An integrated metal hydrogen and oxygen fuel cell system based on aluminum-lithium alloy

Abstract

This invention discloses an integrated metal-hydrogen-oxygen fuel cell system based on an aluminum-lithium alloy. By optimizing the elemental composition and surface morphology of the metal-air battery anode, this invention significantly improves the hydrogen generation efficiency and stability while maintaining stable battery operating voltage. The use of 2195 aluminum-lithium alloy anode enhances electrochemical activity, and the optimized morphology exposes more reaction sites, ensuring continuous hydrogen production from side reactions and providing sufficient and stable fuel for the hydrogen-oxygen fuel cell. This system, by coupling the metal-air battery with the hydrogen-oxygen fuel cell, achieves efficient hydrogen recycling, avoiding the hydrogen waste problem in traditional batteries, and further improving the overall system energy efficiency and battery performance.

Description

Technical Field

[0001] This invention belongs to the field of high-energy power sources, and more specifically, relates to an integrated metal hydrogen-oxygen fuel cell system based on an aluminum-lithium alloy. Background Technology

[0002] With the development of science and technology, the development and design of high-energy portable power supplies and emergency devices for environmental and energy applications is of great significance. Metal-air batteries use metal as the negative electrode fuel and oxygen as the positive electrode fuel to convert the chemical energy of the fuel into electrical energy. They consist of a metal negative electrode, a salt or alkaline aqueous solution electrolyte, and an oxygen positive electrode. Common materials for the metal negative electrode are Mg, Al, Zn, Fe, Li, and their alloys; the positive electrode catalyst is generally Pt; MnO2 and other active materials; and the electrolyte is generally a strong alkaline aqueous solution such as KOH or NaOH. Hydrogen-oxygen fuel cells use hydrogen and oxygen from the air as fuel to convert chemical energy into electrical energy. They consist of a hydrogen anode, a membrane, and an oxygen cathode. Hydrogen and oxygen, under the action of catalysts on the electrodes, generate water through the electrolyte. Commonly used hydrogen-oxygen fuel cells are proton exchange membrane fuel cells. These types of batteries are essentially just energy conversion devices. They have advantages such as high conversion efficiency, large capacity, high specific energy, wide power range, and no need for recharging. Metal-air batteries possess advantages such as high theoretical energy density, long shelf life, abundant raw materials, and high safety, making them widely applicable in portable power supplies, emergency power supplies, and other fields. However, the application of alkaline aluminum-air batteries faces the problem of hydrogen evolution side reaction at the negative electrode, which reduces the utilization rate of metals and the output voltage of individual cells, thus limiting the practical application of metal-air batteries.

[0003] To address the hydrogen evolution side reaction caused by corrosion of the negative electrode in metal-air batteries, the following three methods are currently employed.

[0004] (1) Adding other elements such as Sn, In, and Zn to the metal anode to form an alloy can increase the hydrogen evolution overpotential and suppress hydrogen evolution by side reactions. Currently, the highest hydrogen evolution suppression efficiency of this alloying method is 76%, which cannot effectively solve the hydrogen evolution problem.

[0005] (2) Add corrosion inhibitors such as NaCl, ZnO, and CaO to the electrolyte. Adding corrosion inhibitors to the electrolyte will reduce the conductivity of the electrolyte and significantly reduce the current density of the battery.

[0006] (3) Using pure magnesium or aluminum alloys as the negative electrode of a metal-air battery increases hydrogen evolution. This is then connected to a hydrogen-oxygen fuel cell via a gas pipeline to absorb the hydrogen produced by the side reaction of the metal-air battery negative electrode, forming a "dual fuel cell." However, this method results in excessive hydrogen evolution from the pure magnesium or aluminum negative electrode, limiting the hydrogen absorption capacity of the composite hydrogen-oxygen fuel cell. Therefore, the excessive amount of hydrogen produced by the side reaction of the air battery leads to reduced hydrogen utilization and wasted resources. The metal-air battery and the hydrogen-oxygen fuel cell are connected via a simple gas pipeline. This is essentially a combination of two independent batteries, which also reduces the energy utilization rate of the battery, thus hindering the development of high-energy battery power sources.

