A reverse electrode design method for fuel cell

Abstract

The present application provides a reverse polarity design method for a fuel cell, comprising the following steps: S01, connecting an external power supply and a single cell in series, respectively introducing hydrogen into the anode of the single cell and introducing air into the cathode of the single cell until the voltage of the single cell is stable; when the voltage of the single cell is stable, maintaining the supply of air to the cathode of the single cell, cutting off the supply of hydrogen to the anode of the single cell, and introducing N2 into the anode; S02, testing the performance parameters of the single cell, and when the single cell is reverse polarity, cutting off the external power supply, and testing the performance parameters of the single cell again; S03, stopping the introduction of N2 into the anode, and then introducing H2 into the anode, connecting the single cell and the external power supply in series again to activate the single cell. The method of the present application is simple to operate, has low experimental cost, short experimental time, and good repeatability, making it easy to check the impact of reverse polarity on vehicle operating conditions when necessary.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and in particular to a reverse pole design method for a fuel cell. Background Art

[0002] A fuel cell is a device that generates electricity through the chemical conversion of fuel and oxygen. Its structure primarily consists of bipolar plates, membrane electrode, and end plates. Under normal circumstances, a fuel cell stack is immune to reverse polarity. However, when a fuel cell stack is used in a vehicle, it is inevitably subject to conditions such as startup and rapid load changes. Under these conditions, reverse polarity can easily occur due to uneven gas concentrations or issues with the fuel cell stack's internal materials.

[0003] To ensure proper stack operation, fuel cells must not experience reverse polarity under normal circumstances. However, reverse polarity in a fuel cell stack can pose significant risks to the stack, potentially damaging the cells and even shortening their lifespan. Long-term, uncorrected reverse polarity can lead to failure or even explosion. Existing fuel cell reverse polarity testing methods are complex, lack reproducibility, and are expensive, making them difficult to meet the needs of fuel cell reverse polarity research. Summary of the Invention

[0004] Based on this, the present invention provides a fuel cell reverse pole design method, aiming to address the problems of existing fuel cell reverse pole experimental methods, which are overly complex, have poor repeatability, are expensive, and are difficult to meet the needs of fuel cell reverse pole research. This method can simulate reverse pole experiments, is simple to operate, has low experimental costs, and shortens experimental time, making it convenient to examine the impact of reverse pole on vehicle operating conditions when needed.

[0005] To achieve the above objectives, an embodiment of the present invention provides a method for designing a reverse electrode of a fuel cell, comprising the following steps:

[0006] S01, connecting an external power supply and a single cell in series, respectively passing hydrogen into the anode of the single cell and air into the cathode of the single cell until the voltage of the single cell stabilizes; when the voltage of the single cell stabilizes, keeping air flowing into the cathode of the single cell, cutting off the hydrogen supply to the anode of the single cell, and passing N2 into the anode;

[0007] S02, testing the performance parameters of the single cell; when the single cell has reverse polarity, cutting off the external power supply, and testing the performance parameters of the single cell again;

[0008] S03, stop introducing N2 into the anode, then introduce H2 into the anode, and connect the single cell and the external power supply in series again to activate the single cell.

[0009] As a preferred embodiment, in step S01,

[0010] The single cell is an activated cell.

[0011] The activation treatment time is preferably two hours.

[0012] The temperature of the single cell is 59°C-65°C, preferably 60°C; the dew point temperatures of the cathode and the anode are both 59°C-65°C, preferably 60°C.

[0013] When the cell is in a startup state (i.e., working state), when starting a reverse polarity test, air is first introduced into the cathode of the cell, and after 0.5 seconds to 1.0 seconds, hydrogen is introduced into the anode of the cell until the voltage of the cell stabilizes.

[0014] When the cell is in a stopped state (i.e., non-working state), when starting the reverse polarity test, air is first introduced into the cathode of the cell, and then nitrogen is introduced into the anode of the cell after 0.5 seconds to 1.0 seconds. After introducing nitrogen for 2 seconds to 3 seconds, the introduction of nitrogen is stopped and hydrogen is introduced into the anode of the cell until the voltage of the cell stabilizes. When stopping the reverse polarity test, the hydrogen supply to the anode of the cell is first cut off, and the air supply to the cathode of the cell is cut off 10 seconds to 15 seconds after the hydrogen supply is cut off.

