CN108899561B - Method for improving oxygen concentration of cathode of air self-breathing fuel cell - Google Patents
Method for improving oxygen concentration of cathode of air self-breathing fuel cell Download PDFInfo
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- CN108899561B CN108899561B CN201810562472.4A CN201810562472A CN108899561B CN 108899561 B CN108899561 B CN 108899561B CN 201810562472 A CN201810562472 A CN 201810562472A CN 108899561 B CN108899561 B CN 108899561B
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M8/00—Fuel cells; Manufacture thereof
- H01M8/02—Details
- H01M8/0202—Collectors; Separators, e.g. bipolar separators; Interconnectors
- H01M8/0247—Collectors; Separators, e.g. bipolar separators; Interconnectors characterised by the form
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/50—Fuel cells
Abstract
The invention discloses a method for improving the cathode oxygen concentration of an air self-breathing fuel cell by utilizing a magnetic porous medium structure, which is characterized by comprising the following steps of: the device comprises an air self-breathing fuel cell cathode gas channel, an air self-breathing fuel cell anode gas channel, a catalytic layer and a proton exchange membrane; importantly wherein the cathode gas channel consists of a magnet and a porous structure; the magnet is combined with a porous structure formed by a ferromagnetic material, a high gradient magnetic field is formed in a cathode gas channel, and the obvious action of Kelvin force on paramagnetic oxygen and diamagnetic water is utilized to achieve the purposes of improving the oxygen concentration of the cathode and discharging the cathode to generate water, so that the power of the fuel cell is improved; the method can obviously improve the power of the air self-breathing fuel cell and has wide application prospect.
Description
Technical Field
The invention relates to a method for improving cathode oxygen concentration in air self-breathing hydrogen-oxygen fuel cell utilization, in particular to a method for promoting oxygen enrichment in a cathode gas channel of an air self-breathing fuel cell by using a high gradient magnetic field generated in a magnetic porous medium structure under a magnetic field environment.
Background
The hydrogen-oxygen fuel cell has the anode consuming hydrogen and the cathode consuming oxygen, and realizes the conversion process of chemical energy and electric energy under the action of the catalyst layer. When the supply of hydrogen is sufficient, the amount of oxygen supplied determines the output electric power of the fuel cell to some extent. In large vehicles such as hydrogen-oxygen fuel cell vehicles, the cathode of the hydrogen-oxygen fuel cell is continuously supplied with sufficient oxygen by compressed air, and the battery system is large and complex because of the air compression device.
The portable application of the hydrogen-oxygen fuel cell with high volume energy density has wide market prospect. The concept of the air self-breathing hydrogen-oxygen fuel cell proposed in recent years is to adopt the natural convection of air in a cathode gas channel to realize the supply of cathode oxygen, thereby reducing the complexity of a cell system.
The advantages of the system simplification presented by air self-breathing hydrogen-oxygen fuel cells are obvious, but the sudden drop of electric power caused by insufficient supply of cathode oxygen provided by natural convection is also fatal. Meanwhile, the accumulation of water generated by the fuel cell reaction on the cathode side undoubtedly forms a further obstacle to the circulation of cathode gas and oxygen supply, and affects the electric power of the cell. The prior art methods of accelerating water removal through the use of hydrophobic cathode materials do not appear to achieve the goal of further increasing the electrical power of air-breathing fuel cells in environments with lower oxygen concentrations.
The search for a structural design capable of effectively enriching oxygen and draining water is an effort to further improve the volume energy density of the air self-breathing fuel cell.
Disclosure of Invention
The invention aims to reform the design of a cathode gas channel of the existing air self-breathing fuel cell and provides a method for improving the cathode oxygen concentration of the air self-breathing fuel cell by utilizing a magnetic porous medium structure, so that the volume energy density of the air self-breathing fuel cell is further improved.
The technical scheme adopted for achieving the aim of the invention is that the method for improving the oxygen concentration of the cathode of the air self-breathing fuel cell by utilizing the magnetic porous medium structure is characterized in that: the oxygen enrichment of the cathode is realized through the adsorption of the gradient magnetic field on the surface of the porous structure to the oxygen.
