Fuel cell test system and method

Abstract

The invention discloses a fuel cell test system and method. The fuel cell test system comprises a test stack and a test analysis device, the test analysis device is connected with the test stack to detect the performance of the test stack, and the test stack comprises two end plates and more than two test single cells arranged between the two end plates. The pseudo single pools are arranged between two adjacent test single pools; and the test analysis device is respectively connected with the more than two test single cells so as to obtain performance parameters of different test single cells in the same test pile. The fuel cell test system provided by the invention can perform rapid detection and effective comparison on the performance of various test single cells, is beneficial to rapid model selection of single cell membrane electrodes, and improves the development efficiency of fuel cells.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cell testing, and in particular to a fuel cell testing system and method capable of rapid model selection and performance comparison. Background Art

[0002] At present, the design iteration cycle of fuel cells is slow, especially the selection and development of membrane electrode components, which requires multiple rounds of design verification experiments such as subscale material screening and short stack verification, resulting in a waste of time, materials and other resources. As market changes gradually accelerate, new fuel cell product indicators are released almost every year, which also poses higher challenges to the selection and development of membrane electrode components for various manufacturers.

[0003] At present, the traditional membrane electrode selection has the following practical problems. Traditional membrane electrode screening is usually carried out using small samples. In order to ensure data reproducibility, it is usually necessary to repeat the test of 3-5 samples of the same membrane electrode; and each time the membrane electrode is replaced, the test fixture needs to be reassembled, which is too cumbersome, and the cycle of repeated testing of multiple samples is long, which greatly affects the work efficiency. Moreover, when the membrane electrode samples of the same batch are assembled in batches, due to unavoidable human factors such as different assembly precision, the contact resistance size and press-fitting uniformity of each sample are different. Limited by the influence of different membrane electrode test states, effective quantitative comparison and separation of performance loss cannot be carried out.

[0004] Based on this, it is necessary to propose a technical solution to overcome the shortcomings of the existing technology. Summary of the invention

[0005] In order to overcome the defects of the prior art, the present invention proposes a fuel cell testing system and method, which can effectively compare the performance of multiple test cells, facilitate the rapid selection of single cell membrane electrode, and improve the development efficiency of fuel cells.

[0006] The present invention is implemented through the following technical scheme: a fuel cell testing system, including a test stack and a test analysis device, wherein the test analysis device is connected to the test stack to detect the performance of the test stack, wherein the test stack includes two end plates, two or more test cells arranged between the two end plates, and a dummy cell arranged between two adjacent test cells; the test analysis device is connected to the two or more test cells respectively to obtain performance parameters of different types of test cells in the same test stack.

[0007] As a further improved technical solution, the dummy cell is further arranged between the two end plates and the test cell adjacent to the two end plates.

[0008] As a further improved technical solution, the pseudo single cell includes a pseudo bipolar plate through which the reaction gas does not flow and a pseudo membrane electrode without a CCM layer.

[0009] As a further improved technical solution, the test system includes a pressure-applying device for applying pressure to the two end plates, and the pressure-applying device uses an air bag to apply pressure.

[0010] As a further improved technical solution, different types of test cells include: test cells with the same bipolar plates and different membrane electrodes; or test cells with the same membrane electrodes and different bipolar plates; or test cells with different bipolar plates and membrane electrodes.

[0011] As a further improved technical solution, the number of each test cell is no less than 3 pieces, and the number of all test cells is no more than 50 pieces.

[0012] As a further improved technical solution, the bipolar plate has a thickness of 0.5-3 mm and is made of flexible graphite, layered graphite or metal.

[0013] The present invention is also implemented through the following technical scheme: a fuel cell testing method, the testing method is applied to the fuel cell testing system as described above, the testing and analysis device includes a CVM module, an EIS module and a polarization loss analysis module respectively connected to the two or more test cells; the testing method includes: obtaining the performance parameters of the two or more test cells, and analyzing to obtain the polarization loss performance of different types of test cells in the same test stack.

