Low-energy-consumption solid fuel cell type oxygen sensor and preparation method thereof

Abstract

The invention discloses a low-energy-consumption solid fuel cell type oxygen sensor and a preparation method thereof. The low-energy-consumption solid fuel cell type oxygen sensor comprises a membrane electrode component, and the membrane electrode component comprises a first conductive substrate, an anode catalyst layer, a solid electrolyte layer, a cathode catalyst layer and a second conductive substrate which are sequentially stacked. The solid electrolyte layer is used for separating the anode catalyst layer and the cathode catalyst layer and conducting protons, a preparation material of the anode catalyst layer and a preparation material of the cathode catalyst layer respectively comprise carrier materials loaded with catalytic metal particles, and the anode catalyst layer is used for carrying out oxidation reaction; and the cathode catalyst layer is used for oxygen to generate electrochemical reduction reaction. The low-energy-consumption solid-state fuel cell type oxygen sensor is free of an external power supply, all-solid-state, long in service life and high in stability.

Description

Technical Field

[0001] This application relates to the field of electrochemical technology, and in particular to a low-energy solid fuel cell-type oxygen sensor and its preparation method. Background Technology

[0002] Accurate monitoring of oxygen concentration is crucial in fields such as industrial safety, environmental monitoring, medical respiratory care, food packaging, and safety in confined spaces.

[0003] Traditional electrochemical oxygen sensors (such as those based on galvanic cells) typically use liquid or gel electrolytes, which are susceptible to electrolyte evaporation, drying out, or leakage, leading to sensor performance degradation and shortened lifespan, especially under high-temperature or long-term continuous operation conditions. Furthermore, some electrochemical oxygen sensors require an external power source (such as a potentiostat) to maintain the working electrode potential, increasing system complexity and power consumption. Fuel cell oxygen sensors are a special type of electrochemical sensor. In self-powered (without an external power supply) fuel cell oxygen sensors, a pair of electrodes with a potential difference is required to provide the driving force. Traditional electrode designs often use completely different material systems (such as platinum cathode / zinc anode), resulting in different electrode aging mechanisms, interface mismatch, and limited long-term stability. Summary of the Invention

[0004] Therefore, it is necessary to provide a low-energy-consumption solid-state fuel cell oxygen sensor that is all-solid-state, has a long lifespan, and high stability, without external power supply, and its preparation method.

[0005] One embodiment of this application provides a low-energy solid-state fuel cell type oxygen sensor.

[0006] A low-energy solid-state fuel cell-type oxygen sensor includes a membrane electrode assembly (MEA). The MEA comprises a first conductive substrate, an anode catalyst layer, a solid electrolyte layer, a cathode catalyst layer, and a second conductive substrate, which are sequentially stacked. The solid electrolyte layer separates the anode catalyst layer and the cathode catalyst layer and conducts protons. The anode catalyst layer is used for oxidation reactions, and the cathode catalyst layer is used for supplying oxygen for electrochemical reduction reactions. The materials used to prepare the anode catalyst layer and the cathode catalyst layer respectively include a support material loaded with catalytic metal particles. The loading amount of catalytic metal particles in the anode catalyst layer is less than that in the cathode catalyst layer. The catalytic metal particles include one or more of platinum nanoparticles, palladium nanoparticles, and gold nanoparticles. The support material includes one or more of tungsten trioxide composite materials, cerium dioxide composite materials, and tin dioxide composite materials.

[0007] In some embodiments, the loading of the catalytic metal particles in the cathode catalyst layer is 25% to 35%.

[0008] In some embodiments, the loading of the catalytic metal particles in the anode catalyst layer is 8% to 12%.

[0009] In some embodiments, the solid electrolyte layer includes a proton exchange membrane layer.

[0010] In some embodiments, the first conductive substrate and the second conductive substrate each independently comprise carbon paper.

[0011] In some embodiments, the low-energy solid fuel cell oxygen sensor further includes a first current collector and a second current collector, which are respectively stacked and connected to both sides of the membrane electrode component. The first current collector and the second current collector are used to collect current and to diffuse gas, respectively.

[0012] In some embodiments, the first current collector and the second current collector are respectively connected to leads for exporting current signals.

[0013] In some embodiments, the first and / or the second current collection network are respectively covered with a waterproof and breathable membrane.

[0014] In some embodiments, the low-energy solid fuel cell oxygen sensor further includes a first cover and a second cover, which are used to enclose the membrane electrode assembly, the first current collector, and the second current collector.

[0015] In some embodiments, the first cover and / or the second cover are provided with ventilation holes.

[0016] In some embodiments, the first cover and the second cover are detachably connected.

[0017] One embodiment of this application provides a method for fabricating a low-energy solid-state fuel cell type oxygen sensor.

