Membrane electrode gas transmission resistance analysis method and device and storage medium

Abstract

The invention relates to a membrane electrode gas transmission resistance analysis method and device and a storage medium. The method comprises the following steps: acquiring a limit concentration current density set corresponding to a plurality of test temperatures; each limit concentration current density, the test temperature corresponding to each limit concentration current density, the test pressure corresponding to each limit concentration current density and the fixed test parameters are input into a preset total transmission resistance calculation model corresponding to the target gas for resistance value analysis processing, and a total transmission resistance set corresponding to the multiple test temperatures is obtained; performing fitting processing on the pressure and total resistance relation curves corresponding to the plurality of test temperatures to obtain a pressure and total resistance fitting curve; and determining the first target transmission resistance of the target gas in the runner of the target membrane electrode and the carbon paper base material under the target pressure condition based on the curve slope value of the pressure and total resistance fitting curve. The transmission capacity of the target gas in the membrane electrode runner and the carbon paper can be quantitatively analyzed, and performance development of the membrane electrode is facilitated.

Description

Technical Field

[0001] The present disclosure relates to the field of fuel cell technology, and in particular to a membrane electrode gas transmission resistance analysis method, device, storage medium and electronic equipment. Background Art

[0002] As the core power generation component in fuel cells, the performance of membrane electrodes is an absolute reflection of the power generation capacity of fuel cells. The power generation capacity of current membrane electrodes is mainly expressed by polarization performance, but in the development process of membrane electrodes, many factors will affect its performance. For example, in the electrochemical reaction of membrane electrodes, there will be resistance to the transmission of oxygen in the flow channel, gas diffusion layer, and catalyst layer. In particular, in the resin of the catalyst layer, the adsorption force between the sulfonic acid group and platinum (Platinum, Pt), and the water layer on the surface of Pt under high electric density will seriously hinder the transmission of oxygen, increase the polarization loss of membrane electrode mass transfer, and reduce its final performance. Summary of the invention

[0003] In order to solve at least one of the technical problems mentioned above, the present disclosure proposes a membrane electrode gas transport resistance analysis method, device, storage medium and electronic device.

[0004] According to one aspect of the present disclosure, a membrane electrode gas transport resistance analysis method is provided, comprising:

[0005] Obtaining a set of limiting concentration current densities corresponding to multiple test temperatures of a target gas in a target membrane electrode and fixed test parameters corresponding to the set of limiting concentration current densities, wherein the set of limiting concentration current densities includes limiting concentration current densities corresponding to multiple test pressures, and the limiting concentration current density is used to characterize the current density when the target gas is completely consumed under the conditions of the test temperature and the test pressure;

[0006] Input each limiting concentration current density, the test temperature corresponding to each limiting concentration current density, the test pressure corresponding to each limiting concentration current density and the fixed test parameters into the preset total transmission resistance calculation model corresponding to the target gas to perform resistance value analysis and processing, and obtain the total transmission resistance set corresponding to the multiple test temperatures;

[0007] Fitting the pressure-total resistance relationship curves corresponding to the multiple test temperatures to obtain a pressure-total resistance fitting curve, wherein the pressure-total resistance relationship curve is determined by the total transmission resistance set;

[0008] The first target transmission resistance of the target gas in the flow channel of the target membrane electrode and the carbon paper substrate under the target pressure condition is determined based on the curve slope value of the pressure and total resistance fitting curve.

[0009] In some possible implementations, the multiple test temperatures are determined based on a preset temperature range and a preset temperature difference, the multiple test pressures are determined based on a preset pressure range and a preset pressure difference, and the method further includes:

[0010] Obtaining an intake air temperature and a gas flow rate corresponding to the target gas, wherein the intake air temperature is kept at the same temperature as the test temperature;

[0011] Based on the fixed test parameters, the intake temperature, the gas flow rate, each test temperature and each test pressure corresponding to each test temperature, a gas complete consumption experiment is performed on the target gas to obtain a set of limiting concentration current densities corresponding to each test temperature;

[0012] The limiting concentration current density set corresponding to the multiple test temperatures is determined based on the limiting concentration current density set corresponding to each test temperature.

[0013] In some possible implementations, the method further includes:

[0014] The pressure-resistant transmission resistance corresponding to each test temperature is determined based on the intersection of the pressure-total resistance relationship curve corresponding to each test temperature and the coordinate axis Y axis. The pressure-resistant transmission resistance is used to characterize the sum of the second target transmission resistance and the third target transmission resistance. The second target transmission resistance is used to characterize the transmission resistance of the target gas in the microporous layer and the pore size of the catalytic layer of the target membrane electrode. The third target transmission resistance is used to characterize the transmission resistance of the target gas in the catalytic layer resin of the target membrane electrode.

[0015] In some possible implementations, the method further includes:

[0016] Determine a target pressure transmission resistance corresponding to a plurality of target test temperatures, wherein the target pressure transmission resistance is determined by an intersection of the pressure-total resistance relationship curve and a coordinate axis Y, and the plurality of target test temperatures are determined based on the plurality of test temperatures;

[0017] Based on the multiple target test temperatures, the target pressure transmission resistance and diffusion resistance calculation models corresponding to the multiple target test temperatures, equations are solved to obtain a first constant and a second constant in the diffusion resistance calculation model, and the diffusion resistance calculation model is:

[0018] R0=xT -1 / 2 +yT -1 e 17200 / RT (1)

[0019] Wherein, R0 is the pressure transmission resistance, x is the first constant, y is the second constant, T is the battery temperature, the temperature unit is Fahrenheit, xT-1 / 2 is the transport resistance in the pores of the microporous layer and the catalyst layer, yT -1 e 17200 / RT is the transmission resistance in the catalyst layer resin;

[0020] A resistance value analysis is performed based on the compressive transmission resistance at the target temperature, the first constant, the second constant and the diffusion resistance calculation model to obtain the second target transmission resistance and the third target transmission resistance under the target temperature condition.

[0021] In some possible implementations, the method further includes:

[0022] A preset total transmission resistance calculation model corresponding to the target gas is constructed, and the preset total transmission resistance calculation model is:

[0023]

[0024] Among them, R All is the total transmission resistance, n is the number of transferred electrons, F is the Faraday constant, P is the intake pressure, is the relative humidity, a, b, c, d, f and g are all constants, T is the battery temperature, i is the limiting concentration current density, R is the universal gas constant, and λ is the mole fraction of the target gas.

[0025] In some possible implementations, constructing a preset total transmission resistance calculation model corresponding to the target gas includes:

[0026] The calculation formula of the diffusion flux is determined according to the proportional relationship between the concentration gradient of the target gas in the consumption process and the reactant flux, and the formula is as follows:

[0027]

[0028] Where N is the diffusion flux, D is the component diffusion coefficient, C is the gas inlet concentration, C0 is the gas outlet concentration, x is the diffusion distance, and A is the active area;

[0029] The calculation formula of the diffusion flux is deduced based on the equivalent relationship between the consumption rate of the target gas in a stable state and the diffusion flux, and a proportional relationship formula between the diffusion distance and the diffusion coefficient is obtained, which is as follows:

[0030]

[0031]

[0032] Where I is the reaction current, is the consumption rate;

[0033] According to the relationship between the proportional relationship and the target gas transmission time per unit distance and the proportional relationship formula between the diffusion distance and the diffusion coefficient, a calculation formula for the total transmission resistance when the gas outlet concentration of the target gas is 0 is determined. The total transmission resistance R All The formula is as follows:

[0034]

[0035] The calculation formula of the total transmission resistance is derived according to the relationship between the gas concentration and the gas mole fraction of the target gas and the humidity equivalence relationship to obtain the preset total transmission resistance calculation model. The humidity equivalence relationship is used to characterize the equivalence relationship between the ratio of the water partial pressure to the saturation pressure and the relative humidity.

