A medium temperature ammonia fuel cell

Abstract

The application discloses a medium-temperature ammonia fuel cell, which comprises an ammonia decomposition hydrogen production cell and a fuel cell; the ammonia decomposition hydrogen production cell is connected with a power supply device at both ends; the ammonia decomposition hydrogen production cell is provided with an ammonia gas inlet and a reaction product outlet at both ends, and the reaction product outlet is communicated with an inlet channel of the fuel cell; ammonia gas enters the ammonia decomposition hydrogen production cell through the ammonia gas inlet, hydrogen is generated after the ammonia gas passes through an ammonia cracking layer, and the hydrogen is oxidized to generate proton hydrogen after passing through a hydrogen oxidation electrocatalytic layer; the proton hydrogen is subjected to a hydrogen evolution reaction to generate hydrogen after passing through a first solid acid electrolyte membrane to a hydrogen evolution electrocatalytic layer, and the hydrogen enters the fuel cell through the reaction product outlet and reacts with oxygen in the fuel cell. The cell of the application can realize water-free proton transmission and work at a temperature of 250 DEG C, ammonia is decomposed into hydrogen, hydrogen is converted into protons, hydrogen is generated by driving through a solid acid electrolyte membrane to a hydrogen evolution electrocatalytic layer by electricity, no impurity ion which poisons the electrolyte membrane is generated, and the damage to the proton exchange membrane is reduced.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and specifically to a medium-temperature ammonia fuel cell. Background Technology

[0002] Fuel cells are a new type of power generation device characterized by their pollution-free and high efficiency. Their working principle involves directly converting the chemical energy of stored fuel into electrical energy without combustion. Because combustion is omitted, they are not subject to the limitations of the Carnot cycle, thus achieving a high theoretical energy conversion efficiency, typically reaching 50%-60%. Furthermore, no combustion waste is released into the environment during power generation, making them widely recognized as the cleanest energy technology of the 21st century. Ammonia, as an emerging low-carbon energy carrier, is considered one of the long-term technological options for addressing climate change. When used in conjunction with fuel cells, its energy content can be efficiently converted as needed without generating COx or other exhaust emissions, making it one of the ideal fuels for future automotive fuel cells.

[0003] Currently, automotive fuel cells are generally proton exchange membrane fuel cells (PEMFCs). However, PEMFCs have some unavoidable problems: (1) The operating temperature range is 60-80℃, and they cannot work above 100℃, which places high demands on the thermal management of automotive batteries; (2) They require cumbersome water management to cope with the hydration effect of the perfluorosulfonic acid membrane and avoid the risk of the catalyst being flooded; (3) The core component, the perfluorosulfonic acid membrane, is expensive. In addition, when ammonia is used as fuel in a PEMFC, the protons in the perfluorosulfonic acid membrane will react with the high concentration of ammonia to generate NH4+. 4+ Ions cause irreversible degradation of PEMFC performance. Summary of the Invention

[0004] To address the aforementioned problems in the prior art, the present invention provides a medium-temperature ammonia fuel cell.

[0005] This invention discloses a medium-temperature ammonia fuel cell, comprising a first porous substrate, an ammonia decomposition layer, a hydroxide electrocatalytic layer, a first solid acid electrolyte membrane, a hydrogen evolution electrocatalytic layer, a second porous substrate, a first bipolar plate, an anode catalyst layer, a second solid acid electrolyte membrane, a cathode catalyst layer, a gas diffusion layer, a second bipolar plate, and an end plate arranged sequentially; the structure from the first porous substrate to the second porous substrate forms an ammonia decomposition hydrogen production battery, and the structure from the first bipolar plate to the end plate forms a fuel cell;

[0006] The two ends of the ammonia decomposition hydrogen production battery are connected to a power supply device, and the ammonia decomposition hydrogen production battery is started after power is turned on.

[0007] The ammonia decomposition hydrogen production battery has an ammonia inlet and a reaction product outlet at both ends. The reaction product outlet is connected to the fuel cell inlet channel. Ammonia enters the ammonia decomposition hydrogen production battery through the ammonia inlet, and after passing through the ammonia cracking layer, the ammonia produces hydrogen. The hydrogen passes through the hydroxide electrocatalytic layer and is oxidized to produce protonated hydrogen. The protonated hydrogen passes through the first solid acid electrolyte membrane to the hydrogen evolution electrocatalytic layer and undergoes a hydrogen evolution reaction to produce hydrogen. The hydrogen enters the fuel cell through the reaction product outlet and reacts with oxygen in the air in the fuel cell.