[0014] As a further improved technical solution, the polarization loss performance of different types of test cells in the same test stack obtained by the analysis includes: Calculate the leakage current polarization loss η_cross, η_cross=E_rev-E_ocv; Calculate the activation polarization loss η_act, η_act=E_ocv-(a*Ln(j)+b); Calculate the ohmic polarization loss η_ohm, η_ohm=j*HFR; Calculate the concentration polarization loss η_conc, η_conc=(E_ocv-η_act)-(η_ohm+U); Wherein, E_rev is the reversible potential, E_ocv is the measured open circuit voltage, HFR is the average high-frequency impedance value of the test cell, j is the current density, a and b are Tafel constants, and U is the average voltage of the test cell.

[0015] As a further improved technical solution, the test method includes: gradually reducing the current density of the test cell, and calculating the above-mentioned polarization loss value at each current density, wherein at each current density, the temperature, flow rate and pressure of the test stack are maintained within a constant range.

[0016] As a further improved technical solution, the test method includes: setting no less than four test points with a current density of ≤0.1 A / cm2, and calculating the activation polarization loss at these test points.

[0017] As a further improved technical solution, the test stack is activated before the test, so that the performance parameters of the test cell are obtained when the test stack operates in a stable state.

[0018] The fuel cell testing system provided by the present invention arranges a plurality of different types of test cells in the same test stack, so that the test environments of the different types of test cells are basically the same, and the performance parameters of the plurality of test cells can be obtained at one time. Moreover, since the plurality of test cells are in the same test environment, the problem of the incomparability of the performance parameters caused by the differences in the assembled test environments is eliminated, so that the comparison of the performance parameters is more effective and reliable, which is conducive to improving the efficiency of membrane electrode selection and the development efficiency of fuel cells. The fuel cell testing method provided by the present invention proposes a calculation method for quantitatively decomposing the polarization performance of the test cell, which can analyze and compare the three polarization losses of activation polarization loss, ohmic polarization loss, and concentration polarization loss one by one, and has a significant and clear guiding significance for identifying the performance differences of the membrane electrode and determining the material selection and improvement direction of the membrane electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic block diagram of the fuel cell testing system of the present invention.

[0020] Figure 2 It is a schematic diagram of a test stack of a fuel cell test system of the present invention.

[0021] Figure 3 It is a polarization curve diagram of different membrane electrodes in an embodiment of the fuel cell testing system of the present invention.

[0022] Figure 4 It is an activation polarization loss curve diagram of different membrane electrodes in an embodiment of the fuel cell testing system of the present invention.

[0023] Figure 5 It is a concentration polarization loss curve diagram of different membrane electrodes in an embodiment of the fuel cell testing system of the present invention.

[0024] Figure 6It is a graph showing the ohmic polarization loss of different membrane electrodes in one embodiment of the fuel cell testing system of the present invention.

[0025] The figure numbers are as follows: 1. test stack; 11. end plate; 121. first test cell; 122. second test cell; 123. third test cell; 124. fourth test cell; 13. dummy cell; 14. pressure device; 2. test and analysis device; 21. CVM module; 22. EIS module; 23. polarization loss analysis module. DETAILED DESCRIPTION

[0026] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0027] The technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0028] See also Figure 1 and Figure 2 As shown, the present invention provides a fuel cell testing system. The fuel cell testing system includes a test stack 1 and a test analysis device 2. The test analysis device 2 is connected to the test stack 1 to detect the performance of the test stack 1. The test stack 1 includes two end plates 11, two or more test cells arranged between the two end plates 11, and a dummy cell 13 arranged between two adjacent test cells. The test analysis device 2 is connected to the two or more test cells respectively to obtain the performance parameters of different types of test cells in the same test stack 1.

