Fuel cell electrochemical active area parameter measuring method based on potential scanning

Abstract

The invention discloses a fuel cell electrochemical active area parameter measurement method based on potential scanning, belongs to the technical field of fuel cells, and solves the problem that the scanning rate affects a measurement result when an electrochemical active area is measured. According to the invention, hydrogen is supplied to the anode of the fuel cell, inert gas is supplied to the cathode of the fuel cell, and the flow of the cathode and the anode is set, so that the system is ensured to operate at a set temperature, and the stability of the gas inlet humidity of the anode and the cathode is maintained; according to the method, the current density response at each scanning rate is recorded, then the obtained current density is analyzed, the electrochemical active area parameter of the fuel cell membrane electrode is accurately calculated, and the measurement method provided by the invention ensures that the stable and reliable electrochemical active area can be obtained even under non-ideal conditions.

Description

Technical Field

[0001] The invention belongs to the technical field of fuel cells and relates to a method for measuring electrochemical active area parameters of a fuel cell based on potential scanning. Background Art

[0002] With the increase of global energy demand and the increasing prominence of environmental problems, the development and application of clean energy technology has become increasingly important. Fuel cells, as an efficient and environmentally friendly energy conversion device, have attracted widespread attention because of their ability to directly convert chemical energy into electrical energy.

[0003] In fuel cells, the performance of the catalyst is crucial to the efficiency of the cell, and the electrochemically active area (ECSA), as an important indicator to measure the surface activity of the catalyst, directly affects the performance of the fuel cell. The larger the ECSA, the more catalyst surface area can participate in the electrochemical reaction, improving the catalytic efficiency. Therefore, improving the ECSA of the catalyst has become a key direction to improve the efficiency of fuel cells.

[0004] In the prior art, the electrochemical active area measurement method is usually based on applying a voltage at a fixed scan rate to the electrode to obtain the active surface area through electrochemical testing. However, a fixed scan rate will affect the measurement results, but different scan rates may also cause changes in the kinetics and mass transfer behavior of the reaction during the measurement process, thereby affecting the accurate evaluation of ECSA, making the electrochemical active area measurement method limited. It is difficult to eliminate or reduce the impact of the scan rate on ECSA measurement with the prior art. Summary of the invention

[0005] The technical solution of the present invention is used to solve the problem that the scanning rate affects the measurement result when measuring the electrochemical active area.

[0006] The present invention solves the above technical problems through the following technical solutions:

[0007] A method for measuring electrochemical active area parameters of a fuel cell based on potential scanning comprises the following steps:

[0008] Step 1, introducing a gas under certain conditions into the anode and cathode of the fuel cell to be tested;

[0009] Step 2, the fuel cell to be tested operates stably under specified conditions;

[0010] Step 3, connecting to an external excitation source, applying voltages at different scan rates, performing multiple sets of linear potential cycle scans, and recording multiple sets of response current densities;

[0011] Step 4: Analyze the response current density to obtain the electrochemical active area parameters of the fuel cell.

[0012] Furthermore, the gas under certain conditions is specifically: one side of the fuel cell is hydrogen or a mixture of hydrogen and inert gas, the volume concentration of hydrogen in the mixture is not less than 5%, and the other side is a single component inert gas or a mixture of inert gases.

[0013] Furthermore, the inert gas is nitrogen, helium or argon.

[0014] Furthermore, the criterion for the stable operation of the fuel cell to be tested under the specified conditions is that the voltage fluctuation collected by the fuel cell is always less than the starting voltage V1 within t1.

[0015] Furthermore, the scanning rate is set to 0.01-0.05 V / s.

[0016] Furthermore, the step 4 further comprises the following steps:

[0017] Step 41, obtaining a response current density curve, taking the peak and valley parts on the response current density curve as the analysis interval, and obtaining the analysis intervals corresponding to different scanning rates;

[0018] Step 42, within the analytical range, linear fitting is performed between different scanning rates x and the hydrogen desorption integral areas y corresponding to different scanning rates, and the slope of the linear relationship obtained by fitting is the electrochemical active area parameter excluding the influence of the scanning rate.

[0019] Furthermore, the linear relationship is y=kx+b.

[0020] Furthermore, the electrochemical active area parameter includes a catalyst active area.

[0021] An electronic device includes a memory and a processor, wherein the memory is used to store a program that supports the processor to execute the above-mentioned fuel cell electrochemical active area parameter measurement method based on potential scanning, and the processor is configured to execute the program stored in the memory.

[0022] A storage medium stores a computer program, which, when executed by a processor, performs the steps of the above-mentioned method for measuring the electrochemical active area parameters of a fuel cell based on potential scanning.