[0015] The flow rate of the hydrogen is 0.2L / min-0.3L / min; the flow rate of the air is 0.8L / min-0.9L / min; the excess coefficient of the hydrogen is set to 1.5; the excess coefficient of the air is set to 2.5; the flow rate of the nitrogen is 0.2L / min-0.3L / min.

[0016] The constant current applied by the external power supply to the single cell is 0.2A·cm -2 .

[0017] The external power supply is an external DC power supply.

[0018] As a preferred embodiment, in step S02,

[0019] The performance parameters include the polarization curve, CV curve (current-voltage curve measured by cyclic voltammetry) and LSV curve (voltammetry curve measured by linear voltammetry) of the single cell.

[0020] The polarization curve is tested under the conditions of 60° C.-65° C., 70% RH-100% RH, H 2 / air and no back pressure.

[0021] The CV curve and the LSV curve were tested under conditions of 60° C.-65° C., 70% RH-100% RH, H 2 / N 2 and no back pressure.

[0022] The reverse polarity generation condition is that the reverse polarity voltage of the single cell is -0.2V.

[0023] The reverse polarity test was conducted under conditions of 60° C.-65° C., 70% RH-100% RH, H 2 / air and no back pressure.

[0024] As a preferred embodiment, in step S03,

[0025] The flow rate of the hydrogen is 0.2 L / min-0.3 L / min; the excess coefficient of the hydrogen is set to 1.5.

[0026] The constant current applied by the external power supply to the single cell is 0.2A·cm -2 .

[0027] The activation treatment time is preferably two hours.

[0028] The temperature of the single cell is 59°C-65°C, preferably 60°C; the dew point temperatures of the cathode and the anode are both 59°C-65°C, preferably 60°C.

[0029] This application uses a single battery plus an external power supply to simulate the reverse polarity of a fuel cell stack, effectively simplifying the experimental operation, facilitating simulation of reverse polarity experiments, and making it easy to check the impact of reverse polarity on vehicle operating conditions when needed. This application method is simple to operate, has low experimental costs, short experimental time, and good repeatability. It can effectively solve the problems of existing fuel cell reverse polarity experimental methods that are overly complex, have poor repeatability, high experimental costs, and are difficult to meet the needs of fuel cell reverse polarity research.

[0030] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0032] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, top, bottom...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0033] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0034] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element.

[0035] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features specified as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0036] Generally, to ensure the normal operation of the fuel cell stack, under normal circumstances, the fuel cell will not experience reverse polarity. The reverse polarity of the fuel cell stack will bring great harm to the fuel cell stack. In severe cases, it will burn the battery and even affect the service life of the battery. Long-term reverse polarity of the battery without correction will cause battery failure or even cause an explosion accident. The existing fuel cell reverse polarity experimental method is too complicated, has poor repeatability, and has high experimental costs. It is difficult to meet the use needs of fuel cell reverse polarity research. Based on this, it is necessary to provide a fuel cell reverse polarity design method to solve the above technical problems.

[0037] To achieve the above objectives, an embodiment of the present invention provides a method for designing a reverse electrode of a fuel cell, comprising the following steps:

[0038] S01, connecting an external power supply and a single cell in series, respectively passing hydrogen into the anode of the single cell and air into the cathode of the single cell until the voltage of the single cell stabilizes; when the voltage of the single cell stabilizes, keeping air flowing into the cathode of the single cell, cutting off the hydrogen supply to the anode of the single cell, and passing N2 into the anode;

[0039] S02, testing the performance parameters of the single cell; when the single cell has reverse polarity, cutting off the external power supply, and testing the performance parameters of the single cell again;

[0040] S03, stop introducing N2 into the anode, then introduce H2 into the anode, and connect the single cell and the external power supply in series again to activate the single cell.

[0041] As a preferred embodiment, in step S01,

[0042] The single cell is an activated cell.

[0043] The activation treatment is preferably carried out for two hours. The activation treatment (common activation treatment methods may be used) ensures that the polarization curve (ie, rated voltage density performance) of the single cell no longer changes.

[0044] The temperature of the single cell is 59°C-65°C, preferably 60°C; the dew point temperatures of the cathode and the anode are both 59°C-65°C, preferably 60°C.