[0036] In some possible implementations, the calculation formula of the total transmission resistance is derived according to the relationship between the gas concentration and the gas mole fraction of the target gas and the humidity equivalent relationship to obtain the preset total transmission resistance calculation model, including:

[0037] The relationship between the total transmission resistance and the pressure, the water partial pressure and the gas mole fraction is determined according to the relationship between the gas concentration and the gas mole fraction. The formula is as follows:

[0038]

[0039] Where, P is the intake pressure; P W It is water partial pressure;

[0040] The preset total transmission resistance calculation model is determined based on the relationship between the total transmission resistance and the pressure, the water partial pressure and the mole fraction and the humidity equivalence relationship.

[0041] According to a second aspect of the present disclosure, a membrane electrode gas transmission resistance analysis device is provided, the device comprising:

[0042] A parameter acquisition module, used to obtain a set of limiting concentration current densities corresponding to multiple test temperatures of a target gas in a target membrane electrode and fixed test parameters corresponding to the set of limiting concentration current densities, wherein the set of limiting concentration current densities includes limiting concentration current densities corresponding to multiple test pressures, and the limiting concentration current density is used to characterize the current density when the target gas is completely consumed under the conditions of the test temperature and the test pressure;

[0043] A total transmission resistance determination module, used for inputting each limiting concentration current density, the test temperature corresponding to each limiting concentration current density, the test pressure corresponding to each limiting concentration current density and the fixed test parameters into a preset total transmission resistance calculation model corresponding to the target gas to perform resistance value analysis and processing, and obtain a total transmission resistance set corresponding to the multiple test temperatures;

[0044] A fitting module, used for fitting the pressure and total resistance relationship curves corresponding to the multiple test temperatures to obtain a pressure and total resistance fitting curve, wherein the pressure and total resistance relationship curve is determined by the total transmission resistance set;

[0045] The target transmission resistance determination module is used to determine the first target transmission resistance of the target gas in the flow channel of the target membrane electrode and the carbon paper substrate under the target pressure condition based on the curve slope value of the pressure and total resistance fitting curve.

[0046] According to a third aspect of the present disclosure, an electronic device is provided, comprising at least one processor and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the at least one processor implements the membrane electrode gas transmission resistance analysis method as described in any one of the first aspects by executing the instructions stored in the memory.

[0047] According to a fourth aspect of the present disclosure, a computer-readable storage medium is provided, in which at least one instruction or at least one program is stored, and the at least one instruction or at least one program is loaded and executed by a processor to implement the membrane electrode gas transport resistance analysis method as described in any one of the first aspects.

[0048] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

[0049] The implementation of this disclosure has the following beneficial effects:

[0050] Obtain a set of limiting concentration current densities corresponding to multiple test temperatures of the target gas in the target membrane electrode and fixed test parameters corresponding to the limiting concentration current density set, the limiting concentration current density set includes limiting concentration current densities corresponding to multiple test pressures, and the limiting concentration current density is used to characterize the current density when the target gas is completely consumed under the test temperature and test pressure conditions; input each limiting concentration current density, the test temperature corresponding to each limiting concentration current density, the test pressure corresponding to each limiting concentration current density, and the fixed test parameters into a preset total transmission resistance calculation model corresponding to the target gas for resistance value analysis and processing, and obtain a total transmission resistance set corresponding to multiple test temperatures; fit the pressure and total resistance relationship curves corresponding to the multiple test temperatures to obtain a pressure and total resistance fitting curve, and the pressure and total resistance relationship curve is determined by the total transmission resistance set; determine the first target transmission resistance of the target gas in the flow channel of the target membrane electrode and the carbon paper substrate under the target pressure condition based on the curve slope value of the pressure and total resistance fitting curve. The transmission of target gas in the flow channel and carbon paper substrate is affected by intermolecular diffusion and Fick's law. Therefore, the total transmission resistance is calculated using the limiting concentration current density under multiple test pressure conditions corresponding to multiple test temperatures, and the pressure-total resistance relationship curve corresponding to the total transmission resistance set at multiple test temperatures is fitted. This helps to reflect the difference between intermolecular diffusion and Fick diffusion, thereby determining the transmission resistance in the flow channel and carbon paper substrate under the target pressure, and achieving quantitative analysis of the transmission capacity of the target gas in the membrane electrode flow channel and carbon paper matching, which is beneficial to the performance development of the membrane electrode.

[0051] Further features and aspects of the present disclosure will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the technical solution of the present application, the following is a brief introduction to the drawings required for use in the embodiments or prior art descriptions. Obviously, the drawings described below are only some embodiments of the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0053] Figure 1 A schematic flow chart showing a method for analyzing membrane electrode gas transmission resistance according to an embodiment of the present disclosure;

[0054] Figure 2 A coordinate schematic diagram showing a relationship curve between total transmission resistance and test pressure corresponding to multiple test temperatures according to an embodiment of the present disclosure;

[0055] Figure 3 A schematic diagram showing a flow chart of a method for determining a set of limiting concentration current densities according to an embodiment of the present disclosure;

[0056] Figure 4 A coordinate schematic diagram showing a current density and voltage relationship curve corresponding to a test temperature of 50 degrees according to an embodiment of the present disclosure;

[0057] Figure 5 A coordinate diagram showing a current density and voltage relationship curve corresponding to a test temperature of 60 degrees according to an embodiment of the present disclosure;

[0058] Figure 6 A coordinate diagram showing a current density and voltage relationship curve corresponding to a test temperature of 70 degrees according to an embodiment of the present disclosure;

[0059] Figure 7 A coordinate diagram showing a current density and voltage relationship curve corresponding to a test temperature of 80 degrees according to an embodiment of the present disclosure;

[0060] Figure 8 A schematic diagram showing a flow chart of a method for determining a second target transmission resistance and a third target transmission resistance according to an embodiment of the present disclosure;

[0061] Fig. 9 A schematic diagram showing a flow chart of a method for inferring a preset total transmission resistance calculation model according to an embodiment of the present disclosure;

[0062] Fig.10 A schematic diagram showing a flow chart of a method for reasoning a preset total transmission resistance calculation model adapted to basic experimental data according to an embodiment of the present disclosure;

[0063] Fig.11 A schematic structural diagram of a membrane electrode gas transmission resistance analysis device according to an embodiment of the present disclosure is shown;

[0064] Fig.12 A block diagram of an electronic device according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0065] The following will be combined with the drawings in the embodiments of this specification to clearly and completely describe the technical solutions in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0066] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product, or server that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products, or devices.

[0067] Various exemplary embodiments, features and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise specified.

[0068] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0069] The term "and / or" herein is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the term "at least one" herein represents any combination of at least two of any one or more of a plurality of. For example, including at least one of A, B, and C can represent including any one or more elements selected from the set consisting of A, B, and C.

[0070] In addition, in order to better illustrate the present disclosure, numerous specific details are given in the following specific embodiments. It should be understood by those skilled in the art that the present disclosure can also be implemented without certain specific details. In some examples, methods, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present disclosure.

[0071] Figure 1 A schematic diagram of a flow chart of a membrane electrode gas transmission resistance analysis method according to an embodiment of the present disclosure is shown, as shown in FIG. Figure 1 As shown, the above method includes:

[0072] S101, obtaining a set of limiting concentration current densities corresponding to multiple test temperatures of a target gas in a target membrane electrode and fixed test parameters corresponding to the set of limiting concentration current densities, wherein the set of limiting concentration current densities includes limiting concentration current densities corresponding to multiple test pressures, and the limiting concentration current density is used to characterize the current density when the target gas is completely consumed under the test temperature and test pressure conditions;

[0073] The target membrane electrode can be the core power generation component in a hydrogen fuel cell. The present application is also applicable to other components with similar structures to the membrane electrode, such as internal combustion engines, in addition to the membrane electrode. The target gas can be any reaction gas in the membrane electrode. Exemplarily, the target gas is oxygen. In other embodiments, the target gas can also be hydrogen, which is not limited here. The test temperature is used to characterize the battery temperature when the target gas is subjected to a complete gas consumption experimental analysis, and the test pressure is used to characterize the intake pressure when the target gas is subjected to a complete gas consumption experimental analysis. The set of limiting concentration current densities corresponding to multiple test temperatures is obtained based on multiple test temperatures, multiple test pressures, fixed test parameters, the intake temperature corresponding to the target gas, and the gas flow rate for conducting a complete gas consumption experimental analysis on the target gas. The set of limiting concentration current densities includes limiting concentration current densities corresponding to multiple test pressures. Fixed test parameters include, but are not limited to, relative humidity and target gas mole fraction. Solid test parameters are used to characterize fixed parameters when conducting a complete gas consumption experiment on the target gas.

