CN112670537A

CN112670537A - Rapid activation method of metal bipolar plate galvanic pile of proton exchange membrane fuel cell

Info

Publication number: CN112670537A
Application number: CN202011552103.0A
Authority: CN
Inventors: 舒清柱; 孙昕; 邢丹敏; 李光伟; 张扬; 窦永香
Original assignee: Sunrise Power Co Ltd
Current assignee: Sunrise Power Co Ltd
Priority date: 2020-12-24
Filing date: 2020-12-24
Publication date: 2021-04-16
Anticipated expiration: 2040-12-24
Also published as: CN112670537B

Abstract

The invention discloses a method for quickly activating a metal bipolar plate stack of a proton exchange membrane fuel cell, which comprises the following steps: performing rapid working condition activation on a polarization curve under a certain condition, performing high-electric density gradient steady state activation, taking the activation as an activation period, and finally performing intermittent cyclic activation; polarization curve fast sweep working condition activation process: the proton exchange membrane is quickly wetted in a short time by adopting a forced variable-load activation process, and in the processes of gradient loading and quick load reduction, the voltage is from high to first to high, which is equivalent to quick potential scanning, so that the catalyst is subjected to an oxidation-reduction process in a short time; high-density gradient steady-state activation process: the method further improves the activation efficiency, greatly shortens the activation time and cost, and has important significance for the large-scale production of proton exchange membrane fuel cell stacks.

Description

Rapid activation method of metal bipolar plate galvanic pile of proton exchange membrane fuel cell

Technical Field

The invention relates to the technical field of fuel cells, in particular to a method for quickly activating a metal bipolar plate stack of a proton exchange membrane fuel cell.

Background

Proton Exchange Membrane Fuel Cells (PEMFCs) have become the focus of research and development at home and abroad in recent years due to their characteristics of low operating temperature, fast start-up, high power density, no exhaust gas emission, etc. In the process of PEMFC development, many factors must be considered, and activation of PEMFC is a decisive factor for its commercial application. The PEMFC can greatly improve the performance through the activation energy, reach a stable state, and simultaneously can detect whether the fuel cell has the delivery requirement, thereby ensuring the product quality.

The core component of the PEMFC is a Membrane Electrode (MEA), the membrane electrode assembly includes an electrocatalyst, a proton exchange membrane, a gas diffusion layer, etc., and the activation of the PEMFC is essentially the activation of the MEA, i.e., the performance of the MEA is improved, including the electrocatalytic activity, the utilization rate of the catalyst, etc. Usually, a new PEMFC stack or module is assembled and then activated sufficiently to achieve its optimum state and performance. The activation process of PEMFC usually takes several hours or even days, which not only consumes a lot of hydrogen, nitrogen, etc., but also delays the production cycle of PEMFC.

The activation process of PEMFCs is various, and can be classified into: PEMFC pre-treatment activation (before discharge), PEMFC in-situ activation (just beginning discharge), and PEMFC restorative activation (after a period of discharge), among others. In the existing activation process, in-situ activation is mainly used, namely an activation method for improving the performance of the PEMFC by adopting a discharge mode after the PEMFC is assembled and before the PEMFC is used formally is determined by a current loading mode and test conditions. The loading mode of the current can be divided into constant current and variable current; the test conditions can be divided into constant parameter tests and variable parameter tests; the whole activation process can be divided into continuous activation and batch activation.

The prior art discloses a method for activating a fuel cell stack (application number is 110416556A), and the technical scheme is that a high potential is quickly formed for a period of time by using the surface of an electrode in the processes of primary pre-wetting activation and secondary pre-wetting activation of the stack, so that unstable catalysts on the surface of the electrode and impurities on the surface of the oxidized electrode are eliminated; then, through a variable-current humidification and activation process and operation under high current density, water generated by reaction quickly humidifies a membrane electrode, and quick humidification of a proton exchange membrane and a catalyst layer resin is realized; the electric pile is controlled to run in the cross of high and low current density, so that the electrode can quickly form a stable gas and electron transmission channel, the accelerated activation of the fuel cell electric pile is realized, and the activation time can be controlled to be about 2 h. However, although this method can eliminate impurities on the surface of the catalyst to some extent, the continuous high potential causes corrosion of the carbon support, which affects the battery life.