The porous structure comprises an air self-breathing fuel cell cathode gas channel, an air self-breathing fuel cell anode gas channel, a catalytic layer and a proton exchange membrane.
The air self-breathing fuel cell cathode gas channel and the air self-breathing fuel cell anode gas channel are oppositely arranged in parallel. A catalyst layer and a proton exchange membrane are clamped between the air self-breathing fuel cell cathode gas channel and the air self-breathing fuel cell anode gas channel.
The air self-breathing fuel cell cathode gas channel enriches oxygen in the air. And hydrogen is introduced into the air self-breathing fuel cell anode gas channel.
The air self-breathing fuel cell cathode gas channel includes a magnet and a porous structure.
The porous structure comprises a porous combined structure or a multi-filament combined structure.
The magnet divides the porous structure into several regions.
The number of the magnets is M. The number of the separated areas of the porous structure is M-1.
One side of the air self-breathing fuel cell cathode gas channel is connected with the catalyst layer, and the other side of the air self-breathing fuel cell cathode gas channel is communicated with the external atmospheric environment.
One side of the air self-breathing fuel cell anode gas channel is connected with the catalyst layer to form a hydrogen gas channel isolated from the external atmospheric environment.
Further, the magnet is perpendicular to the catalytic layer, and the magnet is magnetized in a direction parallel to the catalytic layer.
The different position magnets are arranged parallel to each other with the N and S poles of the different magnets arranged opposite.
Furthermore, the porous structure is composed of a columnar structure array, and the columnar structure is made of ferromagnetic metal materials or alloy materials. Ferromagnetic materials include iron, cobalt or nickel.
The cross section of the columnar structure comprises a plurality of types, and the cross section of the columnar structure comprises a circle or an equilateral triangle.
In the cross-section: area range of 10-5～5 mm2The height range is 2-40 mm.
The distance range between the columnar structures is 0.1-5 mm.
Further, the distance between every two adjacent magnets is 1-30 cm.
Further, the surface remanence range of the magnet is 0.1-1.5T, and the gradient range of the magnetic field in the porous structure envelope space is 2 multiplied by 101～5×105T/m。
It is worth mentioning that: and a special cathode gas channel design is adopted, so that the enrichment and mass transfer of oxygen are enhanced, and the power of the air self-breathing fuel cell is improved.
Oxygen in air belongs to typical paramagnetic substances, when air enters a magnetic field with gradient, oxygen molecules in the air are subjected to Kelvin force, and the direction of the force points to the direction of increasing magnetic field gradient (Kelvin force)
Wherein mu04 π × 10 for vacuum permeability-7H/m; χ is the magnetic susceptibility, and the oxygen magnetic susceptibility χ =3.45 × 10-3(ii) a B is the magnetic field strength, T).
It is possible to magnetize the porous structure under the magnetic field of the magnet by arranging the porous structure and the magnet in the cathode gas passage. The calculation result shows that the high magnetic field gradient formed in the porous structure can reach 2 multiplied by 105T/m. Water belongs to a diamagnetic substance and is subjected to Kelvin force pointing to the gradient reduction direction of the magnetic field in the gradient magnetic field of the cathode gas channel, so that water generated by cathode reaction is discharged in time, and the mass transfer process of cathode oxygen can be further promoted. Oxygen is enriched within the porous structure due to the effect of the kelvin force.
Because the porous medium structure is close to the cathode catalyst layer, oxygen is continuously consumed, so that the continuous enrichment effect of oxygen can be realized, the oxygen concentration of the cathode is increased, and the power of the fuel cell is improved.
The technical effects of the present invention are undoubted, and the present invention has the following advantages:
1) the invention combines the magnet and the porous structure composed of ferromagnetic material, forms a high gradient magnetic field in the cathode gas channel, and achieves the purpose of improving the cathode oxygen concentration and discharging the cathode generated water by utilizing the obvious effect of Kelvin force on paramagnetic oxygen and diamagnetic water, thereby improving the power of the fuel cell.