[0007] In view of this, the present invention is proposed. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide an integrated metal hydrogen-oxygen fuel cell system based on aluminum-lithium alloy, which solves the problems mentioned in the background art.

[0009] To solve the above-mentioned technical problems, the basic concept of the technical solution adopted by the present invention is as follows:

[0010] An integrated metal-hydrogen-oxygen fuel cell system based on an aluminum-lithium alloy is disclosed, comprising a combined power system formed by coupling a metal-air battery and a hydrogen-oxygen fuel cell. The metal-air battery includes a positive electrode, an electrolyte chamber, a negative electrode tab, an air outlet, and an aluminum-lithium alloy negative electrode. The positive electrode is connected to the electrolyte chamber and is responsible for reacting with oxygen in the air to generate current and support the continuous operation of the battery reaction. The electrolyte chamber is connected to the metal negative electrode tab, where the electrolyte reacts with the aluminum-lithium alloy negative electrode, and current is output through the negative electrode tab. The air outlet is located at the top of the metal-air battery and is used to discharge hydrogen gas generated by the side reaction at the aluminum-lithium alloy negative electrode, which is then transported to the hydrogen-oxygen fuel cell via a gas pipe.

[0011] Optionally, the aluminum-lithium alloy negative electrode is an alloy composed of Al, Mg, Cu, and Li metallic elements.

[0012] Optionally, the positive electrode of the metal-air battery is formed by sequentially stacking and pressing a waterproof and breathable membrane, a nickel mesh, a waterproof and breathable membrane, and a catalyst membrane. The waterproof and breathable membrane is formed by mixing and pressing PTFE and acetylene black or carbon black materials; wherein the PTFE content is 30-50wt% and the thickness of the waterproof and breathable membrane is 0.30mm.

[0013] Optionally, when preparing the positive electrode of the metal-air battery, a membrane electrode with a thickness of 0.56 mm is obtained by stacking and rolling in the order of waterproof and breathable membrane-nickel mesh-waterproof and breathable membrane-catalytic membrane, and then sintering it in a muffle furnace at 300 degrees for 1 hour to obtain a complete air positive electrode.

[0014] Optionally, the catalytic membrane is formed by mixing and pressing PTFE, conductive carbon, activated carbon, and manganese dioxide in a certain proportion, wherein the content of PTFE is 10-15wt%, the content of conductive carbon, activated carbon, and manganese dioxide is 20-30wt%, and the thickness of the nickel mesh is 0.3mm.

[0015] Optionally, the hydrogen-oxygen fuel cell includes an anode plate and a cathode plate. The hydrogen-oxygen fuel cell is equipped with a hydrogen-oxygen fuel cell membrane electrode assembly inside. A hydrogen-oxygen fuel cell tab is provided above the anode plate. The anode portion of the anode plate is provided with an anode hydrogen inlet connected to the gas outlet of the metal-air battery, which is used to introduce the hydrogen generated by the metal-air battery into the anode of the hydrogen-oxygen fuel cell for reaction.

[0016] Optionally, the opposite sides of the anode and cathode plates are coated with anodic and cathode catalysts, respectively, with catalyst loadings of 0.5 mg / cm³ for the anode and cathode catalyst layers, respectively. 2 And cathode 0.25mg / cm 2 Pt / C.

[0017] Optionally, a proton exchange membrane is provided inside the battery membrane electrode, and a titanium mesh is provided on the other side of the anode plate of the anode catalyst layer.

[0018] Optionally, the circuits of the metal-air battery and the hydrogen-oxygen fuel cell can be connected in series, parallel, or a combination of series and parallel.

[0019] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art. Of course, any product implementing the present invention does not necessarily need to achieve all of the following advantages at the same time:

[0020] 1. By optimizing the elemental composition and surface morphology of the metal-air battery anode, the hydrogen generation efficiency and stability were significantly improved while maintaining stable battery operating voltage. The use of a 2195 aluminum-lithium alloy anode enhanced electrochemical activity, and the optimized morphology exposed more reaction sites, ensuring continuous hydrogen production from side reactions and providing sufficient and stable fuel for the hydrogen-oxygen fuel cell. This system, by coupling the metal-air battery with the hydrogen-oxygen fuel cell, achieves efficient hydrogen recycling, avoiding the hydrogen waste problem in traditional batteries, and further improving the overall system energy efficiency and battery performance.

