AN ORGANIC FUEL CELL

Field of the Invention

The present invention relates to a fuel cell, particularly to an organic fuel cell.

Background of the Invention

A fuel cell is a device that transforms chemical energy into electrical energy. A fuel cell usually comprises a membrane electrode assembly, which comprises an anode, a cathode, and a proton exchange membrane between the anode and the cathode.

The anode is a gas diffusion electrode, of which supporting material is usually made of conductive carbon fibers or carbon cloth. There is anode catalyst that catalyzes anode reaction between anode and proton exchange membrane. The anode catalyst is usually Pt powder, Pt alloy powder, Pt powder on a carrier or Pt alloy powder on a carrier. Said Pt alloy comprises Pt and one or more selected from the group consisting of Ru, Sn, Ir, Os and Re. Said carrier is a conductive carrier with a large specific surface, such as active carbon. Outside the anode, there is a guide plate, which is made of such as graphite material or metal material.

The cathode is also a gas diffusion electrode, in the same structure as the anode. The difference between the anode and the cathode lies in: the catalyst between cathode and proton exchange membrane is a cathode catalyst that catalyzes cathode reaction, The cathode catalyst is usually Pt powder or Pt powder on a carrier. There is also a guide plate made of graphite or metal material outside the cathode.

The proton exchange membrane is a semi-permeable membrane that is permeable to water but impermeable to gas. It has proton conduction effect and can prevent the oxidant and the fuel from mixing together and exploding.

For example, in a fuel cell system with methanol and hydrogen as its fuel and air or oxygen as its oxidant, the following electrochemical reactions occur in the cell:

If the fuel is methanol, the electrochemical reaction at anode is as follows: CH ₃ OH+H ₂ O→CO ₂ +6H ⁺ +6e (1)

If the fuel is hydrogen, the electrochemical reaction at anode is as follows: 3η. ₂ →6i?+6e (2)

Meanwhile, the electrochemical reaction at cathode is as follows: 3/2O ₂ +6H ^f +6e→3H ₂ O, (3) The electrode reactions (1) and (3) and the electrode reactions (2) and (3) cause the following overall reactions, respectively:

CH ₃ OH+3/2O ₂ →Cθ2+2H ₂ O (4)

3H ₂ +3/2O ₂ →3H ₂ O (5)

Above electrochemical reactions at the anode and the cathode leads to potential difference between anode and cathode; under that potential difference, the electrons produced at the anode flow through the guide plate outside of anode and the external conductor, and are finally captured by the cathode. The protons created at the anode pass through the proton exchange membrane to cathode directly, so that electric current is formed. The fuel in said fuel cell comprises not only methanol and hydrogen but also other organic fuel. For example, said organic fuel can be one or more selected from the group consisting of liquid alcohols, liquid ethers, and liquid organic acids, or one or more selected from the group consisting of liquid alcohol solutions and liquid organic acid solutions, preferably one or more selected from the group consisting of methanol, alcohol, formic acid, and ether, or one or more selected from the group consisting of methanol solution, alcohol solution, and formic acid solution.

The fuel cell with organic fuel as its fuel has advantages including low pollution, low noise, simple structure, portability, and wide and easy availability of the fuel. In addition, since the organic fuel is in liquid state, it has high specific energy and needn't to be stored in pressured gas cylinder, and thereby is highly portable. In addition, compared with flammable and explosive hydrogen gas, the organic fuel delivers higher safety.

Though said organic fuel cell has above advantages, it also has some disadvantages. For example, one major disadvantage is: the Pt catalyst has poor catalytic effect to organic fuel, and carbon monoxide as an intermediate is produced

during the catalytic oxidation process of the organic fuel and it will combine with Pt in the catalyst to form a stable complex compound, which causes the catalyst deactivated. As a result, compared with a fuel cell with hydrogen as the fuel, a fuel cell with organic fuel delivers very low electrode power density per unit area. It is reported that a fuel cell with hydrogen as the fuel usually delivers electrode power density per unit area higher than 10 times of the electrode power density per unit area in a fuel cell with methanol as the fuel. To obtain a same power in an organic fuel cell as in a hydrogen fuel cell, the active area of electrodes must be several times larger than that in a hydrogen fuel cell, and the amount of precious metals (e.g., Pt) in the catalyst has to be increased by several times. Consequently, the cost of organic fuel cell is increased greatly.