[0029] The fuel cell testing system provided by the present invention arranges a plurality of different types of test cells in the same test stack 1, so that the test environments of the different types of test cells are basically the same, and the performance parameters of the plurality of test cells can be obtained at one time. Moreover, since the plurality of test cells are in the same test environment, the problem of incomparability of performance parameters due to differences in the assembled test environments is eliminated, so that the comparison of performance parameters is more effective and reliable, which is conducive to improving the efficiency of membrane electrode selection and improving the development efficiency of fuel cells.

[0030] See also Figure 2As shown, it shows an embodiment in which the test stack 1 includes four test cells. That is, in this embodiment, the test cells include a first test cell 121, a second test cell 122, a third test cell 123 and a fourth test cell 124. The first test cell 121 to the fourth test cell 124 are arranged in sequence from one end plate 11 to the other end plate 11. It can be understood that in other embodiments, the types of test cells included in a test stack 1 can also be two, three or more.

[0031] In this embodiment, different types of test cells include test cells with the same bipolar plates and different membrane electrodes. That is, in this embodiment, the materials and structures of the bipolar plates of the first test cell 121, the second test cell 122, the third test cell 123, and the fourth test cell 124 are exactly the same, and only the materials or structures of the membrane electrodes are different. In this way, the performance differences of the test cells caused by the differences in the bipolar plates are avoided, and the performance differences are ensured to be caused by the membrane electrodes, which is conducive to the rapid selection of membrane electrodes. In another embodiment, different types of test cells can also be test cells with the same membrane electrodes and different bipolar plates. In this way, data on the effects of different bipolar plates on the performance of the test cells can be obtained, which can be used to identify the characteristics of the ohmic-mass transfer loss difference of the bipolar plate itself. Of course, in other embodiments, different types of test cells can also be test cells with different bipolar plates and membrane electrodes; in this way, it is adopted when the performance differences of the test cells are not distinguished as being caused by the bipolar plates or the membrane electrodes, but only the overall evaluation of the performance of the test cells is adopted.

[0032] In this embodiment, the number of each test cell is not less than 3, and the number of all test cells is not more than 50. The number of each test cell is not less than 3 to ensure the stability and reliability of the test data, obtain average data with high credibility, and avoid unreliable test data due to random anomalies. Preferably, the number of each test cell is 5-10. The number of all test cells is not more than 50 to avoid the impact of uneven fluid distribution on test data caused by the excessive length of the test stack 1.

[0033] Further, in order to ensure that the performance of the test cell matches the performance of the actual battery stack, the bipolar plate used in the test cell in this embodiment is the same as the bipolar plate in the actual battery stack. The traditional fuel cell test adopts a small sample method, such as a 5*5 square centimeter membrane electrode. The bipolar plate of the membrane electrode test tooling usually adopts a specific machined graphite bipolar plate, and its thickness and material are different from the bipolar plate used in the actual battery stack. Usually, the graphite plate used in the traditional test has a thickness of ≥5mm, and the material is mostly crystalline graphite with strong conductivity; while the bipolar plate usually used in the actual battery stack is 1-2mm thick, and the material is mostly flexible graphite or layered graphite, and the conductivity and flow field structure of the two are very different. Therefore, the traditional test is very different from the actual use environment, and the performance of the actual battery stack cannot be effectively compared. The bipolar plate used in the test cell of this embodiment is the same as the bipolar plate in the actual battery stack, which ensures that the performance of the test cell can be effectively compared with the performance of the actual battery stack. In one embodiment of the present application, the bipolar plate has a thickness of 0.5-3 mm and is made of flexible graphite, layered graphite or metal, which is the same as or close to the bipolar plate used in an actual fuel cell stack.

