Method and activation control device for activating a proton exchange membrane fuel cell

Abstract

This invention relates to an activation method and activation control device for a proton exchange membrane fuel cell. The method includes: introducing air into the cathode and hydrogen into the anode of the proton exchange membrane fuel cell, and adjusting the temperature to a preset gas dew point temperature; adjusting the operating temperature of the membrane electrode to a first temperature, discharging at a low current density, and continuing to discharge for a first time; the first temperature is lower than the gas dew point temperature; raising the operating temperature of the membrane electrode to a preset second temperature, then increasing the discharge current density and continuing to discharge for a second time, while reducing the gas flow rates of air and hydrogen, so that the discharge voltage is lower than a voltage threshold and the second temperature is higher than the gas dew point temperature; during the last period of discharge operation, determining whether activation is complete based on the discharge voltage fluctuation, and if not, performing a cycle. Compared with the prior art, this invention shortens the activation time of the membrane electrode and reduces energy and hydrogen consumption.

Description

Technical Field

[0001] This invention relates to the field of fuel cell activation technology, and in particular to an activation method and activation control device for a proton exchange membrane fuel cell. Background Technology

[0002] Newly fabricated membrane electrodes require activation treatment to achieve optimal performance. Common activation methods include alternating current method, alternating voltage method, hydrogen pump method, and cathode starvation method. The first two are relatively simple to operate and control, but they are time-consuming and consume a lot of hydrogen. For example, the invention with publication number CN110783589A proposes a rapid activation method for the membrane electrode of a proton exchange membrane fuel cell and its application. The rapid activation method is a continuous high-frequency voltage forced activation with the voltage decreasing linearly at a constant rate.

[0003] In addition, the hydrogen pump method requires an external power supply and has high equipment requirements; the cathode starvation method requires strict monitoring of process changes to avoid phenomena such as reverse polarity that damage the catalyst. Summary of the Invention

[0004] The purpose of this invention is to overcome the defects of the prior art by providing an activation method and activation control device for a proton exchange membrane fuel cell, thereby shortening the activation time of the membrane electrode and reducing energy and hydrogen consumption.

[0005] The objective of this invention can be achieved through the following technical solutions: An activation method for a proton exchange membrane fuel cell includes the following steps: S1: Obtain the proton exchange membrane fuel cell to be activated, introduce air into the cathode of the proton exchange membrane fuel cell and hydrogen into the anode, and adjust the air and hydrogen to the preset gas dew point temperature. S2: Adjust the operating temperature of the membrane electrode to a preset first temperature, discharge at a relatively low current density, and continue discharging for a preset first time; the first temperature is lower than the gas dew point temperature. S3: Increase the operating temperature of the membrane electrode to a preset second temperature, then increase the discharge current density and continue discharging for a preset second time, while reducing the gas flow rates of air and hydrogen, so that the discharge voltage is lower than a preset voltage threshold and the second temperature is higher than the gas dew point temperature. S4: During the last period of time in step S3, determine whether the discharge voltage fluctuation is less than the preset voltage fluctuation threshold. If so, determine that the activation is complete and end the process; otherwise, restore the gas flow rates of air and hydrogen to the initial values ​​in step S1 and return to step S2.

[0006] Furthermore, in step S1, the gas dew point temperature is within the range of 35°C to 60°C.

[0007] Furthermore, in step S2, the expression for calculating the first temperature is: Tcell0 = T1 - Δt1 In the formula, Tcell0 is the first temperature, T1 is the gas dew point temperature, Δt1 is the change in the first temperature, and the value of Δt1 ranges from 0 to 5℃.

[0008] Furthermore, in step S2, the value of the smaller current density ranges from 50 to 200 mA / cm². 2 The value of the first time interval is in the range of 5 to 10 minutes.

[0009] Furthermore, in step S3, the expression for calculating the second temperature is: Tcell1 = T1 + Δt2 In the formula, Tcell1 is the second temperature, T1 is the gas dew point temperature, Δt2 is the change in the second temperature, and the value of Δt2 ranges from 10 to 20℃.

[0010] Furthermore, in step S3, the improved current density ranges from 500 to 2000 mA / cm². 2 The value of the second time is in the range of 5~20 mins.

[0011] Furthermore, in step S3, the voltage threshold is 0.6V.

[0012] Furthermore, in step S4, the discharge voltage fluctuation is determined during the last 2 minutes of step S3.

[0013] Furthermore, the voltage fluctuation threshold is 5mV / min.

[0014] The present invention also provides an activation control device for a proton exchange membrane fuel cell, used to control the activation process of the proton exchange membrane fuel cell, characterized in that it includes a memory and a processor, wherein the memory stores a computer program, and the processor calls the computer program to execute the steps of the method described above.

