Sensor device and method
A contaminant sensor with a matching catalyst composition to the fuel cell's response allows real-time monitoring and filter alerts, addressing the degradation and detection challenges of air filters in fuel cell systems, ensuring effective fuel cell performance.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- NAT RES COUNCIL OF CANADA
- Filing Date
- 2024-04-12
- Publication Date
- 2026-05-26
AI Technical Summary
Existing air filters in fuel cell systems degrade over time and lack effective real-time monitoring, leading to unpredictable filtering performance, while multiple contaminant sensors are costly and prone to cross-sensitivity issues, and unknown contaminants can affect fuel cell performance without detection.
A contaminant sensor with a sensing element matching the fuel cell catalyst composition, providing direct correlation with the fuel cell's response, allowing real-time monitoring without calibration, and triggering alerts for filter replacement when contaminants exceed a threshold.
The sensor accurately monitors air quality and filter status in real-time, ensuring fuel cell performance by directly correlating with the fuel cell's response, avoiding calibration needs and detecting unknown contaminants effectively.
Smart Images
Figure 2026516666000001_ABST
Abstract
Description
Technical Field
[0001] Cross - reference to Related Applications This application claims priority to U.S. Patent Application No. 63 / 458,755, filed on April 12, 2023, the entire content of which is incorporated herein by reference.
[0002] Field This disclosure generally relates to sensors, and more particularly to chemical sensors for use with fuel cell air flow paths.
Background Art
[0003] Introduction The following paragraphs do not admit that what is discussed in those paragraphs is prior art or part of the knowledge of those skilled in the art.
[0004] Fuel cells, such as proton - exchange membrane fuel cells (PEMFCs), have been developed for use in various systems such as vehicles. In many cases, the system includes a fuel cell stack that utilizes ambient air as a source of oxygen for the internal electrochemical reaction with hydrogen.
[0005] Air pollutants affect the performance and lifespan of the fuel cell stack. Contaminated air entering the fuel cell stack on the cathode side can cause catalyst degradation or damage the gas diffusion layer or membrane within the stack. Chemical contaminants include sulfur compounds (e.g., SO x , H2S), nitrogen compounds (e.g., NO x , NO), ammonia (NH3), carbon monoxide, volatile organic compounds, and other known or unknown contaminants.
[0006] To prevent irreversible degradation and damage to fuel cell stacks that can be caused by airborne pollutants, air filters can be used in the air intake system to continuously remove dust and polluting chemicals. However, when exposed to a polluted gas environment, the air filters themselves also suffer degradation / saturation and gradually lose their filtering function. Predicting the quality of the air to which the air filters are exposed is difficult, making it difficult to predict the filtering function over time. Furthermore, there are currently few options available to provide accurate real-time monitoring of the current state of the air filters themselves. [Overview of the project]
[0007] Sensors can be used to monitor air quality downstream of the filter. However, many air contaminants exist that affect the performance and lifespan of fuel cell stacks. Many sensors are suitable for detecting only one or a few contaminants, and including a sensor for each contaminant would result in excessive cost and / or space requirements in the air intake. Furthermore, these multiple sensors may have cross-sensitivity issues or detection selectivity issues with each other, which can lead to reading errors when multiple contaminants are present. In addition, the performance and lifespan of fuel cell stacks may be affected by contaminants for which sensors are not provided, such as contaminants that were not identified as contaminants at the time of manufacture.
[0008] While there are sensors that broadly monitor relevant pollutants (for example, the sensor disclosed in Japanese Patent Publication No. 2008 / 282680), the difference between the sensor output and the fuel cell response may necessitate a sensor calibration process.