[0034] Please continue reading Figure 2 As shown, two adjacent test cells are separated by a dummy cell 13. Figure 2 As shown, the dummy cell 13 is arranged between the first test cell 121 and the second test cell 122, between the second test cell 122 and the third test cell 123, and between the third test cell 123 and the fourth test cell 124. Further, the dummy cell 13 is also arranged between the two end plates 11 and the test cells adjacent to the two end plates 11. That is, the dummy cell 13 is also arranged between the end plate 11 and the first test cell 121, and between the fourth test cell 124 and the end plate 11. The dummy cell 13 is arranged between adjacent test cells of different types, which can isolate the test cells (that is, the real cells) on both sides thereof from having different power generation effects due to different materials and structures, and avoid the difference in flow resistance of the cells caused thereby, which affects the air intake of the cells and affects the accuracy of the performance test of the real cells. The dummy cell 13 is arranged between the end plate 11 and the test cell, which can eliminate the influence of the end plate effect of the edge of the stack on the distribution of gas fluid, and ensure the accuracy of the performance test of the test cell.

[0035] The pseudo cell 13 includes a pseudo bipolar plate through which the reaction gas does not flow and a pseudo membrane electrode without a CCM (Catalyst-coated Membrane) layer. Except that the reaction gas of the cathode and anode does not flow, the pseudo bipolar plate is made of the same material, thickness, area and other dimensions as the real bipolar plate included in the test cell, so as to avoid or reduce the influence of the material and size of the pseudo bipolar plate on the performance of the test cell. The pseudo membrane electrode is based on the real membrane electrode, but the CCM layer is removed and only the gas diffusion layer is included.

[0036] Please continue reading Figure 2 , the test system includes a pressure device 14 for applying pressure to the two end plates. The pressure device 14 applies force to the end plate 11 to apply pressure to the entire test stack 1. The pressure device 14 applies the same assembly pressure to the test stack 1 as the actual stack, so that the pressure environment of the test stack 1 is the same as that of the actual stack. In this embodiment, the pressure device uses an airbag to apply pressure. The pressure device 14 includes one or more airbags, which can provide a certain pressure by inflation. The airbag can apply force to the end plate 11 through a support rod, a push rod and a pressure plate. In this embodiment, the pressure device 14 is also configured to be pressure-adjustable, and the pressure is adjusted by the amount of inflation to meet the test requirements under different assembly pressures. The pressure device 14 used in this embodiment is convenient for operators to quickly assemble the test cell on site, does not require a press to assemble the stack, is easy to disassemble and assemble, and can adjust different pressing forces. This application does not limit the specific structure of the pressure device 14.

[0037] Please also read Figure 1As shown, the test stack 1 is electrically connected to the test and analysis device 2. In this embodiment, the test and analysis device 2 includes a CVM module 21, an EIS module 22 and a polarization loss analysis module 23 respectively connected to the two or more test cells, which can be used for polarization performance testing. The CVM module 21, also known as the fuel cell single-chip voltage inspection module (Cell Voltage Monitor), is mainly used to accurately detect the single-cell voltage of the fuel cell stack in real time, and to perform real-time analysis and processing on the monitored single-chip voltage data group to monitor, diagnose and store the state and performance of the fuel cell single-chip battery. The CVM module 21 includes a CVM channel connected to each test cell. The EIS module 22, also known as the electrochemical impedance detection module (Electrochemical Impedance Spectroscopy), is an important means for detecting the performance and characteristics of the fuel cell system. The EIS module 22 includes an EIS channel connected to each test cell to detect the EIS performance of a test cell. In other embodiments, in addition to being used for polarization performance testing, the testing and analysis device 2 can also be used for various types of tests such as single cell sensitivity, durability, low temperature startup, impact vibration, etc., so as to comprehensively evaluate the robustness performance of the membrane electrode.

[0038] Based on the above test system, the present invention provides a fuel cell test method. The test method is applied to the above fuel cell test system, and the test method includes: obtaining the performance parameters of the two or more test cells, and analyzing and obtaining the polarization loss performance of different types of test cells in the same test stack 1.