[0023] The advantages of the present invention are:

[0024] (1) The present invention supplies hydrogen to the anode of the fuel cell and inert gas to the cathode, and sets the anode and cathode flow rates to ensure that the system operates at a set temperature and maintains the stability of the anode and cathode air intake humidity. By connecting to an electrochemical workstation, multiple sets of linear potential scans are performed at different scanning rates, and the current density response at each scanning rate is recorded. The obtained current density is then analyzed to accurately calculate the electrochemical active area parameters of the fuel cell membrane electrode.

[0025] (2) The present invention is based on the linear potential cycle scanning method, optimizes the existing potential scanning process and ECSA measurement method, and can effectively reduce the influence of the scanning rate on the results, thereby more accurately characterizing the actual electrochemical active area of ​​the fuel cell membrane electrode. Through multiple sets of scanning rate data, the errors caused by the scanning rate can be effectively identified and eliminated. Compared with the existing methods, the present invention can provide more stable and reliable electrochemical active area measurement results and effectively improve the evaluation accuracy of fuel cell performance. Overcome the influence of the scanning rate on the test results and further improve the overall performance of the fuel cell.

[0026] (3) The present invention can more accurately reduce or eliminate the interference of the scan rate on the ECSA measurement by mathematically fitting and analyzing the current data at different scan rates, and obtain a more realistic electrochemical active area. The measurement method proposed in the present invention ensures that a stable and reliable electrochemical active area can be obtained even under non-ideal conditions (such as higher or lower scan rates). BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a flow chart of a method for measuring electrochemical active area parameters of a fuel cell based on potential scanning according to Embodiment 1 of the present invention;

[0028] Figure 2 is a schematic diagram of linear fitting based on different scanning rates x and different hydrogen desorption integrated areas y according to the second embodiment of the present invention;

[0029] Figure 3 It is a schematic diagram of linear fitting based on different scanning rates x and different hydrogen desorption integrated areas y according to the third embodiment of the present invention. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific embodiments:

[0032] Embodiment 1

[0033] like Figure 1 Specifically, a method for measuring the electrochemical active area parameters of a fuel cell based on potential scanning is disclosed, comprising the following steps:

[0034] Step 1, introducing a gas under certain conditions into the anode and cathode of the fuel cell to be tested;

[0035] The gas under certain conditions is specifically as follows: one side of the fuel cell is hydrogen or a mixture of hydrogen and inert gas, the volume concentration of hydrogen in the mixture is not less than 5%, and the other side is a single component inert gas or a mixture of inert gases; the inert gas includes but is not limited to nitrogen, helium, argon, etc., and the certain conditions include temperature, flow, pressure, humidification and other conditions. The specific condition parameters involved in the gas under certain conditions in this embodiment are set according to the actual working conditions that need to be tested.

[0036] In this embodiment, when setting gas conditions for the fuel cell to be tested, in order to ensure that the fuel cell is in an appropriate working state before measurement, the gas under certain conditions is introduced into the anode and cathode of the fuel cell to be tested until the voltage of each fuel cell is reduced to a preset value, thereby providing a conditional basis for subsequent tests.

[0037] Step 2: The fuel cell to be tested operates stably under specified conditions. The criterion for stable operation is that the voltage fluctuation collected by the fuel cell is always less than the starting voltage V1 within t1.

[0038] Step 3, after the fuel cell under test meets the test conditions, connect the external excitation source to the fuel cell under test, apply different scan rate voltages to the fuel cell, perform multiple sets of linear potential cyclic scans (CV scans) at different scan rates, and record the response current density corresponding to the multiple sets of linear potential cyclic scans.

[0039] In this embodiment, after the fuel cell under test meets the test conditions, an external excitation source is connected to the fuel cell under test, and multiple sets of linear potential cycle scans at different scanning rates are performed on the fuel cell. The scanning rate is set to 0.01V / s~0.05V / s. By performing multiple linear potential scans at different scanning rates, the current density response under each scan is recorded, and the current density response corresponding to each scanning rate has different characteristics.

[0040] Step 4, analyzing the response current density to obtain the electrochemical active area parameter of the fuel cell;

[0041] In this embodiment, the electrochemical active area parameter includes but is not limited to the catalyst active area.

[0042] Furthermore, the step 4 further comprises the following steps:

[0043] Step 41, obtaining a response current density curve, taking the peak and valley parts on the response current density curve as the analysis interval, and obtaining the analysis intervals corresponding to different scanning rates;

[0044] Step 42, within the analytical range, linear fitting is performed between different scanning rates x and the hydrogen desorption integral areas y corresponding to different scanning rates, and the slope of the linear relationship obtained by fitting is the electrochemical active area parameter excluding the influence of the scanning rate.