[0018] A method for fabricating a low-energy solid-state fuel cell-based oxygen sensor includes the following steps:

[0019] An anode slurry is placed on a first conductive substrate to form an anode catalyst layer;

[0020] A cathode slurry is disposed on a second conductive substrate to form a cathode catalyst layer; wherein, the materials for preparing the anode catalyst layer and the materials for preparing the anode catalyst layer respectively include a support material loaded with catalytic metal particles, wherein the catalytic metal particles include one or more of platinum nanoparticles, palladium nanoparticles and gold nanoparticles, and the support material includes one or more of tungsten trioxide composite material, cerium dioxide composite material and tin dioxide composite material.

[0021] Furthermore, a membrane electrode assembly is formed by stacking and connecting the first conductive substrate, the anode catalyst layer, the solid electrolyte layer, the cathode catalyst layer, and the second conductive substrate in that order.

[0022] In some embodiments, the loading of the catalytic metal particles in the cathode catalyst layer is 25% to 35%.

[0023] In some embodiments, the loading of the catalytic metal particles in the anode catalyst layer is 8% to 12%.

[0024] In some embodiments, the method for preparing the carrier material includes the following steps:

[0025] Ammonium paratungstate and urea are ground and mixed evenly, heated to a preset temperature and kept at that temperature for at least 4 hours, and then cooled to obtain WO3 powder.

[0026] WO3 powder and dispersant stabilizer were dissolved in a solvent, and a platinum-containing precursor solution was added and ultrasonically dispersed. A reducing agent solution was added dropwise under stirring to carry out a reduction reaction, and Pt / WO3 powder was obtained by solid-liquid separation.

[0027] In some embodiments, the dispersion stabilizer includes trisodium citrate.

[0028] In some embodiments, the platinum-containing precursor includes chloroplatinic acid.

[0029] In some embodiments, the reducing agent includes a sodium borohydride solution.

[0030] In some embodiments, the solid-liquid separation process includes centrifugal washing and drying.

[0031] In some embodiments, when heated to a preset temperature, the temperature is increased to 400°C to 450°C at a rate of 2°C / min to 3°C / min, and then increased to 650°C to 700°C at a rate of 1°C / min to 2°C / min.

[0032] In some embodiments, when the first conductive substrate, the anode catalyst layer, the solid electrolyte layer, the cathode catalyst layer, and the second conductive substrate are stacked and connected in that order, the following steps are included:

[0033] The first conductive substrate, the anode catalyst layer, the solid electrolyte layer, the cathode catalyst layer, and the second conductive substrate are stacked and then hot-pressed at 90℃~95℃ and 0.5MPa~0.8MPa for 30s~60s to form a membrane electrode component.

[0034] In some embodiments, the method for fabricating the low-energy solid-state fuel cell type oxygen sensor further includes the following steps: fabricating a first current collector and a second current collector on the first conductive substrate and the second conductive substrate, respectively.

[0035] In some embodiments, the method for preparing the low-energy solid fuel cell type oxygen sensor further includes the following step: preparing waterproof and breathable membranes on the first current collector and the second current collector respectively.

[0036] In some embodiments, the method for fabricating the low-energy solid fuel cell oxygen sensor further includes the following step: encapsulating a stacked assembly consisting of the first current collector, the membrane electrode component, and the second current collector in a first cover and a second cover.

[0037] In the aforementioned low-energy solid-state fuel cell-type oxygen sensor, both the anode and cathode catalyst layers are made of carrier materials loaded with catalytic metal particles. The anode catalyst layer is used for oxidation reactions, while the cathode catalyst layer is used for the electrochemical reduction of oxygen. The sensor generates a self-generated current using this electrochemical reduction reaction, eliminating the need for external power supply. It boasts advantages such as simple structure, no risk of electrolyte leakage, and high stability, making it suitable for unattended oxygen concentration monitoring scenarios, particularly showing significant application potential in environments such as monitoring gas leaks in electrical equipment insulation (e.g., SF6 leaks). The core of this low-energy solid-state fuel cell-type oxygen sensor lies in the fact that both the cathode and anode utilize carrier materials loaded with catalytic metal particles. However, by precisely controlling the loading of catalytic metal particles such as platinum (Pt), palladium, and gold, the cathode exhibits higher catalytic activity for efficient oxygen reduction, while the anode has relatively lower catalytic activity. This creates a stable potential difference between the two, driving the sensor's operation. This design combines the stability advantages of material uniformity with the performance advantages of functional differentiation. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings. In the following description, the same reference numerals denote the same parts.

[0040] Figure 1 This is a schematic diagram of a low-energy solid-state fuel cell type oxygen sensor according to an embodiment of this application;

[0041] Figure 2 This is a schematic diagram of the process for fabricating a low-energy solid-state fuel cell oxygen sensor according to an embodiment of this application;

[0042] Figure 3 This is a schematic diagram of the response time of the low-energy solid fuel cell oxygen sensor described in Embodiment 1 of this application, where the horizontal axis represents time (s) and the vertical axis represents current (nA).