[0021] 2. The integrated metal-hydrogen-oxygen fuel cell system of this invention can effectively utilize the hydrogen produced by the negative electrode side reaction of a metal-air battery. By efficiently transferring the hydrogen to the hydrogen-oxygen fuel cell for secondary power generation, the utilization efficiency of hydrogen is greatly improved, thereby increasing the overall energy output of the system. This design avoids the potential safety hazards caused by hydrogen accumulation in the metal-air battery, effectively reducing the risk of explosion due to hydrogen accumulation. Simultaneously, the timely utilization of hydrogen makes the system operation more stable, reduces battery temperature, and extends the service life of the equipment. This integrated structural design is simple and compact, with easy-to-assemble modules, convenient for carrying and maintenance, and can flexibly adapt to the needs of different scenarios. The system is not only suitable for portable power supplies but can also provide stable backup power in emergency situations, meeting various power requirements and possessing broad application prospects and market potential.

[0022] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0023] The accompanying drawings described below are merely some embodiments. Those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0024] In the picture:

[0025] Figure 1 Elemental analysis and SEM images of the aluminum-lithium alloy anode in the metal-air battery of this invention;

[0026] Figure 2 This is a schematic diagram of the integrated metal hydrogen-oxygen fuel cell system structure in this invention;

[0027] Figure 3 The discharge curve of the hydrogen-oxygen fuel cell in Example 1 at low current density;

[0028] Figure 4 The discharge curve of the hydrogen-oxygen fuel cell in Example 2 under high current density is shown.

[0029] The attached diagram lists the components represented by each number as follows:

[0030] 1. Metal-air battery; 2. Hydrogen-oxygen fuel cell; 3. Positive electrode of metal-air battery; 4. Electrolyte chamber; 5. Negative electrode tab; 6. Air outlet of air battery; 7. Aluminum-lithium alloy negative electrode; 8. Anode plate; 9. Cathode plate; 10. Anode hydrogen inlet; 11. Battery membrane electrode; 12. Hydrogen-oxygen fuel cell tab.

[0031] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0032] The invention will now be described in further detail with reference to the accompanying drawings.

[0033] Please see Figure 1-4 As shown, this embodiment provides an integrated metal-hydrogen-oxygen fuel cell system based on an aluminum-lithium alloy, a combined power system formed by coupling a metal-air battery 1 and a hydrogen-oxygen fuel cell 2. The metal-air battery 1 includes a metal-air battery positive electrode 3, an electrolyte chamber 4, a negative electrode tab 5, an air battery outlet 6, and an aluminum-lithium alloy negative electrode 7. The metal-air battery positive electrode 3 is connected to the electrolyte chamber 4 and is responsible for reacting with oxygen in the air to generate current and support the continuous operation of the battery reaction. The electrolyte chamber 4 is connected to the metal negative electrode tab 5, and the electrolyte in the electrolyte chamber reacts with the aluminum-lithium alloy negative electrode 7, outputting current through the negative electrode tab 5. The air battery outlet 6 is located at the top of the metal-air battery 1 and is used to discharge hydrogen gas generated by the side reaction of the aluminum-lithium alloy negative electrode 7, which is then transported to the hydrogen-oxygen fuel cell 2 through a gas pipe.

[0034] This invention modifies the elements and morphology of the metal anode in an air battery. The increase in lithium in the aluminum-lithium alloy increases the electrochemical activity of the metal-air battery 1. Uniform corrosion in the aluminum-lithium alloy effectively exposes corrosion sites, providing a stable hydrogen source. The integrated metal-hydrogen-oxygen fuel cell system structure significantly improves the battery's energy utilization rate.

[0035] In this embodiment, the aluminum-lithium alloy anode 7 is an alloy composed of Al, Mg, Cu, and Li metallic elements.