[0039] Specifically, the testing method includes: Calculate the leakage current polarization loss η_cross, η_cross=E_rev-E_ocv; Calculate the activation polarization loss η_act, η_act=E_ocv-(a*Ln(j)+b); Calculate the ohmic polarization loss η_ohm, η_ohm=j*HFR; Calculate the concentration polarization loss η_conc, η_conc=(E_ocv-η_act)-(η_ohm+U); Wherein, E_rev is the reversible potential, E_ocv is the measured open circuit voltage, HFR is the average high-frequency impedance value of the test cell, j is the current density, a and b are Tafel constants, and U is the average voltage of the test cell.

[0040] In this embodiment, the polarization loss analysis module 23 is embedded with a polarization loss analysis program. By testing the original data information such as current, voltage, EIS impedance value, temperature, pressure, flow rate, etc. obtained by the analysis device 2, the correspondence of the channels and the corresponding membrane electrode material types are set. The polarization loss analysis program performs polarization loss decomposition calculations on these input data, and can output polarization curves, activation polarization loss, ohmic polarization loss, and concentration polarization loss comparison curves. In one embodiment, the polarization curve data is obtained by online testing of the CVM module 21 and the EIS module 22 of the analysis device 2, which includes the collected CVM data and EIS data, and the polarization loss is calculated based on the Tafel polarization theory.

[0041] Specifically, first, the value of the open circuit voltage E_ocv is obtained through online testing, and the reversible potential E_rev is calculated based on the actual set temperature and pressure. The calculation method of E_rev can refer to the following formula:

[0042] in, The calculation method of the reversible potential E_rev is known to those skilled in the art, and other methods may be used, or 1.23 V may be directly used as an approximate substitute. Then, the leakage current polarization loss caused by hydrogen permeation current and internal short-circuit current is η_cross=E_rev-E_ocv.

[0043] Secondly, the ohmic polarization loss is calculated based on the average HFR (High-Frequency Impedance) value of the single cell obtained by online testing. Among them, HFR=R / n*A_act; R is the measurement impedance; n is the number of effective single cells; A_act is the active area. Then the ohmic loss is η_ohm=j*HFR; where j is the current density.

[0044] Then, calculate the activation polarization loss. At low current density, such as current density ≤ 0.1A / cm 2 When the concentration loss and ohmic loss of the test cell are negligible, it is mainly due to the influence of activation polarization of ORR (oxygen reduction reaction) and HOR (hydrogen oxidation reaction), which can be fitted using the Tafel equation Y=a*Ln(j)+b. The activation polarization loss caused by ORR and HOR is η_act=E_ocv-(a*Ln(j)+b); where a and b are called Tafel constants, a is a constant mainly related to temperature, and b represents the overpotential value when the current density is unit value, and its size is related to factors such as the properties of the electrode material, the surface state of the electrode, the composition of the solution and the temperature. In some embodiments, to ensure the reliability of the fitting data, it is usually ≤0.1A / cm2 The number of polarization curve test points is ≥ 4.

[0045] Finally, the concentration polarization loss is calculated. The concentration polarization loss η_conc=(E_ocv-η_act)-(η_ohm+U)=(a*Ln(j)+b)-E_IR_Free;wherein, U is the average voltage of a single cell, and E_IR_Free is j*HFR+U, which represents the sum of the ohmic loss and the measured voltage.

[0046] It should be noted that before testing, the test stack needs to be fully activated to remove impurities on the catalyst surface, open the medium transmission channels in the membrane and catalytic layer, and allow the membrane electrode to be fully hydrated so that the stack can operate in a stable state and perform performance comparisons of different single cells.