In addition, the prior art also discloses an activation method of a fuel cell stack, which comprises the steps of firstly introducing hydrogen into an anode of the stack to be activated, introducing air or oxygen into a cathode of the stack to be activated, and enabling the stack to be in an open-circuit state; performing intermittent anoxic treatment on the cell stack, namely performing reduction operation after the cell stack is in an oxygen starvation state; and finally, performing constant-current discharge activation, loading the cell stack to a set current, and performing intermittent anoxic treatment on the cell stack after the cell stack is in a stable working state. The aim of activating the galvanic pile is achieved by repeating the steps, and the method adopts an intermittent oxygen-deficient activation method of the galvanic pile, so that the risk of large voltage fluctuation of the galvanic pile, even low transient state, and certain safety problem can be caused.

Disclosure of Invention

According to the problems existing in the prior art, the invention discloses a method for quickly activating a metal bipolar plate stack of a proton exchange membrane fuel cell, which is mainly applied to the activation process of the Proton Exchange Membrane Fuel Cell (PEMFC), and specifically comprises the following steps:

performing rapid working condition activation on a polarization curve under a certain condition, performing high-electric density gradient steady state activation, taking the activation as an activation period, and finally performing intermittent cyclic activation;

polarization curve fast sweep working condition activation process: the proton exchange membrane is quickly wetted in a short time by adopting a forced variable-load activation process, and the potential is changed from high to low to high in the gradient loading and quick load reduction processes, which is equivalent to quick potential scanning, so that the catalyst is subjected to a redox process in a short time;

high-density gradient steady-state activation process: the mass transfer channel in the battery is further opened by adopting high-density constant-current activation, so that three interfaces of a catalyst layer are constructed to promote the electrochemical reaction, and the water balance state in the battery can be effectively adjusted by properly reducing the air humidity during high-density operation;

intermittent cyclic activation process: and stopping the reactor for a certain time after the high-density gradient steady-state activation process is finished, and returning to the polarization curve fast-sweeping working condition activation process to perform intermittent cyclic operation to finish the activation process of the galvanic pile.

Further, three-cavity air tightness detection is carried out on the assembled galvanic pile, and the three-cavity air tightness detection comprises three-cavity external leakage, hydrogen single-cavity pressure maintaining, mutual connection of hydrogen and oxygen cavities and water connection of the hydrogen and oxygen cavities;

performing electrochemical leakage test on the galvanic pile, namely introducing air to the cathode of the galvanic pile and introducing hydrogen to the anode of the galvanic pile, closing a hydrogen tail valve when the hydrogen pressure reaches a set value, continuously adjusting the hydrogen pressure to a set threshold value, stopping air inlet when the total voltage of the galvanic pile does not increase, observing the change condition of single voltage of the galvanic pile, and judging whether each galvanic pile is qualified in leakage test;

carrying out a polarization curve fast sweeping working condition activation process: setting the temperature of the battery, the humidity of the gas, the air metering ratio, the loading rate, the initial value of the pressure of the air and the hydrogen entering the pile, and after the initial electric density point is stably operated for a set time; keeping the temperature, the gas humidity and the loading rate of the battery unchanged, setting an air metering ratio, sequentially increasing the stacking pressure of air and hydrogen, and stably operating at the increased electric density point for a set time; loading the mixture to three different electrical density points at the same loading rate, keeping the metering ratio and the pressure of hydrogen and air entering the reactor unchanged, and stably operating at the three electrical density points for set time respectively; finally, the power density is reduced to 0 rapidly at a certain load reduction rate, and air intake is stopped and kept for a certain time.

Further, the high-density gradient steady-state activation process is as follows: setting the temperature of the galvanic pile, the air humidity and the air metering ratio value, setting the hydrogen to be in a backflow humidifying mode, and setting the tail exhaust mode to be pulse exhaust;

gradually loading to a set threshold value at a certain loading rate, then adjusting the stack pressure of air and hydrogen to be respectively a set value A, and stably operating for a certain time at the electric density point;

continuously increasing the loading rate to a higher electric density point, then regulating the stack pressure of air and hydrogen to be respectively kept at a set value A, and stably operating for a certain time at the electric density point;

and finally, rapidly reducing the current density to 0 at a set load reduction rate, closing a load switch, stopping air inflow and water circulation, and stopping the machine.