2) The method of the invention can obviously improve the power of the air self-breathing fuel cell and has wide application prospect.
Drawings
FIG. 1 is a schematic diagram of an air self-breathing fuel cell in accordance with the present invention;
fig. 2 is an enlarged view of the cathode gas passage of the air self-breathing fuel cell of the present invention.
In the figure: an air self-breathing fuel cell cathode gas channel 1, a magnet 101, a porous structure 102, an air self-breathing fuel cell anode gas channel 2, a catalyst layer 3 and a proton exchange membrane 4.
Detailed Description
The present invention is further illustrated by the following examples, but it should not be construed that the scope of the above-described subject matter is limited to the following examples. Various substitutions and alterations can be made without departing from the technical idea of the invention and the scope of the invention is covered by the present invention according to the common technical knowledge and the conventional means in the field.
Example 1:
a method for improving the oxygen concentration of the cathode of an air self-breathing fuel cell by utilizing a magnetic porous medium structure is characterized in that: the oxygen enrichment of the cathode is realized through the adsorption of the gradient magnetic field on the surface of the porous structure to the oxygen.
The porous structure comprises an air self-breathing fuel cell cathode gas channel 1, an air self-breathing fuel cell anode gas channel 2, a catalyst layer 3 and a proton exchange membrane 4.
The air self-breathing fuel cell cathode gas channel 1 and the air self-breathing fuel cell anode gas channel 2 are oppositely arranged in parallel. A catalyst layer 3 and a proton exchange membrane 4 are clamped between the air self-breathing fuel cell cathode gas channel 1 and the air self-breathing fuel cell anode gas channel 2.
The air self-breathing fuel cell cathode gas channel 1 is enriched with oxygen in the air. And hydrogen is introduced into the air self-breathing fuel cell anode gas channel 2.
The air self-breathing fuel cell cathode gas channel 1 includes a magnet 101 and a porous structure 102.
The magnet 101 is perpendicular to the catalytic layer 3, and the magnet 101 is magnetized in a direction parallel to the catalytic layer 3. The different-position magnets 101 are arranged in parallel with each other, and the N and S poles of the different-position magnets 101 are arranged oppositely.
The porous structure 102 comprises a porous composite structure or a multi-filament composite structure.
The magnet 101 divides the porous structure 102 into several areas.
The number of magnets 101 is M. The number of regions into which the porous structure 102 is divided is M-1.
The distance between two adjacent magnets 101 is 1-30 cm.
One side of the air self-breathing fuel cell cathode gas channel 1 is connected with the catalyst layer 3, and the other side is communicated with the external atmosphere environment.
One side of the air self-breathing fuel cell anode gas channel 2 is connected with the catalyst layer 3 to form a hydrogen gas channel isolated from the external atmospheric environment.
The porous structure 102 is composed of an array of columnar structures, and the columnar structures are made of ferromagnetic metal materials or alloy materials. Ferromagnetic materials include iron, cobalt or nickel.
The cross section of the columnar structure comprises a plurality of types, and the cross section of the columnar structure comprises a circle or an equilateral triangle.
In the cross-section: area range of 10-5～5 mm2The height range is 2-40 mm. The distance range between the columnar structures is 0.1-5 mm.
The surface remanence range of the magnet 101 is 0.1-1.5T, and the gradient range of the magnetic field in the space enveloped by the porous structure 102 is 2 multiplied by 101～5×105T/m。
The invention can realize the enrichment of oxygen in the cathode gas channel of the air self-breathing fuel cell only by Kelvin force, thereby achieving the purpose of improving the cathode oxygen concentration of the air self-breathing fuel cell. On the basis of proposing a theoretical scheme, the high-gradient magnetic field is formed through reasonable structural design. The air self-breathing fuel cell cathode can well adsorb oxygen of air and accelerate the discharge of water generated by the cathode reaction of the fuel cell.