[0045] When the cell is in the startup state (i.e., operating state), a reverse polarity test is initiated by first introducing air into the cathode of the cell. After 0.5 to 1.0 seconds, hydrogen is introduced into the anode of the cell until the cell voltage stabilizes. This delayed introduction of hydrogen leads to the presence of air on the anode side due to the concentration gradient, thus creating a hydrogen-air interface.

[0046] When the cell is in a stopped state (i.e., non-operating state), a reverse polarity test is initiated by first introducing air to the cell's cathode. After 0.5 to 1.0 seconds, nitrogen is introduced to the cell's anode. After 2 to 3 seconds, the nitrogen supply is stopped and hydrogen is introduced to the cell's anode until the cell's voltage stabilizes. When the reverse polarity test is terminated, the hydrogen supply to the cell's anode is first cut off. After 10 to 15 seconds, the air supply to the cell's cathode is cut off. This results in a lower hydrogen concentration than air (oxygen). Once the concentration difference between the two sides is inconsistent, the air at the cathode is drawn to the anode by the concentration gradient, forming a hydrogen-air interface at the cathode. This creates a high anode potential under the action of an external power source, further contributing to the formation of a hydrogen-air interface.

[0047] The flow rate of the hydrogen is 0.2L / min-0.3L / min; the flow rate of the air is 0.8L / min-0.9L / min; the excess coefficient of the hydrogen is set to 1.5; the excess coefficient of the air is set to 2.5; the flow rate of the nitrogen is 0.2L / min-0.3L / min.

[0048] The constant current applied by the external power supply to the single cell is 0.2A·cm -2 .

[0049] The external power supply is an external DC power supply.

[0050] Due to the continuous current output, the H₂ concentration on the anode side of the cell gradually decreases, and the output current gradually decreases. At this point, the cell, under the action of the external DC power supply, changes from a generator to a load. To maintain a constant current output, the power supply increases the potential on the cathode side of the cell, exceeding the anode potential, resulting in reverse polarity.

[0051] As a preferred embodiment, in step S02,

[0052] The performance parameters include the cell's polarization curve, CV curve (current-voltage curve measured by cyclic voltammetry), and LSV curve (volt-ampere curve measured by linear voltammetry). Each time a reverse polarity experiment is performed, the cell's performance (including polarization curve, CV curve, and LSV curve) will change before and after the reverse polarity test. Therefore, the polarization curve should be recorded for each experiment, and the performance degradation before and after the reverse polarity test should be compared.

[0053] The polarization curve is tested under the conditions of 60° C.-65° C., 70% RH-100% RH, H 2 / air and no back pressure.

[0054] The CV curve and the LSV curve were tested under conditions of 60° C.-65° C., 70% RH-100% RH, H 2 / N 2 and no back pressure.

[0055] The reverse polarity condition is that the reverse polarity voltage of the cell is -0.2 V. By cutting off the external power supply, the reverse polarity can be forcibly stopped, thereby protecting the cell and the test platform.

[0056] The reverse electrode test was conducted at 60°C-65°C, 70% RH-100% RH, H2 / air and no back pressure. In this application, the membrane electrode active area is based on the single cell. The reverse electrode design adopts the constant current mode, and 0.2A·cm is applied to the single cell. -2 The constant current is recorded during the experiment, and the change of single cell voltage over time is recorded.

[0057] As a preferred embodiment, in step S03,

[0058] The flow rate of the hydrogen is 0.2 L / min-0.3 L / min; the excess coefficient of the hydrogen is set to 1.5.

[0059] The constant current applied by the external power supply to the single cell is 0.2A·cm -2 .

[0060] The activation treatment is preferably performed for two hours. The activation treatment prevents the polarization curve (ie, rated voltage point performance) of the cell from changing, thereby restoring the cell's performance as much as possible for subsequent experiments.

[0061] The temperature of the single cell is 59°C-65°C, preferably 60°C; the dew point temperatures of the cathode and the anode are both 59°C-65°C, preferably 60°C.

