A test system and test method for obtaining polarization loss distribution of proton exchange membrane fuel cell

Abstract

The present invention belongs to the field of fuel cells, and specifically relates to a test system and a test method for obtaining the polarization loss distribution of a proton exchange membrane fuel cell, comprising the following steps: obtaining the voltage, temperature, current density and high-frequency impedance at different positions of the fuel cell reaction zone and the humidity and pressure on the anode and cathode sides through a multifunctional test board module; calculating the reversible electromotive force and activation polarization loss at different positions of the fuel cell according to the obtained temperature, humidity, pressure and current density; obtaining the ohmic polarization loss at different positions of the fuel cell according to the obtained current density and high-frequency impedance; calculating the mass transfer polarization loss at different positions of the fuel cell according to the obtained voltage, reversible electromotive force, activation polarization loss and ohmic polarization loss. Compared with the prior art, the present invention solves the problem that the distribution of activation polarization loss, ohmic polarization loss and mass transfer polarization loss cannot be obtained in the prior art.

Description

Technical Field

[0001] The invention belongs to the field of fuel cells, and in particular relates to a test system and a test method for obtaining polarization loss distribution of a proton exchange membrane fuel cell. Background Art

[0002] Proton exchange membrane fuel cells are widely used in automobiles, portable electronic devices, power stations and other fields due to their high efficiency, fast start-up and no pollution. In order to meet the power requirements, fuel cells often have a large reaction area. At the same time, due to the complex heat transfer, mass transfer and electrochemical reactions inside the fuel cell, there are uneven distributions of multiple physical fields such as pressure, temperature, humidity, and current density during operation. The water vapor transmission capacity in some local areas is poor, resulting in uneven reactions inside the fuel cell, which in turn limits the improvement of fuel cell performance.

[0003] The performance loss of proton exchange membrane fuel cells can be divided into three types: activation polarization loss, ohmic polarization loss, and mass transfer polarization loss, which are closely related to the distribution of multi-physical fields. Obtaining the multi-physical field distribution inside the fuel cell and analyzing the source of polarization loss in the large-area reaction area of ​​the fuel cell are of great significance for studying the performance attenuation mechanism of the fuel cell and guiding the design of the fuel cell.

[0004] Chinese invention patent CN 113030736A discloses an integrated fuel cell multifunctional online testing device, which can be installed on a fuel cell stack to test the fuel cell assembly force, GDL compression rate, current density, impedance, gas temperature and humidity, and water distribution online. Chinese invention patent CN 109301289A discloses a testing device for the internal temperature and pressure distribution of a large-area fuel cell, which can simultaneously test the temperature distribution and pressure distribution inside the cell online during the steady-state operation or dynamic load change of the fuel cell. Although the current fuel cell testing device can obtain the distribution of multiple physical fields such as temperature, humidity, pressure, current density, etc. at different positions inside the fuel cell, it is difficult to decouple the source of performance loss inside the fuel cell, and it is impossible to further obtain the distribution of activation polarization loss, ohmic polarization loss, and mass transfer polarization loss that are truly related to the performance and life of the fuel cell.

[0005] Therefore, it is necessary to propose a test system and test method that can obtain the distribution of activation polarization loss, ohmic polarization loss, and mass transfer polarization loss that are truly related to the performance and life of fuel cells. Summary of the invention

[0006] The purpose of the present invention is to solve at least one of the above problems and to provide a test system and test method for obtaining the polarization loss distribution of proton exchange membrane fuel cells, so as to solve the problem that the distribution of activation polarization loss, ohmic polarization loss and mass transfer polarization loss cannot be obtained in the prior art, and to realize the construction of the relationship between multi-physical field test data and battery performance distribution.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] The first aspect of the present invention discloses a test system for obtaining polarization loss distribution of a proton exchange membrane fuel cell, which is installed inside the fuel cell and comprises:

[0009] A multifunctional test board module, which is installed inside the fuel cell and includes an anode-side multifunctional measuring board attached to the anode side of the membrane electrode and a cathode-side multifunctional measuring board attached to the cathode side of the membrane electrode, wherein the test area of ​​the measuring board is not less than the reaction area of ​​the fuel cell, and the test area of ​​the measuring board is divided into a plurality of independent areas, which respectively test the voltage, temperature, current density and high-frequency impedance at different positions of the reaction area of ​​the fuel cell and the humidity and pressure on the cathode and anode sides;

[0010] a data acquisition module, the data acquisition module is electrically connected to the multifunctional test board module and is used to collect electrical signals from the multifunctional test board module;

[0011] a polarization loss separation module, which is electrically connected to the data acquisition module and is used to process the data collected by the data acquisition module at different positions of the fuel cell, and calculate the activation polarization loss, ohmic polarization loss and mass transfer polarization loss at different positions of the fuel cell;

[0012] a display module, the display module being electrically connected to the polarization loss separation module and being used for displaying the distribution of activation polarization loss, ohmic polarization loss and mass transfer polarization loss calculated by the polarization loss separation module inside the fuel cell;

[0013] a fuel cell workstation connected to the gas channel of the fuel cell and used for supplying reaction gas to the fuel cell;

[0014] A load is electrically connected to the positive and negative electrodes of the fuel cell to form an external circuit of the fuel cell.

[0015] The different positions of the fuel cell refer to the M×N equal-area partitions into which the fuel cell reaction area is divided, the total number of rows of the partitions is M, and the total number of columns of the partitions is N. For the partition kl, the number of its row is k, the number of its column is l, the value range of k is an integer from 1 to M, and the value range of l is an integer from 1 to N. Therefore, the expression of different positions of the fuel cell reaction area is equivalent to the expression of partition kl, both of which represent any partition of the fuel cell reaction area.

[0016] Preferably,

[0017] The temperature and current density at different positions of the fuel cell reaction zone and the humidity and pressure on the cathode side are obtained through a cathode side multifunctional measuring plate installed on the cathode side of the fuel cell stack;

[0018] The humidity and pressure of the anode side at different positions of the fuel cell reaction zone are obtained by an anode side multifunctional measuring plate installed on the anode side of the fuel cell stack;

[0019] The voltage at different positions of the fuel cell reaction zone is obtained by the potential difference between the anode-side multifunctional measuring plate and the cathode-side multifunctional measuring plate installed on the anode side and the cathode side at corresponding positions;

[0020] The high-frequency impedance at different positions of the fuel cell reaction zone is obtained by electrochemical impedance spectroscopy testing.

[0021] More preferably,

[0022] The temperature, current density, and humidity and pressure at different positions of the fuel cell reaction zone are obtained through a multifunctional measuring board installed on the cathode side of the fuel cell stack; the multifunctional measuring board installed on the cathode side is provided with a temperature and humidity sensor at each partition to obtain the temperature at the partition and the humidity at the cathode side; the multifunctional measuring board installed on the cathode side is provided with a pressure sensor at each partition to obtain the gas pressure on the cathode side at the partition; the multifunctional measuring board installed on the cathode side is provided with a resistor of known resistance at each partition, and the resistor is connected in series with the current collection area of ​​the partition, and the current flowing through the resistor is calculated by measuring the voltage across the resistor, and the current density of the partition can be calculated by further combining the area of ​​the partition;

[0023] The humidity and pressure of the anode side at different positions of the fuel cell reaction area are obtained by a multifunctional measuring board installed on the anode side of the fuel cell stack; the multifunctional measuring board installed on the anode side is provided with a humidity sensor at each partition to obtain the humidity of the anode side at the partition; the multifunctional measuring board installed on the anode side is provided with a pressure sensor at each partition to obtain the gas pressure of the anode side at the partition;

[0024] The voltage at different positions in the fuel cell reaction zone is obtained by the potential difference at the partition through the multifunctional measuring board installed on the anode side and the cathode side.

