Activation method for improving power density of proton exchange membrane fuel cell

Abstract

The invention discloses an activation method for improving the power density of a proton exchange membrane fuel cell, and relates to the technical field of fuel cells, and the specific process is as follows: S1) connecting the fuel cell to a fuel cell test system, purging with N2, and setting the temperature of a humidifier, a gas path pipeline and the cell; s2) after a certain temperature is reached, replacing reaction gas air and H2, testing an I-V curve, and determining peak power density; and S3) setting a battery temperature gradient (60-85 DEG C) and a current density gradient (0.05 A / cm < 2 >-3A / cm < 2 >), and testing to obtain an I-V curve, namely open-circuit voltage, rated power density and peak power density. Compared with a traditional activation method, the high-efficiency activation method for the proton exchange membrane fuel cell has the advantages that the rated power density and the peak power density of the fuel cell are respectively improved by 45% and 20%.

Description

Technical Field

[0001] This invention belongs to the field of fuel cell technology, specifically relating to an activation method for improving the power density of a proton exchange membrane fuel cell. Background Technology

[0002] A fuel cell is a chemical device that directly converts the chemical energy of fuel into electrical energy, unaffected by the Carnot cycle effect, and boasts high energy conversion efficiency. Among them, proton exchange membrane fuel cells (PEMFCs) have broad application prospects in the field of new energy due to their advantages such as fast start-up, high energy density, and environmental friendliness.

[0003] Activation is a crucial step before PEMFCs are put into operation, with the core objective of activating the membrane electrode assembly (MEA) to bring it to its rated or optimal performance state. Activation enhances the activity of the platinum-carbon catalyst, improves catalyst utilization efficiency, and strengthens proton exchange membrane hydration, thereby improving the fuel cell's output performance. During activation, the cell's rated power density or peak power density will continuously rise to a stable value, indicating that activation is complete.

[0004] Existing PEMFC activation methods are mainly divided into two categories: offline activation and online activation. Offline activation, such as the steam treatment method proposed by Mohammad et al., can improve MEA performance, but it requires 2.5 hours, which is time-consuming. Online activation, such as the voltage regulation method proposed by Weng et al., the constant current activation method proposed by Boaventura, and the high temperature and high pressure method proposed by Qi, simplifies the process, but has obvious drawbacks: it is controlled by only a single parameter (voltage, current, temperature), resulting in low activation efficiency, easy flooding under high current density, and consumption of a lot of time and hydrogen, leading to high activation costs. Summary of the Invention

[0005] To address the technical problems of existing PEMFC activation methods, such as low activation efficiency, high cost, severe water flooding at high current densities, and limited power density improvement, this invention provides an activation method to improve the power density of proton exchange membrane fuel cells. By coordinating temperature and current density dual gradients, efficient activation is achieved, significantly improving the battery power density.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] An activation method for improving the power density of a proton exchange membrane fuel cell includes the following steps:

[0008] S1. Connect the assembled proton exchange membrane fuel cell to the fuel cell test system, clean the membrane electrode surface with N2, and set the temperature of the humidifier, gas pipeline and battery to 65~80℃.

[0009] S2. After the battery temperature reaches the set value, replace the purge gas with the reaction gas air and H2, test the IV curve, and increase the current density sequentially until the voltage stabilizes.

[0010] S3. Set the battery temperature gradient and current density gradient, and test to obtain the IV curve; the battery temperature gradient range is 60℃-85℃, and the temperature gradient increment is 1℃-6℃; the current density gradient range is 0.05A / cm²-3A / cm², and the current density gradient increment is 0.05A / cm²-0.2A / cm².

[0011] S4. Process the IV curve data obtained from the test to obtain the open-circuit voltage, rated power density, and peak power density of the fuel cell.

[0012] As a further technical solution of the present invention: In step S1, the humidifier includes an anode humidifier and a cathode humidifier, the temperature of the anode humidifier is set to 70°C, and the temperature of the cathode humidifier is set to 50°C.

[0013] As a further technical solution of the present invention: the gas pipeline includes a cathode gas pipeline and an anode gas pipeline, both of which are set to a temperature of 70°C.