[0043] Figure 4 This is a schematic diagram of the steady-state current values ​​of the low-energy solid fuel cell oxygen sensor described in Embodiment 1 of this application at various concentrations, where the horizontal axis represents concentration and the vertical axis represents current (nA).

[0044] Explanation of reference numerals in the attached figures

[0045] 10. Low-energy solid fuel cell type oxygen sensor; 100. Membrane electrode assembly; 210. First current collector; 220. Second current collector; 300. Lead wire; 400. Waterproof and breathable membrane; 510. First cover; 520. Second cover. Detailed Implementation

[0046] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0047] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0048] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0049] In the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0050] In this document, "optionally," "optionally," and "optional" mean that something is optional, that is, it is selected from either "with" or "without." If multiple "options" appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "option" is independent. In this application, descriptions such as "optionally contains" and "optionally includes" indicate "contains or does not contain."

[0051] In this application, unless otherwise stated, the sum of the parts of each component in the composition may be 100 parts by weight. Unless otherwise specified, the percentages (including weight percentages) in this application are based on the total weight of the composition, and "wt%" in this document means mass percentage.

[0052] In this document, unless otherwise stated, the reaction steps may be performed in the order described herein or not. For example, other steps may be included between reaction steps, and the order of reaction steps may be appropriately interchanged. This is something that those skilled in the art can determine based on conventional knowledge and experience. Preferably, the reaction methods described herein are performed sequentially.

[0053] In this application, when numerical intervals (i.e., numerical ranges) are mentioned, unless otherwise specified, the distribution of selectable numerical values ​​within the numerical interval is considered continuous, and includes the two endpoints of the numerical interval (i.e., the minimum and maximum values), as well as every numerical value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that numerical interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints, which is equivalent to directly listing every integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed in this application should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical interval" can be broadly included to include percentage intervals, ratio intervals, proportion intervals, etc.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0055] This application provides a low-energy solid-state fuel cell oxygen sensor to address at least one of the following technical problems of conventional oxygen sensors: (1) Electrochemical oxygen sensors (such as galvanic cells) typically use liquid or gel electrolytes, which pose a risk of electrolyte evaporation, drying, or leakage, leading to sensor performance degradation and shortened lifespan, especially under high temperature or long-term continuous operation conditions. (2) Some electrochemical oxygen sensors require an external power source (such as a potentiostat) to maintain the working electrode potential, increasing system complexity and power consumption. (3) Fuel cell oxygen sensors are a special type of electrochemical sensor. In self-driven (without external power supply) fuel cell oxygen sensors, a pair of electrodes with a potential difference is required to provide driving force. However, conventional electrode designs typically use completely different material systems (such as platinum cathode / zinc anode), resulting in different electrode aging mechanisms, interface mismatch, and limited long-term stability. The low-energy solid-state fuel cell oxygen sensor will be described below with reference to the accompanying drawings.

[0056] This application provides a low-energy solid-state fuel cell-type oxygen sensor according to one embodiment. For an example, please refer to [link to relevant documentation]. Figure 1 As shown, Figure 1This is a schematic diagram of the structure of a low-energy solid-state fuel cell type oxygen sensor provided in one embodiment of this application. The low-energy solid-state fuel cell type oxygen sensor of this application can be applied to harsh industrial environments such as monitoring leakage of insulating gases such as sulfur hexafluoride (SF6) in power equipment.

[0057] SF6 gas is widely used in power equipment such as high-voltage switches, GIS (gas-insulated switchgear), and transformers due to its excellent insulation and arc-quenching properties. However, SF6 is a potent greenhouse gas with a global warming potential approximately 23,500 times that of CO2, and leaks can have severe environmental impacts. Furthermore, SF6 leaks can also lead to a decline in equipment insulation performance, causing power outages. Therefore, continuous and reliable leak monitoring of SF6 electrical equipment is crucial.

[0058] Currently, SF6 leak monitoring mainly employs technologies such as infrared absorption, ultrasonic leak detection, and gas imaging. These methods often involve complex equipment, high costs, or require manual intervention, making it difficult to achieve long-term online, unattended distributed monitoring. Oxygen concentration monitoring can serve as an indirect and efficient leak indication method: when SF6 leaks, it is usually accompanied by changes in internal pressure or air intrusion, leading to abnormal local oxygen concentrations. By deploying low-cost, low-power, and highly reliable oxygen sensors, the sealing status of the equipment can be reflected in real time, providing important evidence for early leak warning. The all-solid-state, self-driven, low-energy solid-state fuel cell-type oxygen sensor proposed in this application is suitable for the harsh operating conditions of SF6 leak monitoring: it has no risk of electrolyte leakage, requires no external power supply, has a robust structure, fast response, and long lifespan, making it ideal for integration into intelligent power equipment condition monitoring systems to achieve early, reliable, and low-power monitoring of SF6 leaks.