[0015] Compared with the prior art, the present invention has the following advantages: (1) Traditional activation processes may operate under single, gentle conditions for a long time, while the present invention accelerates the formation and stabilization of the internal structure of the membrane electrode by actively and rapidly creating enhanced working conditions. Specifically, after completing the gas dew point and preliminary wetting in steps S1 and S2, the working temperature and current density are increased in step S3, which greatly enhances the electrochemical reaction kinetics and forces the catalyst, ionomer and proton membrane in the membrane electrode to rapidly adjust, reconstruct and form an effective reaction interface under high current density, thereby completing the activation process that may take several hours in a short time using traditional methods. Furthermore, reducing the discharge voltage to below 0.6V allows for slight reactant concentration polarization at local reaction sites within the membrane electrode, effectively exposing and activating reaction sites that are difficult to access under normal flow rates, thus accelerating the uniform activation process of the entire electrode and shortening the activation time of the membrane electrode.

[0016] (2) Traditional methods may maintain a high and constant gas flow rate throughout the activation process, resulting in a large amount of unreacted hydrogen being directly discharged and wasted. In the process of accelerating activation in step S3, the present invention reduces the discharge voltage by reducing the gas flow rate, thereby maximizing the transmission and utilization efficiency of hydrogen in the diffusion layer and catalyst layer, and reducing the escape of hydrogen that is directly discharged through the flow channel due to excessive supply.

[0017] (3) Overall, the present invention achieves a reduction in the activation time of the membrane electrode and a decrease in energy and hydrogen consumption without increasing the equipment requirements and operational complexity. Attached Figure Description

[0018] Figure 1 This is a schematic flowchart of an activation method for a proton exchange membrane fuel cell provided in an embodiment of the present invention; Figure 2 This is a detailed flowchart illustrating an activation method for a proton exchange membrane fuel cell provided in an embodiment of the present invention. Figure 3 This is a schematic diagram illustrating the relationship between the polarization performance and the number of activation cycles of three membrane electrodes from the same batch, as provided in an embodiment of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0021] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0022] Example 1 like Figure 1 and Figure 2 As shown, this embodiment provides an activation method for a proton exchange membrane fuel cell, including the following steps: S1: Obtain the proton exchange membrane fuel cell to be activated, introduce air into the cathode of the proton exchange membrane fuel cell and hydrogen into the anode, and adjust the air and hydrogen to the preset gas dew point temperature. The gas dew point temperature is within the range of 35℃ to 60℃.

[0023] The gas dew point refers to the temperature at which water vapor in a gas begins to condense into liquid water when cooled while maintaining constant pressure. In this design, air is introduced into the membrane electrode cathode and hydrogen into the anode, with the gas dew point specified as 35°C to 60°C. This means that all gases entering the battery are humidified to ensure that their humidity reaches saturation at the corresponding temperatures. This helps maintain the moisture content of the membrane electrode and optimizes the performance and lifespan of the fuel cell.

[0024] S2: Adjust the operating temperature of the membrane electrode to a preset first temperature, discharge at a relatively low current density, and continue discharging for a preset first time; the first temperature is lower than the gas dew point temperature; The operating temperature of a membrane electrode is the temperature of the clamp or electrode plate.

[0025] The formula for calculating the first temperature is: Tcell0 = T1 - Δt1 In the formula, Tcell0 is the first temperature, T1 is the gas dew point temperature, Δt1 is the change in the first temperature, and the value of Δt1 ranges from 0 to 5℃.

[0026] The range of smaller current densities is 50~200 mA / cm². 2 The value range for the first time is 5~10 mins.

[0027] Essentially, this step sets the operating temperature of the membrane electrode (the temperature of the clamp or electrode plate) to Tcell0, and discharges at a low current density I0 for time1, requiring Tcell0 = T1 - Δt1, where Δt1 = 0~5℃, time1 = 5~10 mins, and I0 = 50~200 mA / cm². 2 .

[0028] S3: Increase the operating temperature of the membrane electrode to a preset second temperature, then increase the discharge current density and continue discharging for a preset second time, while reducing the gas flow rates of air and hydrogen, so that the discharge voltage is lower than a preset voltage threshold and the second temperature is higher than the gas dew point temperature. The formula for calculating the second temperature is: Tcell1 = T1 + Δt2 In the formula, Tcell1 is the second temperature, T1 is the gas dew point temperature, Δt2 is the change in the second temperature, and the value of Δt2 ranges from 10 to 20℃.

[0029] The improved current density ranges from 500 to 2000 mA / cm². 2 The second time range is 5~20 mins, and the voltage threshold is 0.6V.

[0030] Essentially, this step raises the operating temperature of the membrane electrode to Tcell1. Once Tcell1 is reached, the discharge current density is increased to I1 and continuously run for time2. The requirements are: Tcell1 = T1 + Δt2, Δt2 = 10~20℃, time2 = 5~20 mins, and I1 = 500~2000 mA / cm². 2 And reduce the gas flow rate to make the discharge voltage lower than 0.6V.