[0036] In this embodiment, the metal-air battery positive electrode 3 is formed by sequentially stacking and pressing a waterproof and breathable membrane, a nickel mesh, a waterproof and breathable membrane, and a catalyst membrane. The waterproof and breathable membrane is formed by mixing and pressing PTFE and acetylene black or carbon black materials; wherein the PTFE content is 30-50wt%, and the thickness of the waterproof and breathable membrane is 0.30mm.

[0037] In this embodiment, when preparing the metal-air battery cathode 3, a membrane electrode with a thickness of 0.56 mm is obtained by stacking and rolling in the order of waterproof and breathable membrane-nickel mesh-waterproof and breathable membrane-catalytic membrane. After sintering in a muffle furnace at 300 degrees for 1 hour, a complete air cathode is obtained.

[0038] In this embodiment, the catalytic membrane is formed by mixing and pressing PTFE, conductive carbon, activated carbon, and manganese dioxide in a certain proportion, wherein the content of PTFE is 10-15wt%, the content of conductive carbon, activated carbon, and manganese dioxide is 20-30wt%, and the thickness of the nickel mesh is 0.3mm.

[0039] In this embodiment, the hydrogen-oxygen fuel cell 2 includes an anode plate 8 and a cathode plate 9. The hydrogen-oxygen fuel cell 2 is provided with a membrane electrode assembly. A hydrogen-oxygen fuel cell tab 12 is provided above the anode plate 8. The anode portion of the anode plate 8 is provided with an anode hydrogen inlet 10 that is connected to the outlet of the metal-air battery 1, which is used to introduce the hydrogen generated by the metal-air battery 1 into the anode of the hydrogen-oxygen fuel cell 2 for reaction.

[0040] In this embodiment, the opposite sides of the anode plate 8 and the cathode plate 9 are coated with an anode catalyst and a cathode catalyst, respectively. The catalyst loading of the anode catalyst layer and the cathode catalyst layer is 0.5 mg / cm³ for the anode and cathode catalyst layers, respectively. 2 And cathode 0.25mg / cm 2 Pt / C.

[0041] In this embodiment, a proton exchange membrane is disposed inside the battery membrane electrode 11, and a titanium mesh is disposed on the other side of the anode plate 8 of the anode catalyst layer. The titanium mesh electrode area is 16 cm². 2 .

[0042] In this embodiment, the circuits of the metal-air battery 1 and the hydrogen-oxygen fuel cell 2 are connected in series, parallel, or a combination of series and parallel.

[0043] Example 1

[0044] The negative electrode material is made of 2195 aluminum-lithium alloy, which has a uniform surface defect morphology, improving electrochemical activity and system energy utilization. During the reaction process of the metal-air battery 1, the aluminum-lithium alloy negative electrode 7 comes into contact with the electrolyte and undergoes an oxidation reaction, generating electrons and hydrogen. The generated hydrogen serves as the fuel source for the hydrogen-oxygen fuel cell 2. The negative electrode area is 30 cm². 2 This ensures sufficient reaction surface area to maintain stable current output.

[0045] The positive electrode is composed of a waterproof and breathable layer, a current collector nickel mesh, and a catalyst layer stacked together. The catalyst layer contains manganese dioxide catalyst, PTFE binder, conductive carbon, and activated carbon. These materials are mixed and then subjected to coarse and fine pressing on a roller press to form a 0.35 mm thick catalyst film, in which the PTFE content is 10 wt%, and the content of conductive carbon, activated carbon, and manganese dioxide is 33.3 wt%.

[0046] The waterproof and breathable layer is made of a mixture of 30% PTFE and 70% carbon black, with a thickness of 0.30 mm, ensuring unobstructed airflow to the positive electrode and preventing electrolyte leakage. The current collector uses a 0.3 mm thick nickel mesh to support the positive electrode structure and ensure efficient electron conduction.

[0047] A waterproof and breathable membrane, a nickel mesh, another waterproof and breathable membrane, and a catalytic membrane are stacked sequentially and pressed together using a roller press to obtain a membrane electrode assembly (MEA) with a total thickness of 0.56 mm. After assembly, the MEA is sintered in a muffle furnace at 300 °C for 1 hour to ensure electrode structure stability and improve conductivity and catalytic efficiency. The prepared MEA is used as the positive electrode in the metal-air battery 1. The electrolyte chamber 4 is filled with 100 ml of 4M KOH solution to support the negative electrode oxidation reaction and participate in the side reaction to generate hydrogen gas, while ensuring the high-efficiency operation of the battery.