[0059] To more clearly illustrate the structure of the low-energy solid-state fuel cell oxygen sensor, the following description, in conjunction with the accompanying drawings, will be provided.

[0060] For example, please refer to Figure 1As shown, a low-energy solid-state fuel cell type oxygen sensor 10 includes a membrane electrode assembly 100. The membrane electrode assembly 100 includes a first conductive substrate, an anode catalyst layer, a solid electrolyte layer, a cathode catalyst layer, and a second conductive substrate, which are sequentially stacked. The solid electrolyte layer separates the anode catalyst layer and the cathode catalyst layer and conducts protons. The anode catalyst layer is used for oxidation reactions, and the cathode catalyst layer is used to supply oxygen for electrochemical reduction reactions. The materials used to prepare the anode catalyst layer and the cathode catalyst layer each include a support material loaded with catalytic metal particles. The loading amount of catalytic metal particles in the anode catalyst layer is less than that in the cathode catalyst layer. The catalytic metal particles include one or more of platinum nanoparticles, palladium nanoparticles, and gold nanoparticles. The support material includes one or more of tungsten trioxide composite materials, cerium dioxide composite materials, and tin dioxide composite materials.

[0061] In the aforementioned low-energy solid-state fuel cell oxygen sensor 10, the anode catalyst layer and the cathode catalyst layer are respectively made of a support material loaded with catalytic metal particles. The anode catalyst layer is used for oxidation reaction, and the cathode catalyst layer is used for electrochemical reduction reaction of oxygen. The electrochemical reduction reaction of oxygen generates a self-generated current, requiring no external power supply. It has advantages such as simple structure, no risk of electrolyte leakage, and high stability, making it suitable for unattended oxygen concentration monitoring scenarios, especially in environments such as monitoring of insulating gas leaks in power equipment (e.g., SF6 leaks). The core of the aforementioned low-energy solid-state fuel cell oxygen sensor 10 lies in the fact that both the cathode and anode use support materials loaded with catalytic metal particles. However, by precisely controlling the loading of catalytic metal particles such as platinum (Pt), palladium, and gold, the cathode has higher catalytic activity for efficient oxygen reduction, while the anode has relatively lower catalytic activity. This creates a stable potential difference between the two, driving the sensor to work, combining the stability advantages of material uniformity with the performance advantages of functional differentiation.

[0062] In some embodiments, the loading of catalytic metal particles in the cathode catalyst layer preparation material is 25% to 35%. For example, the loading of catalytic metal particles in the cathode catalyst layer preparation material includes, but is not limited to, 25%, 30%, 35%, or any range between the two mentioned above.

[0063] In some embodiments, the loading of catalytic metal particles in the anode catalyst layer preparation material is 8% to 12%. For example, the loading of catalytic metal particles in the anode catalyst layer preparation material includes, but is not limited to, 8%, 9%, 10%, 11%, 12%, or any range between the foregoing.

[0064] In this application, by adjusting key parameters, such as the loading amount of noble metal catalytic metal particles, within the same material system, a functional electrode with a moderate potential difference can be constructed. This can achieve a unity of material homogeneity and functional heterogeneity between electrodes, which is beneficial to improving the overall consistency, interface compatibility and service life of the sensor.

[0065] In some embodiments, the solid electrolyte layer includes a proton exchange membrane layer. Proton exchange membranes (such as Nafion membranes), as a solid electrolyte, possess excellent proton conductivity, chemical stability, and gas selectivity. Introducing them into oxygen sensors can completely solve the problems of leakage and volatilization of liquid electrolytes, enabling a fully solid-state sensor and greatly improving reliability and lifespan.

[0066] In some embodiments, the first conductive substrate and the second conductive substrate each independently comprise carbon paper.

[0067] In some embodiments, the low-energy solid fuel cell type oxygen sensor 10 further includes a first current collector 210 and a second current collector 220, which are respectively stacked and connected to both sides of the membrane electrode component 100. The first current collector 210 and the second current collector 220 are used to collect current and for gas diffusion, respectively.

[0068] In some embodiments, the first current collector 210 and the second current collector 220 are respectively connected to leads 300 for exporting current signals. For example, the leads 300 export the current signals to an external measurement circuit.

[0069] In some embodiments, the first collector 210 and / or the second collector 220 are respectively covered with a waterproof and breathable membrane 400.

[0070] In some embodiments, the low-energy solid fuel cell type oxygen sensor 10 further includes a first cover 510 and a second cover 520, which are used to wrap the membrane electrode assembly 100, the first current collector 210 and the second current collector 220.