[0009] The drawings included herein are for illustrative purposes only and are not intended to limit the scope of what is taught. [Brief explanation of the drawing]
[0010] [Figure 1] This is a schematic diagram of a fuel cell. [Figure 2] This is a perspective view of a fuel cell system. [Figure 3] This is the circuit diagram for the first pollutant sensor. [Figure 4] This is the circuit diagram for the second pollutant sensor. [Figure 5] This is a schematic diagram of the pollutant monitoring system. [Figure 6] This is a flowchart showing the method for manufacturing a pollutant sensor. [Figure 7] This is a flowchart showing how to monitor the deterioration of the intake filter. [Figure 8] This is a graph of the cyclic voltammogram curve from a cyclic voltammogram scan after N2 purging. [Figure 9] This is a graph of the cyclic voltammogram curve from a cyclic voltammogram scan after O2 / N2 mixed gas purging. [Figure 10] This is a graph of the cyclic voltammogram curve from a cyclic voltammogram scan after purging with a 0.5 ppm SO2 mixed gas. [Figure 11] This is a graph of the cyclic voltammogram curve from a cyclic voltammogram scan after purging with a 1 ppm SO2 mixed gas. [Figure 12] This is a graph of the cyclic voltammogram curve from a cyclic voltammogram scan after purging with a 2 ppm SO2 mixed gas. [Figure 13] This is a graph of the linear sweep voltammogram curve obtained from a linear sweep voltammogram scan after O2 / N2 mixed gas purging. [Figure 14] This is a graph of the linear sweep voltammogram curve from a linear sweep voltammogram scan after purging with a 0.5 ppm SO2 mixed gas. [Figure 15] This is a graph of the linear sweep voltammogram curve from a linear sweep voltammogram scan after purging with a 1 ppm SO2 mixed gas. [Figure 16] A graph of a linear sweep voltammogram curve from a linear sweep voltammogram scan after purging with a 2 ppm SO2 mixed gas. [Figure 17] A graph of a cyclic voltammogram curve from a cyclic voltammogram scan after purging with a 2 ppm SO2 mixed gas for a long time. [Figure 18] A graph of a linear sweep voltammogram curve from a linear sweep voltammogram scan after purging with a 2 ppm SO2 mixed gas for a long time. [Figure 19] A graph of a cyclic voltammogram curve from a cyclic voltammogram scan after purging with an artificial O2 / N2 mixed gas after purging with a 2 ppm SO2 mixed gas for a long time. [Figure 20] A graph of a linear sweep voltammogram curve from a linear sweep voltammogram scan after purging with an artificial O2 / N2 mixed gas after purging with a 2 ppm SO2 mixed gas for a long time. [Figure 21] A graph combining the curves of FIGS. 9 to 12. [Figure 22] A graph combining the curves of FIGS. 13 to 16, FIGS. 18 and FIG. 20.
Mode for Carrying Out the Invention
[0011] To provide examples of embodiments of each claimed invention, various apparatuses or methods are described below. The embodiments described below do not limit the claimed invention, and the claimed invention can include apparatuses and methods different from those described below. The claimed invention is not limited to apparatuses and methods having all the features of any one of the apparatuses or methods described below, or to features common to a plurality or all of the apparatuses or methods described below. The apparatuses or methods described below may not be embodiments of the claimed invention. The inventions disclosed in the apparatuses or methods described below that are not claimed herein can be the subject of another means of protection, such as a continuing patent application, and the applicant, inventor, and / or owner do not intend to abandon, disclaim, or publicly dedicate such inventions by their disclosure herein.
[0012] The teachings described herein relate to a contaminant sensor and a method of manufacturing a contaminant sensor. The contaminant sensor includes a sensing element composed of a material having the same composition as the composition of the catalyst material of a fuel cell in which the sensor is used, such that the output of the sensor corresponds to the response of the fuel cell.
[0013] The sensor can be used without a calibration step because the output of the sensor is directly correlated to the response of the fuel cell. Further, or alternatively, the sensor can be manufactured by using a sample of a catalyst without disclosure of the composition of the sample. Thus, the catalyst composition can remain confidential to the supplier of the sample even while the contaminant sensor is being manufactured by another party for use in a fuel cell.
[0014] The teachings described herein also relate to monitoring air quality at the air inlet of a fuel cell system and to a system for monitoring air quality. By monitoring contaminants such as SO2 that may contaminate the fuel cell catalyst, the performance and / or lifespan of the fuel cell can be improved. If contaminants are detected or detected at an amount or rate exceeding a predetermined threshold, the air filter can be replaced or an alert can be generated to notify the user to replace the air filter. The output of the sensor can be used to monitor contamination events without applying a calibration coefficient to the output of the sensor.