[0025] Preferably, the electrochemical impedance spectroscopy test is specifically:

[0026] The constant current disturbance mode is adopted to apply the AC current disturbance under certain conditions to the fuel cell;

[0027] Calculate the ratio of voltage to current at different positions of the fuel cell reaction zone, take the real part, and obtain the high-frequency impedance at different positions of the fuel cell reaction zone;

[0028] The certain conditions are: frequency 1000 Hz, amplitude 10% of the direct current.

[0029] The second aspect of the present invention discloses a test method for obtaining polarization loss distribution of a proton exchange membrane fuel cell, using any of the test systems described above to perform the test, comprising the following steps:

[0030] S1: The voltage, temperature, current density and high-frequency impedance at different positions of the fuel cell reaction zone and the humidity and pressure on the anode and cathode sides are obtained through the multifunctional test board module;

[0031] S2: Calculating the reversible electromotive force at different positions of the fuel cell according to the temperature, humidity, pressure and current density obtained in step S1;

[0032] S3: Calculating the anode activation polarization loss and cathode activation polarization loss at different positions of the fuel cell according to the temperature, humidity, pressure and current density obtained in step S1;

[0033] S4: Obtaining ohmic polarization losses at different positions of the fuel cell according to the current density and high-frequency impedance obtained in step S1;

[0034] S5: Calculate the mass transfer polarization loss at different positions of the fuel cell based on the voltage obtained in step S1, the reversible electromotive force obtained in step S2, the anode activation polarization loss and cathode activation polarization loss obtained in step S3, and the ohmic polarization loss obtained in step S4.

[0035] Preferably, the calculation expression of the reversible electromotive force is:

[0036]

[0037] Where, T kl is the temperature at partition kl; The electrochemical reaction of the fuel cell is at a temperature of T kl , pressure is the Gibbs free energy change under one atmosphere; n is the number of converted electrons; F is the Faraday constant; R is the gas constant; is the hydrogen partial pressure at the partition k1 on the anode side; is the water vapor partial pressure at the partition kl on the cathode side; is the oxygen partial pressure at the partition k1 on the cathode side.

[0038] Preferably,

[0039] The calculation expression of the hydrogen partial pressure at the partition k1 on the anode side is:

[0040]

[0041] In the formula, is the pressure at the partition kl on the anode side; is the humidity at partition kl on the anode side; The temperature is T kl The saturated vapor pressure of water vapor at ;

[0042] The calculation expression of water vapor partial pressure at the partition kl on the cathode side is:

[0043]

[0044] In the formula, is the humidity at the partition kl on the cathode side;

[0045] The calculation expression of the oxygen partial pressure at the partition kl on the cathode side is:

[0046]

[0047] In the formula, is the pressure at the partition kl on the cathode side; N is the total number of partitions; i is the operating current density of the fuel cell; S Cath is the stoichiometric ratio of the cathode; k is the row where partition kl is located, l is the column where partition kl is located, i k,x is the current density of the partition determined by row k and column x, and i k,0 =0.

[0048] Preferably,

[0049] The calculation expression of anode activation polarization loss is:

[0050]

[0051] The calculation expression of cathode activation polarization loss is:

[0052]

[0053] Where R is the gas constant; T kl is the temperature at partition kl; F is the Faraday constant; is the activation polarization of the anode at partition kl; is the activation polarization of the cathode at partition kl; α an is the transfer coefficient of the anode; α cath is the cathode transfer coefficient; k is the row where partition kl is located, l is the column where partition kl is located, i k,l is the current density of the partition determined by row k and column l, and i k,0 =0; is the initial exchange current density of the anode at partition kl; is the initial exchange current density of the cathode at partition kl.

[0054] Preferably,

[0055] The calculation expression of the initial exchange current density of the anode at the partition kl is:

[0056]

[0057] The calculation expression of the initial exchange current density of the cathode at the partition kl is:

[0058]

[0059] In the formula, is the anode reference current density; is the cathode reference current density; A Pt,an A is the specific surface area of ​​the anode catalyst; Pt,cath is the specific surface area of ​​cathode catalyst; L Pt,an is the anode catalyst loading; L Pt,cath is the cathode catalyst loading; is the hydrogen partial pressure at the partition k1 on the anode side; is the reference pressure of hydrogen; is the oxygen partial pressure at the partition kl on the cathode side; is the oxygen reference pressure; is the hydrogen pressure correlation coefficient; is the oxygen pressure correlation coefficient; E an is the activation energy of hydrogen oxidation; E cath is the activation energy of oxygen reduction; T ref is the reference temperature.