[0062] This application uses a single battery plus an external power supply to simulate the reverse polarity of a fuel cell stack, effectively simplifying the experimental operation, facilitating simulation of reverse polarity experiments, and making it easy to check the impact of reverse polarity on vehicle operating conditions when needed. This application method is simple to operate, has low experimental costs, short experimental time, and good repeatability. It can effectively solve the problems of existing fuel cell reverse polarity experimental methods that are overly complex, have poor repeatability, high experimental costs, and are difficult to meet the needs of fuel cell reverse polarity research.

[0063] Example 1

[0064] A method for designing a reverse electrode of a fuel cell comprises the following steps:

[0065] S01, connecting an external power supply and a single cell in series, respectively passing hydrogen into the anode of the single cell and air into the cathode of the single cell until the voltage of the single cell stabilizes; when the voltage of the single cell stabilizes, keeping air flowing into the cathode of the single cell, cutting off the hydrogen supply to the anode of the single cell, and passing N2 into the anode;

[0066] S02, testing the performance parameters of the single cell; when the single cell has reverse polarity, cutting off the external power supply, and testing the performance parameters of the single cell again;

[0067] S03, stop introducing N2 into the anode, then introduce H2 into the anode, and connect the single cell and the external power supply in series again to activate the single cell.

[0068] In step S01,

[0069] The single cell is an activated cell.

[0070] The activation treatment lasts for two hours.

[0071] The temperature of the single cell is 60° C.; the dew point temperatures of the cathode and the anode are both 60° C.

[0072] In this embodiment, the cell is in a startup state (i.e., a working state). When the reverse polarity test is started, air is first introduced into the cathode of the cell, and 0.5 seconds later, hydrogen is introduced into the anode of the cell until the voltage of the cell stabilizes.

[0073] The flow rate of the hydrogen is 0.2 L / min; the flow rate of the air is 0.8 L / min; the excess coefficient of the hydrogen is set to 1.5; the excess coefficient of the air is set to 2.5; and the flow rate of the nitrogen is 0.2 L / min.

[0074] The constant current applied by the external power supply to the single cell is 0.2A·cm -2 .

[0075] The external power supply is an external DC power supply.

[0076] In step S02,

[0077] The performance parameters include the polarization curve, CV curve and LSV curve of the single cell.

[0078] The polarization curve test was conducted under the conditions of 60° C., 70% RH, H 2 / air and no back pressure.

[0079] The CV curve and the LSV curve were tested under the conditions of 60° C., 70% RH, H 2 / N 2 and no back pressure.

[0080] The reverse polarity generation condition is that the reverse polarity voltage of the single cell is -0.2V.

[0081] The reverse polarity test was conducted at 60° C., 70% RH, H 2 / air and no back pressure.

[0082] In step S03,

[0083] The flow rate of the hydrogen is 0.2 L / min; the excess coefficient of the hydrogen is set to 1.5.

[0084] The constant current applied by the external power supply to the single cell is 0.2A·cm -2 .

[0085] The activation treatment lasts for two hours.

[0086] The temperature of the single cell is 60° C.; the dew point temperatures of the cathode and the anode are both 60° C.

[0087] After testing, it was found that this embodiment can successfully simulate the reverse polarity experiment of a fuel cell with good repeatability.

[0088] Example 2

[0089] A method for designing a reverse electrode of a fuel cell comprises the following steps:

[0090] S01, connecting an external power supply and a single cell in series, respectively passing hydrogen into the anode of the single cell and air into the cathode of the single cell until the voltage of the single cell stabilizes; when the voltage of the single cell stabilizes, keeping air flowing into the cathode of the single cell, cutting off the hydrogen supply to the anode of the single cell, and passing N2 into the anode;

[0091] S02, testing the performance parameters of the single cell; when the single cell has reverse polarity, cutting off the external power supply, and testing the performance parameters of the single cell again;

[0092] S03, stop introducing N2 into the anode, then introduce H2 into the anode, and connect the single cell and the external power supply in series again to activate the single cell.

[0093] In step S01,

[0094] The single cell is an activated cell.

[0095] The activation treatment lasts for two hours.

[0096] The temperature of the single cell is 60° C.; the dew point temperatures of the cathode and the anode are both 60° C.