Example 2:
as shown in fig. 1 and fig. 2, a method for increasing oxygen concentration of cathode of air self-breathing fuel cell by using magnetic porous medium structure is characterized in that: the oxygen enrichment of the cathode is realized through the adsorption of the gradient magnetic field on the surface of the porous structure to the oxygen.
The porous structure comprises an air self-breathing fuel cell cathode gas channel 1, an air self-breathing fuel cell anode gas channel 2, a catalyst layer 3 and a proton exchange membrane 4.
The air self-breathing fuel cell cathode gas channel 1 and the air self-breathing fuel cell anode gas channel 2 are oppositely arranged in parallel. A catalyst layer 3 and a proton exchange membrane 4 are clamped between the air self-breathing fuel cell cathode gas channel 1 and the air self-breathing fuel cell anode gas channel 2.
The air self-breathing fuel cell cathode gas channel 1 is enriched with oxygen in the air. And hydrogen is introduced into the air self-breathing fuel cell anode gas channel 2.
The air self-breathing fuel cell cathode gas channel 1 includes a magnet 101 and a porous structure 102.
The magnet 101 is perpendicular to the catalytic layer 3, and the magnet 101 is magnetized in a direction parallel to the catalytic layer 3. The different magnets 101 are arranged parallel to each other with the N and S poles of the different magnets 101 arranged opposite each other.
The porous structure 102 comprises a porous composite structure or a multi-filament composite structure.
The magnet 101 divides the porous structure 102 into several areas.
The number of magnets 101 is M. The number of regions into which the porous structure 102 is divided is M-1.
The distance between the two adjacent magnets 101 is 2.8 cm.
One side of the air self-breathing fuel cell cathode gas channel 1 is connected with the catalyst layer 3, and the other side is communicated with the external atmosphere environment.
One side of the air self-breathing fuel cell anode gas channel 2 is connected with the catalyst layer 3 to form a hydrogen gas channel isolated from the external atmospheric environment.
The porous structure 102 is composed of an array of columnar structures, and the columnar structures are made of ferromagnetic metal materials or alloy materials. Ferromagnetic materials include iron, cobalt or nickel.
The cross section of the columnar structure is circular.
In the cross-section: area of 2X 10-4mm2And the height is 3 mm. The distance between the columnar structures is 0.3 mm.
The surface remanence of the magnet 101 is 0.6T, and the magnetic field gradient in the space enveloped by the porous structure 102 is 4 multiplied by 105T/m。
The invention can realize the enrichment of oxygen in the cathode gas channel of the air self-breathing fuel cell only by Kelvin force, thereby achieving the purpose of improving the cathode oxygen concentration of the air self-breathing fuel cell. On the basis of proposing a theoretical scheme, the high-gradient magnetic field is formed through reasonable structural design. The air self-breathing fuel cell cathode can well adsorb oxygen of air and accelerate the discharge of water generated by the cathode reaction of the fuel cell.
Claims (4)
1. A method for improving the oxygen concentration of the cathode of an air self-breathing fuel cell by utilizing a magnetic porous medium structure is characterized in that: realizing cathode oxygen enrichment through the adsorption of the gradient magnetic field on the surface of the porous structure (102) to oxygen;
the device comprises an air self-breathing fuel cell cathode gas channel (1), an air self-breathing fuel cell anode gas channel (2), a catalyst layer (3) and a proton exchange membrane (4);
the air self-breathing fuel cell cathode gas channel (1) and the air self-breathing fuel cell anode gas channel (2) are oppositely arranged in parallel; a catalyst layer (3) and a proton exchange membrane (4) are clamped between the air self-breathing fuel cell cathode gas channel (1) and the air self-breathing fuel cell anode gas channel (2);
the air self-breathing fuel cell cathode gas channel (1) is enriched with oxygen in the air; hydrogen is introduced into the air self-breathing fuel cell anode gas channel (2);
the air self-breathing fuel cell cathode gas channel (1) comprises a magnet (101) and a porous structure (102);
the porous structure (102) comprises a porous composite structure or a multi-filament composite structure; the porous structure (102) is composed of a ferromagnetic material;
the magnet (101) divides the porous structure (102) into a plurality of areas;
the number of magnets (101) is M; the number of the separated areas of the porous structure (102) is M-1;
one side of the air self-breathing fuel cell cathode gas channel (1) is connected with the catalyst layer (3), and the other side is communicated with the external atmosphere environment; the magnet (101) is vertical to the catalytic layer (3), and the magnet (101) is magnetized along the direction parallel to the catalytic layer (3); the magnets (101) at different positions are arranged in parallel with each other, and the N poles and the S poles of the different magnets (101) are arranged oppositely;
one side of the air self-breathing fuel cell anode gas channel (2) is connected with the catalyst layer (3) to form a hydrogen gas channel isolated from the external atmospheric environment.