[0060] Preferably, the calculation expression of ohmic polarization loss is:

[0061]

[0062] In the formula, is the high frequency impedance at partition kl; k is the row where partition kl is located, l is the column where partition kl is located, i k,lis the current density of the partition determined by row k and column l, and i k,0 =0.

[0063] Preferably, the calculation expression of mass transfer polarization loss is:

[0064]

[0065] In the formula, is the reversible electromotive force at the fuel cell partition kl; is the measured voltage at the fuel cell partition kl; is the ohmic polarization loss at the fuel cell partition kl; is the anode activation polarization loss at the fuel cell partition kl; is the cathode activation polarization loss at the fuel cell partition kl.

[0066] Compared with the prior art, the present invention has the following beneficial effects:

[0067] The present invention makes full use of the data of temperature, humidity, pressure, current density, and high-frequency impedance at different positions of the fuel cell reaction zone measured by the fuel cell testing device, and obtains the distribution of the three polarization losses inside the fuel cell, thereby truly realizing the online test of the fuel cell reaction state, changing the current situation that the existing technology can only obtain the overall polarization loss of the fuel cell. By comparing the changes of the three polarization losses between different partitions of the fuel cell reaction zone (for example, analyzing the changes of mass transfer polarization losses at the inlet and outlet of the reaction gas), it is helpful to analyze the phenomenon and causes of uneven distribution of fuel cell performance, and then guide the design of the fuel cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 It is a schematic flow chart of a test method for obtaining polarization loss distribution of a proton exchange membrane fuel cell according to the present invention;

[0069] Figure 2 A schematic diagram of a partitioning method for dividing different positions of a fuel cell reaction zone in Example 1 of the present invention;

[0070] Figure 3 It is a schematic diagram of the structure of the test system for obtaining the polarization loss distribution of the proton exchange membrane fuel cell according to the present invention;

[0071] In the figure: 1-fuel cell workstation; 2-load; 3-data acquisition module; 4-polarization loss separation module; 5-display module; 6-anode side multifunctional measurement board; 7-membrane electrode; 8-end plate; 9-single cell; 10-cathode side multifunctional measurement board. DETAILED DESCRIPTION

[0072] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0073] Example 1

[0074] A test system and test method for obtaining polarization loss distribution of proton exchange membrane fuel cells, such as Figure 1-3 As shown, the test system is installed inside the fuel cell and includes:

[0075] A multifunctional test board module, which is installed inside the fuel cell and includes an anode-side multifunctional measuring board 6 attached to the anode side of the membrane electrode 7 and a cathode-side multifunctional measuring board 10 attached to the cathode side of the membrane electrode 7. The test area of ​​the measuring board is not less than the reaction area of ​​the fuel cell. The test area of ​​the measuring board is divided into multiple independent areas, which respectively test the voltage, temperature, current density and high-frequency impedance at different positions of the fuel cell reaction area and the humidity and pressure on the cathode and anode sides;

[0076] a data acquisition module 3, the data acquisition module 3 is electrically connected to the multifunctional test board module and is used to collect electrical signals of the multifunctional test board module;

[0077] a polarization loss separation module 4, which is electrically connected to the data acquisition module 3 and is used to process the data at different positions of the fuel cell collected by the data acquisition module 3, and calculate the activation polarization loss, ohmic polarization loss and mass transfer polarization loss at different positions of the fuel cell;

[0078] a display module 5, the display module 5 being electrically connected to the polarization loss separation module 4 and being used for displaying the distribution of the activation polarization loss, ohmic polarization loss and mass transfer polarization loss calculated by the polarization loss separation module 4 inside the fuel cell;

[0079] a fuel cell workstation 1, the fuel cell workstation 1 being connected to the gas channel of the fuel cell and used for supplying reaction gas to the fuel cell;

[0080] A load 2 is electrically connected to the positive and negative electrodes of the fuel cell to form an external circuit of the fuel cell.