Due to the adoption of the technical scheme, the method for quickly activating the metal bipolar plate stack of the proton exchange membrane fuel cell provided by the invention has the advantages that the quick activation of the stack is realized by combining an intermittent cyclic activation method of high-density steady-state operation through a polarization curve quick sweeping working condition, and the method is not only suitable for a short stack, but also applicable to a high-power stack and has strong practicability; the activation of the polarization curve under the fast sweeping working condition can be used as an effective forced variable load activation process, and can also be used as a judgment basis for the activation state of the fuel cell stack, and can be realized by using a manual loading method, or can be finished by adopting program setting, so that the operation is convenient and fast; the high-voltage operation condition is used in the loading and activating process of the galvanic pile, and the activation humidification condition of the fast sweeping working condition of the first polarization curve is distinguished from the humidification condition of the same subsequent step, so that the adjustment of water balance is facilitated; finally, the PEMFC rapid activation process provided by the method improves the activation efficiency, greatly shortens the activation time and cost, and has important significance for the large-scale production of proton exchange membrane fuel cell stacks.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a plot of polarization curve fast-scan behavior (I-V) and High Frequency Resistance (HFR) during activation in example 1.

FIG. 2(a) FIG. 2(b) are respectively a low density point (150mA cm) in the activation process of example 1^-2) And high electric density (1600mA cm)^-2) Alternating current impedance (EIS) diagram of (a).

FIG. 3 is a comparison of polarization curve fast sweep performance (I-V) during activation for example 2.

FIG. 4 is a graph of the power change during steady state activation for example 2.

FIG. 5 is a graph comparing the performance of comparative example 1 and example 1 before and after activation.

FIG. 6 is a graph comparing the performance of comparative example 2 and example 1 before and after activation.

FIG. 7 is a graph comparing the performance of comparative example 3 and example 1 before and after activation.

Detailed Description

In order to make the technical solutions and advantages of the present invention clearer, the following describes the technical solutions in the embodiments of the present invention clearly and completely with reference to the drawings in the embodiments of the present invention:

the invention discloses a method for quickly activating a metal bipolar plate galvanic pile of a proton exchange membrane fuel cell, which is characterized in that experimental verification is respectively carried out on galvanic piles with different power levels, a fuel cell test platform and a voltage inspection system are used for detecting the voltage of each section of the cell, the rapid working condition activation of a polarization curve is firstly carried out under certain conditions, then the high-density gradient steady-state activation is carried out, the activation period is taken as one activation period, and then the intermittent cyclic activation is carried out, and the specific technical scheme is as follows:

s1 polarization curve fast-sweep operating mode activation

S11, the proton exchange membrane can be wetted rapidly in the shortest time through the one-time rapid forced load-changing activation process, and the proton conductivity of the proton exchange membrane is improved; the used test conditions of high pressure, high humidity and the like are favorable for establishing a gas-liquid transmission channel in the battery; in the gradient loading and rapid load reduction processes, the catalyst undergoes a redox process in a short time, which is beneficial to removing impurities on the surface of the catalyst.

S12, the activation process can be used as an effective activation process and can also be used as the judgment basis of the activation state of the fuel cell stack. The polarization curve quick-sweep working condition activation can be realized by using a manual loading method, and can also be finished by adopting program setting, so that the operation is convenient and fast.

S2 high-density steady-state activation

The mass transfer channel in the battery is further opened through high-density constant-current activation, three interfaces of the catalyst layer are effectively constructed, the utilization rate of the catalyst is improved, and the electrochemical reaction is promoted. Since the cathode water yield of the battery itself is large at the time of high-density operation, it is necessary to appropriately reduce the air humidity to adjust the water balance state inside the battery.

S3 intermittent cyclic activation

The steps S1 and S2 are combined to be a complete activation process, and shutdown operation is carried out after each cycle of activation, and the main purpose is to enable the battery to carry out self-internal water balance adjustment.

Example 1 a newly assembled stack of 15 metal plate bipolar plates was rapidly activated by the following specific steps:

(1) accurately connecting the assembled galvanic pile with an air tightness detection device, and carrying out three-cavity air tightness detection, including three-cavity external leakage, hydrogen single-cavity pressure maintaining, hydrogen-oxygen cavity mutual serial connection, hydrogen-oxygen cavity serial water cavity serial connection and other air tightness tests;

(2) after the air tightness detection is qualified, the fuel cell is accurately connected to a test platform, and the fuel cell comprises pipes and lines connected with water, gas, electricity, temperature and humidity sensors and the likeAnd then carrying out electrochemical leakage test on the electric pile. Specifically, the method comprises setting air metering ratio at 2.5 and 100mA cm^-2Introducing air into the cathode of the battery by the required air amount, wherein the air tail discharge mode is normal discharge; and adjusting a hydrogen proportional valve, introducing hydrogen to the anode of the battery, closing a hydrogen tail discharge valve when the hydrogen pressure reaches 10-20 kPa, continuously adjusting the hydrogen pressure to 50 +/-2 kPa, stopping gas inlet when the total voltage of the galvanic pile does not increase, starting timing for 1min, and observing the change condition of the single-section voltage of the galvanic pile.