[0097] In this embodiment, the cell is in a stopped state (i.e., a non-working state). When the reverse polarity test is started, air is first introduced into the cathode of the cell, and nitrogen is introduced into the anode of the cell 0.5 seconds later. After 2 seconds of nitrogen introduction, the introduction of nitrogen is stopped and hydrogen is introduced into the anode of the cell until the voltage of the cell stabilizes. When the reverse polarity test is stopped, the hydrogen supply to the anode of the cell is first cut off, and the air supply to the cathode of the cell is cut off 10 seconds after the hydrogen supply is cut off.

[0098] The flow rate of the hydrogen is 0.2 L / min; the flow rate of the air is 0.8 L / min; the excess coefficient of the hydrogen is set to 1.5; the excess coefficient of the air is set to 2.5; and the flow rate of the nitrogen is 0.2 L / min.

[0099] The constant current applied by the external power supply to the single cell is 0.2A·cm -2 .

[0100] The external power supply is an external DC power supply.

[0101] In step S02,

[0102] The performance parameters include the polarization curve, CV curve and LSV curve of the single cell.

[0103] The polarization curve test was conducted under the conditions of 60° C., 70% RH, H 2 / air and no back pressure.

[0104] The CV curve and the LSV curve were tested under the conditions of 60° C., 70% RH, H 2 / N 2 and no back pressure.

[0105] The reverse polarity generation condition is that the reverse polarity voltage of the single cell is -0.2V.

[0106] The reverse polarity test was conducted at 60° C., 70% RH, H 2 / air and no back pressure.

[0107] In step S03,

[0108] The flow rate of the hydrogen is 0.2 L / min; the excess coefficient of the hydrogen is set to 1.5.

[0109] The constant current applied by the external power supply to the single cell is 0.2A·cm -2 .

[0110] The activation treatment lasts for two hours.

[0111] The temperature of the single cell is 60° C., and the dew point temperature of the cathode and the anode are both 60° C. After testing, this embodiment can successfully simulate the reverse polarity experiment of the fuel cell with good repeatability.

[0112] Example 3

[0113] A method for designing a reverse electrode of a fuel cell comprises the following steps:

[0114] S01, connecting an external power supply and a single cell in series, respectively passing hydrogen into the anode of the single cell and air into the cathode of the single cell until the voltage of the single cell stabilizes; when the voltage of the single cell stabilizes, keeping air flowing into the cathode of the single cell, cutting off the hydrogen supply to the anode of the single cell, and passing N2 into the anode;

[0115] S02, testing the performance parameters of the single cell; when the single cell has reverse polarity, cutting off the external power supply, and testing the performance parameters of the single cell again;

[0116] S03, stop introducing N2 into the anode, then introduce H2 into the anode, and connect the single cell and the external power supply in series again to activate the single cell.

[0117] In step S01,

[0118] The single cell is an activated cell.

[0119] The activation treatment lasts for two hours.

[0120] The temperature of the single cell is 65° C.; the dew point temperatures of the cathode and the anode are both 65° C.

[0121] In this embodiment, the cell is in a startup state (i.e., a working state). When the reverse polarity test is started, air is first introduced into the cathode of the cell, and 1.0 second later, hydrogen is introduced into the anode of the cell until the voltage of the cell stabilizes.

[0122] The flow rate of the hydrogen is 0.3 L / min; the flow rate of the air is 0.9 L / min; the excess coefficient of the hydrogen is set to 1.5; the excess coefficient of the air is set to 2.5; and the flow rate of the nitrogen is 0.3 L / min.

[0123] The constant current applied by the external power supply to the single cell is 0.2A·cm -2 .

[0124] The external power supply is an external DC power supply.

[0125] In step S02,

[0126] The performance parameters include the polarization curve, CV curve and LSV curve of the single cell.

[0127] The polarization curve test was conducted under the conditions of 65° C., 100% RH, H 2 / air and no back pressure.

[0128] The CV curve and the LSV curve were tested under the conditions of 65° C., 100% RH, H 2 / N 2 and no back pressure.

[0129] The reverse polarity generation condition is that the reverse polarity voltage of the single cell is -0.2V.

[0130] The reverse polarity test was conducted under the conditions of 65° C., 100% RH, H 2 / air and no back pressure.

[0131] In step S03,

[0132] The flow rate of the hydrogen is 0.3 L / min; the excess coefficient of the hydrogen is set to 1.5.