[0081] More specifically, in this embodiment:

[0082] like Figure 1 As shown, this embodiment provides a test method for obtaining polarization loss distribution of a proton exchange membrane fuel cell, which specifically includes the following steps:

[0083] Step 1: Obtain the voltage, temperature, current density, high-frequency impedance at different positions of the fuel cell reaction zone, and the humidity and pressure on the anode and cathode sides.

[0084] like Figure 2 As shown, the different positions of the reaction zone refer to the M×N partitions into which the fuel cell reaction zone is divided. The total number of rows of the partitions is M, and the total number of columns of the partitions is N. For partition kl, the number of its row is k, the number of its column is l, the value range of k is an integer from 1 to M, and the value range of l is an integer from 1 to N. Therefore, the expression of different positions of the fuel cell reaction zone is equivalent to the expression of partition kl, both of which represent any partition of the fuel cell reaction zone.

[0085] like Figure 3 As shown, the cathode-side multifunctional measuring board 10 is placed on the cathode side of the membrane electrode 7, and the anode-side multifunctional measuring board 6 is placed on the anode side of the membrane electrode 7. The two sides of the multifunctional measuring board are clamped by the remaining single cells 9 and the end plates 8 to form a fuel cell stack. The fuel cell workstation 1 supplies the fuel cell stack with reactant gas, and the load 2 forms an external circuit of the fuel cell stack.

[0086] The temperature, current density, cathode side humidity and pressure at different positions of the fuel cell reaction zone are obtained through the cathode side multifunctional measuring board 10 installed in the fuel cell stack; the cathode side multifunctional measuring board 10 is provided with a temperature and humidity sensor at each partition to obtain the temperature of the partition and the humidity of the cathode side; the cathode side multifunctional measuring board 10 is provided with a pressure sensor at each partition to obtain the gas pressure on the cathode side of the partition; the cathode side multifunctional measuring board 10 is provided with a resistor of known resistance at each partition, the resistor is connected in series with the current collection area of ​​the partition, and the current flowing through the resistor is calculated by measuring the voltage across the resistor, and the current density of the partition can be calculated by further combining the area of ​​the partition.

[0087] The humidity and pressure on the anode side at different positions of the fuel cell reaction zone are obtained through the anode side multifunctional measuring board 6 installed in the fuel cell stack; the anode side multifunctional measuring board 6 is provided with a humidity sensor at each partition to obtain the humidity on the anode side at the partition; the anode side multifunctional measuring board 6 is provided with a pressure sensor at each partition to obtain the gas pressure on the anode side at the partition.

[0088] The voltage at different positions of the fuel cell reaction zone is obtained by the potential difference between the multifunctional measuring board 6 installed on the anode side and the multifunctional measuring board 10 installed on the cathode side at the positions.

[0089] Use electrochemical impedance spectroscopy to obtain the high-frequency impedance at different positions of the fuel cell reaction zone: set load 2 to constant current perturbation mode, apply an AC current disturbance with a frequency of 1000 Hz and an amplitude of 10% of the DC current to the fuel cell stack, calculate the ratio of the voltage to the current at different positions of the fuel cell and take its real part to obtain the high-frequency impedance at different positions of the fuel cell.

[0090] The data acquisition module 3 is used to collect the voltage, temperature, current density, high-frequency impedance at different positions of the fuel cell reaction zone and the humidity and pressure signals on the anode and cathode sides output by the multifunctional measuring board module.

[0091] The measured data is processed by the polarization loss separation module 4 to separate the activation polarization loss, ohmic polarization loss and mass transfer polarization loss at different positions of the fuel cell. The specific polarization loss separation method is described in the following steps 2 to 5.