[0031] S4: During the last period of time in step S3, determine whether the discharge voltage fluctuation is less than the preset voltage fluctuation threshold. If so, determine that the activation is complete and end the process; otherwise, restore the gas flow rates of air and hydrogen to the initial values ​​in step S1 and return to step S2.

[0032] Preferably, in the last 2 minutes of step S3, the discharge voltage fluctuation is judged, and the voltage fluctuation threshold is 5mV / min.

[0033] In other words, in the last 2 minutes of step S3, if the discharge voltage fluctuation is less than 5mV / min, the activation is considered complete and the activation ends; if the discharge voltage fluctuation is greater than 5mV / min, the gas flow rate is increased to the initial value and the membrane electrode operating temperature is reduced to Tcell0, and steps S2 and S3 are repeated.

[0034] In this embodiment, the gas dew point temperature is set to 40°C; the membrane electrode operating temperatures are Tcell0 = 38°C, Tcell1 = 65°C, time1 = 5 mins, time2 = 10 mins, and I0 = 150 mA / cm². 2 I1 = 1000 mA / cm 2 The relationship between the polarization performance of three membrane electrodes from the same batch and the number of activation cycles is as follows: Figure 3 As shown, after two cycles, the performance remained basically stable, and the activation was complete.

[0035] Example 2 This embodiment provides an activation control device for a proton exchange membrane fuel cell, used to control the activation process of the proton exchange membrane fuel cell. It is characterized by including a memory and a processor. The memory stores a computer program, and the processor calls the computer program to execute the steps of an activation control method for a proton exchange membrane fuel cell as described in Embodiment 1.

[0036] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A method of activating a proton exchange membrane fuel cell, characterized by, Includes the following steps: S1: Obtain the proton exchange membrane fuel cell to be activated, introduce air into the cathode of the proton exchange membrane fuel cell and hydrogen into the anode, and adjust the air and hydrogen to the preset gas dew point temperature. S2: Adjust the operating temperature of the membrane electrode to a preset first temperature, discharge at a relatively low current density, and continue discharging for a preset first time; the first temperature is lower than the gas dew point temperature. S3: Increase the operating temperature of the membrane electrode to a preset second temperature, then increase the discharge current density and continue discharging for a preset second time, while reducing the gas flow rates of air and hydrogen, so that the discharge voltage is lower than a preset voltage threshold and the second temperature is greater than the gas dew point temperature. S4: During the last period of time in step S3, determine whether the discharge voltage fluctuation is less than the preset voltage fluctuation threshold. If so, determine that the activation is complete and end the process; otherwise, restore the gas flow rates of air and hydrogen to the initial values ​​in step S1 and return to step S2.

2. The method of claim 1, wherein the proton exchange membrane fuel cell is activated by, In step S1, the gas dew point temperature is within the range of 35°C to 60°C.

3. The method of claim 1, wherein the step of activating the proton exchange membrane fuel cell is performed at a temperature of about 80°C to about 100°C. In step S2, the expression for calculating the first temperature is: Tcell0 = T1 - Δt1 In the formula, Tcell0 is the first temperature, T1 is the gas dew point temperature, Δt1 is the change in the first temperature, and the value of Δt1 ranges from 0 to 5℃.

4. The method of claim 1, wherein the proton exchange membrane fuel cell is activated by, In step S2, the smaller current density ranges from 50 to 200 mA / cm². 2 The value of the first time interval is in the range of 5 to 10 minutes.

5. The method of claim 1, wherein the proton exchange membrane fuel cell is activated by, In step S3, the expression for calculating the second temperature is: Tcell1 = T1 + Δt2 In the formula, Tcell1 is the second temperature, T1 is the gas dew point temperature, Δt2 is the change in the second temperature, and the value of Δt2 ranges from 10 to 20℃.

6. The method of claim 1, wherein the proton exchange membrane fuel cell is activated by, In step S3, the value range of the raised current density is 500-2000 mA / cm 2 , and the value range of the second time is 5-20 mins.

7. The method of claim 1, wherein the activation is performed at a temperature of 80°C to 100°C. In step S3, the voltage threshold is 0.6V.

8. The method of claim 1, wherein the proton exchange membrane fuel cell is activated by, In step S4, the discharge voltage fluctuation is determined during the last 2 minutes of step S3.

9. The activation method for a proton exchange membrane fuel cell according to claim 1, characterized in that, The voltage fluctuation threshold is 5mV / min.

10. An activation control device of a proton exchange membrane fuel cell for controlling an activation process of a proton exchange membrane fuel cell, characterized by, It includes a memory and a processor, the memory storing a computer program, and the processor calling the computer program to perform the steps of the method as described in any one of claims 1 to 9.

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