[0015] As illustrated in Figure 1, the fuel cell 100 includes a membrane 102 (e.g., Nafion®) between catalyst layers 104. The fuel cell 100 may also be a proton exchange membrane fuel cell. A fuel source 106 (e.g., hydrogen fuel) is provided in the catalyst layer 104 on one side of the membrane 102, and an air source 108 is provided in the catalyst layer 104 on the opposite side of the membrane 102 to generate an electron flow 110. It will be understood that the fuel cell 100 may also include a diffusion layer 112, as illustrated.
[0016] Each catalyst layer 104 comprises a catalyst material 114 (e.g., platinum) supported by a support material 116 (e.g., a carbon support), and may include one or more additional components 118 (e.g., polytetrafluoroethylene and / or ionomer solution). The catalyst material 114 may contain platinum or consist of platinum, or may contain non-platinum catalyst components such as non-platinum metals or consist of non-platinum catalyst components.
[0017] The exemplary fuel cell 100 in Figure 1 has the same catalyst layer 104 used on both the fuel source side and the air source side, but it will be understood that the fuel source side catalyst layer 104a may be different from the air source side catalyst layer 104b. The fuel source side catalyst layer 104a may contain different components and / or different proportions of components than the catalyst layer 104b. In some examples, the fuel source side catalyst material 114a may be different from the air source side catalyst material 114b.
[0018] As illustrated in Figure 2, the fuel cell 100 may be used in a fuel cell system 120. The fuel cell system 120 includes an air passage 122 extending between a passage inlet 124 and a passage outlet 126 (for example, directly outside the housing of the fuel cell 100, as illustrated). The fuel cell 100 is located within the air passage 122, and an air supply source 108 is provided through the air passage 122. The filter 128 is located within the air passage 122 between the passage inlet 124 and the fuel cell 100. It will be understood that the fuel cell system 120 may be a vehicle such as a car, boat, or airplane. The air passage 122 may extend through an air cooler 130 (for example, an air-to-air intercooler) upstream of the fuel cell, and the air cooler 130 may be located downstream of the filter 128.
[0019] A contaminant sensor 140 is located in the air passage 122 between the filter 128 and the fuel cell 100. The contaminant sensor 140 can be used to monitor the air quality in the air passage 122 downstream of the filter 128 and upstream of the fuel cell 100.
[0020] It will be understood that various types of sensor structures can be used in the contaminant sensor 140. As illustrated in Figures 3 and 4, the contaminant sensor 140 may include multiple electrodes 142, including a detection electrode 144 and an auxiliary electrode 146. The contaminant sensor 140 may include a power supply 148 coupled between the detection electrode 144 and the auxiliary electrode 146. The output of the contaminant sensor 140 may include a current flowing through or from the detection electrode 144, and the contaminant sensor 140 may include an ammeter 150 for measuring the current flowing through or from the detection electrode 144. A voltmeter 152 is provided for measuring potential.
[0021] As illustrated in Figure 3, the contaminant sensor 140 may be a two-electrode sensor 140a that can be operated to apply a known potential between a detection electrode 144 and an auxiliary electrode 146. As illustrated in Figure 4, the contaminant sensor 140 may be a three-electrode sensor 140b that includes a reference electrode 154 for measuring the potential of the detection electrode 144. It will be understood that the electrodes of the sensor may be coupled by an electrolyte in the detection cell 156. As illustrated in Figures 3 and 4, the detection electrode 144 of the contaminant sensor 140 includes a detection element 160.
[0022] The inventors discovered that by matching the composition of the sensing element of the contaminant sensor 140 to the composition of the catalyst 104 of the fuel cell 100, the sensor output of the contaminant sensor 140 corresponds to the response of the fuel cell 100. The sensor composition of the sensing element 160 establishes a direct correlation between the sensor response and the degradation of the fuel cell. The sensor 140 reacts to contaminants simultaneously, just as the catalyst layer 104 of the fuel cell 100 reacts to the same contaminants.
[0023] The sensing element 160 has a composition based on the material of the fuel cell catalyst layer 104 of the fuel cell 100 in which the sensor is provided. In some embodiments, the air supply source side catalyst layer 104b has a different composition from that of the fuel supply source side catalyst layer 104a, and the composition of the sensing element 160 is based on the composition of the air supply source side catalyst layer 104b.