[0045] In this embodiment, within the analysis interval, the analysis interval is analyzed by a preset analysis method to obtain a linear relationship y=kx+b between different scanning rates x and the hydrogen desorption integral area y corresponding to different scanning rates. The value of the slope k is obtained after fitting the linear relationship. The k value obtained by fitting is the electrochemical active area value obtained by excluding the influence of the scanning rate. Obtaining this parameter by linear fitting can effectively avoid the influence of the scanning rate.

[0046] In this embodiment, through multiple sets of scan rate data, the errors caused by the scan rate can be effectively identified and eliminated. For example, a higher scan rate will cause the electrode surface to fail to fully reach the steady-state condition, while a lower scan rate may be affected by factors such as diffusion. By mathematically fitting and analyzing the current data at different scan rates, the interference of the scan rate on the ECSA measurement can be more accurately reduced or eliminated, and a more realistic electrochemical active area can be obtained. The measurement method proposed in this embodiment ensures that even under non-ideal conditions (such as higher or lower scan rates), a stable and reliable electrochemical active area can be obtained.

[0047] Embodiment 2

[0048] The method for measuring the electrochemical active area parameters of a fuel cell based on potential scanning provided in this embodiment is as follows:

[0049] Step 1, introducing a gas under certain conditions into the anode and cathode of the fuel cell to be tested;

[0050] The gas under certain conditions is as follows: the anode side of the fuel cell is hydrogen or a mixture of hydrogen and inert gas, and the volume concentration of hydrogen in the mixture is not less than 5%; the cathode side of the fuel cell is a single component inert gas or a mixture of inert gases, and the inert gas includes but is not limited to nitrogen, helium, argon, etc. The certain conditions include temperature, flow rate, pressure, humidification, etc. In this embodiment, the reaction area is 300cm 2Taking a fuel cell as an example, the anode gas temperature is 50°C, the cathode gas temperature is 50°C, the anode pressure is 0kPa, the anode flow rate is 2-20ml / min, the cathode flow rate is 4-50ml / min, and the battery temperature is 50°C.

[0051] Step 2: The fuel cell to be tested operates stably under specified conditions. The criterion for stable operation is that the voltage fluctuation of the fuel cell is always less than 0.1V within 5 minutes.

[0052] Step 3, after the object under test meets the test conditions, connect the external excitation source, perform multiple sets of linear potential cycle scans at different scan rates on the fuel cell, the scan rate is set to 0.01V / s to 0.05V / s, and record the response current density under the multiple sets of linear potential cycle scans.

[0053] Step 4, analyzing the response current density to obtain an electrochemical active area parameter of the fuel cell;

[0054] Furthermore, the step 4 specifically includes the following steps:

[0055] Step 41, obtaining the peak and valley portions of the response current density curve as the analysis interval, and obtaining the analysis intervals corresponding to different scanning rates;

[0056] Step 42, within the analytical range, linear fitting is performed between different scanning rates x and the hydrogen desorption integral areas y corresponding to different scanning rates, and the slope of the linear relationship obtained by fitting is the electrochemical active area parameter excluding the influence of the scanning rate.

[0057] like Figure 2 As shown, specifically, within the analytical range, different scanning rates x and the hydrogen desorption integral areas y corresponding to different scanning rates are linearly related: y=kx+b, and the linear relationship is fitted to obtain the k value, and the k value obtained by fitting is the electrochemical active area value obtained by excluding the influence of the scanning rate.

[0058] Embodiment 3

[0059] The method for measuring the electrochemical active area parameters of a fuel cell based on potential scanning provided in this embodiment is as follows:

[0060] Step 1, introducing a gas under certain conditions into the anode and cathode of the fuel cell to be tested;

[0061] The gas under certain conditions is as follows: the anode side of the fuel cell is hydrogen or a mixture of hydrogen and inert gas, and the volume concentration of hydrogen in the mixture is not less than 5%; the cathode side of the fuel cell is a single component inert gas or a mixture of inert gases, and the inert gas includes but is not limited to nitrogen, helium, argon, etc. The certain conditions include temperature, flow rate, pressure, humidification, etc. In this embodiment, the reaction area is 300cm 2 Taking a fuel cell as an example, the anode gas temperature is 70°C, the cathode gas temperature is 70°C, the anode pressure is 40kPa, the anode flow rate is 2-20ml / min, the cathode flow rate is 4-50ml / min, and the battery temperature is 70°C.

