 1. FIG. 2 is a schematic diagram illustrating an enlarged part of the fuel electrode illustrated in FIG. 1. It is a figure explaining the direction orthogonal to the surface of a fuel electrode. It is another perspective view showing the structure of the fuel cell which concerns on one embodiment of this invention. It is a figure showing the one aspect | mode of the fuel cell which concerns on an Example. It is a figure showing the other aspect of the fuel cell which concerns on an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,30 ... Power generation part, 11, 31 ... Electrolyte membrane, 12, 32 ... Fuel electrode, 12A, 13A, 32A, 33A ... Current collector, 12B, 13B, 32B, 33B ... Catalyst layer, 12C ... Conductive aid, 12D ... Binder, 12E ... Catalyst, 13,33 ... Oxygen electrode, 14 ... Fuel chamber, 15 ... Oxygen chamber, 15A ... Flow port, 20, 40 ... Support member, 32C, 33C ... Flow path

Claims (11)

Having a power generation part in which a fuel electrode and an oxygen electrode are arranged to face each other through an electrolyte membrane;
An angle formed by an orthogonal line orthogonal to the surface of the fuel electrode and the direction of gravity is in a range of 30 ° to 90 °.   The fuel cell according to claim 1, further comprising a support member that supports the power generation unit.   2. The fuel cell according to claim 1, wherein liquid fuel is supplied to the fuel electrode, and hydrogen ions are generated by a direct oxidation reaction of the liquid fuel.   2. The fuel cell according to claim 1, wherein a fuel containing an organic substance is used as the liquid fuel supplied to the fuel electrode.   The fuel cell according to claim 4, wherein the organic substance includes methanol.   The fuel cell according to claim 4, wherein the concentration of the organic substance in the liquid fuel is 5% by mass or more and 60% by mass or less.   2. The fuel cell according to claim 1, further comprising a fuel chamber in which liquid fuel is sealed adjacent to the fuel electrode.   2. The fuel cell according to claim 1, wherein the fuel electrode has a catalyst layer containing a catalyst, and the catalyst contains ruthenium in a range of 5 mass% to 60 mass%. The fuel electrode has a catalyst layer containing a catalyst, and the catalyst layer contains platinum supported in a range of 0.5 mg · cm ^{-2 to} 10 mg · cm ^-2. 1. The fuel cell according to 1.   The fuel electrode has a catalyst layer including a catalyst, a conductive additive, and a binder, and the content of the binder is 5% by mass or more and 80% by mass or less with respect to the total of the catalyst, the conductive auxiliary agent, and the binder. 2. The fuel cell according to claim 1, which is within a range. 2. The fuel cell according to claim 1, further comprising means for controlling the maximum surface temperature in the power generation unit to be 10 ° C. or higher and 80 ° C. or lower during power generation.

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