[0024] As described above, the catalyst layer 104 may have a composition that combines two or more different components. The catalyst layer 104 may have a composition that combines four or more different components (for example, a catalyst material 114, a support material 116, and a solution 118 containing at least two components). The catalyst layer 104 may have a composition that includes platinum and one or more additional components. The catalyst layer 104 may have a composition that includes platinum and three or more additional components. The catalyst layer 104 may have a composition that includes platinum, a support component (for example, a carbon support), and one or more additional components. The catalyst layer 104 may have a composition that includes platinum, a support component (for example, a carbon support), and one or more additional components or two or more additional components.
[0025] In some embodiments, the sensing element includes or consists of one or more of the materials of the catalyst layer 104 of the fuel cell 100 in which the sensor is provided. In some embodiments, the sensing element includes or consists of all of the materials of the catalyst layer 104 of the fuel cell 100 in which the sensor is provided. The materials may be provided to the sensing element 160 in the same proportions as those provided in the fuel cell layer, or in different proportions.
[0026] In some embodiments, the sensing element 160 includes or consists of the catalyst material 114 of the fuel cell 100 on which the sensor is provided. In some embodiments, the sensing element 160 includes or consists of the catalyst material 114 and a support material, the support material may be the same support material 116 as the support material of the fuel cell 100. In some embodiments, the sensing element 160 includes or consists of all the components of the catalyst layer 104 of the fuel cell 100 on which the sensor is provided.
[0027] By monitoring this sensor output, a real-time indicator of air quality and a corresponding indicator of the filter 128's status are obtained. Since the sensing element responds in the same way as the catalyst layer 104 of the fuel cell 100, the pollutant sensor 140 is applicable to any gas mixture containing unknown pollutants, avoiding the detection selectivity problems of many other gas sensors.
[0028] The inventors have found that calibration is unnecessary in some embodiments. The sensor output is a reliable indicator of the fuel cell's response, and as will be further described elsewhere in this specification, in some embodiments the contaminant sensor can be used without a calibration process and / or without applying a calibration coefficient when calculating whether a contaminant is detected.
[0029] In some embodiments, the contaminant sensor 140 includes a coating 162 located on the sensing element 160. The coating 162 may be formed of the same material as the membrane 102 of the fuel cell 100. The membrane layer 102 may have a composition including a membrane component (e.g., Nafion®).
[0030] As illustrated in Figure 5, the fuel cell system 120 may be part of a pollutant monitoring system 170. The pollutant monitoring system 170 includes the fuel cell system 120 having a pollutant sensor 140 in an air passage 122. The pollutant monitoring system 170 also includes a detection system 176 for detecting pollutant events. The detection system 176 may be a simple warning or alarm trigger, such as by a simple circuit that responds to the output of the sensor 140. In some embodiments, the detection system 176 includes one or more processors 172 communicatively coupled to the pollutant sensor 140 to receive the output of the pollutant sensor 140. In some embodiments, one or more data storage devices 174 may be communicatively coupled to one or more processors 172.
[0031] One or more data storage devices 174 contain instructions stored to operate one or more processors 172. These instructions include instructions to operate one or more processors 172 to receive the output of a contaminant sensor 140 and process the output of the contaminant sensor to detect a contamination event without applying a calibration coefficient to the output. The instructions may also include instructions to operate one or more processors 172 to generate a warning in response to the detection of a contamination event. In one embodiment, the instructions may allow setting a contamination threshold level below which no warning is generated.
[0032] Referring here to Figure 6, a flowchart of method 200 for manufacturing a contaminant sensor (e.g., contaminant sensor 140) for use in an air passage upstream of the fuel cell in a fuel cell system (e.g., in air passage 122). The fuel cell may be a proton exchange membrane fuel cell.
[0033] Method 200 includes receiving a sample of fuel cell catalyst material in step 202. The sample has the same sample composition as the catalyst composition of the catalyst material. In some embodiments, the sample is received from a third party and the sample composition is not disclosed.
[0034] Method 200 also includes, in step 204, using a sample of cell catalyst material as a sensing element on a detection electrode (e.g., detection electrode 144). Using a sample of cell catalyst material as a sensing element on a detection electrode may involve using the sample without knowing its composition. Thus, the party supplying the sample may know the sample composition but can utilize the services of another party to construct the sensor without disclosing the sample composition to the other party. The composition of the catalyst may be a secret (such as a trade secret) that the supplying party does not want to disclose.