[0008] Preferably, the ammonia cracking layer includes an ammonia cracking hydrogen production catalyst and a corresponding support. The cracking catalyst includes one or a combination of Ru-based and Cs-based catalysts. The particle size of the ammonia cracking catalyst is 20nm-300nm. The support includes, but is not limited to, carbon support, perovskite, graphene, and carbon nanotubes.

[0009] Preferably, both the hydrogen hydroxide electrocatalytic layer and the hydrogen evolution electrocatalytic layer include a catalytic host and a corresponding support. The catalytic host includes a solid acid and Pt or Pd. The support includes, but is not limited to, carbon support, perovskite, graphene, and carbon nanotubes.

[0010] Preferably, both the first solid acid electrolyte membrane and the second solid acid electrolyte membrane comprise a host and a composite, wherein the host comprises CsH2PO4 and CsHPO4, and the composite comprises epoxy resin, SiO2, and SiP2O7.

[0011] Preferably, both the anode catalyst layer and the cathode catalyst layer include a catalyst and a corresponding support, wherein the catalyst includes Pt or Pd; and the support includes, but is not limited to, carbon support, perovskite, graphene, and carbon nanotubes.

[0012] Preferably, the gas diffusion layer includes, but is not limited to, a carbon support.

[0013] Preferably, the materials used for the first porous substrate and the second porous substrate include any one of graphite, stainless steel plated with gold or amorphous carbon, and titanium alloy plate.

[0014] Preferably, the end plate is made of any one of stainless steel or titanium alloy plates with gold or amorphous carbon plating.

[0015] Preferably, the ammonia gas introduced is humidified ammonia gas, and the pressure of the humidifying ammonia gas is 0.3 atm-0.7 atm.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] This invention relates to an ammonia decomposition hydrogen production battery, an electrochemical battery with anhydrous proton transport and an operating temperature up to 250°C, using a solid acid electrolyte. In this battery, after ammonia decomposes into hydrogen, the hydrogen is immediately converted into protons, which are then electrically driven through the solid acid electrolyte membrane to the hydrogen evolution electrocatalytic layer to produce hydrogen gas. This hydrogen gas does not need to be separated from any unreacted ammonia or other products, and does not produce any impurity ions that poison the electrolyte membrane, thus reducing irreversible damage to the proton exchange membrane. Starting the ammonia decomposition hydrogen production battery can rapidly produce hydrogen gas, which is then used by a hydrogen fuel cell. According to the Teschatel principle, the hydrogen fuel cell continuously consumes hydrogen gas, which drives the ammonia decomposition hydrogen production battery to continuously generate hydrogen gas. This battery can generate electricity sustainably, far exceeding the performance of traditional ammonia fuel cells that rely solely on ammonia cracking. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the medium-temperature ammonia fuel cell of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] The present invention will now be described in further detail with reference to the accompanying drawings:

[0021] Reference Figure 1 The present invention provides a medium-temperature ammonia fuel cell comprising, in sequence, a first porous substrate 1, an ammonia decomposition layer 2, a hydroxide electrocatalytic layer 3, a first solid acid electrolyte membrane 4, a hydrogen evolution electrocatalytic layer 5, a second porous substrate 6, a first bipolar plate 7, an anode catalyst layer 8, a second solid acid electrolyte membrane 9, a cathode catalyst layer 10, a gas diffusion layer 11, a second bipolar plate 12, and an end plate 13; the structure of the first porous substrate 1 to the second porous substrate 6 forms an ammonia decomposition hydrogen production battery, and the structure of the first bipolar plate 7 to the end plate 13 forms a fuel cell;

[0022] Specifically, the ammonia decomposition hydrogen production battery is an electrochemical cell with anhydrous proton transport and a working temperature of up to 250°C using a solid acid electrolyte. In this battery, after ammonia decomposes into hydrogen, the hydrogen is immediately converted into protons, which are then used by electricity to pass through the proton conduction membrane to produce hydrogen gas. The produced hydrogen gas is then transferred to the next stage connected to the fuel cell, where chemical energy is converted into electrical energy. According to the Teschatel principle, the fuel cell continuously consumes hydrogen gas, which drives the electrochemical cell to continuously generate hydrogen gas. This composite battery can generate electricity sustainably, far exceeding the performance of traditional ammonia fuel cells that rely solely on ammonia decomposition.