Leakage test standard: if the single voltage is kept above 500mV within 1min, the battery is qualified in leakage test; if the single voltage drops below 500mV within 1min, the battery is unqualified for leakage test.

And after the leakage test is finished, opening a hydrogen tail discharge valve, adjusting the hydrogen pressure to be 0kPa, and simultaneously stopping air.

(3) Carrying out polarization curve fast sweeping working condition activation: after the leakage test of the galvanic pile is qualified, various parameters are set according to the test condition 1, the temperature of the battery is 75 ℃, the air is humidified by 100 percent, the hydrogen adopts a backflow humidification mode, the tail discharge method is pulse discharge, and the galvanic pile operates according to the working condition 1. Firstly, the air metering ratio is set to be 2.6 and is set to be 20mA cm^-2The loading rate of/s is gradually loaded to 200mA cm^-2Regulating the stacking pressure of air and hydrogen to 40kPa and 60kPa respectively, and stably operating at the electric density point for 1 min; setting air metering ratio at 2.2, 20mA cm^-2The loading rate of/s is gradually loaded to 400mA cm^-2Regulating the stacking pressure of air and hydrogen to be 80kPa and 100kPa respectively, and stably operating at the electric density point for 1 min; setting air metering ratio at 2 and 20mA cm^-2The loading rate of/s is gradually loaded to 600mA cm^-2Regulating the stacking pressure of air and hydrogen to 110kPa and 130kPa respectively, and stably operating at the electric density point for 1 min; setting air metering ratio at 2 and 20mA cm^-2The loading rate of/s is gradually loaded to 800mA cm^-2Regulating the stacking pressure of air and hydrogen to 125kPa and 145kPa respectively, and stably operating at the electric density point for 1 min; setting air metering ratio at 2 and 20mA cm^-2The loading rate of/s is gradually loaded to 1000mA cm^-2The pile-entering pressure of the air and the hydrogen is respectively 150kPa and170kPa, and stably operating for 1min at the electric density point; continuing to load to 1200mA cm at the same loading rate^-2/s，1400mA cm^-2/s，1600mA cm^-2The metering ratio and the pressure of hydrogen and air entering the reactor are kept unchanged at the/s electric density point, and the reactor stably operates for 1min at the three electric density points respectively; then 50mA cm^-2And reducing the load reduction rate of/s to 0 rapidly, stopping air intake, and keeping for 1-3 min.

(4) Carrying out high-density steady-state activation: and (3) operating a galvanic pile operating condition II after the operation in the step (3), wherein the operating process of the operating condition II is as follows: the temperature of the galvanic pile is set to be 75 ℃, the air humidity is 30% -40% for humidification, the air metering ratio is 2, the hydrogen adopts a backflow humidification mode, and the tail exhaust method is pulse exhaust. At 20mA cm^-2The loading rate of/s is gradually loaded to 1400mA cm^-2Regulating the stacking pressure of air and hydrogen to 150kPa and 170kPa respectively, and stably operating at the electric density point for 10 min; then at 20mA cm^-2The loading rate of/s is gradually loaded to a higher electric density point 1600mA cm^-2Regulating the stack pressure of air and hydrogen to be respectively maintained at 150kPa and 170kPa, and stably operating at the electric density point for 5 min; then 50mA cm^-2And the load reduction rate of the/s enables the current density to be rapidly reduced to 0, the load switch is closed, air inflow and water circulation are stopped, and the machine is stopped for 10-15 min.

(5) Intermittent cyclic activation: and (3) combining the activation steps (2) and (3) to form a complete activation process for 1 time, stopping the reactor after each time of cyclic activation, wherein the stopping time is about 10-15 min, and repeating the process to perform intermittent cyclic operation for 2 times to complete the activation of the galvanic pile.