2. The method for increasing the oxygen concentration of the cathode of the air self-breathing fuel cell by using the magnetic porous medium structure as claimed in claim 1, wherein the method comprises the following steps: the porous structure (102) is composed of a columnar structure array, and the columnar structure is made of ferromagnetic metal materials or alloy materials; ferromagnetic materials include iron, cobalt or nickel;
the cross section of the columnar structure comprises a circle or an equilateral triangle;
in the cross-section: area range of 10-5～5 mm2The height range is 2-40 mm;
the distance range between the columnar structures is 0.1-5 mm.
3. The method for increasing the oxygen concentration of the cathode of the air self-breathing fuel cell by using the magnetic porous medium structure as claimed in claim 1, wherein the method comprises the following steps: the distance between two adjacent magnets (101) is 1-30 cm.
4. The method of claim 1 for enhancing air self-breathing fuel power using magnetic porous media structureThe method for controlling the oxygen concentration of the cathode of the cell is characterized in that: the surface remanence range of the magnet (101) is 0.1-1.5T, and the gradient range of the magnetic field in the enveloping space of the porous structure (102) is 2 multiplied by 101～5×105T/m。
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| CN113851686B (en) * | 2021-11-30 | 2022-03-11 | 华中科技大学 | Hydrogen fuel cell stack device based on magnetic field regulation and control |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2268022Y (en) * | 1996-09-25 | 1997-11-19 | 赵福平 | high-gradient magnetic separation Qxygen generator |
| CN1215623A (en) * | 1998-10-12 | 1999-05-05 | 李榕生 | Compact high-efficiency low-energy consumption magnetic gas separating apparatus and its use |
| CN1245734A (en) * | 1998-10-12 | 2000-03-01 | 李榕生 | Compact type high-efficiency low energy consumption gas magnetic separation equipment and its application |
| CN101054164A (en) * | 2007-02-07 | 2007-10-17 | 北京科技大学 | Stacked magnet array structure device and method for enriching oxygen in air by magnetic force |
| CN103884153A (en) * | 2014-03-24 | 2014-06-25 | 浙江大学 | Gradient magnetic field auxiliary low temperature fractionation air separation method and device |
-
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- 2018-06-04 CN CN201810562472.4A patent/CN108899561B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2268022Y (en) * | 1996-09-25 | 1997-11-19 | 赵福平 | high-gradient magnetic separation Qxygen generator |
| CN1215623A (en) * | 1998-10-12 | 1999-05-05 | 李榕生 | Compact high-efficiency low-energy consumption magnetic gas separating apparatus and its use |
| CN1245734A (en) * | 1998-10-12 | 2000-03-01 | 李榕生 | Compact type high-efficiency low energy consumption gas magnetic separation equipment and its application |
| CN101054164A (en) * | 2007-02-07 | 2007-10-17 | 北京科技大学 | Stacked magnet array structure device and method for enriching oxygen in air by magnetic force |
| CN103884153A (en) * | 2014-03-24 | 2014-06-25 | 浙江大学 | Gradient magnetic field auxiliary low temperature fractionation air separation method and device |
Non-Patent Citations (1)
| Title |
|---|
| "质子交换膜燃料电池阴极输运特性及性能优化";李文安;《中国优秀硕士学位论文全文数据库工程科技Ⅱ辑》;20110915(第2011年09期);第C042-672页 * |
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