[0062] Step 2: The fuel cell to be tested operates stably under specified conditions. The criterion for stable operation is that the voltage fluctuation of the fuel cell is always less than 0.1V within 5 minutes.

[0063] Step 3, after the object under test meets the test conditions, connect the external excitation source, perform multiple sets of linear potential cycle scans at different scan rates on the fuel cell, the scan rate is set to 0.01V / s to 0.05V / s, and record the response current density under the multiple sets of linear potential cycle scans.

[0064] Step 4, analyzing the response current density to obtain an electrochemical active area parameter of the fuel cell;

[0065] Furthermore, the step 4 specifically includes the following steps:

[0066] Step 41, obtaining the peak and valley portions of the response current density curve as the analysis interval, and obtaining the analysis intervals corresponding to different scanning rates;

[0067] Step 42, within the analytical range, linear fitting is performed between different scanning rates x and the hydrogen desorption integral areas y corresponding to different scanning rates, and the slope of the linear relationship obtained by fitting is the electrochemical active area parameter excluding the influence of the scanning rate.

[0068] like Figure 3 As shown, specifically, within the analytical range, different scanning rates x and the hydrogen desorption integral areas y corresponding to different scanning rates are linearly related: y=kx+b, and the linear relationship is fitted to obtain the k value, and the k value obtained by fitting is the electrochemical active area value obtained by excluding the influence of the scanning rate.

[0069] Embodiment 4

[0070] The present invention also provides an electronic device, comprising a memory and a processor, wherein the memory is used to store a program that supports the processor to execute the method for measuring the electrochemical active area parameters of a fuel cell based on potential scanning in Example 1, 2 or 3, and the processor is configured to execute the program stored in the memory.

[0071] Embodiment 5

[0072] The present invention also provides a storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the method for measuring the electrochemical active area parameters of a fuel cell based on potential scanning in Embodiment 1, 2 or 3 are executed.

[0073] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for measuring electrochemical active area parameters of a fuel cell based on potential scanning, characterized in that: The following steps are involved: Step 1, introducing a gas under certain conditions into the anode and cathode of the fuel cell to be tested; Step 2, the fuel cell to be tested operates stably under specified conditions; Step 3, connecting to an external excitation source, applying voltages at different scan rates, performing multiple sets of linear potential cycle scans, and recording multiple sets of response current densities; Step 4: Analyze the response current density to obtain the electrochemical active area parameters of the fuel cell.

2. The method for measuring the electrochemical active area parameter of a fuel cell based on potential scanning according to claim 1, characterized in that: The gas under certain conditions is specifically: one side of the fuel cell is hydrogen or a mixture of hydrogen and inert gas, the volume concentration of hydrogen in the mixture is not less than 5%, and the other side is a single component inert gas or a mixture of inert gases.

3. The method for measuring the electrochemical active area parameter of a fuel cell based on potential scanning according to claim 2, characterized in that: The inert gas is nitrogen, helium or argon.

4. The method for measuring the electrochemical active area parameter of a fuel cell based on potential scanning according to claim 1, characterized in that: The criterion for the stable operation of the fuel cell to be tested under the specified conditions is that the voltage fluctuation collected by the fuel cell is always less than the starting voltage V1 within t1.

5. The method for measuring the electrochemical active area parameters of a fuel cell based on potential scanning according to claim 1, characterized in that: The scanning rate is set to 0.01-0.05 V / s.

6. The method for measuring the electrochemical active area parameters of a fuel cell based on potential scanning according to claim 1, characterized in that: The step 4 further comprises the following steps: Step 41, obtaining a response current density curve, taking the peak and valley parts on the response current density curve as the analysis interval, and obtaining the analysis intervals corresponding to different scanning rates; Step 42, within the analytical range, linear fitting is performed between different scanning rates x and the hydrogen desorption integral areas y corresponding to different scanning rates, and the slope of the linear relationship obtained by fitting is the electrochemical active area parameter excluding the influence of the scanning rate.

7. The method for measuring the electrochemical active area parameters of a fuel cell based on potential scanning according to claim 6, characterized in that: The linear relationship is y=kx+b.

8. The method for measuring the electrochemical active area parameters of a fuel cell based on potential scanning according to claim 7, characterized in that: The electrochemical active area parameter includes the catalyst active area.

9. An electronic device, comprising a memory and a processor, characterized in that: The memory is used to store a program that supports the processor to execute the method for measuring the electrochemical active area parameter of a fuel cell based on potential scanning as described in any one of claims 1 to 8, and the processor is configured to execute the program stored in the memory.

10. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for measuring the electrochemical active area parameter of a fuel cell based on potential scanning according to any one of claims 1 to 8 are executed.

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