(6) And (3) testing the performance of the activation process: monitoring high frequency impedance value (HFR) in real time during the activation operation of the galvanic pile, and performing high frequency impedance value (HFR) monitoring at 150mA cm after the activation of each cycle is finished^-2And 1400mA cm^-2And (4) carrying out full-frequency alternating current impedance test on the galvanic pile.

(7) In this embodiment, the performance of the stack in comparison with the initial state of the stack and the rapid working condition of the polarization curve in the activation process is shown in fig. 1, and it can be seen from the diagram that, compared with the initial state of the stack, the performance of the stack after the activation for the 1 st time is significantly improved, mainly due to the rapid wetting of the proton exchange membrane and the hydration of the polymers in the electrode diffusion layer and the catalyst layer, the proton conductivity of the stack is rapidly improved, and the performance of the stack is greatly increased; after the 2 nd activation, the performance of the pile is further improved, and particularly the performance of the pile is obviously improved in a mass transfer polarization control area, which is probably because after gas pressurization, gas and liquid transmission channels in the electrode are further opened to remove impurities in a flow field and promote the formation of a gas, liquid and solid three-phase reaction interface, thereby efficiently and stably improving the performance of the fuel cell.

(8) In this example, the AC impedance after the initial state and the activation of the stack are compared, as shown in FIG. 2, it can be obtained from the figure that the stack is activated for the 1 st time and then at a low density point (150mA cm)^-2) The ohmic resistance and the activation resistance are obviously reduced, and are further reduced after the 2 nd activation, which proves that the ohmic resistance is gradually reduced, and the activity and the utilization rate of the catalyst are greatly improved along with the activation; at a high electrical density point (1600mA cm)^-2) The impedance change mainly reflects the mass transfer performance of the galvanic pile, and as can be seen from the figure, the mass transfer impedance of the galvanic pile is increased and then reduced, which shows that the humidification condition in the activation process of the galvanic pile is adjusted in time to be beneficial to the management of water balance, thereby reducing the mass transfer impedance.

(9) In this example, the performance of the cell stack after the 2 nd activation is almost unchanged from the average voltage after the 3 rd activation, and it is proved that the activation of the cell stack can be completed only by the first 2 activation, and the activation time is shortened to about 1 hour. As can be seen from table 1, example 1 has the shortest activation time and the least hydrogen consumption, significantly improves the activation efficiency, and reduces the activation cost.

Table 1 is a comparison table of the activation time and hydrogen consumption of example 1 and comparative examples 1, 2 and 3.

Example 2

(1) The 370-joint high-power metal bipolar plate galvanic pile which is newly assembled is quickly activated, and the activation working condition process is consistent with that of the embodiment 1.

(2) The same activation process and conditions as in example 1 were used to activate a 370-section high-power stack, and the results are shown in fig. 3 and 4. Compared with the initial state of the galvanic pile, the polarization performance of the galvanic pile after the activation for the 1 st time is obviously improved, and the performance after the activation for the 2 nd time is increased by less than 10mV compared with the performance voltage after the activation for the 1 st time, which shows that the 370-section high-power metal bipolar plate galvanic pile is basically activated and completed after only 1 activation.

(3) The test result of the embodiment 2 shows that the invention is not only suitable for short stacks, but also suitable for high-power galvanic piles, has stronger practicability and operability, shortens the quick time of 370-section high-power metal bipolar plate galvanic piles to within 1h, greatly improves the resource utilization rate and saves the activation cost.

Comparative example 1

Comparative example 1 is different from example 1 in that step (3) in example 1 is not performed, and a high-electric-density steady-state activation process is not performed, and only a medium electric density (800mA cm) is performed^-2) Intermittent steady state activation.

In the embodiment, the galvanic pile is activated for 5 times according to the operation condition, the performance of the galvanic pile is increased after the activation for the first 4 times, and the polarization curve performance before and after the activation for the galvanic pile after the 5 th time is compared with that of the embodiment 1, as shown in fig. 5. As can be seen from the graph, in comparative example 1, even if 5 times of activation were performed, the activation performance did not reach the highest output with about 3 times of activation time and 2 times of hydrogen consumption compared to example 1, indicating that without the activation steps of (3) and (4) in example 1, the activation efficiency of the stack was the lowest.

Since this embodiment does not have an activation step for the fast-scan condition of the polarization curve, there is no detection data for the activation process.

Comparative example 2

Comparative example 2 is different from example 1 in that the high-electric-density steady-state activation process in example 1 is not performed, and only the medium-electric-density (800mA cm) is performed^-2) Steady state activation of.