Investigations show that the low electrode power density in organic fuel cell is resulted from the slow catalytic oxidation process of organic fuel at anode. Temperature has direct influence to the performance of methanol fuel cells. As mentioned in Journal of Power Sources 2005, 139: 79-90 and Journal of Power Sources 2002, 109: 76-88, the electrode power density of a fuel cell increases as the temperature rises. Therefore, how to increase the temperature in fuel cells in order to increase application of the fuel cells in electronic products and widen applicability of the fuel cells has become a hot spot in research in recent years. For instance, US20030003336 discloses a method for controlling the temperature in polymeric solid electrolyte fuel cell; said fuel cell comprises an anode, a cathode, and polymeric solid electrolyte between the anode and the cathode; said method comprises: supplying oxidizer stream to the cathode of the fuel cell, supplying methanol fuel stream to the anode of fuel cell, measuring the indicated temperature in fuel cell, and adjusting the characteristic of the fuel stream according to the measured temperature; wherein, said characteristic of the fuel stream is concentration or partial pressure of methanol in the fuel stream. However, that method is complicated to implement.

Another commonly used method for increasing the temperature in fuel cell is to heat the cell shell with an external heat source, so as to increase the temperature

within the fuel cell and thereby increase the electrode power density in the fuel cell. Though that method can increase the electrode power density in fuel cell to a certain degree, the increase of power density is very limited; furthermore, it is found that the heat power consumed is by far higher than the increased power in fuel cell; apparently, it is a worthless method.

Summary of the Invention

The object of the present invention is to provide an organic fuel cell with high power density, so as to overcome the shortcomings of low power density in organic fuel cells in the prior art.

In order to effectively improve the utilization of the external energy for the fuel cell, the present inventor attempts to embed a heat-conducting component into the cell, especially between the electrodes, so that the electrodes are directly heated; in that way, the electrode reaction rate can be increased effectively, and the purpose of increasing power density in organic fuel cell significantly at lower energy consumption can be obtained.

In addition, it is well-known that electronic devices such as notebook computers give off a large quantity of heat during operating. For example, when a notebook computer operates at room temperature, the temperature on its bottom can be up to 40 ^° C or above; such heat is directly emitted to the atmosphere at present, resulting increased ambient temperature and "thermal pollution". For that reason, an additional cooling system is usually required to reduce the ambient temperature and protect the electronic device or make the environment comfort. However, a conventional organic fuel cell delivers more than 2 times of power density when it operates at 40 ^° C than at room temperature. Basing on this fact, the inventor assumes that if the heat generated by a portable electronic device can be transferred to the electrodes of an organic fuel cells in that electronic device to increase the intramural temperature of the organic fuel cells, the power density of the organic fuel cells will be increased by several times, without any additional heating. That approach can not only improve power density of organic fuel cells but also effectively reduce "thermal pollution" when the

electronic device operates.

The organic fuel cell provided by the present invention comprises a membrane electrode assembly and a cell shell; said membrane electrode assembly, which is accommodated in said cell shell, comprises an anode, a cathode, and a proton exchange membrane between the anode and the cathode; wherein said organic fuel cell further comprises at least a heat-conducting component, one part of which is embedded in said cell shell and the other protrudes outside from the cell shell.

Since the organic fuel cell provided by the present invention comprises a heat-conducting component directly embedded into the cell shell, it can effectively transfer external heat to the electrode reactions in the cell; therefore, the temperature of electrode reactions is increased, the oxidation rate of the liquid fuel is increased effectively, and thereby the power density in the cell is increased. The power density in the organic fuel cell provided by the present invention can be up to 76MW/cm ² (at ambient temperature), which is significantly higher than the power density (35MW/cm ² ) of the congeneric cells in prior art. The process for preparation of organic fuel cell provided by the present invention is simple and easy to implement.

In addition, if the other part different from the part embedded in said cell shell of the heat-conducting component is close to or contacts with the heat dissipating unit or heat generating component of the electronic device that uses the cell, the heat generated from the electronic device when operating can be effectively transferred to the cell. As a result, not only the power density of the cell can be greatly improved, but also the "thermal pollution" when the electronic device operates can be effectively reduced.

Brief Description of the Drawings

Figs. 1-12 are views showing the structure of the organic fuel cell provided by the present invention.

Detailed Description of the Preferred Embodiments An organic fuel cell provided by the present invention is shown in Figs.1-12.

The cell comprises a membrane electrode assembly and a cell shell 4; said membrane electrode assembly comprises an anode 11, a cathode 13, and proton exchange membrane 12 between the anode 11 and the cathode 13; wherein, said cell further comprises at least a heat-conducting component 3, which is partially embedded in said cell shell 4 and partially protrudes outside from said cell shell 4.