[0023] The two ends of the ammonia decomposition hydrogen production battery are connected to a power supply device, and the ammonia decomposition hydrogen production battery is started after power is turned on.

[0024] The ammonia decomposition hydrogen production battery has an ammonia inlet and a reaction product outlet at both ends. The reaction product outlet is connected to the fuel cell inlet channel. Ammonia enters the ammonia decomposition hydrogen production battery through the ammonia inlet, and after passing through the ammonia cracking layer 2, the ammonia produces hydrogen. After passing through the hydroxide electrocatalytic layer 3, the hydrogen is oxidized to produce proton hydrogen. The proton hydrogen passes through the first solid acid electrolyte membrane 4 to the hydrogen evolution electrocatalytic layer 5 and undergoes a hydrogen evolution reaction to produce hydrogen. The hydrogen enters the fuel cell through the reaction product outlet and reacts with oxygen in the air in the fuel cell.

[0025] Specifically, the first porous substrate 1 and the second porous substrate 6 in the ammonia decomposition hydrogen production battery are connected to a power supply device, and the ammonia decomposition hydrogen production battery is started after power is applied; the first porous substrate 1 is provided with an ammonia inlet, and the second porous substrate 6 is provided with a reaction product outlet. The materials used for the first porous substrate 1 and the second porous substrate 6 include any one of graphite, stainless steel plated with gold or amorphous carbon, and titanium alloy plate; the ammonia cracking layer 2 includes an ammonia cracking hydrogen production catalyst and a corresponding support. The cracking catalyst includes one or a combination of Ru-based and Cs-based catalysts; the particle size of the ammonia cracking catalyst is 20nm-300nm; the support includes, but is not limited to, carbon support, perovskite, graphene, and carbon nanotubes; the hydroxide electrocatalytic layer 3 and the hydrogen evolution electrocatalytic layer 5 both include a catalyst host and a corresponding support. The catalyst host includes a solid acid and Pt or Pd, and the support includes, but is not limited to, carbon support, perovskite, graphene, and carbon nanotubes; the gas diffusion layer includes, but is not limited to, a carbon support, such as carbon paper or carbon cloth; therefore, ammonia gas is converted into hydrogen gas after passing through the ammonia cracking layer 2, and the hydrogen gas is oxidized to produce H after passing through the hydroxide electrocatalytic layer 3. + H + After passing through the solid acid electrolyte membrane to the hydrogen evolution electrocatalytic layer 5, a hydrogen evolution reaction occurs to produce hydrogen gas. The hydrogen gas then enters the fuel cell through the outlet of the second porous substrate. The end plate 13 of the fuel cell is provided with an air inlet and a reactant outlet. In the fuel cell, the hydrogen gas produced by the ammonia decomposition hydrogen production battery reacts with oxygen in the air to convert chemical energy into electrical energy.

[0026] In this embodiment, both the first solid acid electrolyte membrane 4 and the second solid acid electrolyte membrane 9 include a host and a composite. The host includes CsH2PO4 and CsHPO4; the composite includes epoxy resin, SiO2, and SiP2O7. Both the anode catalyst layer 8 and the cathode catalyst layer 10 include a catalyst and a corresponding support. The catalyst includes Pt or Pd; the support includes, but is not limited to, carbon support, perovskite, graphene, and carbon nanotubes. The end plate 13 is made of any one of stainless steel or titanium alloy plates with a gold-plated or amorphous carbon-plated surface.

[0027] In this embodiment, the ammonia gas introduced is humidified ammonia gas, and the pressure of the humidifying ammonia gas is 0.3 atm-0.7 atm.