[0047] Furthermore, the test is carried out by load reduction polarization, that is, the current density of the test cell is gradually reduced, and the above polarization loss value is calculated at each current density. In this way, the influence of low-density high-potential oxidation in the load-up test can be avoided. During the test, when the load is reduced to the low-density point, in order to avoid the influence of oxidation, the test should be carried out as quickly as possible. In the process of reducing the load from high density to low density, at each current density, the temperature, flow rate and pressure of the test stack are maintained in a constant range. Maintaining in a constant range means ensuring that the temperature, flow rate and pressure of the stack remain unchanged as much as possible, only changing the current, and conducting a single condition comparative test, so as to ensure that the Tafel polarization fitting relationship Y=a*Ln(j)+b obtained based on low density can be extended to a large density point. It can be understood that in actual operation, due to the limitations of the stability and control capabilities of the test system, at different current densities, the temperature, flow rate and pressure of the test stack are allowed to fluctuate to a certain extent, which still does not deviate from the above-mentioned maintenance in a constant range.

[0048] See also Figures 3 to 6 As shown, it is the polarization loss data obtained by testing a test stack 1 including three types of membrane electrodes. The model information of the three membrane electrodes used, namely membrane electrode A, membrane electrode B, and membrane electrode C, is shown in the following table. It should be noted that the raw materials listed in the following table can all be purchased from the market.

[0050] The testing process is as follows: First, assemble and connect the components: according to the raw materials shown in Table 1, prepare 10 single cells of membrane electrode models A, B and C respectively; 4 single cells of pseudo membrane electrode (without catalyst layer and proton exchange membrane); Figure 2The test stack 1 is assembled in the manner shown, by setting the airbag pressure to be consistent with the pressure of the actual stack in use; connecting the CVM channel and the EIS channel of the stack to obtain the CVM signal and the EIS signal; placing the test stack on the stack test bench, and activating the stack according to the enterprise's internal control standard procedures to achieve a fully activated state.

[0051] Then, the load reduction polarization test was carried out according to the following current densities: 3, 2.5, 2.1, 1.5, 1.3, 1.1, 0.9, 0.7, 0.5, 0.3, 0.1, 0.05, 0.02, 0.01, 0.005, the unit is A / cm 2 , and the current density is 0.1A / cm 2 When the current density is less than 0.1A / cm 2 The load is reduced every 1 minute; at the same time, the CVM value, EIS value and HFR value of each polarization current point are collected.

[0052] The collected temperature, pressure, current, CVM value of each channel, and HFR high-frequency impedance value of each channel are input into the polarization loss analysis module. The number of membrane electrode samples, the corresponding CVM channel and EIS channel are set. The polarization loss analysis module processes the data based on the calculation method described above, separates the three polarization curves, and the corresponding activation polarization loss (including leakage current loss), ohmic polarization loss, and concentration polarization loss, and obtains the following: Figures 3 to 6 The graph shown.

[0053] from Figures 3 to 6 The polarization curves and polarization loss curves of the three membrane electrodes shown can be seen: In terms of polarization performance: membrane electrode C (high activity + 8um membrane) ≥ membrane electrode B (high activity + 15um membrane) > membrane electrode A (low activity + 15um membrane); In terms of activation polarization voltage loss: membrane electrode A> membrane electrode B= membrane electrode C; In terms of ohmic polarization voltage loss: membrane electrode A = membrane electrode B > membrane electrode C; In terms of concentration polarization voltage loss: membrane electrode A = membrane electrode B > membrane electrode C; In summary, membrane electrode C can show higher performance among the three, mainly because the ohmic loss, activation loss and concentration loss are all the smallest. Compared with membrane electrode A, membrane electrode B uses a highly active catalyst and its performance is relatively good. Compared with the traditional use of small samples for membrane electrode performance screening tests, the test method of this application can greatly improve the test efficiency and shorten the material selection cycle. Compared with the traditional small sample screening test, it can save at least two weeks of development time and greatly improve the efficiency of product iteration.