[0071] In some embodiments, the first cover 510 and / or the second cover 520 are provided with ventilation holes.

[0072] In some embodiments, the first cover 510 and the second cover 520 are detachably connected.

[0073] One embodiment of this application provides a method for fabricating a low-energy solid-state fuel cell type oxygen sensor 10.

[0074] See Figure 2As shown, a method for fabricating a low-energy solid-state fuel cell type oxygen sensor 10 includes the following steps:

[0075] S10. The anode slurry is placed on the first conductive substrate to form an anode catalyst layer.

[0076] S20. A cathode slurry is deposited on a second conductive substrate to form a cathode catalyst layer. The anode catalyst layer and the cathode catalyst layer are each made of a support material loaded with catalytic metal particles. The loading of catalytic metal particles in the anode catalyst layer is controlled to be less than that in the cathode catalyst layer. The catalytic metal particles include one or more of platinum nanoparticles, palladium nanoparticles, and gold nanoparticles. The support material includes one or more of tungsten trioxide composite materials, cerium dioxide composite materials, and tin dioxide composite materials.

[0077] S30. A membrane electrode assembly is formed by stacking and connecting the first conductive substrate, the anode catalyst layer, the solid electrolyte layer, the cathode catalyst layer, and the second conductive substrate in that order.

[0078] In some embodiments, the loading of catalytic metal particles in the cathode catalyst layer is 25% to 35%.

[0079] In some embodiments, the loading of catalytic metal particles in the anode catalyst layer is 8% to 12%.

[0080] In some embodiments, the method for preparing the carrier material includes the following steps:

[0081] Ammonium paratungstate and urea are ground and mixed evenly, heated to a preset temperature and kept at that temperature for at least 4 hours, and then cooled to obtain WO3 powder.

[0082] WO3 powder and dispersant stabilizer were dissolved in a solvent, and a platinum-containing precursor solution was added and ultrasonically dispersed. A reducing agent solution was added dropwise under stirring to carry out a reduction reaction, and Pt / WO3 powder was obtained by solid-liquid separation.

[0083] In some embodiments, the dispersion stabilizer includes trisodium citrate.

[0084] In some embodiments, the platinum-containing precursor includes chloroplatinic acid.

[0085] In some embodiments, the reducing agent includes a sodium borohydride solution.

[0086] In some of these embodiments, the solvent includes ethanol.

[0087] In some embodiments, the solid-liquid separation process includes centrifugal washing and drying.

[0088] In some embodiments, when heated to a preset temperature, the temperature is increased to 400°C to 450°C at a rate of 2°C / min to 3°C / min, and then increased to 650°C to 700°C at a rate of 1°C / min to 2°C / min.

[0089] In some embodiments, heating to a preset temperature is carried out in an air atmosphere within a muffle furnace.

[0090] For example, in preparing a tungsten trioxide composite material with a platinum nanoparticle loading of 10%, 9g of ammonium paratungstate and 2.956g of urea were ground and mixed evenly. The mixture was heated to 400℃ at 2℃ / min and then to 650℃ at 1℃ / min in an air atmosphere in a muffle furnace. After heating to the preset temperature, the temperature was held for 4 hours, and then cooled to obtain WO3 powder. 180mg of WO3 powder and 135mg of trisodium citrate were dissolved in 22.5 mL of ethanol, and 2 mL of 50mM chloroplatinic acid solution was added. The mixture was ultrasonically dispersed for 30 min. Sodium borohydride solution with a pH of 13 was added dropwise under stirring to carry out the reduction reaction. After the reaction was completed, the mixture was centrifuged, washed, and dried to obtain 10wt% Pt / WO3 powder.

[0091] For example, in one specific embodiment, when the anode slurry is placed on the first conductive substrate to form the anode catalyst layer, 80 mg of 10 wt% Pt / WO3 powder is weighed, and 17 mL of a dispersant composed of isopropanol, 5 wt% Nafion solution, and deionized water in a volume ratio of 8:1:8 is added. The mixture is then ultrasonically treated for 30 min to form the anode slurry. The anode slurry is then sprayed onto the first conductive substrate, such as carbon paper, and dried to form the anode catalyst layer.

[0092] For example, in one specific embodiment, when the cathode slurry is placed on the second conductive substrate to form the cathode catalyst layer, 80 mg of 30 wt% Pt / WO3 powder is weighed, and 17 mL of a dispersant consisting of isopropanol, 5 wt% Nafion solution, and deionized water in a volume ratio of 8:1:8 is added. The mixture is then ultrasonically treated for 30 min to form the cathode slurry. The cathode slurry is then sprayed onto the second conductive substrate, such as carbon paper, and dried to form the cathode catalyst layer.