[0133] The constant current applied by the external power supply to the single cell is 0.2A·cm -2 .

[0134] The activation treatment lasts for two hours.

[0135] The temperature of the single cell is 65° C., and the dew point temperature of the cathode and the anode are both 65° C. After testing, this embodiment can successfully simulate the reverse polarity experiment of the fuel cell with good repeatability.

[0136] Example 4

[0137] A method for designing a reverse electrode of a fuel cell comprises the following steps:

[0138] S01, connecting an external power supply and a single cell in series, respectively passing hydrogen into the anode of the single cell and air into the cathode of the single cell until the voltage of the single cell stabilizes; when the voltage of the single cell stabilizes, keeping air flowing into the cathode of the single cell, cutting off the hydrogen supply to the anode of the single cell, and passing N2 into the anode;

[0139] S02, testing the performance parameters of the single cell; when the single cell has reverse polarity, cutting off the external power supply, and testing the performance parameters of the single cell again;

[0140] S03, stop introducing N2 into the anode, then introduce H2 into the anode, and connect the single cell and the external power supply in series again to activate the single cell.

[0141] In step S01,

[0142] The single cell is an activated cell.

[0143] The activation treatment lasts for two hours.

[0144] The temperature of the single cell is 65° C.; the dew point temperatures of the cathode and the anode are both 65° C.

[0145] In this embodiment, the cell is in a stopped state (i.e., a non-working state). When the reverse polarity test is started, air is first introduced into the cathode of the cell, and nitrogen is introduced into the anode of the cell 1.0 second later. After 3 seconds of nitrogen introduction, the introduction of nitrogen is stopped and hydrogen is introduced into the anode of the cell until the voltage of the cell stabilizes. When the reverse polarity test is stopped, the hydrogen supply to the anode of the cell is first cut off, and 15 seconds after the hydrogen supply is cut off, the air supply to the cathode of the cell is cut off.

[0146] The flow rate of the hydrogen is 0.3 L / min; the flow rate of the air is 0.9 L / min; the excess coefficient of the hydrogen is set to 1.5; the excess coefficient of the air is set to 2.5; and the flow rate of the nitrogen is 0.3 L / min.

[0147] The constant current applied by the external power supply to the single cell is 0.2A·cm -2 .

[0148] The external power supply is an external DC power supply.

[0149] In step S02,

[0150] The performance parameters include the polarization curve, CV curve and LSV curve of the single cell.

[0151] The polarization curve test was conducted under the conditions of 65° C., 100% RH, H 2 / air and no back pressure.

[0152] The CV curve and the LSV curve were tested under the conditions of 65° C., 100% RH, H 2 / N 2 and no back pressure.

[0153] The reverse polarity generation condition is that the reverse polarity voltage of the single cell is -0.2V.

[0154] The reverse polarity test was conducted under the conditions of 65° C., 100% RH, H 2 / air and no back pressure.

[0155] In step S03,

[0156] The flow rate of the hydrogen is 0.3 L / min; the excess coefficient of the hydrogen is set to 1.5.

[0157] The constant current applied by the external power supply to the single cell is 0.2A·cm -2 .

[0158] The activation treatment lasts for two hours.

[0159] The temperature of the single cell is 65° C., and the dew point temperature of the cathode and the anode are both 65° C. After testing, this embodiment can successfully simulate the reverse polarity experiment of the fuel cell with good repeatability.

[0160] Comparative Example 1

[0161] A method for designing a reverse electrode of a fuel cell comprises the following steps:

[0162] S01, connecting an external power supply and a single cell in series, respectively passing hydrogen into the anode of the single cell and air into the cathode of the single cell until the voltage of the single cell stabilizes; when the voltage of the single cell stabilizes, keeping air flowing into the cathode of the single cell, cutting off the hydrogen supply to the anode of the single cell, and passing N2 into the anode;

[0163] S02, testing the performance parameters of the single cell; when the single cell has reverse polarity, cutting off the external power supply, and testing the performance parameters of the single cell again;

[0164] S03, stop introducing N2 into the anode, then introduce H2 into the anode, and connect the single cell and the external power supply in series again to activate the single cell.

[0165] In step S01,

[0166] The single cell is an activated cell.