In the organic fuel cell provided by the present invention, said heat-conducting component 3 can be at any position in said cell shell 4, as long as it can transfer the heat to the membrane electrode assembly in the cell to increase oxidation rate of the organic fuel. For example, the part of said heat-conducting component 3 embedded in the cell shell 4 can be at any of the following positions: (1) between the cathode 13 and the cell shell 4 (Fig. l and Fig.3); (2) between the anode 11 and the cell shell 4 (Fig.2 and Fig.3); (3) between the anode 11 and the proton exchange membrane 12 (Fig.5 and Fig.6); (4) between the cathode 13 and the proton exchange membrane 12 (Fig.4 and Fig.6).

Preferably, as shown in Figs.5-11, the organic fuel cell provided by the present invention further comprises a guide plate. Said guide plate is preferably between the membrane electrode assembly and the cell shell 4. Said guide plate can comprise an anode guide plate 21 and/or a cathode guide plate 23, designed to guide flow direction of the fuel and/or oxidant, so as to improve the utilization of the fuel. Preferably, said organic fuel cell comprises both an anode guide plate 21 and a cathode guide plate 23; in that case, said anode guide plate 21 is preferably between the anode 11 of the membrane electrode assembly and the inner wall of the cell shell 4, and said cathode guide plate 23 is preferably between the cathode 13 of the membrane electrode assembly and the inner wall of the cell shell 4. If the organic fuel cell provided by the present invention comprises both an anode guide plate 21 and a cathode guide plate 23, the part of said heat-conducting component 3 embedded in the cell shell 4 can be at any of the following positions: (5) between the anode guide plate 21 and the inner wall of the cell shell 4 (Fig.7 and Fig.9); (6) between the cathode guide plate 23 and the inner wall of the cell shell 4 (Fig.8 and Fig.9); (7) between the anode 11 and the

anode guide plate 21 (Fig.10); or (8) between the cathode 13 and the cathode guide plate 23 (Fig.11).

Said heat-conducting component 3 can be made of any material with superior heat-conducting property, such as one or more selected from the group consisting of Ag, Cu, Al, Au, and other alloy materials; or a sheet material coated with a heat-conducting layer formed by above heat-conducting material to afford heat-conducting property to the sheet material. For example, said sheet material can be PTFE, which is not heat-conductive per se. Said heat-conducting layer can be coated through a vapor deposition process, plasma process, arc process, electroplating process, or any other appropriate coating technique. Above processes are known to those skilled in the art, and will not be described further here.

Preferably, said heat-conducting component 3 of the present invention has an oxidation resistant coating layer, hydrophilic coating layer, or hydrophobic coating layer. For example, if the heat-conducting component 3 is arranged within the membrane electrode assembly, i.e., between the anode 11 and the proton exchange membrane 12 and/or between the cathode 13 and the proton exchange membrane 12, the surface of said heat-conducting component 3 is preferably treated by oxidation protection treatment, for example, the surface of said heat-conducting component is gold-plated. If said heat-conducting component 3 is arranged between the cathode 13 and the proton exchange membrane 12 and/or the cell shell 4 of the fuel cell, it can be performed by hydrophobe treatment to obtain hydrophobic property, so that the water produced at the cathode 13 can impregnate reversely to the anode 11. Said hydrophobe treatment can be carried out by dipping PTFE onto the surface of the heat-conducting component 3 to form a PTFE layer, so as to obtain hydrophobic property. If said heat-conducting component 3 is arranged in the vicinity of the the anode 11 of the fuel cell, it can be treated by hydrophilicity treatment to obtain hydrophilic property, in order to absorb water impregnating reversely from the cathode 13 and facilitate the diffusion of the organic fuel to the catalyst. Said hydrophilicity treatment can be done by dipping NAFION solution onto the surface of the heat-conducting component 3 to form a NAFION layer, so as to obtain hydrophilic

property. Preferably, the thickness of above oxidation resistant coating layer, hydrophilic coating layer or hydrophobic coating layer is of 5-10μm.