[0014] As a further technical solution of the present invention: In step S1, the cell chip CCM of the proton exchange membrane fuel cell is a commercially available common CCM, and the gas diffusion layer GDL is a commercially available common electrochemical experimental GDL.

[0015] As a further technical solution of the present invention: in step S3, the battery temperature gradient increment is 2℃, 3℃, 4℃ or 5℃.

[0016] As a further technical solution of the present invention: in step S3, the current density gradient increment is 0.05A / cm², 0.1A / cm², 0.15A / cm² or 0.2A / cm².

[0017] As a further technical solution of the present invention: in step S1, the set temperature of the battery is 65°C.

[0018] This technology proposes an activation method to improve the power density of proton exchange membrane fuel cells, which has the following advantages and beneficial effects:

[0019] 1. High activation efficiency: Compared with traditional constant current activation (such as Comparative Example 1 which requires 0.5 hours), this method shortens the activation time by more than 30% through dual gradient synergistic regulation, reduces single-cell experimental testing time and hydrogen consumption, and lowers activation costs.

[0020] 2. Reduced flooding: The gradient adaptation design of temperature and current density can dynamically balance the hydration requirements of the membrane electrode and the gas diffusion efficiency, significantly reducing the number of floodings under high current density and improving activation stability.

[0021] 3. Significantly improved power density: Compared with traditional activation methods, the rated power density of fuel cells is increased by 45%, the peak power density is increased by 20%, and the open-circuit voltage is increased to over 0.90V, greatly optimizing the battery output performance. Attached Figure Description

[0022] Figure 1 This is a polarization curve of the fuel cell after activation in Example 1 of the present invention;

[0023] Figure 2 This is a polarization curve of the fuel cell after activation in Example 2 of the present invention;

[0024] Figure 3 This is a polarization curve of the fuel cell after activation in Example 3 of the present invention;

[0025] Figure 4 This is a polarization curve of the fuel cell after activation in Example 4 of the present invention;

[0026] Figure 5 This is a polarization curve of the fuel cell after Comparative Example 1 (constant current activation) of the present invention;

[0027] Figure 6 This is a table comparing the open-circuit voltage, rated power density, and peak power density of embodiments and comparative examples of the present invention. Detailed Implementation

[0028] The present invention will be further described below with reference to the embodiments. It should be noted that these are merely examples and descriptions of the inventive concept. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the inventive concept or exceed the scope defined in the claims, they should all be considered to fall within the protection scope of the present invention.

[0029] like Figure 1-6 As shown, the present invention proposes a method for activating a proton exchange membrane fuel cell, comprising the following steps:

[0030] S1. Connect the fuel cell to the fuel cell test system and purge it with N2, while setting a fixed temperature for the humidifier, gas pipeline and battery.

[0031] S2. After reaching the specified temperature, replace the reaction gases with air and H2, test the IV curve, and gradually increase the current density until the voltage stabilizes.

[0032] S3. Set the battery temperature gradient (60 ℃-85 ℃) and current density gradient (0.05 A / cm). 2 -3 A / cm 2 The IV curve was obtained through testing.

[0033] S4. After processing the data, the open-circuit voltage, rated power density, and peak power density can be obtained.

[0034] Furthermore, the battery temperature described in step S1 is 65 °C.

[0035] Furthermore, the fuel cell chip (CCM) assembled in step S1 is a commercially available CCM.

[0036] Furthermore, the gas diffusion layer (GDL) assembled in step S1 is a commercially available gas diffusion layer for electrochemical experiments.

[0037] Furthermore, the battery temperature gradient increments mentioned in step S3 are 2 °C, 3 °C, 4 °C, and 5 °C.

[0038] Furthermore, the current density gradient increment in step S3 is 0.05 A / cm. 2 0.1 A / cm 2 0.15 A / cm 2 and 0.2 A / cm 2 .