[0167] The activation treatment lasts for two hours.

[0168] The temperature of the single cell is 60° C.; the dew point temperatures of the cathode and the anode are both 60° C.

[0169] In this embodiment, the cell is in a startup state (i.e., a working state). When the reverse polarity test is started, air is first introduced into the cathode of the cell, and 2.0 seconds later, hydrogen is introduced into the anode of the cell until the voltage of the cell stabilizes.

[0170] The flow rate of the hydrogen is 0.2 L / min; the flow rate of the air is 0.8 L / min; the excess coefficient of the hydrogen is set to 1.5; the excess coefficient of the air is set to 2.5; and the flow rate of the nitrogen is 0.2 L / min.

[0171] The constant current applied by the external power supply to the single cell is 0.2A·cm -2 .

[0172] The external power supply is an external DC power supply.

[0173] In step S02,

[0174] The performance parameters include the polarization curve, CV curve and LSV curve of the single cell.

[0175] The polarization curve test was conducted under the conditions of 60° C., 70% RH, H 2 / air and no back pressure.

[0176] The CV curve and the LSV curve were tested under the conditions of 60° C., 70% RH, H 2 / N 2 and no back pressure.

[0177] The reverse polarity generation condition is that the reverse polarity voltage of the single cell is -0.2V.

[0178] The reverse polarity test was conducted at 60° C., 70% RH, H 2 / air and no back pressure.

[0179] In step S03,

[0180] The flow rate of the hydrogen is 0.2 L / min; the excess coefficient of the hydrogen is set to 1.5.

[0181] The constant current applied by the external power supply to the single cell is 0.2A·cm -2 .

[0182] The activation treatment lasts for two hours.

[0183] The temperature of the single cell is 60° C.; the dew point temperatures of the cathode and the anode are both 60° C.

[0184] Comparative Example 2

[0185] A method for designing a reverse electrode of a fuel cell comprises the following steps:

[0186] S01, connecting an external power supply and a single cell in series, respectively passing hydrogen into the anode of the single cell and air into the cathode of the single cell until the voltage of the single cell stabilizes; when the voltage of the single cell stabilizes, keeping air flowing into the cathode of the single cell, cutting off the hydrogen supply to the anode of the single cell, and passing N2 into the anode;

[0187] S02, testing the performance parameters of the single cell; when the single cell has reverse polarity, cutting off the external power supply, and testing the performance parameters of the single cell again;

[0188] S03, stop introducing N2 into the anode, then introduce H2 into the anode, and connect the single cell and the external power supply in series again to activate the single cell.

[0189] In step S01,

[0190] The single cell is an activated cell.

[0191] The activation treatment lasts for two hours.

[0192] The temperature of the single cell is 65° C.; the dew point temperatures of the cathode and the anode are both 65° C.

[0193] In this embodiment, the cell is in a stopped state (i.e., a non-working state). When the reverse polarity test is started, air is first introduced into the cathode of the cell, and nitrogen is introduced into the anode of the cell 1.0 second later. After 3.5 seconds of nitrogen introduction, the introduction of nitrogen is stopped and hydrogen is introduced into the anode of the cell until the voltage of the cell stabilizes. When the reverse polarity test is stopped, the hydrogen supply to the anode of the cell is first cut off, and 10 seconds after the hydrogen supply is cut off, the air supply to the cathode of the cell is cut off.

[0194] The flow rate of the hydrogen is 0.3 L / min; the flow rate of the air is 0.9 L / min; the excess coefficient of the hydrogen is set to 1.5; the excess coefficient of the air is set to 2.5; and the flow rate of the nitrogen is 0.3 L / min.

[0195] The constant current applied by the external power supply to the single cell is 0.2A·cm -2 .

[0196] The external power supply is an external DC power supply.

[0197] In step S02,

[0198] The performance parameters include the polarization curve, CV curve and LSV curve of the single cell.

[0199] The polarization curve test was conducted under the conditions of 65° C., 100% RH, H 2 / air and no back pressure.

[0200] The CV curve and the LSV curve were tested under the conditions of 65° C., 100% RH, H 2 / N 2 and no back pressure.

[0201] The reverse polarity generation condition is that the reverse polarity voltage of the single cell is -0.2V.