Preferably, if said heat-conducting component 3 is partially embedded in the cell shell 4 in one or more ways of (4), (5), (6), (10), and (11), there are through holes (not shown) that are permeable to liquids and gases distributing on the part of said heat-conducting component 3 in the cell shell 4. Said through holes can be in regular or irregular shapes. There is no limitation to the size and shape of the through holes; preferably, the through holes are small as far as possible, provided that they are permeable to liquids. Preferably, the total area of said through holes is 5-20% of one , surface area of that part embedded in the cell shell of said heat-conducting component with through holes thereon. Preferably, the through holes are distributed evenly on the surface of the heat-conducting component, so that the fuel and oxidant for the cell can be distributed evenly to the electrodes. If the fuel cell provided by the present invention comprises a guide plate, the through holes on said heat-conducting component are preferably in the same distribution form as the through holes on the guide plate.

There is no special requirement for the shape of the heat-conducting component 3. For example, the heat-conducting component 3 can be in sheet shape. Said heat-conducting component is preferably in thickness of 0.05-30mm, more preferably 0.1 -20mm, optimally 0.1-10mm. Said heat-conducting component can protrude outside from the cell shell 4 in one or more directions; and the length of said heat-conducting component 3 can be determined as required on the basis that said heat-conducting component can receive external heat successfully. The external heat can be received by means of the heat-conducting component 3 directly contacting the external heat source or the heat-conducting component 3 being at a position in the heat dissipating coverage of the heat dissipating unit such as a fan. Said external heat source can be a separate heating device or the electronic device that uses the cell, and preferably the electronic device itself in the present invention.

As shown in above description of the present invention, said heat-conducting component in the present invention can also serve as an anode guide plate, a cathode

guide plate, an anode supporting material, or a cathode supporting material, so as to substitute the anode guide plate, cathode guide plate, anode supporting material, or cathode supporting material, or reinforce the anode guide plate, cathode guide plate, anode supporting material, or cathode supporting material. There is no limitation to the number of said heat-conducting component 3. Said heat-conducting component 3 can be one or more, for example 1-4; and preferably, each membrane electrode assembly comprises two heat-conducting components 3; more preferably, said two heat-conducting components 3 transfer heat to the anode 11 and the cathode 13 simultaneously. According to the present invention, said anode 11 is a gas diffusion electrode, with supporting material made of conductive carbon fibers or carbon cloth. There is anode catalyst that catalyzes anode reaction between the anode and the proton exchange membrane. The anode catalyst is usually Pt powder, Pt alloy powder, Pt powder on a carrier or Pt alloy powder on a carrier. Said Pt alloy comprises Pt and one or more of Ru, Sn, Ir, Os and Re. Said carrier is a conductive carrier with a large specific surface, such as active carbon.

The cathode 13 is also a gas diffusion electrode, in the same structure as the anode. The difference between the anode and the cathode lies in: the catalyst between the cathode 13 and the proton exchange membrane 12 is a cathode catalyst that catalyzes cathode reaction. The cathode catalyst is usually Pt powder or Pt powder on a carrier.

The proton exchange membrane 12 according to the present invention can be any proton exchange membrane suitable to be used in fuel cells, such as a semi-permeable membrane that is permeable to water but impermeable to gases and possess proton conduction effect, e.g., the well-known NAFION membrane, the proton exchange membrane disclosed in US 5795496, or the proton exchange membrane disclosed in US20030129467.

The optional guide plate can be a commonly used guide plate made of graphite material or metal material in fuel cell field and is designed to guide the flow direction of the fuel and oxidant into the fuel cell; said guide plate comprises multiple through

holes. Said metal material can be one or more selected from the group consisting of steel, copper, titanium, silver, and their alloys.

The present invention only involves modifications to internal structure of fuel cell, and has no special limitation to other structures in fuel cell, such as supply of oxidant and deoxidizer required for operation of fuel cell, i.e., the oxidant and deoxidizer can be supplied in a conventional way.

Said fuel can be any organic fuel suitable for fuel cell, such as one or more selected from the group consisting of methanol, alcohol, dimethoxymethane, trimethoxy methane, and their solutions. In the present invention, said fuel is preferably methanol and/or methanol solution. Said oxidant can be any oxidative gas, preferably be air and/or oxygen.

In the fuel cell provided by the present invention, said membrane electrode assembly can be a membrane electrode assembly group comprising a number of membrane electrodes assembly in series, and each of membrane electrodes assembly comprises an anode, a cathode, and proton exchange membrane between the anode and the cathode. Said membrane electrode assembly group is accommodated in the cell shell (as shown in Fig.12). Preferably, the membrane electrode assembly group comprises 2-200 membrane electrode assemblies. A fuel cell comprising multiple membrane electrode assemblies is also referred to a fuel cell pack. In the membrane electrode assemblies, the number and arrangement of the heat-conducting components can be identical or different.