[0039] The activation method for a proton exchange membrane fuel cell, completed by the above steps, is applied in the fuel cell testing phase. Further demonstration is provided below with reference to specific examples:

[0040] Example 1

[0041] (1) Connect the fuel cell to the fuel cell test system and clean the membrane electrode surface with N2. At the same time, set the temperature of the anode humidifier to 70 ℃, the temperature of the cathode humidifier to 50 ℃, and the temperature of the cathode and anode gas pipelines to 70 ℃.

[0042] (2) The battery temperature is set to 65 ℃. After reaching the specified temperature, the reaction gases air and H2 are replaced, and the current density is set to 0 A / cm. 2 The open-circuit voltage was measured, and the current density was set to 0.1 A / cm². 2 Test the IV curve, with the current density set to 0.2 A / cm². 2 Test the IV curve, with the current density set to 0.3 A / cm². 2 Test the IV curve, with the current density set to 0.4 A / cm². 2Test the IV curve, with the current density set to 0.5 A / cm². 2 Test IV curve;

[0043] (3) When the battery temperature rises to 67 ℃, test the IV curve. The current density is set as shown in (2), with an increment of 0.1 A / cm. 2 The current density is from 0.5 A / cm². 2 1 A / cm was measured 2 Finish;

[0044] (4) When the battery temperature rises to 70 ℃, test the IV curve. The current density is set as shown in (2), with an increment of 0.1 A / cm. 2 Current density from 1 A / cm 2 1.5 A / cm was measured. 2 Finish;

[0045] (5) When the battery temperature rises to 72 ℃, test the IV curve. The current density is set as shown in (2), with an increment of 0.1 A / cm. 2 The current density is from 1.5 A / cm². 2 2 A / cm was measured 2 Finish;

[0046] (6) When the battery temperature rises to 75 ℃, test the IV curve. The current density is set as shown in (2), with an increment of 0.1 A / cm. 2 Current density from 2 A / cm 2 2.5 A / cm was measured. 2 Finish;

[0047] (7) After obtaining the IV curve through testing, the saved data can be processed to obtain the open-circuit voltage, rated power density, and peak power density, such as... Figure 1 As shown, the open-circuit voltage is 0.907 V, and the rated power density is 1.04 W / cm². 2 The peak power density is 1.32 W / cm². 2 .

[0048] Example 2

[0049] (1) Connect the fuel cell to the fuel cell test system and clean the membrane electrode surface with N2. At the same time, set the temperature of the anode humidifier to 70 ℃, the temperature of the cathode humidifier to 50 ℃, and the temperature of the cathode and anode gas pipelines to 70 ℃.

[0050] (2) The battery temperature is set to 68 ℃. After reaching the specified temperature, the reaction gases air and H2 are replaced, and the current density is set to 0 A / cm. 2The open-circuit voltage was measured, and the current density was set to 0.1 A / cm². 2 Test the IV curve, with the current density set to 0.2 A / cm². 2 Test the IV curve, with the current density set to 0.3 A / cm². 2 Test the IV curve, with the current density set to 0.4 A / cm². 2 Test the IV curve, with the current density set to 0.5 A / cm². 2 Test the IV curve, with the current density set to 0.6 A / cm². 2 Test the IV curve, with the current density set to 0.7 A / cm². 2 Test the IV curve, with the current density set to 0.8 A / cm². 2 Test IV curve;

[0051] (3) When the battery temperature rises to 73 ℃, test the IV curve. The current density is set as shown in (2), with an increment of 0.1 A / cm. 2 The current density is from 0.8 A / cm². 2 1.6 A / cm was measured. 2 Finish;

[0052] (4) When the battery temperature rises to 78 ℃, test the IV curve. The current density is set as shown in (2), with an increment of 0.1 A / cm. 2 The current density is from 1.6 A / cm². 2 2.5 A / cm was measured. 2 Finish;

[0053] (5) After obtaining the IV curve through testing, the saved data can be processed to obtain the open-circuit voltage, rated power density, and peak power density, such as... Figure 2 As shown, the open-circuit voltage is 0.901 V, and the rated power density is 0.98 W / cm³. 2 The peak power density is 1.13 W / cm². 2 .