[0092] Step 2: Calculate the reversible electromotive force at different positions of the fuel cell according to temperature, humidity, pressure, and current density; the calculation expression of the reversible electromotive force is:

[0093]

[0094] Where, T kl is the temperature at partition kl; The electrochemical reaction of the fuel cell is at a temperature of T kl , pressure is the Gibbs free energy change under one atmosphere; n is the number of converted electrons; F is the Faraday constant; R is the gas constant; is the hydrogen partial pressure at the partition k1 on the anode side; is the water vapor partial pressure at the partition kl on the cathode side; is the oxygen partial pressure at the partition k1 on the cathode side.

[0095] The calculation expression of the hydrogen partial pressure at the anode side partition kl is:

[0096] The calculation expression of the hydrogen partial pressure at the partition k1 on the anode side is:

[0097]

[0098] In the formula, is the pressure at the partition kl on the anode side; is the humidity at partition kl on the anode side; The temperature is T kl The saturated vapor pressure of water vapor at ;

[0099] The calculation expression of water vapor partial pressure at the partition kl on the cathode side is:

[0100]

[0101] In the formula, is the humidity at the partition kl on the cathode side;

[0102] The calculation expression of the oxygen partial pressure at the partition kl on the cathode side is:

[0103]

[0104] In the formula, is the pressure at the partition kl on the cathode side; N is the total number of partitions; i is the operating current density of the fuel cell; S Cath is the stoichiometric ratio of the cathode; k is the row where partition kl is located, l is the column where partition kl is located, i k,x is the current density of the partition determined by row k and column x, and i k,0 =0.

[0105] Step 3, according to the temperature, humidity, pressure, and current density, the anode activation polarization loss and cathode activation polarization loss at different positions of the fuel cell are calculated; the calculation expression of the anode activation polarization loss at different positions is:

[0106]

[0107] The calculation expression of cathode activation polarization loss is:

[0108]

[0109] Where R is the gas constant; T kl is the temperature at partition kl; F is the Faraday constant; is the activation polarization of the anode at partition kl; is the activation polarization of the cathode at partition kl; α an is the transfer coefficient of the anode; α cath is the cathode transfer coefficient; is the initial exchange current density of the anode at partition kl; is the initial exchange current density of the cathode at partition kl.

[0110] The calculation expression of the initial exchange current density of the anode at the partition kl is:

[0111]

[0112] The calculation expression of the initial exchange current density of the cathode at the partition kl is:

[0113]

[0114] In the formula, is the anode reference current density; is the cathode reference current density; A Pt,an A is the specific surface area of ​​the anode catalyst; Pt,cath is the specific surface area of ​​cathode catalyst; L Pt,an is the anode catalyst loading; L Pt,cath is the cathode catalyst loading; is the reference pressure of hydrogen; is the oxygen reference pressure; is the hydrogen pressure correlation coefficient; is the oxygen pressure correlation coefficient; E an is the activation energy of hydrogen oxidation; E cath is the activation energy of oxygen reduction; T ref is the reference temperature.

[0115] Step 4: Calculate the ohmic polarization loss at different positions of the fuel cell according to the current density and high-frequency impedance; the calculation expression of the ohmic polarization loss at different positions of the fuel cell is:

[0116]

[0117] In the formula, is the high frequency impedance at partition kl.

[0118] Step 5: Calculate the mass transfer polarization loss at different positions of the fuel cell based on the voltage value, reversible electromotive force, activation polarization loss and ohmic polarization loss; the calculation expression of the mass transfer polarization loss at different positions of the fuel cell is:

[0119]

[0120] In the formula, is the measured voltage value at the fuel cell partition k1.

[0121] The display module 5 displays the distribution of the three separated polarization losses of the fuel cell inside the fuel cell.

[0122] Analyzing the distribution of different types of polarization losses (activation polarization loss, ohmic polarization loss, mass transfer polarization loss) inside the fuel cell will help increase the understanding of the uneven distribution of fuel cell performance and provide guidance for improving the design of fuel cells to enhance fuel cell performance and life.