[0048] Hydrogen generated at the aluminum-lithium alloy negative electrode 7 is discharged through the air battery outlet 6 and transported via a gas path to the anode hydrogen inlet 10 of the hydrogen-oxygen fuel cell 2. The hydrogen-oxygen fuel cell 2 employs a proton exchange membrane fuel cell (PEMFC) structure, using Nafion 212 as the electrolyte membrane. Both the anode and cathode use a 60% Pt / C catalyst with loadings of 0.5 mg / cm³. 2 and 0.25 mg / cm 2 Hydrogen gas decomposes into electrons and protons at the anode. Protons migrate through the proton exchange membrane to the cathode, where they combine with oxygen to form water. Electrons are transferred through an external circuit to form an electric current, which is output from the electrode tab 12 of the hydrogen-oxygen fuel cell. The titanium mesh current collector at the anode collects electrons and transfers them to the circuit, ensuring stable system operation.

[0049] The hydrogen passage in the anode chamber of the hydrogen-oxygen fuel cell 2 is connected to the gas outlet at the top of the aluminum-lithium-air battery, such as... Figure 2 As shown, the anode of the hydrogen-oxygen fuel cell 2 is vertically positioned directly above the aluminum-lithium-air battery. The dual hydrogen inlets of the hydrogen-oxygen fuel cell 2 are connected to the aluminum-lithium-air battery, ensuring that all hydrogen produced by the aluminum-lithium-air battery can enter the hydrogen-oxygen fuel cell 2. The dual inlets ensure uniform hydrogen coverage at the anode of the hydrogen-oxygen fuel cell 2, improving the discharge stability of the hydrogen-oxygen fuel cell 2. Unreacted hydrogen is recycled back to the hydrogen-oxygen fuel cell 2, improving the utilization rate of hydrogen in the fuel cell system and avoiding resource waste. In the integrated aluminum-lithium-air battery / hydrogen-oxygen fuel cell system structure, the tabs of both battery modules are on the same side, facilitating the connection of the battery circuitry.

[0050] The aluminum-lithium-air battery module of Example 1 and the hydrogen-oxygen fuel cell 2 were subjected to constant current discharge tests. The aluminum-lithium-air battery was tested at 5 mA / cm². 2 Operating under constant current discharge conditions, it maintained a stable power output. Meanwhile, the hydrogen-oxygen fuel cell 2 operated at 0-15 mA / cm². 2 Tests within the constant current discharge range demonstrated excellent electrochemical reaction performance; specific discharge curves are shown below. Figure 3 As shown.

[0051] Depend on Figure 3It can be seen that under the above test conditions, the average discharge voltage of the aluminum-lithium air battery is 1.53V, which is comparable to the performance of other commercial aluminum alloy air batteries on the market. However, the advantage of this system lies in its higher efficiency and more stable performance. Meanwhile, the hydrogen-oxygen fuel cell 2 operates at 0-15mA / cm². 2 The average discharge voltage within the range is 0.7V, and the discharge curve remains stable even under different current density conditions, indicating that the catalytic layer and proton exchange membrane structure of the battery ensure long-term stable power output. Tests show that the system achieves a hydrogen utilization rate of up to 74%. This means that the hydrogen generated through the negative electrode side reaction of the aluminum-lithium air battery is efficiently utilized by the hydrogen-oxygen fuel cell 2, reducing hydrogen waste. Traditional metal-air batteries 1 often suffer energy loss due to hydrogen evolution side reactions, while this system achieves effective hydrogen utilization and recycling by recovering hydrogen and using it for power generation in the hydrogen-oxygen fuel cell 2.

[0052] Specifically, the coupling structure of the integrated aluminum-lithium-air battery and hydrogen-oxygen fuel cell system not only improves the overall energy utilization of the system but also enhances the utilization efficiency of the metal anode. This dual-cell module design allows for the full utilization of the by-reaction products of the aluminum-lithium-air battery, avoiding resource waste found in traditional batteries. Furthermore, the system's stability and output voltage smoothness indicate its suitability for long-term operation.