[0074] In some embodiments, a set of limiting concentration current densities corresponding to multiple test temperatures of oxygen in the target membrane electrode and a set of limiting concentration current densities obtained by performing a complete gas consumption experiment on oxygen are obtained, and some fixed variables, namely fixed test parameters, are input. The limiting concentration current density set includes limiting concentration current densities corresponding to multiple test pressures, and the limiting concentration current density is used to characterize the current density when oxygen is completely consumed under the test temperature and test pressure conditions. Fixed test parameters include, but are not limited to, relative humidity and oxygen mole fraction in the battery. The test temperature is the battery temperature, and the test pressure is the oxygen intake pressure.

[0075] S102, inputting each limiting concentration current density, the test temperature corresponding to each limiting concentration current density, the test pressure corresponding to each limiting concentration current density and the fixed test parameters into a preset total transmission resistance calculation model corresponding to the target gas to perform resistance value analysis and processing, and obtain a total transmission resistance set corresponding to multiple test temperatures;

[0076] The fixed test parameters, each limiting concentration current density in the limiting concentration current density set corresponding to each test temperature in the limiting concentration current density set corresponding to multiple test temperatures, the test pressure corresponding to each limiting concentration current density, and the preset total transmission resistance calculation model corresponding to each test temperature input target gas are subjected to resistance value analysis and processing to obtain the total transmission resistance set corresponding to multiple test temperatures, and the total transmission resistance set includes the total transmission resistance corresponding to multiple test pressures. The limiting concentration current density set corresponding to multiple test temperatures and the total transmission resistance set corresponding to multiple test temperatures are in a one-to-one correspondence, and the limiting concentration current density in the limiting concentration current density set corresponding to multiple test temperatures and the total transmission resistance in the total transmission resistance set corresponding to multiple test temperatures are also in a one-to-one correspondence. The preset total transmission resistance calculation model is used to characterize the relationship model between the total transmission resistance, intake pressure, battery temperature, relative humidity, limiting concentration current density and gas mole fraction of the target gas.

[0077] In some embodiments, a set of limiting concentration current densities corresponding to multiple test temperatures are obtained by conducting a gas complete consumption experiment on oxygen at multiple test temperatures and multiple test pressures under each test temperature condition. The set of limiting concentration current densities corresponding to each test temperature includes limiting concentration current densities corresponding to multiple test pressures. Each limiting concentration current density in the set of limiting concentration current density corresponding to each test temperature among the multiple test temperatures, the test pressure corresponding to each limiting concentration current density, each test temperature, and fixed test parameters are input into a preset total transmission resistance calculation model corresponding to oxygen to calculate the resistance value, so as to obtain a set of total transmission resistances corresponding to the multiple test temperatures of oxygen.

[0078] S103, fitting the pressure and total resistance relationship curves corresponding to the multiple test temperatures to obtain a pressure and total resistance fitting curve, where the pressure and total resistance relationship curve is determined by the total transmission resistance set;

[0079] The total transmission resistance is linearly related to the intake pressure. The total transmission resistance set corresponding to each test temperature in the multiple test temperatures is plotted on the coordinate axis with the intake pressure as the X-axis and the total transmission resistance as the Y-axis to obtain the pressure and total resistance relationship curves corresponding to the multiple total transmission resistance sets. It is stated here that the curve does not completely refer to a curved line, but can also be a straight line. Here, the relationship curve is used to characterize the relationship diagram in the coordinate system. The pressure and total resistance relationship curves corresponding to the multiple test temperatures are fitted to obtain the pressure and total resistance fitting curves.

[0080] In some embodiments, the total transmission resistance corresponding to different test temperatures and different test pressures is brought in, and the relationship curve between the test pressure and the total transmission resistance corresponding to different test temperatures is plotted and fitted to obtain a fitting formula. The multiple test temperatures for the complete consumption experiment of oxygen gas are 50 degrees, 60 degrees, 70 degrees and 80 degrees, respectively, wherein the unit of the test temperature is degrees Celsius, abbreviated as degrees, and the multiple test pressures are 50 kPa, 100 kPa, 150 kPa and 200 kPa, respectively, and the unit of the test pressure is kPa. Each test pressure in the total transmission resistance set corresponding to each test temperature in the multiple test temperatures and the total transmission resistance corresponding to each test pressure are plotted in a coordinate axis with the intake pressure as the X-axis and the total transmission resistance as the Y-axis, as shown in FIG. Figure 2 As shown, four pressure-total resistance relationship curves corresponding to 50 degrees, 60 degrees, 70 degrees and 80 degrees are obtained. R0 is proportional to pressure, indicating that no water condensation occurs during the formation of limiting current. R0 tends to decrease with the increase of test temperature. The pressure-total resistance relationship curve of 50 degrees is: y=1.2434x+98.532, the pressure-total resistance relationship curve of 60 degrees is: y=1.0591x+95.231, the pressure-total resistance relationship curve of 70 degrees is: y=1.0326x+89.455, and the pressure-total resistance relationship curve of 80 degrees is: y=1.0381x+77.723. The four pressure-total resistance relationship curves corresponding to 50 degrees, 60 degrees, 70 degrees and 80 degrees are fitted, and the pressure-total resistance fitting curve obtained is also the linear relationship between the intake pressure and the total resistance after fitting.

[0081] In some embodiments, in a fuel cell, the resistance that needs to be overcome for oxygen diffusion and reaction is the flow resistance R l , Carbon paper resistance R GDL , Catalytic layer resistance R CL , carbon paper resistance R GDL It is divided into substrate resistance R S and microporous layer resistance R M , where the flow resistance R L and substrate resistance R S Affected by intermolecular diffusion and Fick's law, the resistance of the microporous layer R M and the catalyst layer resistance R CL The pressure has little influence on the oxygen. Therefore, the part with less influence on the oxygen is defined as R0, and the total oxygen transport resistance R in the target membrane electrode can be obtained. All The linear relationship formula with the intake pressure P is:

[0082] R All =R0+R d P (8)

[0083] Among them, R0 is the resistance of the microporous layer which is less affected by pressure. M and the catalyst layer resistance R CL , R d is the intermolecular diffusion resistance coefficient that is easily affected by pressure, P is the target pressure, R d P represents the transmission resistance value of oxygen in the flow channel and the carbon paper substrate.

[0084] S104, determining a first target transmission resistance of the target gas in the flow channel of the target membrane electrode and the carbon paper substrate under the target pressure condition based on the curve slope value of the pressure and total resistance fitting curve.

[0085] In the formula corresponding to the pressure and total resistance fitting curve, the slope value of the curve is R d , its intersection with the vertical axis is R0, and R d Multiplying by the target pressure P, the oxygen transmission resistance corresponding to the flow channel and the carbon paper substrate is obtained.

[0086] The transmission resistance of the target gas in the flow channel of the target membrane electrode and the carbon paper substrate is affected by intermolecular diffusion and Fick's law. The curve slope value can be the intermolecular diffusion resistance coefficient that is susceptible to pressure. The target transmission resistance of the target gas in the flow channel of the target membrane electrode and the carbon paper substrate under the condition of the target pressure is determined according to the curve slope value of the pressure and total resistance fitting curve and the target pressure, that is, the first target transmission resistance. The target pressure is any pressure that meets the preset pressure range.