The activation of the cell stack was performed a total of 4 times according to the operation conditions in this example, and the results are shown in fig. 6. From the figure, the performance of the electric pile is obviously improved after the 1 st activation, the performance of the electric pile is mainly improved to a certain extent in a middle and high electric density region after the 2 nd activation, but the performance of the electric pile is almost unchanged after the 3 rd activation, and the performance of the electric pile is slightly reduced after the 4 th activation. And the polarization curve performance before and after activation is still slightly worse compared to example 1. The high electrical density activation process of step (4) in example 1 proves to be crucial to the activation effect of the stack.

Comparative example 3

Comparative example 3 is different from example 1 in that step (3) in example 1 is not performed.

The activation of the cell stack was performed a total of 4 times according to the operation conditions in this example, and the results are shown in fig. 7. It can be seen from the figure that if only high-electric-density steady-state cyclic activation is performed, the final performance of the stack in the high-electric-density mass transfer polarization control region is lower than that of example 1, which proves that continuous high-electric-density activation can affect the mass transfer performance of the stack, and the hydrogen consumption of the embodiment is much greater than that of example 1. The polarization curve fast-sweeping working condition activation process of the step (3) in the example 1 is proved to be very important for the activation effect of the galvanic pile.

The analysis of the above embodiment shows that the embodiment reduces the time by about 1.5-3 times, so that the performance of the battery reaches a better state, the air consumption in the whole activation process is greatly reduced, the air consumption is about 1/2 of the comparative example, the activation efficiency is remarkably improved, the activation time is further shortened, and the activation cost is reduced.

In addition, the polarization curve fast-sweeping working condition activation adopted by the method is an activation process, and can also be used as a judgment basis for the state of the activation process of the galvanic pile, so that the performance change rule from the initial state to the completion of activation of the galvanic pile can be more clearly recognized, and the further understanding of the activation mechanism is facilitated.

Finally, the invention is not only suitable for short stacks, but also suitable for high-power galvanic piles, has stronger practicability and operability, shortens the activation time of 370-section high-power metal bipolar plate galvanic piles to be within 1h, greatly improves the resource utilization rate and saves the activation cost.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.

Claims

1. A rapid activation method for a proton exchange membrane fuel cell metal bipolar plate stack is characterized by comprising the following steps: performing rapid working condition activation on a polarization curve under a certain condition, performing high-electric density gradient steady state activation, taking the activation as an activation period, and finally performing intermittent cyclic activation;

polarization curve fast sweep working condition activation process: the proton exchange membrane is quickly wetted in a short time by adopting a one-time forced load-changing activation process, and the potential is set to be increased from high to low in the processes of gradient loading and quick load reduction, so that the catalyst is subjected to one oxidation-reduction process in a short time;

high-density gradient steady-state activation process: the mass transfer channel in the battery is further opened by adopting high-density constant-current activation, so that three interfaces of a catalyst layer are constructed to promote the electrochemical reaction, and the water balance state in the air humidity regulation battery during high-density operation is reduced;

2. The method of claim 1, further characterized by: the activation process of the polarization curve under the fast sweeping working condition is as follows:

carrying out three-cavity air tightness detection on the assembled galvanic pile, wherein the three-cavity air tightness detection comprises three-cavity external leakage, hydrogen single-cavity pressure maintaining, mutual connection of hydrogen and oxygen cavities and water connection of the hydrogen and oxygen cavities;

carrying out a polarization curve fast sweeping working condition activation process: setting the initial values of battery temperature, gas humidity, air metering ratio, loading rate and air and hydrogen stacking pressure, and after the initial power density point is stably operated for a set time; keeping the temperature, the gas humidity and the loading rate of the battery unchanged, setting an air metering ratio, sequentially increasing the stacking pressure of air and hydrogen, and stably operating at the increased electric density point for a set time; loading the mixture to three different electrical density points at the same loading rate, keeping the metering ratio and the pressure of hydrogen and air entering the reactor unchanged, and stably operating at the three electrical density points for set time respectively; finally, the power density is reduced to 0 rapidly at a certain load reduction rate, and air intake is stopped and kept for a certain time.

3. The method of claim 1, further characterized by: the high-density gradient steady-state activation process comprises the following steps: setting the temperature of the galvanic pile, the air humidity and the air metering ratio value, setting the hydrogen to be in a backflow humidifying mode, and setting the tail exhaust mode to be pulse exhaust;