There is no special limitation to the structures of said fuel supply device, oxidant supply device, and cell shell, and the connections among them; which can be conventional ones in ordinary fuel cells, respectively. Said heat-conducting component in the organic fuel cell provided by the present invention is partially embedded in the cell shell and partially contacts with the external heat source or is at a position to which the heat from the external heat source can be transferred, for example, within the blowing coverage of a fan, so that the heat from the external heat source can be transferred into the cell, to accelerate the reactions in the fuel cell and increase power density in the fuel cell. Said external heat

source can be a separate heating device or waste heat from the electronic device that uses the fuel cell such as the heat generated when the electronic device operates. Said electronic device can be a mobile telephone, PDA, or notebook computer, for example. The present invention will be further explained by the following embodiments.

Example 1

A cell as shown in Fig.8 is produced; wherein, the heat-conducting component 3 is between the cell shell 4 and the cathode guide plate 23. Wherein, the heat-conducting component 3 is an aluminum sheet in size of

100mm X 100mm X lmm, with through holes of 375mm ² total area evenly distributed on the aluminum sheet; the supporting material for the anode 11 is made of carbon fibers, and the anode catalyst is carbon-carried Pt-Ru catalyst from J-M Company with the content of Pt being 20% (wt), and the content of Ru being 10% (wt); the weight of Pt-Ru catalyst per unit area is 4mg/cm ² ; the anode 11 is in size of 50mm X 50mm X 0.3mm; both the anode guide plate 21 and the cathode guide plate 23 are made of carbon, in size of 50mm X 50mm X 0.3mm.

The supporting material for cathode 13 is made of carbon fibers; the cathode catalyst is carbon-carried Pt catalyst from J-M Company with the content of Pt being 40% (wt.), and the weight of Pt per unit area is lmg/cm ² ; the cathode 13 is in size of 50mm X 50mm X 0.3mm.

The proton exchange membrane is Nafion 115 from DuPont Company.

Example 2 A cell as shown in Fig.9 is produced; wherein, there are two heat-conducting components 3 which is between the cell shell 4 and the cathode guide plate 23 and between the cell shell 4 and the anode guide plate 21, respectively.

Wherein, each of the heat-conducting components 3 is an copper sheet in size of

150mm X 150mm X 0.5mm, with through holes of 375mm ² total area distributed on the copper sheet; the supporting material for the anode 11 is made of carbon fibers,

and the anode catalyst is carbon-carried Pt-Ru catalyst from J-M Company with the content of Pt being 20% (wt.) and the content of Ru being 10% (wt); the weight of Pt-Ru per unit area is 4mg/cm ² ; the anode 11 is in size of 60mm X 60mm X 0.3mm; both the anode guide plate 21 and the cathode guide plate 23 are made of carbon, in size of 60mm X 60mm X 0.3 mm.

There are through holes that are permeable to liquids and gases distributed on said heat-conducting component 3 and said through holes are distributed in the same form as the through holes (main flow channels) on the corresponding guide plates in the fuel cell. The supporting material for cathode 13 is made of carbon fibers; the cathode catalyst is carbon-carried Pt catalyst from J-M Company with the content of Pt being 40% (wt.), and the weight of Pt per unit area is lmg/cm ² ; the cathode 13 is in size of 60mm X 60mm X 0.3mm.

The proton exchange membrane is Nafion 115 from DuPont Company.

Example 3

The cell as shown in Fig.5 is produced; wherein, the heat-conducting component 3 is between the anode 11 and the proton exchange membrane 12.

Wherein, the heat-conducting component 3 is a gold-plated copper sheet in size 45mm X 45mm X 0.2mm treated by a hydrophilicity treatment to obtain hydrophilic property,, with through holes of 375mm ² total area being evenly distributed thereon. The hydrophilicity treatment is carried out by: dipping the heat-conducting component in 5% Nanfion solution for 10 minutes, then blowing drying it at normal temperature, and then drying it for 30 minutes under the protection of inert gas at 120 ^° C; the supporting material for the anode 11 is made of carbon fibers; the anode catalyst is carbon-carried Pt-Ru catalyst from J-M Company with the content of Pt being 20% (wt.), the content of Ru being 10% (wt.), and the weight of Pt-Ru per unit area is 4mg/cm ² ; the anode 11 is in size of 45mm X 45mm X 0.3mm; both the anode guide plate and the cathode guide plate are made of carbon, in size of 45mm X 45mm

X 0.3mm.