[0035] In step 206, method 200 includes assembling a contaminant sensor. The contaminant sensor includes a plurality of electrodes (e.g., electrode 142) including a detection electrode.
[0036] Method 200 may include, in step 208, applying a coating (e.g., coating 162) onto the sample. The coating has the same coating composition as the membrane composition of the fuel cell membrane. Method 200 may also include, in step 210, providing a contaminant sensor for installation in a fuel cell system without knowing the sample composition.
[0037] Referring now to Figure 7, a flowchart of method 300 for monitoring the degradation of the intake filter of a fuel cell system (e.g., fuel cell system 120) is shown.
[0038] Method 300 includes receiving the output of a contaminant sensor (e.g., contaminant sensor 140) in step 302. The contaminant sensor includes a detection electrode located in the air passage between the intake filter and the fuel cell of the fuel cell system. The detection electrode includes a detection element having the same composition as the catalyst composition of the fuel cell catalyst.
[0039] Method 300 includes, in step 304, processing the output of a contaminant sensor and detecting a contamination event without applying a calibration coefficient to the output. Method 300 may also include, in step 306, generating a warning in response to the detection of a contamination event. The warning may include a signal indicating that the air filter needs to be replaced.
[0040] Although the sensor 140 is described as being based on a fuel cell, in some embodiments the sensor is based on any electrochemical device (e.g., a fuel cell or another electrochemical device) which necessarily includes a catalyst layer. [Examples]
[0041] Other aspects and features of this disclosure will become apparent by considering the examples in the following description, which are intended to be illustrative but not restrictive.
[0042] equipment manufacturing The glassy carbon rotating disk electrode was polished using 0.5 μm alumina powder. The glassy carbon rotating disk electrode was ultrasonically treated in water for 5 minutes. The glassy carbon rotating disk electrode was rinsed with acetone and water.
[0043] A catalyst ink was prepared. The catalyst ink was prepared by weighing out platinum (40 wt%) catalyst powder and mixing it appropriately with isopropyl alcohol (IPA) and water to achieve a concentration ratio of 0.5 mg catalyst / mL at a volume ratio of 19:1 IPA to water. The mixture was further ultrasonically mixed for 20-30 minutes to obtain the catalyst ink. 20 μL of the catalyst ink was coated onto a glassy carbon disk using a microsyringe. The catalyst ink was then dried.
[0044] A 0.1 wt% Nafion® solution was prepared. The Nafion® solution was prepared using 0.5 g of a 5 wt% Nafion® solution. This solution was diluted by adding 15 ml of water and 15 ml of IPA to obtain a 0.1 wt% Nafion® solution. After the catalyst ink dried, 10 μL of the 0.1 wt% Nafion® solution was added to the dried catalyst ink. The 0.1 wt% Nafion® solution was then allowed to air dry at room temperature.
[0045] The total catalyst load was 40 μg Pt / cm² relative to the geometric surface area (GSA) of the glassy carbon disk electrode. 2 Controlled (geometric surface area is 0.2 cm²) 2 (That is.)
[0046] A contaminant sensor was constructed using a glassy carbon rotating disk electrode as a detection electrode coated with a layer of catalyst ink and 0.1 wt% Nafion® solution, a saturated calomel electrode (SCE) as a reference electrode, and a platinum wire counter electrode connected via a 0.5 M H2SO4 electrolyte.
[0047] Equipment testing Cyclic voltammetry was used to evaluate the performance of the synthetic electrodes in the presence of different gas concentrations, namely nitrogen gas, an artificial O2 / N2 mixture, a 0.5 ppm SO2 mixture, a 1 ppm SO2 mixture, and a 2 ppm SO2 mixture. Electrochemical data, including cyclic voltammograms (CV) and linear sweep voltammograms (LSV), were recorded using CorrView® and CView® software, while controlling the voltage using a Solartron 1287® potentiostat. Each time the electrolyte was purged with a specific gas or concentration, the required cyclic voltammogram, followed by a linear sweep voltammogram, was recorded as described below, before proceeding to the stability and / or reversibility tests described below.