[0087] In some embodiments, the oxygen pressure and total resistance fitting curve also conforms to the linear relationship of formula (8). Therefore, the first target transmission resistance of the target gas in the flow channel of the target membrane electrode and the carbon paper substrate can be determined according to the product of the curve slope of the oxygen pressure and total resistance fitting curve and the target pressure. The first target transmission resistance is the flow channel resistance R L and substrate resistance R S sum.

[0088] The above technical scheme uses the limiting concentration current density under multiple test pressure conditions corresponding to multiple test temperatures to calculate the total transmission resistance, and fits the pressure and total resistance relationship curve corresponding to the total transmission resistance set at multiple test temperatures, which helps to reflect the difference between intermolecular diffusion and Fick diffusion, thereby determining the transmission resistance in the flow channel and carbon paper substrate under the target pressure, and realizing quantitative analysis of the transmission capacity of the target gas in the membrane electrode flow channel and carbon paper matching, focusing on the transmission state of the target gas in the membrane electrode, and specifically reflecting the gas transmission capacity of the membrane electrode, which is more conducive to the performance development of the membrane electrode.

[0089] See also Figure 3In some embodiments, the plurality of test temperatures are determined based on a preset temperature range and a preset temperature difference, the plurality of test pressures are determined based on a preset pressure range and a preset pressure difference, and the method further comprises:

[0090] S201, obtaining the intake temperature and gas flow rate corresponding to the target gas, wherein the intake temperature and the test temperature are kept at the same temperature;

[0091] S202, performing a gas complete consumption experiment on the target gas based on fixed test parameters, intake temperature, gas flow rate, each test temperature and each test pressure corresponding to each test temperature, to obtain a set of limiting concentration current densities corresponding to each test temperature;

[0092] S203 , determining a set of limiting concentration current densities corresponding to a plurality of test temperatures based on a set of limiting concentration current densities corresponding to each test temperature.

[0093] The test temperature is used to characterize the battery temperature when the target gas is completely consumed experimentally analyzed. The number of test temperatures is greater than or equal to 2. The multiple test temperatures are designed based on the preset temperature difference gradient. The preset temperature range is 50 to 90 degrees. The preset temperature difference is used to characterize the difference between multiple test temperatures. The preset temperature difference is not less than 10 degrees. For example, the preset temperature difference can be 10 degrees. Select multiple test temperatures from the preset temperature range according to the preset temperature difference. The intake temperature is consistent with the battery temperature, that is, the test temperature. If the temperature is too low, the battery performance is poor. If the temperature is too high, the proton membrane glass transition temperature will damage the membrane electrode. The test pressure is used to characterize the intake pressure when the target gas is completely consumed experimentally analyzed. The number of multiple test pressures is greater than or equal to 3. The multiple test pressures are designed based on the preset pressure difference gradient. The preset pressure range is 50 to 200 kPa. The pressure change affects the internal gas concentration. Different pressures help to reflect the differences in intermolecular diffusion and Fick diffusion. The preset pressure difference is used to characterize the difference between multiple test pressures. Exemplarily, the preset pressure difference may be no less than 20 kPa, and exemplary, the preset pressure difference is 50 kPa. Gas pressure is divided into absolute pressure and gauge pressure. The total absolute pressure is the absolute pressure. The gauge pressure is the absolute pressure minus the atmospheric pressure, which is the pressure displayed on a normal pressure gauge. The test pressure is the gauge pressure, which is the total absolute pressure exceeding the surrounding atmospheric pressure.

[0094] Fixed test parameters include but are not limited to relative humidity and the mole fraction of the target gas. The relative humidity ranges from 70 to 100%. If the relative humidity is low, the membrane electrode is too dry. The membrane electrode needs to be kept moist but not blocked by water during the test process. The gas flow rate range is 1 to 3 NLPM at the anode and 3 to 5 NLPM at the cathode. The gas flow rate unit (Normal Liters Per Minute, NLPM) is the flow rate value of the gas per minute under standard conditions. The anode needs to provide excess hydrogen for the reaction. If the cathode flow rate is too low, it is easy to block water. If the flow rate is too high, the membrane electrode will be dried out and the oxygen consumption will be insufficient, making it impossible to form a limiting concentration gradient. The mole fraction range of the target gas is lower than 5%. The higher the concentration, the greater the current density during the test, and the less sufficient the target gas consumption, resulting in inaccurate limiting concentration current density.

[0095] The unit of current density is A / cm 2 The test temperature unit is Celsius °C. When entering the formula, the test temperature needs to be converted into Fahrenheit K. The test pressure unit is Pa.

[0096] In some embodiments, the concentration gradient is obtained by using the difference in oxygen concentration between the inlet and outlet, but the outlet concentration is extremely difficult to obtain. Mass spectrometers are commonly used to analyze the outlet gas components, but mass spectrometers are expensive and difficult to control in precision. Therefore, the design reduces the oxygen concentration so that it is completely consumed internally, and forms a concentration polarization test with an outlet concentration of zero inside the battery, that is, an oxygen complete consumption experiment, to obtain the limiting concentration current density at this concentration. By changing the intake pressure, intermolecular diffusion and Fick diffusion can be affected, and by changing the temperature, resistance that is more affected by temperature and resistance that is less affected by temperature can be distinguished.

[0097] In the process of conducting a gas complete consumption experiment analysis on oxygen using a fuel cell test bench that complies with the national standard GB / T20042.2009 fuel cell test platform, it is necessary to conduct a controlled variable experiment on the oxygen intake pressure, i.e., the test pressure, and the battery temperature, i.e., the test temperature. The specific steps are as follows:

[0098] (1) Set the test temperature, test pressure, intake temperature, relative humidity, gas flow rate and oxygen mole fraction and other parameters, wait for the conditions, and keep the intake temperature consistent with the test temperature;

[0099] (2) Under the gradient corresponding to the preset pressure difference, different test pressures are changed to conduct concentration polarization experiments, i.e., oxygen complete consumption experiments, to obtain a set of limiting concentration current densities corresponding to a test temperature, i.e., limiting concentration current densities corresponding to multiple test pressures at a test temperature. The limiting concentration current density is generally taken as the highest current density point.

[0100] (3) changing the test temperature and repeating step (2) under the gradient corresponding to the preset temperature difference;

[0101] (4) Obtain a set of limiting concentration current densities corresponding to multiple test temperatures.

[0102] In some specific embodiments, the multiple test temperatures include 50 degrees, 60 degrees, 70 degrees and 80 degrees; the multiple test pressures include 50 kPa, 100 kPa, 150 kPa and 200 kPa, and a fuel cell test bench that complies with the fuel cell test platform in the national standard GB / T20042.2009 is used to perform a gas complete consumption experiment analysis on oxygen. When the test temperature is 50 degrees, the oxygen intake temperature is controlled to be 50 degrees, and four gas complete consumption experiments are performed on oxygen at test pressures of 50 kPa, 100 kPa, 150 kPa and 200 kPa, respectively. Figure 4 As shown, the voltage-current density relationship curves for 4 different pressure-concentration polarizations at 50 degrees were obtained, including the voltage-current density relationship curve for 50 kPa concentration polarization at 50 degrees, the voltage-current density relationship curve for 100 kPa concentration polarization at 50 degrees, the voltage-current density relationship curve for 150 kPa concentration polarization at 50 degrees, and the voltage-current density relationship curve for 200 kPa concentration polarization at 50 degrees. Finally, the limiting concentration current density set was obtained when the test temperature was 50 degrees. The limiting concentration current density generally takes the highest point of current density. The limiting concentration current density set includes the limiting concentration current densities corresponding to 50 kPa, 100 kPa, 150 kPa and 200 kPa, respectively. Then, the test temperature was changed to 60 degrees. Similarly, four gas complete consumption experiments were conducted on oxygen at test pressures of 50 kPa, 100 kPa, 150 kPa and 200 kPa, respectively, as shown in FIG. Figure 5 As shown, the voltage-current density relationship curves for polarization at four different pressure concentrations at 60 degrees were obtained; the test temperature was changed to 70 degrees, and similarly, four gas complete consumption experiments were conducted on oxygen at test pressures of 50 kPa, 100 kPa, 150 kPa and 200 kPa, as shown in Figure 6 As shown, the voltage-current density relationship curves for polarization at four different pressure concentrations at 70 degrees were obtained; the test temperature was changed to 80 degrees, and similarly, four gas complete consumption experiments were conducted on oxygen at test pressures of 50 kPa, 100 kPa, 150 kPa and 200 kPa, as shown in Figure 7 As shown, the relationship curves between voltage and current density were obtained at 80 degrees for four different pressure concentration polarizations.