[0053] Furthermore, by Figure 3 The results show that the average discharge voltage of a single aluminum-lithium air battery is 1.5V at a constant current discharge current of 5 mA / cm². The constant current discharge current of the hydrogen-oxygen fuel cell is 0-15 mA / cm². The figure also shows that under the above test conditions, the oxygen fuel cell achieves a constant current discharge current of 0-15 mA / cm². 2 Under constant current discharge, the average discharge voltage is 0.7V, demonstrating excellent discharge performance and high stability.

[0054] Hydrogen absorption rate reaches 74%.

[0055] Example 2

[0056] The aluminum-lithium anode area in Example 2 is 110 cm². 2 In Example 2, the aluminum-lithium anode area was significantly increased, from 30 cm². 2 Expanded to 110cm 2 This means that a larger surface area will improve the reaction efficiency of the electrodes and the overall power output of the battery.

[0057] In Example 2, the PTFE content of the catalyst layer was increased to 15 wt%, and the contents of conductive carbon, activated carbon, and manganese dioxide were 28.3 wt%. The electrolyte volume in Example 2 was increased to 300 ml to match a larger electrode area and ensure the efficiency and stability of the electrolysis reaction.

[0058] In Example 2, during the testing process, the aluminum-lithium air battery module and the hydrogen-oxygen fuel cell 2 were subjected to constant current discharge tests to verify their performance under high current density conditions. The aluminum-lithium air battery was tested at 5 mA / cm². 2 The first fuel cell operated under constant current discharge, maintaining a stable voltage output. The second fuel cell, however, operated under a higher current discharge of 15-25 mA / cm². 2 Constant current discharge tests were conducted within the specified range, and the specific performance data are as follows: Figure 4 As shown. The test results demonstrate the system's excellent performance at different current densities and prove its stability under high load operation. Under the above test conditions, the average discharge voltage of the aluminum-lithium air battery is 1.53V, which is consistent with the performance of other commercial aluminum alloy air batteries on the market. However, the system exhibits stronger stability and performance optimization capabilities at high current densities. The hydrogen-oxygen fuel cell 2 operates at 15-25mA / cm². 2 Within the constant current discharge range, the average discharge voltage remained at 0.6V. Even under higher current density conditions, the voltage decay of the system remained minimal, indicating that the catalyst layer and proton exchange membrane possess excellent stability and durability.

[0059] The system boasts a hydrogen utilization rate of up to 86%, far exceeding that of traditional fuel cell systems. This means that most of the hydrogen generated from the negative electrode of the lithium-aluminum battery is efficiently recovered and used in the power generation process of the hydrogen-oxygen fuel cell 2. This design solves the resource waste problem caused by the hydrogen evolution side reaction in the traditional metal-air battery 1, achieving efficient utilization and recycling of hydrogen. The hydrogen-oxygen fuel cell 2 maintains high-efficiency power generation under different load conditions, further improving the system's energy utilization rate.

[0060] Specifically, as the electrode area of ​​the metal-air battery 1 increases, the system can generate more hydrogen, thus meeting the operational requirements of the hydrogen-oxygen fuel cell 2 under high current density conditions. This modular combined power system, by integrating the aluminum-lithium air battery and the hydrogen-oxygen fuel cell 2, achieves higher power output and is suitable for high-power applications requiring long-term stable power supply. This design can meet the application requirements of high-demand scenarios such as emergency power supplies and backup power systems, while improving energy efficiency and reducing resource waste.

[0061] More specifically, Figure 4 The constant current discharge current of the Alcoa lithium-air battery is 5 mA / cm², and the constant current discharge current of the hydrogen-oxygen fuel cell is 15-25 mA / cm².

[0062] This invention is not limited to the embodiments described above. Anyone should understand that structural changes made under the guidance of this invention, and any technical solutions that are the same as or similar to this invention, fall within the protection scope of this invention. Technical aspects, shapes, and structures not described in detail in this invention are all publicly known technologies.

