A fuel cell applicable to water-soluble gas fuels

Abstract

The present invention relates to the field of fuel cells, and particularly relates to a fuel cell suitable for water-soluble gas fuels, which includes an anion exchange membrane. An anodic flow channel and a cathodic flow channel are respectively arranged on both sides of the anion exchange membrane. A dry anodic ammonia deflector is arranged at the inlet of the anodic flow channel, and wet anodic nitrogen inlets are arranged at intervals along the gas flow direction at the top of the anodic flow channel. This fuel cell is highly efficient and has strong adaptability, which helps to overcome the problem of fuel loss in the channels existing in existing direct water-soluble gas fuel cells.

Description

Technical Field

[0001] The present invention relates to the field of fuel cells, and particularly to a fuel cell suitable for water-soluble gas fuels. Background Art

[0002] In order to achieve zero tailpipe emissions in the ground transportation sector, direct gas fuel exchange membrane fuel cells that produce only nitrogen and water have recently been regarded as a promising transportation power source. In the past two years, when operating at high temperatures (80 °C), the performance supplied by gas fuels has been significantly improved (120 °C) and pressure (up to 4 bar). For most water-soluble gas fuels (methanol, ethanol, propanol, ammonia), there are choices and dilemmas between gas supply and liquid supply. Using liquid fuels in fuel cells has several disadvantages. During startup and shutdown, a large amount of liquid fuel circulating in the anode fuel circuit needs to be managed, which increases the complexity of the system. The mixing of anhydrous fuel with recycled liquid fuel further increases the complexity, while the alternative of storing fuel as a liquid reduces the energy density. Using conductive liquid fuel in high-pressure chimneys also causes corrosion problems and requires non-conductive chimney hardware. Finally, a large amount of liquid water in the fuel cell may lead to increased cathode flooding and fuel crossover.

[0003] The function of the flow channels of an anion exchange membrane fuel cell is mainly to transport reaction gases and discharge the water generated in the reaction, which is related to the efficiency of the entire fuel cell. For the inlet of water-soluble gas fuels, there is a dilemma between battery humidity and inlet fuel loss. Especially in the channels, wetting in the channels has no effect on battery performance, but premature encounter of fuel and water will increase fuel loss. The channels are always in a high-speed flow stage, and fuel saturation cannot be achieved in the channels, which will continuously consume fuel, increase losses, cause losses to the fuel cell, and reduce the battery efficiency at the same time. Summary of the Invention

[0004] The purpose of the present invention is to provide a fuel cell suitable for water-soluble gas fuels, which is efficient and highly adaptable, and helps to overcome the problem of fuel loss in the channels of existing direct water-soluble gas fuel fuel cells.

[0005] The technical solution of the present invention is as follows: A fuel cell suitable for water-soluble gas fuels includes an anion exchange membrane, an anode flow channel and a cathode flow channel are respectively arranged on both sides of the anion exchange membrane. A dry ammonia guide plate for the anode is arranged at the inlet of the anode flow channel, and wet nitrogen inlets for the anode are arranged at intervals along the gas flow direction at the top of the anode flow channel.

[0006] Further, the anode flow channel is arranged on the upper side of the anion exchange membrane, and the cathode flow channel is arranged on the lower side of the anion exchange membrane.

[0007] Further, a dry ammonia gas guide plate for the anode is arranged at intervals from top to bottom at the inlet of the anode flow channel. The dry ammonia gas guide plate for the anode is installed horizontally and is inclined downward toward one end along the gas flow direction.

[0008] Further, a plurality of pairs of wet nitrogen gas inlets for the anode are arranged at intervals along the gas flow direction at the top of the anode flow channel.

[0009] Further, an anode catalyst layer and an anode diffusion layer are sequentially arranged between the anion exchange membrane and the anode flow channel.

[0010] Further, a cathode catalyst layer and a cathode diffusion layer are sequentially arranged between the anion exchange membrane and the cathode flow channel.

[0011] Further, a cathode current collector plate is arranged on the outermost side of the cathode flow channel; an anode current collector plate is arranged on the outermost side of the anode flow channel.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] 1. The fuel cell adopts a structure with an inclined fuel inlet and a dry ammonia gas guide plate for the anode, which increases the flow of fuel to the gas diffusion layer and reduces the possibility of fuel loss.

[0014] 2. The fuel cell adopts a method of dispersed small-hole wet nitrogen gas inlets, uses nitrogen gas as a carrier of water vapor, and reduces the possibility of generating liquid water in the channel, thereby reducing fuel consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a system diagram corresponding to the flow channel of the present invention;

[0016] Figure 2 is the overall structure of the membrane electrode of the present invention

[0017] Figure 3 is a top view schematic diagram of the wet nitrogen gas inlet for the anode of the present invention;

[0018] In the figure: 1 - anode flow channel, 2 - anode diffusion layer, 3 - anode catalyst layer, 4 - anion exchange membrane, 5 - cathode catalyst layer, 6 - cathode diffusion layer, 7 - cathode flow channel, 8 - wet nitrogen gas inlet for the anode, 9 - dry ammonia gas guide plate for the anode. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] In order to make the above features and advantages of the present invention more understandable, specific embodiments are given below in conjunction with the accompanying drawings and are described in detail as follows, but the present invention is not limited thereto.