[0103] The above technical scheme designs a basic and simple temperature and pressure gradient according to the resistance relationship of different layers of the membrane electrode, combining the principles of Fick diffusion, intermolecular diffusion, Knudsen diffusion, etc., and conducts complete consumption experiments of the target gas at different temperatures and different pressures. The limiting concentration current density corresponding to the concentration polarization experiment is obtained accurately and quickly, which greatly saves testing resources and facilitates the quantitative analysis of the transmission resistance of the target gas at different positions of the target membrane electrode.

[0104] In some embodiments, the method further comprises:

[0105] The pressure-resistant transmission resistance corresponding to each test temperature is determined based on the intersection of the pressure-total resistance relationship curve corresponding to each test temperature and the coordinate axis Y axis. The pressure-resistant transmission resistance is used to characterize the sum of the second target transmission resistance and the third target transmission resistance. The second target transmission resistance is used to characterize the transmission resistance of the target gas in the microporous layer and the pore size of the catalyst layer of the target membrane electrode. The third target transmission resistance is used to characterize the transmission resistance of the target gas in the catalyst layer resin of the target membrane electrode.

[0106] The resistance of the target gas in the microporous layer and the catalytic layer is less affected by pressure. Therefore, the ordinate value corresponding to the intersection of the pressure and total resistance relationship curve corresponding to each test temperature and the coordinate axis Y is determined as the pressure-resistant transmission resistance. The pressure-resistant transmission resistance includes the second target transmission resistance of the target gas in the microporous layer and catalytic layer pore size of the target membrane electrode and the third target transmission resistance of oxygen in the catalytic layer resin of the target membrane electrode.

[0107] In some embodiments, the pressure and total resistance relationship curve conforms to the linear relationship formula:

[0108] R All =R0+R d P (8)

[0109] From the formula, we can see that R0 is less affected by pressure, while the resistance of oxygen in the microporous layer of the target membrane electrode is R M and the catalyst layer resistance R CL The part that is less affected by pressure is defined as R0, and the ordinate value R0 of the intersection of the pressure-total resistance curve and the Y axis is determined as the pressure-resistant transmission resistance, and the catalyst layer resistance R CL It can be divided into the pore resistance of the catalyst layer and the resistance of the catalyst layer resin. The diffusion of oxygen in the micropores and the pores of the catalyst layer is mainly affected by Knudsen diffusion. Therefore, R0 can be expressed as the Knudsen diffusion resistance R K Resistance R of catalyst layer resin i The sum of Knudsen diffusion resistance R K is the oxygen transmission resistance in the microporous layer and catalyst layer pore size of the target membrane electrode, and the catalyst layer resin resistance R iIt is the transport resistance of oxygen in the catalyst layer resin of the target membrane electrode.

[0110] The above technical scheme utilizes the linear relationship between the pressure and total resistance curve, and quantitatively analyzes the transmission resistance of different parts of the membrane electrode through the degree to which the transmission resistance of the target gas in the membrane electrode is affected by pressure, so as to quickly and accurately determine the resistance of the microporous layer and the catalytic layer which are less affected by pressure.

[0111] See also Figure 8 In some embodiments, the method further comprises:

[0112] S301, determining target pressure transmission resistances corresponding to multiple target test temperatures, where the target pressure transmission resistances are determined by the intersection of a pressure-total resistance relationship curve and a coordinate axis Y, and the multiple target test temperatures are determined based on the multiple test temperatures;

[0113] S302, solving equations based on multiple target test temperatures and target compressive transmission resistance and diffusion resistance calculation models corresponding to the multiple target test temperatures to obtain a first constant and a second constant in the diffusion resistance calculation model, the diffusion resistance calculation model being:

[0114] R0=xT -1 / 2 +yT -1 e 17200 / RT (1)

[0115] Where R0 is the pressure transmission resistance, x is the first constant, y is the second constant, T is the target temperature in degrees Fahrenheit, xT -1 / 2 is the transport resistance in the pores of the microporous layer and the catalyst layer, yT -1 e 17200 / RT is the transmission resistance in the catalyst layer resin, and e is the base of the natural logarithm;

[0116] S303, performing resistance value analysis based on the target temperature, the first constant, the second constant and the diffusion resistance calculation model to obtain a second target transmission resistance and a third target transmission resistance under the target temperature condition.

[0117] Catalytic layer resin resistance R i It is more sensitive to changes in battery temperature, so the second target transmission resistance R corresponding to the pore size of the microporous layer and the catalyst layer can be adjusted by temperature. K The third target transmission resistance R corresponding to the catalyst layer resin i To distinguish. Select several temperatures from multiple test temperatures as target test temperatures, and the number of target test temperatures is greater than or equal to 2. In the formula corresponding to the pressure and total resistance relationship curve, the slope value of the curve is R d The intersection of the vertical axis and the compressive transmission resistance R0 is the sum of the transmission resistance in the microporous layer and the catalytic layer pore size and the transmission resistance in the catalytic layer resin.d Multiplying by the pressure P, we get the oxygen transmission resistance corresponding to the flow channel and the carbon paper substrate. Based on the pressure and total resistance relationship curves corresponding to multiple target test temperatures, we determine the target pressure transmission resistance corresponding to multiple target test temperatures. Substitute the target pressure transmission resistance R0 corresponding to different target test temperatures into formula (1) to get the equation group about the first constant x and the second constant y. Solve the equation to get the coefficient values ​​of x and y. According to the diffusion resistance calculation model and the fact that the diffusion of the target gas in the micropores and the pore size of the catalyst layer is mainly affected by Knudsen diffusion, we get the following formula:

[0118] R K =xT -1 / 2 (9)

[0119] R i =yT -1 e 17200 / RT (10)

[0120] T is the target temperature, which is any temperature within a preset temperature range.

[0121] Substitute the target temperature and the first constant x into formula (9) to calculate the second target transmission resistance R corresponding to the pore size of the microporous layer and the catalyst layer. K , put the target temperature and the second constant y into formula (10) to calculate the third target transmission resistance R corresponding to the catalyst layer resin i .

[0122] In some embodiments, based on the intersection of the pressure-total resistance relationship curve corresponding to the two target test temperatures of oxygen and the coordinate axis Y, the target pressure transmission resistance corresponding to the two target test temperatures is determined, and the two target test temperatures and the target pressure transmission resistance corresponding to the two target test temperatures are substituted into formula (1) to obtain a set of two-variable linear equations about the first constant x and the second constant y. The two-variable linear equations are solved to obtain the first constant x and the second constant y. The target temperature and the first constant x are substituted into formula (9) to calculate the second target transmission resistance R corresponding to the pore size of the microporous layer and the catalyst layer of the target membrane electrode. K , substituting the target temperature and the second constant y into formula (10), the third target transmission resistance R corresponding to the catalyst layer resin of the target membrane electrode is calculated. i .