Claims

1. An integrated metal-hydrogen-oxygen fuel cell system based on an aluminum-lithium alloy, comprising a combined power system formed by coupling a metal-air battery (1) and a hydrogen-oxygen fuel cell (2), characterized in that, The metal-air battery (1) includes a metal-air battery positive electrode (3), an electrolyte chamber (4), a negative electrode tab (5), an air battery outlet (6), and an aluminum-lithium alloy negative electrode (7). The metal-air battery positive electrode (3) is connected to the electrolyte chamber (4) and is responsible for reacting with oxygen in the air to generate current and support the continuous progress of the battery reaction. The electrolyte chamber (4) is connected to the negative electrode tab (5), and the electrolyte in the electrolyte reacts with the aluminum-lithium alloy negative electrode (7) and outputs current through the negative electrode tab (5). The air battery outlet (6) is located at the top of the metal-air battery (1) and is used to discharge the hydrogen gas generated by the side reaction of the aluminum-lithium alloy negative electrode (7) and transport it to the hydrogen-oxygen fuel cell (2) through the gas pipe. The aluminum-lithium alloy anode (7) is an alloy composed of four metallic elements: Al, Mg, Cu, and Li. In the preparation of the metal-air battery cathode (3), the membrane electrode with a thickness of 0.56 mm is obtained by stacking and rolling in the order of waterproof and breathable membrane-nickel mesh-waterproof and breathable membrane-catalytic membrane. After sintering in a muffle furnace at 300 degrees for 1 hour, a complete air cathode is obtained.

2. The integrated metal hydrogen-oxygen fuel cell system based on an aluminum-lithium alloy structure according to claim 1, characterized in that, The positive electrode of the metal-air battery (3) is formed by stacking and pressing a waterproof and breathable membrane, a nickel mesh, a waterproof and breathable membrane and a catalyst membrane in sequence. The waterproof and breathable membrane is made by mixing and pressing PTFE and carbon black materials. The PTFE content is 30-50wt% and the thickness of the waterproof and breathable membrane is 0.30mm.

3. The integrated metal hydrogen-oxygen fuel cell system based on an aluminum-lithium alloy structure according to claim 2, characterized in that, The catalytic membrane is formed by mixing and pressing PTFE, conductive carbon, activated carbon and manganese dioxide in a certain proportion, wherein the content of PTFE is 10-15wt%, the content of each of conductive carbon, activated carbon and manganese dioxide is 20-30wt%, and the thickness of the nickel mesh is 0.3mm.

4. The integrated metal hydrogen-oxygen fuel cell system based on an aluminum-lithium alloy structure according to claim 3, characterized in that, The hydrogen-oxygen fuel cell (2) includes an anode plate (8) and a cathode plate (9). The hydrogen-oxygen fuel cell (2) is equipped with a membrane electrode assembly (MEA). A hydrogen-oxygen fuel cell tab (12) is provided above the anode plate (8). The anode portion of the anode plate (8) is provided with an anode hydrogen inlet (10) that is connected to the outlet of the metal-air battery (1) for introducing hydrogen generated by the metal-air battery (1) into the anode of the hydrogen-oxygen fuel cell (2) for reaction.

5. The integrated metal hydrogen-oxygen fuel cell system based on an aluminum-lithium alloy structure according to claim 4, characterized in that, The opposite sides of the anode plate (8) and the cathode plate (9) are coated with an anode catalyst and a cathode catalyst, respectively. The catalyst loading of the anode catalyst and the cathode catalyst is 0.5 mg / cm² of Pt / C for the anode and 0.25 mg / cm² of Pt / C for the cathode, respectively.

6. The integrated metal hydrogen-oxygen fuel cell system based on an aluminum-lithium alloy structure according to claim 5, characterized in that, The battery membrane electrode (11) is provided with a proton exchange membrane inside, and an anode catalyst layer is provided on one side of the anode plate (8), while a titanium mesh is provided on the other side of the anode plate (8).

7. The integrated metal hydrogen-oxygen fuel cell system based on an aluminum-lithium alloy structure according to claim 6, characterized in that, The circuits of the metal-air battery (1) and the hydrogen-oxygen fuel cell (2) are connected in series, in parallel or in a hybrid series-parallel manner.

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