[0093] In some embodiments, when the first conductive substrate, the anode catalyst layer, the solid electrolyte layer, the cathode catalyst layer, and the second conductive substrate are stacked and connected in that order, the following steps are included:

[0094] The first conductive substrate, the anode catalyst layer, the solid electrolyte layer, the cathode catalyst layer, and the second conductive substrate are stacked and then hot-pressed at 90℃~95℃ and 0.5MPa~0.8MPa for 30s~60s to form a membrane electrode component.

[0095] In some embodiments, the fabrication method of the low-energy solid fuel cell type oxygen sensor 10 further includes the following steps: fabricating a first current collector 210 and a second current collector 220 on a first conductive substrate and a second conductive substrate, respectively.

[0096] In some embodiments, the preparation method of the low-energy solid fuel cell type oxygen sensor 10 further includes the following steps: preparing waterproof and breathable membranes 400 on the first current collector 210 and the second current collector 220 respectively.

[0097] In some embodiments, the preparation method of the low-energy solid fuel cell type oxygen sensor 10 further includes the following steps: encapsulating a stacked assembly consisting of a first current collector 210, a membrane electrode component 100, and a second current collector 220 in a first cover 510 and a second cover 520.

[0098] In some embodiments, the first cover 510 and the second cover 520 are fixedly connected by fasteners, such as bolts and nuts, to achieve a seal, thus obtaining a complete sensor device.

[0099] Example 1

[0100] This embodiment provides a low-energy solid-state fuel cell type oxygen sensor 10.

[0101] A method for fabricating a low-energy solid fuel cell-type oxygen sensor 10 includes the following steps:

[0102] To prepare a tungsten trioxide composite material with a platinum nanoparticle loading of 10%, 9 g of ammonium paratungstate and 2.956 g of urea were ground and mixed evenly. The mixture was then heated to 400 °C at 2 °C / min in an air atmosphere in a muffle furnace, followed by a further increase to 650 °C at 1 °C / min. After heating to the preset temperature, the temperature was held for 4 h, and then cooled to obtain WO3 powder. 180 mg of WO3 powder and 135 mg of trisodium citrate were dissolved in 22.5 mL of ethanol, and 2 mL of 50 mM chloroplatinic acid solution was added. The mixture was ultrasonically dispersed for 30 min. A sodium borohydride solution with a pH of 13 was added dropwise under stirring to initiate a reduction reaction. After the reaction was complete, the mixture was centrifuged, washed, and dried to obtain 10 wt% Pt / WO3 powder.

[0103] S100. When setting the anode slurry on the first conductive substrate to form the anode catalyst layer, weigh 80 mg of 10wt% Pt / WO3 powder, add 17 mL of a dispersant made of isopropanol, 5wt% Nafion solution, and deionized water in a volume ratio of 8:1:8, and sonicate for 30 min to form the anode slurry. Spray the anode slurry onto the first conductive substrate, such as carbon paper, and dry to form the anode catalyst layer.

[0104] S200. When setting the cathode slurry on the second conductive substrate to form the cathode catalyst layer, weigh 80 mg of 30 wt% Pt / WO3 powder, add 17 mL of a dispersant made of isopropanol, 5 wt% Nafion solution, and deionized water in a volume ratio of 8:1:8, and sonicate for 30 min to form the cathode slurry. Spray the cathode slurry onto the second conductive substrate, such as carbon paper, and dry to form the cathode catalyst layer.

[0105] S300, the first conductive substrate, the anode catalyst layer, the solid electrolyte layer, the cathode catalyst layer and the second conductive substrate are stacked and connected in sequence.

[0106] The structure of the low-energy solid fuel cell oxygen sensor 10 prepared in this embodiment is as follows: Figure 1 As shown, the device includes a waterproof and breathable membrane 400, a first current collector 210, a membrane electrode component 100, a second current collector 220, and a membrane electrode component 400, which are encapsulated between the first cover 510 and the second cover 520 and are stacked together. The membrane electrode component 100 includes a first conductive substrate, an anode catalyst layer, a solid electrolyte layer, a cathode catalyst layer, and a second conductive substrate, which are stacked sequentially.

[0107] The low-energy solid-state fuel cell oxygen sensor 10 assembled in Example 1 was placed in the gas path system and tested under conditions of 25°C and 30% RH. Figure 3 As shown, the measured response time (T90) for 0.05% O2 is only 9s, and the recovery time (T10) is 28s.

[0108] Furthermore, the steady-state current values ​​at each concentration were recorded and curves were plotted as follows: Figure 4 As shown. Within the oxygen concentration range of 0% to 5%, the output current of the low-energy solid fuel cell oxygen sensor 10 exhibits an excellent linear relationship with the concentration, and its detection limit is lower than 0.02% oxygen concentration, indicating that the low-energy solid fuel cell oxygen sensor 10 of this application has high-precision and high-sensitivity detection capabilities.