[0054] Example 3

[0055] (1) Connect the fuel cell to the fuel cell test system and clean the membrane electrode surface with N2. At the same time, set the temperature of the anode humidifier to 70 ℃, the temperature of the cathode humidifier to 50 ℃, and the temperature of the cathode and anode gas pipelines to 70 ℃.

[0056] (2) The battery temperature is set to 60 ℃. After reaching the specified temperature, the reaction gases air and H2 are replaced. The current density is set to 0 A / cm. 2 The open-circuit voltage was measured, and the current density was set to 0.1 A / cm².2 Test the IV curve, with the current density set to 0.2 A / cm². 2 Test the IV curve, with the current density set to 0.3 A / cm². 2 Test the IV curve, with the current density set to 0.4 A / cm². 2 Test the IV curve, with the current density set to 0.5 A / cm². 2 Test the IV curve, with the current density set to 0.6 A / cm². 2 Test IV curve;

[0057] (3) When the battery temperature rises to 65 ℃, test the IV curve. The current density is set as shown in (2), with an increment of 0.1 A / cm. 2 The current density is from 0.6 A / cm². 2 1.2 A / cm was measured. 2 Finish;

[0058] (4) When the battery temperature rises to 70 ℃, test the IV curve. The current density is set as shown in (2), with an increment of 0.1 A / cm. 2 The current density is from 1.2 A / cm². 2 1.8 A / cm was measured. 2 ;

[0059] (5) When the battery temperature rises to 75 ℃, test the IV curve. The current density is set as shown in (2), with an increment of 0.1 A / cm. 2 The current density is from 1.8 A / cm². 2 2.5 A / cm was measured. 2 ;

[0060] (6) After obtaining the IV curve through testing, the saved data can be processed to obtain the open-circuit voltage, rated power density, and peak power density, such as... Figure 3 As shown, the open-circuit voltage is 0.902 V, and the rated power density is 0.91 W / cm². 2 The peak power density is 1.22 W / cm². 2 .

[0061] Example 4

[0062] (1) Connect the fuel cell to the fuel cell test system and clean the membrane electrode surface with N2. At the same time, set the temperature of the anode humidifier to 70 ℃, the temperature of the cathode humidifier to 50 ℃, and the temperature of the cathode and anode gas pipelines to 70 ℃.

[0063] (2) The battery temperature is set to 67 ℃. After reaching the specified temperature, the reaction gases air and H2 are replaced, and the current density is set to 0 A / cm.2 The open-circuit voltage was measured, and the current density was set to 0.1 A / cm². 2 Test the IV curve, with the current density set to 0.2 A / cm². 2 Test the IV curve, with the current density set to 0.3 A / cm². 2 Test the IV curve, with the current density set to 0.4 A / cm². 2 Test the IV curve, with the current density set to 0.5 A / cm². 2 Test the IV curve, with the current density set to 0.6 A / cm². 2 Test the IV curve, with the current density set to 0.75 A / cm². 2 Test IV curve;

[0064] (3) When the battery temperature rises to 70 ℃, the current density is set to 0.8 A / cm. 2 Test the IV curve, with the current density set to 0.9 A / cm². 2 Test the IV curve, with the current density set to 1 A / cm². 2 Test the IV curve, with the current density set to 1.1 A / cm². 2 Test the IV curve, with the current density set to 1.2 A / cm². 2 Test the IV curve, with the current density set to 1.25 A / cm². 2 Test IV curve;

[0065] (4) When the battery temperature rises to 73 ℃, the current density is set to 1.4 A / cm. 2 Test the IV curve, with the current density set to 1.5 A / cm². 2 Test the IV curve, with the current density set to 1.6 A / cm². 2 Test the IV curve, with the current density set to 1.7 A / cm². 2 Test the IV curve, with the current density set to 1.8 A / cm². 2 Test the IV curve, with the current density set to 1.9 A / cm². 2 Test the IV curve, with the current density set to 2 A / cm². 2 Test IV curve;

[0066] (5) When the battery temperature rises to 75 ℃, the current density is set to 2.1 A / cm. 2 The IV curve was tested, with the current density set to 2.25 A / cm². 2 Test IV curve;

[0067] (6) When the battery temperature rises to 78 ℃, the current density is set to 2.3 A / cm. 2 The IV curve was tested, with the current density set to 2.4 A / cm². 2 Test the IV curve, with the current density set to 2.5 A / cm². 2 Test IV curve;

[0068] (7) After obtaining the IV curve through testing, the saved data can be processed to obtain the open-circuit voltage, rated power density, and peak power density, such as... Figure 4 As shown, the open-circuit voltage is 0.905 V, and the rated power density is 0.92 W / cm². 2 The peak power density is 1.25 W / cm². 2 .