[0123] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A test system for obtaining polarization loss distribution of a proton exchange membrane fuel cell, characterized in that: Installed inside the fuel cell, including: A multifunctional test board module, the multifunctional test board module is installed inside a fuel cell, and comprises an anode-side multifunctional measuring board (6) attached to the anode side of a membrane electrode (7) and a cathode-side multifunctional measuring board (10) attached to the cathode side of the membrane electrode (7), wherein the test area of ​​the measuring board is not less than the reaction area of ​​the fuel cell, and the test area of ​​the measuring board is divided into a plurality of independent areas, and the voltage, temperature, current density and high-frequency impedance at different positions of the reaction area of ​​the fuel cell and the humidity and pressure on the cathode and anode sides are tested respectively; a data acquisition module (3), the data acquisition module (3) being electrically connected to the multifunctional test board module and being used for acquiring electrical signals of the multifunctional test board module; a polarization loss separation module (4), the polarization loss separation module (4) being electrically connected to the data acquisition module (3) and used for processing the data at different positions of the fuel cell acquired by the data acquisition module (3) to calculate the activation polarization loss, ohmic polarization loss and mass transfer polarization loss at different positions of the fuel cell; a display module (5), the display module (5) being electrically connected to the polarization loss separation module (4) and used for displaying the distribution of activation polarization loss, ohmic polarization loss and mass transfer polarization loss calculated by the polarization loss separation module (4) inside the fuel cell; A fuel cell workstation (1), the fuel cell workstation (1) being connected to a gas channel of the fuel cell and used for supplying reaction gas to the fuel cell; a load (2), the load being electrically connected to the positive and negative electrodes of the fuel cell to form an external circuit of the fuel cell; Among them, different positions of the fuel cell refer to the M×N partitions of equal area divided into the fuel cell reaction area, the total number of rows of the partitions is M, and the total number of columns of the partitions is N; for partition kl, the label of its row is k, the label of its column is l, the value range of k is an integer from 1 to M, and the value range of l is an integer from 1 to N; therefore, the expression of different positions of the fuel cell reaction area is equivalent to the expression of partition kl, both of which represent any partition of the fuel cell reaction area.

2. A test system for obtaining polarization loss distribution of a proton exchange membrane fuel cell according to claim 1, characterized in that: The temperature and current density at different positions of the fuel cell reaction zone and the humidity and pressure on the cathode side are obtained through a cathode side multifunctional measuring plate (10) installed on the cathode side of the fuel cell stack; The humidity and pressure of the anode side at different positions of the fuel cell reaction zone are obtained by an anode side multifunctional measuring plate (6) installed on the anode side of the fuel cell stack; The voltage at different positions of the fuel cell reaction zone is obtained by the potential difference between the anode-side multifunctional measuring plate (6) and the cathode-side multifunctional measuring plate (10) installed on the anode side and the cathode side at corresponding positions; The high-frequency impedance at different positions of the fuel cell reaction zone is obtained by electrochemical impedance spectroscopy testing.

3. A test system for obtaining polarization loss distribution of a proton exchange membrane fuel cell according to claim 2, characterized in that: The electrochemical impedance spectroscopy test is as follows: The constant current disturbance mode is adopted to apply the AC current disturbance under certain conditions to the fuel cell; Calculate the ratio of voltage to current at different positions of the fuel cell reaction zone, take the real part, and obtain the high-frequency impedance at different positions of the fuel cell reaction zone; The certain conditions are: frequency 1000 Hz, amplitude 10% of the direct current.