[0123] Determine multiple target temperatures, including 50, 60, 70 and 80 degrees, and calculate the corresponding compressive transmission resistance, second target transmission resistance and third target transmission resistance values ​​corresponding to 50, 60, 70 and 80 degrees, respectively, such as Fig. 9As shown, the relationship curves of the compressive transmission resistance R0 corresponding to 50, 60, 70 and 80 degrees with temperature are drawn respectively, and the second target transmission resistance R corresponding to 50, 60, 70 and 80 degrees K The relationship curve with temperature change and the third target transmission resistance R corresponding to 50, 60, 70 and 80 degrees i The relationship curve with temperature change, as shown in the figure, R0 and R i Changes significantly with temperature, R K The change with temperature is small, R0 decreases with the increase of temperature, while in R0, R K The value has almost no change with temperature, but R i The value decreases significantly with increasing temperature, indicating that the R in R0 can be distinguished by changing the temperature. K and R i .

[0124] The above technical scheme, by differentiating the second target transmission resistance corresponding to the pore size of the microporous layer and the catalyst layer and the third target transmission resistance corresponding to the catalyst layer resin through the change of temperature gradient, quantitatively reflects the oxygen transmission resistance of different components in the membrane electrode, and expands the performance manifestation and development guidance methods in the membrane electrode development process.

[0125] In some embodiments, the method further comprises:

[0126] Construct a preset total transmission resistance calculation model corresponding to the target gas. The preset total transmission resistance calculation model is:

[0127]

[0128] Among them, R All is the total transmission resistance, n is the number of transferred electrons, F is the Faraday constant, P is the intake pressure, is the relative humidity, a, b, c, d, f and g are all constants, T is the battery temperature, i is the limiting concentration current density, R is the universal gas constant, and λ is the mole fraction of the target gas.

[0129] According to the equivalent relationship between the diffusion flux corresponding to the target gas in the target membrane electrode and the consumption rate of the target gas, the equivalent relationship between the ratio of the diffusion distance to the diffusion coefficient and the gas transmission resistance, the relationship between the gas concentration and the gas mole fraction, and the relationship between the ratio of the water partial pressure and the saturation pressure and the relative humidity, a relationship model between the total transmission resistance, the number of transferred electrons, the Faraday constant, the inlet pressure, the relative humidity, the battery temperature, the limiting concentration current density, the universal gas constant and the gas mole fraction is obtained.

[0130] In some embodiments, the preset total transmission resistance calculation model corresponding to oxygen is as follows:

[0131]

[0132] Among them, R All is the total transport resistance of oxygen in the target membrane electrode, n is the number of oxygen transfer electrons, n=4, F is the Faraday constant, P is the inlet pressure, is the relative humidity, a, b, c, d, f and g are all constants, a = -5800.2206; b = 1.3914993; c = -0.048640239; d = 0.41764768 × 10 -4 ; f = -0.14452093; g = 6.5459673; T is the battery temperature, i is the limiting concentration current density, R is the universal gas constant, is the mole fraction of oxygen.

[0133] The total transmission resistance of oxygen in the target membrane electrode can be obtained by bringing the limiting concentration current density obtained from the experiment, the experimental variable parameters test temperature, i.e., battery humidity, test pressure, i.e., intake pressure, relative humidity and oxygen mole fraction in the fixed test parameters, and related constants into the preset total transmission resistance calculation model corresponding to oxygen.

[0134] In the above technical solution, under the condition of fixed mole fraction of target gas, the total transmission resistance corresponding to the corresponding target gas can be obtained by bringing in the test conditions. The test is designed theoretically and the results are calculated using data, which greatly saves test resources and test time.

[0135] See also Fig. 9 In some embodiments, a preset total transmission resistance calculation model corresponding to the target gas is constructed, including:

[0136] S401. Determine a calculation formula for diffusion flux according to the proportional relationship between the concentration gradient of the target gas during consumption and the reactant flux. The formula is as follows:

[0137]

[0138] Where N is the diffusion flux, D is the component diffusion coefficient, C is the gas inlet concentration, C0 is the gas outlet concentration, x is the diffusion distance, and A is the active area;

[0139] S402. The calculation formula of the diffusion flux is deduced based on the equivalent relationship between the consumption rate of the target gas under a stable state and the diffusion flux, and a proportional relationship formula between the diffusion distance and the diffusion coefficient is obtained, which is as follows:

[0140]

[0141]

[0142] Where I is the reaction current, is the consumption rate;

[0143] S403, according to the relationship between the proportional relationship and the target gas transmission time within a unit distance and the proportional relationship formula between the diffusion distance and the diffusion coefficient, determine the calculation formula of the total transmission resistance when the gas outlet concentration of the target gas is 0, the total transmission resistance R All The formula is as follows:

[0144]

[0145] S404. The calculation formula of the total transmission resistance is derived according to the relationship between the gas concentration and the gas mole fraction of the target gas and the humidity equivalence relationship to obtain a preset total transmission resistance calculation model. The humidity equivalence relationship is used to characterize the equivalence relationship between the ratio of the water partial pressure to the saturation pressure and the relative humidity.

[0146] In the electrochemical reaction inside the fuel cell, the consumption of the reactant, i.e., the target gas, on the electrode will form a gradient concentration inside the fuel cell. In this state, concentration polarization will be formed. The concentration gradient and the reactant flux in the concentration polarization process conform to the proportional relationship in Fick's law in the one-dimensional diffusion process. In this way, the calculation formula (3) of the diffusion flux N of the target gas in the consumption process is determined. In a stable state, such as when the target gas consumption state is stable, the consumption rate of the reactant is equal to the diffusion flux, and the equivalent formula (4) of the consumption rate and the diffusion flux N is obtained. According to the calculation formula of the diffusion flux N and the equivalent formula of the consumption rate and the diffusion flux N, the expression formula (5) of the proportional relationship between the diffusion distance and the diffusion coefficient is determined. The proportional relationship between the diffusion distance and the diffusion coefficient is defined as the gas transmission resistance R1, that is, the time required for gas transmission per unit distance. In the cathode reaction of the fuel cell, the total transmission resistance of the target gas is R All By designing the test, the target gas introduced into the fuel cell is completely consumed, and the concentration gradient of oxygen inside the battery can be obtained through the gas inlet concentration of the target gas, forming a concentration polarization test with a gas outlet concentration of 0. The current at this time is the limiting concentration current density, and formula (5) can be transformed into formula (6). Formula (6) is derived based on the relationship between the gas concentration of the target gas and the gas mole fraction, and the equivalent relationship between the ratio of the water partial pressure to the saturation pressure and the relative humidity, to obtain the preset total transmission resistance calculation model.

[0147] In some embodiments, according to the proportional relationship between the concentration gradient of oxygen in the target membrane electrode during the concentration polarization process and the reactant flux in the first-order diffusion process Fick's law, the relationship formula (3) between the diffusion flux of the target gas, the component diffusion coefficient, the gas inlet concentration, the gas outlet concentration, the diffusion distance and the active area is determined; in a stable state, according to the oxygen consumption rate being equal to the diffusion flux, the relationship formula (4) between the reaction current, the number of transferred electrons and the Faraday constant is obtained, and the formula (3) and the formula (4) are combined to obtain the formula (5), and according to the equivalent relationship between the ratio of the diffusion distance to the diffusion coefficient and the time required for gas transmission per unit distance, i.e., the gas transmission resistance, the total transmission resistance calculation formula (6) corresponding to the concentration polarization of oxygen at the outlet concentration of 0 is determined. Finally, according to the relationship between the gas concentration of oxygen and the oxygen mole fraction, and the equivalent relationship between the ratio of the water partial pressure to the saturation pressure and the relative humidity, the formula (6) is derived to obtain the preset total transmission resistance calculation model.

[0148] The above technical solution uses theoretical deduction to derive a calculation method that meets the basic capabilities of a hydrogen fuel laboratory based on the principles of gas diffusion flux and concentration gradient. The results can be obtained by applying given experimental conditions, providing theoretical support to improve the accuracy of experimental results and calculation efficiency.