[0202] The reverse polarity test was conducted under the conditions of 65° C., 100% RH, H 2 / air and no back pressure.

[0203] In step S03,

[0204] The flow rate of the hydrogen is 0.3 L / min; the excess coefficient of the hydrogen is set to 1.5.

[0205] The constant current applied by the external power supply to the single cell is 0.2A·cm -2 .

[0206] The activation treatment lasts for two hours.

[0207] The temperature of the single cell is 65° C.; the dew point temperatures of the cathode and the anode are both 65° C.

[0208] It can be seen that compared with the above comparative embodiment, this embodiment can successfully simulate the reverse polarity experiment of the fuel cell, is simple to operate, has low cost, good repeatability, and good safety.

[0209] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention specification under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for designing a reverse electrode of a fuel cell, characterized in that: The steps include: S01, connecting an external power supply and a single cell in series, respectively passing hydrogen into the anode of the single cell and air into the cathode of the single cell until the voltage of the single cell stabilizes; when the voltage of the single cell stabilizes, keeping air flowing into the cathode of the single cell, cutting off the hydrogen supply to the anode of the single cell, and passing N2 into the anode; S02, testing the performance parameters of the single cell; when the single cell has reverse polarity, cutting off the external power supply, and testing the performance parameters of the single cell again; S03, stopping the flow of N2 into the anode, then flowing H2 into the anode, and connecting the single cell and the external power supply in series again to activate the single cell; In step S01, when the cell is in the startup state and the reverse polarity test is started, air is first introduced into the cathode of the cell, and then hydrogen is introduced into the anode of the cell for 0.5 to 1.0 seconds until the voltage of the cell stabilizes. In step S01, when the cell is in a stopped state and a reverse polarity test is initiated, air is first introduced into the cathode of the cell, and then nitrogen is introduced into the anode of the cell after 0.5 to 1.0 seconds. After 2 to 3 seconds of nitrogen introduction, the introduction of nitrogen is stopped and hydrogen is introduced into the anode of the cell until the voltage of the cell stabilizes. When the reverse polarity test is terminated, the hydrogen supply to the anode of the cell is first cut off, and 10 to 15 seconds after the hydrogen supply is cut off, the air supply to the cathode of the cell is cut off. In step S03, the flow rate of the hydrogen is 0.2 L / min-0.3 L / min; the excess coefficient of the hydrogen is set to 1.5; The constant current applied by the external power supply to the single cell is 0.2A·cm -2 ; The temperature of the single cell is 59° C.-65° C.; the dew point temperatures of the cathode and the anode are both 59° C.-65° C.

2. The method for designing a counter electrode of a fuel cell according to claim 1, wherein: In step S01, the single cell is a single cell that has undergone activation treatment; The temperature of the single cell is 59° C.-65° C.; the dew point temperatures of the cathode and the anode are both 59° C.-65° C.

3. The method for designing a counter electrode of a fuel cell according to claim 1, wherein: In step S01, the flow rate of hydrogen is 0.2L / min-0.3L / min; the flow rate of air is 0.8L / min-0.9L / min; the excess coefficient of hydrogen is set to 1.5; the excess coefficient of air is set to 2.5; and the flow rate of nitrogen is 0.2L / min-0.3L / min.

4. The method for designing a counter electrode of a fuel cell according to claim 1, wherein: In step S01, the external power supply applies a constant current of 0.2 A·cm to the battery. -2 ; The external power supply is an external DC power supply.

5. The method for designing a counter electrode of a fuel cell according to claim 1, wherein: In step S02, the performance parameters include the polarization curve, CV curve and LSV curve of the single cell.

6. The method for designing a counter electrode of a fuel cell according to claim 5, wherein: The polarization curve test was carried out at 60°C-65°C, 70%RH-100%RH, H2 / air and no back pressure. The CV curve and the LSV curve were tested at 60° C.-65° C., 70% RH-100% RH, H 2 / N 2 and no back pressure conditions; The reverse polarity test was conducted under conditions of 60° C.-65° C., 70% RH-100% RH, H 2 / air and no back pressure.

7. The method for designing a counter electrode of a fuel cell according to claim 5, wherein: In step S01 , the reverse polarity condition is that the reverse polarity voltage of the single cell is −0.2V.