[0020] Reference Figures 1 to 3

[0021] A fuel cell applicable to water-soluble gas fuel includes an anion exchange membrane 4. An anode flow channel 1 and a cathode flow channel 7 are respectively arranged on both sides of the anion exchange membrane. An anode dry ammonia deflector 9 is arranged at the inlet of the anode flow channel, and anode wet nitrogen inlets 8 are arranged at intervals along the gas flow direction at the top of the anode flow channel. The inlet of the anode flow channel adopts the structural design of a deflector, which is convenient for the transport of fuel. For a direct water-soluble gas fuel cell with water-soluble gas fuel, the dissolution of fuel in water is a pain point problem that needs to be solved. By adopting this structural design, the liquid water existing in the anode flow channel is avoided, thus avoiding the problem of fuel loss. At the same time, the wettability of the membrane assembly is also taken into account, ensuring good ionic conductivity, thereby improving the battery performance.

[0022] In this embodiment, the anode flow channel is arranged on the upper side of the anion exchange membrane, and wet nitrogen is blown out from the anode wet nitrogen inlet at the top of the anode flow channel by relying on gravity. The cathode flow channel is arranged on the lower side of the anion exchange membrane.

[0023] In this embodiment, anode dry ammonia deflectors are arranged at intervals from top to bottom at the inlet of the anode flow channel. The anode dry ammonia deflectors are installed horizontally and are inclined downward towards one end along the gas flow direction. The fuel realizes the structure of blowing obliquely downward by relying on the anode dry ammonia deflector, avoiding excessive contact between the fuel and water in the channel and the possibility of the fuel dissolving in water in the channel. Moreover, it is convenient for the transport of fuel, improves the fuel utilization rate, and increases the battery performance.

[0024] In this embodiment, several pairs of anode wet nitrogen inlets are arranged at intervals along the gas flow direction at the top of the anode flow channel. The wet nitrogen is blown into the anode flow channel through the anode wet nitrogen inlets distributed all over the top, increasing the system humidity and reducing fuel loss at the same time.

[0025] In this embodiment, an anode catalyst layer 3 and an anode diffusion layer 2 are sequentially arranged between the anion exchange membrane and the anode flow channel.

[0026] In this embodiment, a cathode catalyst layer 5 and a cathode diffusion layer 6 are sequentially arranged between the anion exchange membrane and the cathode flow channel.

[0027] In this embodiment, a cathode current collector plate is further arranged on the outermost side of the cathode flow channel; an anode current collector plate is further arranged on the outermost side of the anode flow channel.

[0028] When an anion exchange membrane fuel cell operates, the wetted fuel and air enter the corresponding flow channels from the inlets of the anode flow channel and the cathode flow channel respectively, and then pass through the diffusion layer and the microporous layer to reach the catalyst layer for reaction. During the reaction process, the fuel in the anode catalyst layer undergoes an oxidation reaction, losing an electron and generating hydroxide ions. The generated hydroxide ions directly pass through the anion exchange membrane to reach the cathode catalyst layer, while the generated electrons can only reach the cathode catalyst layer through the external circuit, thus forming a connected circuit. Due to the water-soluble property of the fuel and the strong positive correlation between the electrolyte conductivity and water, these two pairs of contradictions are the problems that need to be solved in direct water-soluble gas fuel cells. By using the flow channel with this structure, the fuel and water vapor enter from different directions, greatly reducing the fuel loss in the flow channel and improving the efficiency of the battery operation.

[0029] The above are only the preferred embodiments of the present invention. For those of ordinary skill in the art, according to the teachings of the present invention, designing different forms of fuel cells suitable for water-soluble gas fuels does not require creative labor. Without departing from the principles and spirit of the present invention, all equal changes, modifications, substitutions, and variations made within the scope of the patent application of the present invention shall fall within the scope of the present invention.

Claims

1. A fuel cell applicable to water-soluble gas fuel, characterized in that, it includes an anion exchange membrane, an anode flow channel and a cathode flow channel are respectively arranged on both sides of the anion exchange membrane. The anode flow channel is arranged on the upper side of the anion exchange membrane. An anode dry ammonia guide plate is arranged at the inlet of the anode flow channel, and anode wet nitrogen inlets are arranged at intervals along the length direction at the top of the anode flow channel; the anode dry ammonia guide plates are arranged at intervals from top to bottom at the inlet of the anode flow channel. The anode dry ammonia guide plates are installed horizontally and inclined downward, and the anode gas is blown obliquely downward by relying on the anode dry ammonia guide plates.

2. The fuel cell applicable to water-soluble gas fuel according to claim 1, characterized in that, the cathode flow channel is arranged on the lower side of the anion exchange membrane.

3. The fuel cell applicable to water-soluble gas fuel according to claim 1, characterized in that, several pairs of anode wet nitrogen inlets are arranged at intervals along the length direction at the top of the anode flow channel.

4. The fuel cell applicable to water-soluble gas fuel according to claim 1, 2 or 3, characterized in that, an anode catalyst layer and an anode diffusion layer are sequentially arranged between the anion exchange membrane and the anode flow channel.

5. The fuel cell applicable to water-soluble gas fuel according to claim 4, characterized in that, a cathode catalyst layer and a cathode diffusion layer are sequentially arranged between the anion exchange membrane and the cathode flow channel.

6. The fuel cell applicable to water-soluble gas fuel according to claim 1, 2, 3 or 5, characterized in that, a cathode current collector plate is further arranged on the outermost side of the cathode flow channel; an anode current collector plate is further arranged on the outermost side of the anode flow channel.

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