[0109] Comparative Example 1

[0110] This comparative example provides a low-energy solid-state fuel cell-type oxygen sensor.

[0111] The preparation method is basically the same as that in Example 1, except that Pt / WO3 powder with a platinum loading of 20% is used when preparing the cathode catalyst layer.

[0112] The sensor assembled in this comparative example was tested under the same conditions (25°C, 30%RH, and 0.05%O2). The sensor response time (T90) was measured to be 29 s, the recovery time (T10) to be 55 s, and the steady-state output current was much lower than that of Example 1.

[0113] Comparative Example 2

[0114] This comparative example provides a low-energy solid-state fuel cell-type oxygen sensor.

[0115] The preparation method is basically the same as that in Example 1, except that Pt / / WO3 powder with a platinum loading of 40% is used when preparing the cathode catalyst layer.

[0116] The sensor assembled in this comparative example was tested under the same conditions (25℃, 30%RH, 0.05%O2). The sensor response time (T90) was measured to be 16 s, and the recovery time (T10) was 116 s. This sensor exhibits a relatively fast response speed, but its recovery time is relatively long.

[0117] In summary, compared with the prior art, this application has at least the following beneficial effects:

[0118] (1) Self-driven, no external power supply: Driven by the internal potential difference constructed by the material gradient of the same system, no external power supply or potentiostat is required, making the system simpler.

[0119] (2) All-solid-state long lifespan: The proton exchange membrane solid electrolyte is used, which is leak-free; the anode and cathode materials are of the same origin, with excellent thermal expansion coefficient and chemical compatibility, stable interface, and significantly extended lifespan.

[0120] (3) Uniform material system and stable performance: The cathode and anode use the same material system, such as a carrier material loaded with catalytic metal particles. The loading of catalytic metal particles on the cathode and anode is different, which avoids the problem of mismatch in the aging of heterogeneous material interfaces. The sensor has low long-term drift and high stability.

[0121] (4) High sensitivity and fast response: The cathode uses a high loading of catalytic metal particles (e.g., 25%~35%) to ensure efficient and rapid reduction of oxygen; the anode uses a low loading of catalytic metal particles (e.g., 8%~12%) to provide a stable and matched oxidation reaction. The cathode and anode work together to achieve high sensitivity and fast response.

[0122] (5) Cost controllable: The anode uses catalytic metal particles with low platinum loading, which reduces the total amount of precious metals used while ensuring performance and reducing costs.

[0123] (6) Strong environmental adaptability: The all-solid structure makes it more tolerant to humidity and temperature fluctuations than liquid electrolyte sensors, making it more suitable for complex industrial environments such as outdoor substations and switch stations.

[0124] (7) Application value in SF6 insulation equipment leakage monitoring: It can be used directly or indirectly for leakage monitoring of SF6 electrical equipment. It can also be used for oxygen concentration monitoring: it can be deployed near equipment compartments, gas chambers or vents to monitor the ambient oxygen concentration. If SF6 leakage leads to air intrusion or pressure imbalance, it may cause local oxygen concentration abnormalities, and the sensor can respond quickly and alarm.

[0125] (8) As part of a comprehensive monitoring system: It can be integrated with pressure, temperature, and SF6 concentration sensors (such as those using TCD or NDIR principles) to improve the accuracy and reliability of leak detection through multi-parameter fusion analysis. The self-driving and low-power characteristics of this sensor make it particularly suitable as a node in a wireless sensor network.

[0126] (9) Long-term trend analysis and early warning: With its excellent long-term stability, a historical baseline of oxygen concentration can be established. By analyzing its slow change trend, early warning of leakage can be achieved to prevent problems before they occur.

[0127] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0128] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0129] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A low energy solid state fuel cell type oxygen sensor characterized by, The low-energy solid-state fuel cell type oxygen sensor comprises a membrane electrode component, the membrane electrode component comprises a first conductive substrate, an anode catalyst layer, a solid-state electrolyte layer, a cathode catalyst layer and a second conductive substrate which are sequentially stacked, the solid-state electrolyte layer is used to separate the anode catalyst layer and the cathode catalyst layer and to conduct protons, the anode catalyst layer is used to occur oxidation reaction, the cathode catalyst layer is used for oxygen to occur electrochemical reduction reaction, the preparation material of the anode catalyst layer and the preparation material of the anode catalyst layer respectively comprise a carrier material loaded with catalytic metal particles, wherein the loading amount of catalytic metal particles in the preparation material of the anode catalyst layer is less than the loading amount of catalytic metal particles in the preparation material of the cathode catalyst layer, the catalytic metal particles comprise one or more of platinum nanoparticles, palladium nanoparticles and gold nanoparticles, and the carrier material comprises one or more of tungsten trioxide composite material, cerium dioxide composite material and tin dioxide composite material.