[0048] Cyclic voltammogram test Before the test, dissolved oxygen was removed from the electrolyte by bubbling it with nitrogen gas (N2) for 20 minutes. To obtain a stable cyclic voltammogram curve from the N2-purged solution, three cycles of cyclic voltammogram scans were performed at a scan rate of 5 mV / s with potential windows of -0.24 V and 1.3 V relative to the reference electrode (a stable curve can be obtained using at least two cycles). Figure 8 shows the cyclic voltammetry curve from one of the cyclic voltammogram scans performed after 20 minutes of N2 purging.
[0049] In the oxygen reduction experiment, artificial O2 gas was used to saturate the electrolyte over a 20-30 minute bubbling period prior to the test. Cyclic voltammogram scans were performed in a solution purged with artificial O2 / N2 mixed gas at a scan rate of 5 mV / s for one cycle, with potential windows of -0.24 V and 1.3 V relative to the reference electrode, and then repeated to obtain reproducible CV curves. Figure 9 shows the cyclic voltammetry curve from one of the cyclic voltammogram scans performed after purging the electrolyte with artificial O2 / N2 mixed gas for 30 minutes.
[0050] Next, the electrolyte was saturated with a 0.5 ppm SO2 gas mixture over a 20–30 minute bubbling period prior to the test. Cyclic voltammogram scans were performed in an artificial 0.5 ppm SO2 gas-purged solution at a scan rate of 5 mV / s for one cycle, with potential windows of -0.24 V and 1.3 V relative to the reference electrode, and then repeated to obtain reproducible CV curves. Figure 10 shows the cyclic voltammetry curve from one of the cyclic voltammogram scans performed after purging the electrolyte with a 0.5 ppm SO2 gas mixture for 30 minutes.
[0051] Next, the electrolyte was saturated with a 1 ppm SO2 gas mixture over a 20–30 minute bubbling period prior to the test. Cyclic voltammogram scans were performed in an artificial 1 ppm SO2 gas-purged solution at a scan rate of 5 mV / s for one cycle, with potential windows of -0.24 V and 1.3 V relative to the reference electrode, and then repeated to obtain reproducible CV curves. Figure 11 shows the cyclic voltammetry curve from one of the cyclic voltammogram scans performed after purging the electrolyte with a 1 ppm SO2 gas mixture for 30 minutes.
[0052] Finally, the electrolyte was saturated with a 2 ppm SO2 gas mixture over a 20–30 minute bubbling period prior to the test. Cyclic voltammogram scans were performed in an artificial 2 ppm SO2 gas-purged solution at a scan rate of 5 mV / s for one cycle, with potential windows of -0.24 V and 1.3 V relative to the reference electrode, and then repeated to obtain reproducible CV curves. Figure 12 shows the cyclic voltammetry curve from one of the cyclic voltammogram scans performed after purging the electrolyte with a 2 ppm SO2 gas mixture for 30 minutes.
[0053] Linear sweep voltammogram test In the oxygen reduction experiment, the test solution was saturated with an artificial O2 / N2 gas mixture for a 20-minute bubbling period before each test. Linear sweep voltammogram scans were performed at a scan speed of 5 mV / s and a rotating disk electrode speed of 1600 revolutions per minute (rpm) with potential windows of -0.24 V and 1.3 V relative to the reference electrode, and then repeated to obtain reproducible linear sweep voltammogram curves. Each time, the solution was purged for at least 10 minutes to enable a stable linear sweep voltammogram. Figure 13 shows the linear sweep voltammetry curve from one of the linear sweep voltammogram scans performed after purging the electrolyte with an artificial O2 / N2 gas mixture for 30 minutes.
[0054] Next, the test solution was saturated with a 0.5 ppm SO2 gas mixture for a 20-minute bubbling period before each test. Linear sweep voltammogram scans were performed at a scan speed of 5 mV / s and a rotating disk electrode speed of 1600 revolutions per minute (rpm) with potential windows of -0.24 V and 1.3 V relative to the reference electrode, and then repeated to obtain reproducible linear sweep voltammogram curves. Each time, the solution was purged for at least 10 minutes to enable a stable linear sweep voltammogram. Figure 14 shows the linear sweep voltammetry curve from one of the linear sweep voltammogram scans performed after purging the electrolyte with a 0.5 ppm SO2 gas mixture for 30 minutes.