4. A test method for obtaining polarization loss distribution of a proton exchange membrane fuel cell, characterized in that: The test is performed using the test system as described in any one of claims 1 to 3, comprising the following steps: S1: The voltage, temperature, current density and high-frequency impedance at different positions of the fuel cell reaction zone and the humidity and pressure on the anode and cathode sides are obtained through the multifunctional test board module; S2: Calculating the reversible electromotive force at different positions of the fuel cell according to the temperature, humidity, pressure and current density obtained in step S1; S3: Calculating the anode activation polarization loss and cathode activation polarization loss at different positions of the fuel cell according to the temperature, humidity, pressure and current density obtained in step S1; S4: Obtaining ohmic polarization losses at different positions of the fuel cell according to the current density and high-frequency impedance obtained in step S1; S5: Calculate the mass transfer polarization loss at different positions of the fuel cell according to the voltage obtained in step S1, the reversible electromotive force obtained in step S2, the anode activation polarization loss and the cathode activation polarization loss obtained in step S3, and the ohmic polarization loss obtained in step S4; The calculation expression of reversible electromotive force is: Where, T kl is the temperature at partition kl; The electrochemical reaction of the fuel cell is at a temperature of T kl , pressure is the Gibbs free energy change under one atmosphere; n is the number of converted electrons; F is the Faraday constant; R is the gas constant; is the hydrogen partial pressure at the partition k1 on the anode side; is the water vapor partial pressure at the partition kl on the cathode side; is the oxygen partial pressure at the partition kl on the cathode side; The calculation expression of anode activation polarization loss is: The calculation expression of cathode activation polarization loss is: Where R is the gas constant; T kl is the temperature at partition kl; F is the Faraday constant; is the activation polarization of the anode at partition kl; is the activation polarization of the cathode at partition kl; α an is the transfer coefficient of the anode; α cath is the cathode transfer coefficient; k is the row where partition kl is located, l is the column where partition kl is located, i k,l is the current density of the partition determined by row k and column l, and i k,0 =0; is the initial exchange current density of the anode at partition kl; is the initial exchange current density of the cathode at partition kl; The calculation expression of ohmic polarization loss is: In the formula, is the high frequency impedance at partition kl; k is the row where partition kl is located, l is the column where partition kl is located, i k,l is the current density of the partition determined by row k and column l, and i k,0 =0; The calculation expression of mass transfer polarization loss is: In the formula, is the reversible electromotive force at the fuel cell partition kl; is the measured voltage at the fuel cell partition kl; is the ohmic polarization loss at the fuel cell partition kl; is the anode activation polarization loss at the fuel cell partition kl; is the cathode activation polarization loss at the fuel cell partition kl.

5. A test method for obtaining polarization loss distribution of a proton exchange membrane fuel cell according to claim 4, characterized in that: The calculation expression of the hydrogen partial pressure at the partition k1 on the anode side is: In the formula, is the pressure at the partition kl on the anode side; is the humidity at partition kl on the anode side; The temperature is T kl The saturated vapor pressure of water vapor at ; The calculation expression of water vapor partial pressure at the partition kl on the cathode side is: In the formula, is the humidity at the partition kl on the cathode side; The calculation expression of the oxygen partial pressure at the partition kl on the cathode side is: In the formula, is the pressure at the partition kl on the cathode side; N is the total number of partitions; i is the operating current density of the fuel cell; S Cath is the stoichiometric ratio of the cathode; k is the row where partition kl is located, l is the column where partition kl is located, i k,x is the current density of the partition determined by row k and column x, and i k,0 =0.

6. A test method for obtaining polarization loss distribution of a proton exchange membrane fuel cell according to claim 4, characterized in that: The calculation expression of the initial exchange current density of the anode at the partition kl is: The calculation expression of the initial exchange current density of the cathode at the partition kl is: In the formula, is the anode reference current density; is the cathode reference current density; A Pt,an A is the specific surface area of ​​the anode catalyst; Pt,cath is the specific surface area of ​​cathode catalyst; L Pt,an is the anode catalyst loading; L Pt,cath is the cathode catalyst loading; is the hydrogen partial pressure at the partition k1 on the anode side; is the reference pressure of hydrogen; is the oxygen partial pressure at the partition kl on the cathode side; is the oxygen reference pressure; is the hydrogen pressure correlation coefficient; is the oxygen pressure correlation coefficient; E an is the activation energy of hydrogen oxidation; E cath is the activation energy of oxygen reduction; T ref is the reference temperature.

Images