2. The low energy solid state fuel cell type oxygen sensor of claim 1, wherein, The loading amount of catalytic metal particles in the preparation material of the cathode catalyst layer is 25%-35%; And / or, the loading amount of catalytic metal particles in the preparation material of the anode catalyst layer is 8%-12%.

3. The low energy solid state fuel cell type oxygen sensor of claim 1, wherein, The solid-state electrolyte layer comprises a proton exchange membrane layer.

4. The low energy solid state fuel cell type oxygen sensor according to any one of claims 1 to 3, wherein The first conductive substrate and the second conductive substrate respectively independently comprise carbon paper.

5. The low energy solid state fuel cell type oxygen sensor according to any one of claims 1 to 3, wherein The low-energy solid-state fuel cell type oxygen sensor further comprises a first current collector and a second current collector, the first current collector and the second current collector are respectively stacked and connected on both sides of the membrane electrode component, and the first current collector and the second current collector are respectively used to collect current and to diffuse gas; Optionally, the first current collector and the second current collector are respectively connected with a lead wire for leading out current signal; Optionally, the first current collector and / or the second current collector is respectively covered with a waterproof and breathable film.

6. The low energy solid state fuel cell type oxygen sensor of claim 5, wherein, The low-energy solid-state fuel cell type oxygen sensor further comprises a first cover and a second cover, the first cover and the second cover are used to wrap the membrane electrode component, the first current collector and the second current collector; Optionally, the first cover and / or the second cover is provided with a breathable hole; Optionally, the first cover and the second cover are detachably connected.

7. A method of producing a low energy solid state fuel cell type oxygen sensor, characterized by, The method comprises the following steps: An anode slurry is arranged on the first conductive substrate to form an anode catalyst layer; A cathode slurry is arranged on the second conductive substrate to form a cathode catalyst layer; wherein the preparation material of the anode catalyst layer and the preparation material of the anode catalyst layer respectively comprise a carrier material loaded with catalytic metal particles, the loading amount of catalytic metal particles in the preparation material of the anode catalyst layer is controlled to be less than the loading amount of catalytic metal particles in the preparation material of the cathode catalyst layer, the catalytic metal particles comprise one or more of platinum nanoparticles, palladium nanoparticles and gold nanoparticles, and the carrier material comprises one or more of tungsten trioxide composite material, cerium dioxide composite material and tin dioxide composite material. And, the film electrode component is formed by sequentially laminating and connecting the first conductive substrate, the anode catalyst layer, the solid electrolyte layer, the cathode catalyst layer, and the second conductive substrate.

8. The method of claim 7, wherein the low energy solid state fuel cell type oxygen sensor is prepared by the steps of: At least one of the following conditions is also satisfied: (1) The loading amount of the catalytic metal particles in the preparation material of the cathode catalyst layer is 25% to 35%; (2) The loading amount of the catalytic metal particles in the preparation material of the anode catalyst layer is 8% to 12%; (3) The preparation method of the carrier material includes the following steps: Grind and mix the ammonium paratungstate and urea uniformly, heat to a preset temperature and keep for at least 4 hours, and cool to obtain WO3 powder; Dissolve the WO3 powder and a dispersion stabilizer in a solvent, add a platinum-containing precursor solution, and ultrasonic dispersion; under stirring, dropwise add a reducing agent for reduction reaction, and solid-liquid separation treatment to obtain Pt / WO3 powder; Optionally, the dispersion stabilizer includes trisodium citrate; Optionally, the platinum-containing precursor includes chloroplatinic acid; Optionally, the reducing agent includes sodium borohydride solution; Optionally, the solid-liquid separation treatment includes centrifugal washing and drying; Optionally, when heated to the preset temperature, increase to 400°C to 450°C at 2°C / min to 3°C / min, and then increase to 650°C to 700°C at 1°C / min to 2°C / min.

9. The method of claim 7 or 8, wherein the low energy solid state fuel cell type oxygen sensor is prepared by the steps of: When sequentially laminating and connecting the first conductive substrate, the anode catalyst layer, the solid electrolyte layer, the cathode catalyst layer, and the second conductive substrate, the following steps are included: After laminating the first conductive substrate, the anode catalyst layer, the solid electrolyte layer, the cathode catalyst layer, and the second conductive substrate, hot-press at 90°C to 95°C and 0.5MPa to 0.8MPa for 30s to 60s to form the film electrode component.

10. The method of claim 7 or 8, wherein the low energy solid state fuel cell type oxygen sensor is prepared by the steps of: Further including the following steps: Prepare a first current collector and a second current collector on the first conductive substrate and the second conductive substrate, respectively; Optionally, further including the following steps: Prepare a waterproof and breathable film on the first current collector and the second current collector, respectively; Optionally, further including the following steps: package the laminated assembly composed of the first current collector, the film electrode component, and the second current collector in a first cover and a second cover.

Images