[0054] Through the above description of the specific embodiments, it can be known that the fuel cell testing system provided by the present invention arranges a variety of different types of test cells in the same test stack 1, so that the test environments of different types of test cells are basically the same, and the performance parameters of multiple test cells can be obtained at one time. Since the multiple test cells are in the same test environment, the problem of incomparability of performance parameters caused by differences in the assembled test environments is eliminated, so that the comparison of performance parameters is more effective and reliable, which is conducive to improving the efficiency of membrane electrode selection and the development efficiency of fuel cells. The fuel cell testing method provided by the present invention proposes a calculation method for quantitatively decomposing the polarization performance of the test cell, which can analyze and compare the three major polarization losses of activation polarization loss, ohmic polarization loss, and concentration polarization loss one by one, which has important and clear guiding significance for identifying the performance differences of membrane electrodes and determining the material selection and improvement direction of membrane electrodes.

[0055] The present invention is described by several specific embodiments, and it should be understood by those skilled in the art that various changes and equivalent substitutions may be made to the present invention without departing from the scope of the present invention. In addition, various modifications may be made to the present invention for specific situations or specific circumstances without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed, but should include all implementation methods falling within the scope of the claims of the present invention.

Claims

1. A fuel cell testing system, comprising a test stack and a test analysis device, wherein the test analysis device is connected to the test stack to detect the performance of the test stack, characterized in that: The test stack includes two end plates, two or more test cells arranged between the two end plates, and a dummy cell arranged between two adjacent test cells; the test analysis device is connected to the two or more test cells respectively to obtain performance parameters of different types of test cells in the same test stack.

2. The fuel cell testing system according to claim 1, characterized in that: The dummy cell is also arranged between the two end plates and the test cell adjacent to the two end plates.

3. The fuel cell testing system according to claim 1 or 2, characterized in that: The pseudo single cell includes a pseudo bipolar plate through which reaction gas does not flow and a pseudo membrane electrode without a CCM layer.

4. The fuel cell testing system according to claim 1, characterized in that: The testing system comprises a pressure applying device for applying pressure to the two end plates, and the pressure applying device uses an air bag to apply pressure.

5. The fuel cell testing system according to claim 1, characterized in that: The number of each test cell shall not be less than 3 pieces, and the number of all test cells shall not exceed 50 pieces.

6. A fuel cell testing method, characterized in that: The testing method is applied to a fuel cell testing system as described in any one of claims 1 to 5, wherein the testing and analysis device comprises a CVM module, an EIS module and a polarization loss analysis module respectively connected to the two or more test cells; the testing method comprises: obtaining performance parameters of the two or more test cells, and analyzing to obtain polarization loss performance of different types of test cells in the same test stack.

7. The fuel cell testing method according to claim 6, characterized in that: The analysis results in the following polarization loss performances of different types of test cells in the same test stack: Calculate the leakage current polarization loss η_cross, η_cross=E_rev-E_ocv; Calculate the activation polarization loss η_act, η_act=E_ocv-(a*Ln(j)+b); Calculate the ohmic polarization loss η_ohm, η_ohm=j*HFR; Calculate the concentration polarization loss η_conc, η_conc=(E_ocv-η_act)-(η_ohm+U); Wherein, E_rev is the reversible potential, E_ocv is the measured open circuit voltage, HFR is the average high-frequency impedance value of the test cell, j is the current density, a and b are Tafel constants, and U is the average voltage of the test cell.

8. The fuel cell testing method according to claim 7, characterized in that: The test method comprises: gradually reducing the current density of the test cell, and calculating the polarization loss value at each current density, wherein at each current density, the temperature, flow rate and pressure of the test stack are maintained within a constant range.

9. The fuel cell testing method according to claim 8, characterized in that: The test method includes: setting the current density to ≤0.1A / cm 2 The number of test points is no less than four, and the activation polarization loss is calculated at these test points.

10. The fuel cell testing method according to claim 6 or 7, characterized in that: The test stack is activated before the test so that the performance parameters of the test cell are obtained when the test stack operates in a stable state.

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