[0028] The medium-temperature ammonia fuel cell provided in this application includes an ammonia decomposition hydrogen production battery and a hydrogen fuel cell. By starting the ammonia decomposition hydrogen production battery with a power supply device, hydrogen can be rapidly generated. The generated hydrogen is used by the hydrogen fuel cell, accelerating the reaction at the hydrogen production end. This medium-temperature ammonia fuel cell can operate stably for a long time and has the advantages of high flexibility, low energy consumption, and high utilization rate. The high-purity hydrogen produced by the battery in this application does not need to be separated from any unreacted ammonia or other products, and does not produce any impurity ions that poison the electrolyte membrane, reducing irreversible damage to the proton exchange membrane. Furthermore, it does not require any ammonia removal device, simplifying the structure and improving efficiency. The battery in this application operates efficiently; all the current from the primary battery is directly used to generate hydrogen without any loss due to parasitic reactions, achieving optimal utilization of electrical energy and improving system efficiency. The battery in this application is based on a solid acid electrolyte, and the increased operating temperature reduces the difficulty of thermal management for automotive batteries. The anhydrous proton transport characteristic also greatly simplifies cumbersome water management.

[0029] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A medium-temperature ammonia fuel cell, characterized in that, The device includes, in sequence, a first porous substrate, an ammonia decomposition layer, a hydrogen hydroxide electrocatalytic layer, a first solid acid electrolyte membrane, a hydrogen evolution electrocatalytic layer, a second porous substrate, a first bipolar plate, an anode catalytic layer, a second solid acid electrolyte membrane, a cathode catalytic layer, a gas diffusion layer, a second bipolar plate, and an end plate; the structure from the first porous substrate to the second porous substrate forms an ammonia decomposition hydrogen production battery, and the structure from the first bipolar plate to the end plate forms a fuel cell; The two ends of the ammonia decomposition hydrogen production battery are connected to a power supply device, and the ammonia decomposition hydrogen production battery is started after power is turned on. The ammonia decomposition hydrogen production battery has an ammonia inlet and a reaction product outlet at both ends. The reaction product outlet is connected to the fuel cell inlet channel. Ammonia enters the ammonia decomposition hydrogen production battery through the ammonia inlet, and the ammonia produces hydrogen after passing through the ammonia cracking layer. The hydrogen is oxidized to produce protonated hydrogen after passing through the hydroxide electrocatalytic layer. The protonated hydrogen passes through the first solid acid electrolyte membrane to the hydrogen evolution electrocatalytic layer and undergoes a hydrogen evolution reaction to produce hydrogen. The hydrogen enters the fuel cell through the reaction product outlet and reacts with oxygen in the air in the fuel cell. The ammonia cracking layer includes an ammonia cracking hydrogen production catalyst and a corresponding support. The ammonia cracking hydrogen production catalyst includes one or a combination of Ru-based and Cs-based catalysts. The particle size of the ammonia cracking hydrogen production catalyst is 20nm-300nm. The support includes carbon support, perovskite, graphene, and carbon nanotubes. Both the first solid acid electrolyte membrane and the second solid acid electrolyte membrane comprise a main body and a composite. The main body comprises CsH2PO4 and CsHPO4, and the composite comprises epoxy resin, SiO2, and SiP2O7.

2. The intermediate-temperature ammonia fuel cell as described in claim 1, characterized in that, Both the hydrogen hydroxide electrocatalytic layer and the hydrogen evolution electrocatalytic layer include a catalytic host and a corresponding support. The catalytic host includes a solid acid and Pt or Pd. The support includes a carbon support, perovskite, graphene, or carbon nanotubes.

3. The medium-temperature ammonia fuel cell as described in claim 1, characterized in that, Both the anode catalyst layer and the cathode catalyst layer include a catalyst and a corresponding support. The catalyst includes Pt or Pd; the support includes carbon support, perovskite, graphene, and carbon nanotubes.

4. The medium-temperature ammonia fuel cell as described in claim 1, characterized in that, The gas diffusion layer includes a carbon support.

5. The intermediate-temperature ammonia fuel cell as described in claim 1, characterized in that, The materials used for the first porous substrate and the second porous substrate include any one of graphite, stainless steel plated with gold or amorphous carbon, and titanium alloy plate.

6. The intermediate-temperature ammonia fuel cell as described in claim 1, characterized in that, The end plate is made of any one of stainless steel or titanium alloy plates with gold or amorphous carbon plating.

7. The intermediate-temperature ammonia fuel cell as described in claim 1, characterized in that, The ammonia gas introduced is humidified ammonia gas, and the pressure of the humidified ammonia gas is 0.3 atm-0.7 atm.

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