[0069] Comparative Example 1

[0070] (1) Connect the assembled fuel cell to the fuel cell test system and clean the membrane electrode surface with N2. At the same time, set the anode humidifier temperature to 70°C, the cathode humidifier temperature to 50°C, the cathode and anode gas path pipe temperature to 70°C, and the battery temperature to 70°C.

[0071] (2) After reaching the specified temperature, replace the reaction gases with air and H2, test the IV curve, and increase the current density sequentially until the voltage stabilizes;

[0072] (3) Find the limiting current density of 2.1 A / cm² that corresponds to the final voltage stability under the first polarization curve data. 2 Activation was performed at this current density for 0.5 h.

[0073] (4) After activation, the IV curve is obtained by testing. The saved data is then processed to obtain the open-circuit voltage, rated power density, and peak power density, such as... Figure 5 As shown, the open-circuit voltage is 0.874 V, and the rated power density is 0.72 W / cm². 2 The peak power density is 1.10 W / cm². 2 .

[0074] The above is an exemplary description of the invention. Obviously, the specific implementation of the invention is not limited to the above-described manner. Any non-substantial improvement made using the inventive concept and technical solution of the invention, or the direct application of the inventive concept and technical solution to other situations without modification, is within the protection scope of the invention.

Claims

1. An activation method for improving the power density of a proton exchange membrane fuel cell, characterized in that, Includes the following steps: S1. Connect the assembled proton exchange membrane fuel cell to the fuel cell test system, clean the membrane electrode surface with N2, and set the temperature of the humidifier, gas pipeline and battery to 65~80℃. S2. After the battery temperature reaches the set value, replace the purge gas with the reaction gas air and H2, test the IV curve, and increase the current density sequentially until the voltage stabilizes. S3. Set the battery temperature gradient and current density gradient, and test to obtain the IV curve; the battery temperature gradient range is 60℃-85℃, and the temperature gradient increment is 1℃-6℃; the current density gradient range is 0.05A / cm²-3A / cm², and the current density gradient increment is 0.05A / cm²-0.2A / cm². S4. Process the IV curve data obtained from the test to obtain the open-circuit voltage, rated power density, and peak power density of the fuel cell.

2. The activation method for improving the power density of a proton exchange membrane fuel cell according to claim 1, characterized in that, In step S1, the humidifier includes an anode humidifier and a cathode humidifier, with the anode humidifier temperature set to 70°C and the cathode humidifier temperature set to 50°C.

3. The activation method for improving the power density of a proton exchange membrane fuel cell according to claim 1, characterized in that, The gas pipeline includes a cathode gas pipeline and an anode gas pipeline, both with a temperature set at 70°C.

4. The activation method for improving the power density of a proton exchange membrane fuel cell according to claim 1, characterized in that, In step S1, the proton exchange membrane fuel cell's cell chip (CCM) is a commercially available common CCM, and the gas diffusion layer (GDL) is a commercially available common electrochemical experimental GDL.

5. The activation method for improving the power density of a proton exchange membrane fuel cell according to claim 1, characterized in that, In step S3, the battery temperature gradient increment is 2℃, 3℃, 4℃ or 5℃.

6. The activation method for improving the power density of a proton exchange membrane fuel cell according to claim 1, characterized in that, In step S3, the current density gradient increment is 0.05 A / cm², 0.1 A / cm², 0.15 A / cm², or 0.2 A / cm².

7. The activation method for improving the power density of a proton exchange membrane fuel cell according to claim 1, characterized in that, In step S1, the set temperature of the battery is 65°C.

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