[0055] Next, the test solution was saturated with a 1 ppm SO2 gas mixture over a 20-minute bubbling period before each test. Linear sweep voltammogram scans were performed at a scan speed of 5 mV / s and a rotating disk electrode speed of 1600 revolutions per minute (rpm) with potential windows of -0.24 V and 1.3 V relative to the reference electrode, and then repeated to obtain reproducible linear sweep voltammogram curves. Each time, the solution was purged for at least 10 minutes to enable a stable linear sweep voltammogram. Figure 15 shows the linear sweep voltammetry curve from one of the linear sweep voltammogram scans performed after purging the electrolyte with a 1 ppm SO2 gas mixture for 30 minutes.
[0056] Finally, the test solution was saturated with a 2 ppm SO2 gas mixture for a 20-minute bubbling period before each test. Linear sweep voltammogram scans were performed at a scan speed of 5 mV / s and a rotating disk electrode speed of 1600 revolutions per minute (rpm) with potential windows of -0.24 V and 1.3 V relative to the reference electrode, and then repeated to obtain reproducible linear sweep voltammogram curves. Each time, the solution was purged for at least 10 minutes to enable a stable linear sweep voltammogram. Figure 16 shows the linear sweep voltammetry curve from one of the linear sweep voltammogram scans performed after purging the electrolyte with a 2 ppm SO2 gas mixture for 30 minutes.
[0057] Stability testing The electrolyte was purged with a 2 ppm SO2 mixed gas for 2-3 days. Cyclic voltammogram and linear sweep voltammogram measurements were then performed again to compare the oxygen reduction performance of the detection electrode before and after long-term purging with a 2 ppm SO2 mixed gas.
[0058] Figure 17 shows the cyclic voltammetry curve from one of the cyclic voltammogram scans performed after purging the electrolyte with a 2 ppm SO2 gas mixture for 66 hours. Figure 18 shows the linear sweep voltammetry curve from one of the linear sweep voltammogram scans performed after purging the electrolyte with a 2 ppm SO2 gas mixture for 66 hours.
[0059] Reversibility test Under cyclic voltammogram and linear sweep voltammogram testing, the required cyclic voltammograms and linear sweep voltammograms were scanned as described above. The electrolyte was then purged with an artificial O2 / N2 mixed gas for 20-30 minutes. Cyclic voltammogram and linear sweep voltammogram measurements were then repeated to compare the oxygen reduction performance of the working electrode before and after the SO2 contamination test.
[0060] Figure 19 shows the cyclic voltammetry curve from one of the cyclic voltammogram scans performed after purging the electrolyte with an artificial O2 / N2 gas mixture for 30 minutes following the stability test. Figure 20 shows the linear sweep voltammetry curve from one of the linear sweep voltammogram scans performed after purging the electrolyte with an artificial O2 / N2 gas mixture for 30 minutes following the stability test.
[0061] Referring to Figure 21, a combined cyclic voltammogram curve from Figures 9 to 12 is shown. As illustrated, the artificial air (artificial O2 / N2 mixed gas) curve reached the highest current density, and the SO2 contamination test continued as expected. The electrodes showed the lowest performance and lowest current density in the 2 ppm SO2 test.
[0062] Referring to Figure 22, a combination of the linear sweep voltammogram curves from Figures 13-16, 18, and 20 is shown. As illustrated, the linear sweep voltammogram curves are consistent with the cyclic voltammogram results. Among the linear sweep voltammogram curves, the artificial air curve showed the highest performance, followed in order by the 0.5 ppm SO2, 1 ppm SO2, and then the 2 ppm SO2 curves. The stability test curve and the reversibility test curve showed the lowest performance. The LSV curve shows that the current density steadily decreased as the SO2 pollution of the air increased.
[0063] The 2 ppm SO2 stability test showed that electrolyte conditions did not change significantly even after continuous purging for more than two days. However, the reversibility test yielded the lowest performance among all tests performed, indicating that the SO2 contamination change was irreversible and that oxygen reduction performance could not be recovered after all SO2 contamination tests, which may be due to the used / saturated electrolyte or potential catalyst degradation. In some embodiments, the contaminant sensor may be a sacrificial sensor. The contaminant sensor may be a replaceable sensor that is replaced after contamination is detected.
[0064] The above description provides examples of one or more devices or methods, but it will be understood that other devices or methods may be within the scope of the appended claims.