The supporting material for the cathode 13 is made of carbon fibers; the cathode catalyst is carbon-carried Pt catalyst from J-M Company with the content of Pt being 40% (wt.), and the weight of Pt per unit area is lmg/cm ² ; the cathode 13 is in size of 45mm X 45mm X 0.3mm.

The proton exchange membrane is 1035 PFSA membrane from DuP ont Company.

Example 4 The cell as shown in Fig.6 is produced; wherein, there are two heat-conducting components 3 which is between the anode 11 and the proton exchange membrane 12 and between the cathode 13 and the proton exchange membrane 12, respectively.

Wherein, each of the heat-conducting components 3 is a PTFE sheet coated with copper and then gold, in size of 45mm X 45mm X 0.2mm, with through holes of 365mm ² total area being evenly distributed on the PTFE sheet; the supporting material for the anode 11 is made of carbon fibers, and the anode catalyst is carbon-carried Pt-Ru catalyst from J-M Company with the content of Pt being 20%

(wt.) and the content of Ru being 10% (wt.); the weight of Pt-Ru per unit area is

4mg/cm ² ; the anode 11 is in size of 45mm X 45mm X 0.3mm; both the anode guide plate 21 and the cathode guide plate 23 are made of carbon, in size of 45mm X 45mm

X 0.3mm.

The supporting material for the cathode 13 is made of carbon fibers; the cathode catalyst is carbon-carried Pt catalyst from J-M Company with the content of Pt being 40% (wt.), and the weight of Pt per unit area is lmg/cm ² ; the cathode 13 is in size of 45mm X 45mm X 0.3mm.

The proton exchange membrane is Nafion 115 from DuP ont Company.

Example 5

The cell as shown in Fig.12 is produced; wherein, the membrane electrode assembly is a membrane electrode assembly group comprising 3 identical membrane

electrode assemblies in series; each membrane electrode assembly comprises two heat-conducting components 3, which is between the anode 11 and the proton exchange membrane 12 and between the cathode 13 and the proton exchange membrane 12, respectively. Wherein, each of the heat-conducting components 3 is a PTFE sheet coated with copper and then gold, in size of 45mmx45mm><0.2mm, with through holes of 375mm ² total area distributed on the PTFE sheet; the supporting material for the anode 11 is made of carbon fibers, and the anode catalyst is carbon-carried Pt-Ru catalyst from J-M Company with the content of Pt being 20% (wt.) and the content of Ru being 10% (wt.); the weight of Pt-Ru per unit area is 4mg/cm ² ; the anode 11 is in size of 45mm X 45mm X 0.3mm; both the anode guide plate 21 and the cathode guide plate 23 are made of carbon, in 45mmx45mmxO.3mm.

The supporting material for cathode 13 is made of carbon fibers; the cathode catalyst is carbon-carried Pt catalyst from J-M Company with the content of Pt being 40% (wt.), and the weight of Pt per unit area is lmg/cm ² ; the cathode 13 is in size of 45mm X 45mm X 0.3 mm.

The proton exchange membrane is Nafion 115 from DuP ont Company.

Comparative example 1 An organic fuel cell is produced in the same method as discribed in example 1 except that the organic fuel cell doesn't have a heat-conducting component.

Test of power density of cell

Tests of power density test of the organic fuel cells prepared by the examples 1-5 and the comparative example 1 are carried out. The tests of power density test of the organic fuel cells prepared by the examples 1-5 are carried out as follows: assembling above fuel cell into a cell device at room temperature; making the heat-conducting component contact with a 40 ^° C heat source (to simulate the waste heat from an electronic device); supplying air at atmospheric pressure to the anode of the cell and lmol/1 methanol solution to the cathode of the cell, and then testing the

cell. The test of power density test of the organic fuel cells prepared by the comparative examples 1 is identical to that of the organic fuel cells prepared by the examples 1-5 except that the heat-conducting component doesn't contact with a 40 ⁰ C heat source since the cell doesn't have heat-conducting component. The test results are shown in Table 1. Table 1

Note: Ex. is the abbreviation for example, and CE. is the abbreviation for comparative example.

AS seen from Table 1, compared with the prior art, the organic fuel cell provided by the present invention delivers doubled or higher power density. By contacting with the heat dissipation unit of the electronic device, the fuel cell can effectively utilize the waste heat from the electronic device and thereby increases power density significantly while reducing "thermal pollution".