[0149] See also Fig.10 In some embodiments, the calculation formula of the total transmission resistance is derived based on the relationship between the gas concentration and the gas mole fraction of the target gas and the humidity equivalent relationship to obtain a preset total transmission resistance calculation model, including:

[0150] S4041. Determine the relationship between total transmission resistance and pressure, water partial pressure and gas mole fraction according to the relationship between gas concentration and gas mole fraction. The formula is as follows:

[0151]

[0152] Where, P is the intake pressure; P W It is water partial pressure;

[0153] S4042. Determine a preset total transmission resistance calculation model based on the relationship between the total transmission resistance and pressure, water partial pressure and mole fraction and the humidity equivalence relationship.

[0154] According to the relationship between gas concentration and gas mole fraction, formula (6) is rewritten as the relationship between total transmission resistance and intake pressure, water partial pressure, number of transferred electrons, Faraday constant, limiting concentration current density, universal gas constant, gas mole fraction and battery temperature (7). The humidity equivalent relationship is used to characterize the equivalent relationship between the ratio relationship between water partial pressure and saturation pressure and relative humidity. According to the equivalent relationship between the ratio relationship between water partial pressure and saturation pressure and relative humidity, and the saturation pressure formula at any given temperature of the American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (ASHRAE), the relationship model between total transmission resistance and number of transferred electrons, Faraday constant, intake pressure, relative humidity, limiting concentration current density, universal gas constant, battery temperature and gas mole fraction is obtained, that is, the preset total transmission resistance calculation model.

[0155] In some embodiments, based on formula (6) and the relationship between gas concentration and oxygen mole fraction, the relationship formula (7) between the total transmission resistance of oxygen in the target membrane electrode and the intake pressure, water partial pressure, number of transferred electrons, Faraday constant, limiting concentration current density, universal gas constant, oxygen mole fraction and battery temperature is determined. According to the relationship between the ratio of water partial pressure to saturation pressure and relative humidity, a relationship model (11) between the total transmission resistance and the number of transferred electrons, Faraday constant, intake pressure, relative humidity, limiting concentration current density, universal gas constant, battery temperature, oxygen mole fraction and five constants is obtained, that is, a preset total transmission resistance calculation model corresponding to oxygen.

[0156] The above technical solution, the relationship between gas concentration and gas mole fraction and the humidity equivalence relationship, derives a calculation scheme for the total transmission resistance of the basic capabilities of a hydrogen fuel laboratory, so that the result of the total transmission resistance can be obtained by entering the experimental parameters, which facilitates the disassembly of the total transmission resistance and quantification of it, greatly saving testing resources.

[0157] See also Fig.11 According to a second aspect of the present disclosure, a membrane electrode gas transmission resistance analysis device is provided, the device comprising:

[0158] A parameter acquisition module 10 is used to obtain a set of limiting concentration current densities corresponding to multiple test temperatures of a target gas in a target membrane electrode and fixed test parameters corresponding to the set of limiting concentration current densities, wherein the set of limiting concentration current densities includes limiting concentration current densities corresponding to multiple test pressures, and the limiting concentration current density is used to characterize the current density when the target gas is completely consumed under the test temperature and test pressure conditions;

[0159] The total transmission resistance determination module 20 is used to input each limiting concentration current density, the test temperature corresponding to each limiting concentration current density, the test pressure corresponding to each limiting concentration current density and the fixed test parameters into a preset total transmission resistance calculation model corresponding to the target gas to perform resistance value analysis and processing, and obtain a total transmission resistance set corresponding to multiple test temperatures;

[0160] A fitting module 30 is used to fit the pressure and total resistance relationship curves corresponding to multiple test temperatures to obtain a pressure and total resistance fitting curve, where the pressure and total resistance relationship curve is determined by the total transmission resistance set;

[0161] The target transmission resistance determination module 40 is used to determine the first target transmission resistance of the target gas in the flow channel of the target membrane electrode and the carbon paper substrate under the target pressure condition based on the curve slope value of the pressure and total resistance fitting curve.

[0162] In some embodiments, the plurality of test temperatures are determined based on a preset temperature range and a preset temperature difference, the plurality of test pressures are determined based on a preset pressure range and a preset pressure difference, and the apparatus further comprises:

[0163] An experimental parameter acquisition module is used to obtain the intake temperature and gas flow rate corresponding to the target gas, wherein the intake temperature and the test temperature are kept at the same temperature;

[0164] The gas consumption experiment module is used to perform a gas complete consumption experiment on the target gas based on fixed test parameters, inlet temperature, gas flow rate, each test temperature and each test pressure corresponding to each test temperature, and obtain a set of limiting concentration current density corresponding to each test temperature;

[0165] The limiting concentration current density set determination module is used to determine the limiting concentration current density sets corresponding to multiple test temperatures based on the limiting concentration current density set corresponding to each test temperature.

[0166] In some embodiments, the apparatus further comprises:

[0167] The pressure transmission resistance determination module is used to determine the pressure transmission resistance corresponding to each test temperature based on the intersection of the pressure and total resistance relationship curve corresponding to each test temperature and the coordinate axis Y axis. The pressure transmission resistance is used to characterize the sum of the second target transmission resistance and the third target transmission resistance. The second target transmission resistance is used to characterize the transmission resistance of the target gas in the microporous layer and the pore size of the catalyst layer of the target membrane electrode. The third target transmission resistance is used to characterize the transmission resistance of the target gas in the catalyst layer resin of the target membrane electrode.

[0168] In some embodiments, the apparatus further comprises:

[0169] A target pressure transmission resistance determination module is used to determine the target pressure transmission resistance corresponding to multiple target test temperatures, the target pressure transmission resistance is determined by the intersection of the pressure and total resistance relationship curve and the coordinate axis Y axis, and the multiple target test temperatures are determined based on the multiple test temperatures;

[0170] The constant calculation module is used to solve the equation based on multiple target test temperatures and the target compressive transmission resistance and diffusion resistance calculation models corresponding to the multiple target test temperatures to obtain the first constant and the second constant in the diffusion resistance calculation model. The diffusion resistance calculation model is:

[0171] R0=xT -1 / 2 +yT -1 e 17200 / RT (1)

[0172] Where R0 is the pressure transmission resistance, x is the first constant, y is the second constant, T is the battery temperature in degrees Fahrenheit, xT -1 / 2 is the transport resistance in the pores of the microporous layer and the catalyst layer, yT -1 e 17200 / RT is the transmission resistance in the catalyst layer resin;

[0173] The resistance analysis module is used to analyze the resistance value based on the target temperature, the first constant, the second constant and the diffusion resistance calculation model to obtain the second target transmission resistance and the third target transmission resistance under the target temperature condition.

[0174] In some embodiments, the apparatus further comprises:

[0175] The model building module is used to build a preset total transmission resistance calculation model corresponding to the target gas. The preset total transmission resistance calculation model is:

[0176]

[0177] Among them, R All is the total transmission resistance, n is the number of transferred electrons, F is the Faraday constant, P is the intake pressure, is the relative humidity, a, b, c, d, f and g are all constants, T is the battery temperature, i is the limiting concentration current density, R is the universal gas constant, and λ is the mole fraction of the target gas.