Claims
1. To receive a sample having a sample composition, wherein the sample composition consists of one or more components of the catalyst layer of a fuel cell, including the catalyst material of the fuel cell catalyst layer. Forming a detection element of a detection electrode, wherein the detection element includes the sample, and Assembling a contaminant sensor with multiple electrodes, wherein the multiple electrodes include the detection electrode. A method for manufacturing a contaminant sensor used in an air passage of a fuel cell system located upstream of the fuel cell in the fuel cell system.
2. The method of claim 1, wherein the sample is received from a third party without receiving disclosure of the sample composition.
3. The method according to claim 2, wherein the detection element is formed without knowing the composition of the sample.
4. The method according to any one of claims 1 to 3, wherein the sample composition comprises the catalyst material and one or more additional components of the catalyst layer of the fuel cell.
5. The method of claim 4, wherein the catalyst material contains platinum.
6. The method according to any one of claims 1 to 5, further comprising providing the contaminant sensor for installation in the fuel cell system without knowing the composition of the sample.
7. The method according to any one of claims 1 to 6, wherein the fuel cell is a proton exchange membrane fuel cell.
8. The method according to any one of claims 1 to 7, further comprising applying a coating to the sensing element, wherein the coating has the same coating composition as the membrane composition of the fuel cell membrane.
9. The method according to any one of claims 1 to 8, wherein the fuel cell system is located inside a vehicle.
10. The method according to any one of claims 1 to 9, further comprising installing the contaminant sensor in the fuel cell system, wherein the air passage is a path from an ambient air inlet to the fuel cell for supplying ambient air to the fuel cell.
11. An air passage extending between the path inlet and the path outlet, A fuel cell in the aforementioned air channel, comprising a cell catalyst layer having a catalyst layer composition, The filter in the air passage upstream of the fuel cell, and A sensor in the airflow path between the filter and the fuel cell, wherein the sensor has a plurality of electrodes including a detection electrode, and the detection electrode includes a detection element having the same composition as the catalyst layer composition of the cell catalyst layer, thereby eliminating the need for calibration between the output of the sensor and the response of the fuel cell, A fuel cell system equipped with the following features.
12. The system according to claim 11, wherein the catalyst layer composition is a combination of multiple components.
13. The system according to claim 12, wherein the catalyst layer composition comprises a catalyst material and one or more additional components.
14. The system according to any one of claims 11 to 13, wherein the fuel cell is a proton exchange membrane fuel cell.
15. The system according to any one of claims 11 to 14, wherein the detection electrode includes a coating located on the detection element, and the coating has the same coating composition as the membrane composition of the fuel cell membrane.
16. The system according to any one of claims 11 to 15, wherein the fuel cell system is located inside a vehicle.
17. Receiving the output of a contaminant sensor, wherein the contaminant sensor includes a detection electrode positioned in the airflow path between the intake filter and the fuel cell of the fuel cell system, and This includes processing the output of the contaminant sensor to detect a contamination event without applying a calibration coefficient to the output, The detection electrode includes a detection element having the same composition as the catalyst layer composition of the fuel cell's catalyst layer. A method for monitoring the deterioration of the intake filter of the fuel cell system.
18. The method of claim 17, further comprising generating a warning in response to the detection of the aforementioned contamination event.
19. A fuel cell system including an air passage from the inlet to the fuel cell, wherein the fuel cell system includes an intake filter in the air passage upstream of the fuel cell. A contaminant sensor comprising a detection electrode disposed in the air passage between the intake filter and the fuel cell, wherein the detection electrode includes a detection element having the same composition as the catalyst layer of the fuel cell, A processor communicatively coupled to the contaminant sensor to receive the output of the contaminant sensor, and The processor is equipped with a data storage device that is communicably coupled to the aforementioned processor, The data storage device receives the output of the contaminant sensor. Without applying a calibration coefficient to the output, the output of the contaminant sensor is processed to detect a contamination event. Having instructions stored to operate the aforementioned processor, Pollutant monitoring system.
20. The system of claim 19, wherein the instructions stored in the data storage device include instructions for causing the processor to generate a warning in response to the detection of the contamination event.
21. An apparatus or method comprising any combination of one or more features described above and / or claimed and / or shown in the drawings.