[0178] In some embodiments, the model building module includes:

[0179] The diffusion flux calculation unit is used to determine the calculation formula of the diffusion flux according to the proportional relationship between the concentration gradient of the target gas in the consumption process and the reactant flux. The formula is as follows:

[0180]

[0181] Where N is the diffusion flux, D is the component diffusion coefficient, C is the gas inlet concentration, C0 is the gas outlet concentration, x is the diffusion distance, and A is the active area;

[0182] The diffusion relationship determination unit is used to calculate the calculation formula of the diffusion flux according to the equivalent relationship between the consumption rate of the target gas and the diffusion flux in a stable state, and obtain the proportional relationship formula between the diffusion distance and the diffusion coefficient, which is as follows:

[0183]

[0184]

[0185] Where I is the reaction current, is the consumption rate;

[0186] The total transmission resistance calculation unit is used to determine the total transmission resistance R when the gas outlet concentration of the target gas is 0 based on the relationship between the proportional relationship and the target gas transmission time per unit distance and the proportional relationship formula between the diffusion distance and the diffusion coefficient. All The calculation formula is as follows:

[0187]

[0188] The calculation model determination unit is used to derive the calculation formula of the total transmission resistance according to the relationship between the gas concentration and the gas mole fraction of the target gas and the humidity equivalence relationship to obtain a preset total transmission resistance calculation model. The humidity equivalence relationship is used to characterize the equivalence relationship between the ratio of the water partial pressure to the saturation pressure and the relative humidity.

[0189] In some embodiments, the computing model determining unit includes:

[0190] The first formula derivation unit is used to determine the relationship formula between the total transmission resistance and the pressure, the water partial pressure and the gas mole fraction according to the relationship between the gas concentration and the gas mole fraction. The formula is as follows;

[0191]

[0192] Where, P is the intake pressure; P W It is water partial pressure;

[0193] The second formula derivation unit is used to determine a preset total transmission resistance calculation model based on the relationship between the total transmission resistance and pressure, water partial pressure and mole fraction and the humidity equivalence relationship.

[0194] In some embodiments, the functions or modules included in the device provided by the embodiments of the present disclosure can be used to execute the method described in the above method embodiments. The specific implementation can refer to the description of the above method embodiments, and for the sake of brevity, it will not be repeated here.

[0195] An embodiment of the present application provides a membrane electrode gas transmission resistance analysis device, which may be a terminal or a server. The membrane electrode gas transmission resistance analysis device includes a processor and a memory, in which at least one instruction or at least one program is stored. The at least one instruction or the at least one program is loaded and executed by the processor to implement the membrane electrode gas transmission resistance analysis method provided in the above method embodiment.

[0196] The memory can be used to store software programs and modules. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, application programs required for functions, etc.; the data storage area can store data created according to the use of the device, etc. In addition, the memory can include a high-speed random access memory and can also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other volatile solid-state storage devices. Accordingly, the memory can also include a memory controller to provide the processor with access to the memory.

[0197] The method embodiments provided in the embodiments of the present application can be executed in electronic devices such as mobile terminals, computer terminals, servers or similar computing devices. Fig.12 1 is a hardware structure block diagram of an electronic device for analyzing a membrane electrode gas transmission resistance provided in an embodiment of the present application. Fig.12As shown, the electronic device 900 may have relatively large differences due to different configurations or performances, and may include one or more central processing units (CPU) 910 (the processor 910 may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA), a memory 930 for storing data, and one or more storage media 920 (such as one or more mass storage devices) for storing application programs 923 or data 922. Among them, the memory 930 and the storage medium 920 can be short-term storage or permanent storage. The program stored in the storage medium 920 may include one or more modules, each of which may include a series of instruction operations in the electronic device. Furthermore, the central processing unit 910 can be configured to communicate with the storage medium 920 to execute a series of instruction operations in the storage medium 920 on the electronic device 900. The electronic device 900 may also include one or more power supplies 960, one or more wired or wireless network interfaces 950, one or more input and output interfaces 940, and / or one or more operating systems 921, such as Windows ServerTM, Mac OS XTM, UnixTM, LinuxTM, FreeBSDTM, etc.

[0198] The input / output interface 940 may be used to receive or send data via a network. The specific example of the network may include a wireless network provided by a communication provider of the electronic device 900. In one example, the input / output interface 940 includes a network adapter (Network Interface Controller, NIC), which may be connected to other network devices via a base station so as to communicate with the Internet. In one example, the input / output interface 940 may be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0199] It can be understood by those skilled in the art that Fig.12 The structure shown is only for illustration and does not limit the structure of the above electronic device. Fig.12 More or fewer components as shown, or with Fig.12 Different configurations are shown.

[0200] An embodiment of the present application also provides a computer-readable storage medium, which can be set in an electronic device to store at least one instruction or at least one program related to a membrane electrode gas transmission resistance analysis method in a method embodiment. The at least one instruction or the at least one program is loaded and executed by the processor to implement the membrane electrode gas transmission resistance analysis method provided in the above method embodiment.

[0201] Optionally, in this embodiment, the storage medium may be located in at least one of the multiple network servers of the computer network. Optionally, in this embodiment, the storage medium may include, but is not limited to, various media that can store program codes, such as a USB flash drive, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk, or an optical disk.

[0202] According to one aspect of the present application, a computer program product or a computer program is provided, the computer program product or the computer program comprising computer instructions, the computer instructions being stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device executes the methods provided in the above-mentioned various optional implementations.

[0203] It can be seen from the embodiments of the membrane electrode gas transmission resistance analysis method, device, equipment, terminal, server, storage medium or computer program provided by the present application that the present application obtains a set of limiting concentration current densities corresponding to multiple test temperatures of the target gas in the target membrane electrode and fixed test parameters corresponding to the limiting concentration current density set, the limiting concentration current density set includes limiting concentration current densities corresponding to multiple test pressures, and the limiting concentration current density is used to characterize the current density when the target gas is completely consumed under the test temperature and test pressure conditions; each limiting concentration current density, the test temperature corresponding to each limiting concentration current density, the test pressure corresponding to each limiting concentration current density and the fixed test parameters are input into the preset total transmission resistance calculation model corresponding to the target gas for resistance value analysis and processing, and a total transmission resistance set corresponding to multiple test temperatures is obtained; the pressure and total resistance relationship curves corresponding to multiple test temperatures are fitted to obtain a pressure and total resistance fitting curve, and the pressure and total resistance relationship curve is determined by the total transmission resistance set; based on the curve slope value of the pressure and total resistance fitting curve, the first target transmission resistance of the target gas in the flow channel and the carbon paper substrate of the target membrane electrode under the target pressure condition is determined, and the target pressure is any test pressure among the multiple test pressures. The transmission of target gas in the flow channel and carbon paper substrate is affected by intermolecular diffusion and Fick's law. Therefore, the total transmission resistance is calculated using the limiting concentration current density under multiple test pressure conditions corresponding to multiple test temperatures, and the pressure-total resistance relationship curve corresponding to the total transmission resistance set at multiple test temperatures is fitted. This helps to reflect the difference between intermolecular diffusion and Fick diffusion, thereby determining the transmission resistance in the flow channel and carbon paper substrate under the target pressure, and achieving quantitative analysis of the transmission capacity of the target gas in the membrane electrode flow channel and carbon paper matching, which is beneficial to the performance development of the membrane electrode.

[0204] It should be noted that the above-mentioned sequence of the embodiments of the present application is for description only and does not represent the advantages and disadvantages of the embodiments. The above-mentioned specific embodiments of the present application are described. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0205] Each embodiment in this application is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device, equipment and storage medium embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0206] A person skilled in the art will understand that all or part of the steps to implement the above embodiments may be accomplished by hardware, or may be accomplished by instructing the relevant hardware through a program, and the program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a disk or an optical disk, etc.

[0207] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A membrane electrode gas transmission resistance analysis method, characterized in that: The method comprises: Obtaining a set of limiting concentration current densities corresponding to multiple test temperatures of a target gas in a target membrane electrode and fixed test parameters corresponding to the set of limiting concentration current densities, wherein the set of limiting concentration current densities includes limiting concentration current densities corresponding to multiple test pressures, and the limiting concentration current density is used to characterize the current density when the target gas is completely consumed under the conditions of the test temperature and the test pressure; Input each limiting concentration current density, the test temperature corresponding to each limiting concentration current density, the test pressure corresponding to each limiting concentration current density and the fixed test parameters into the preset total transmission resistance calculation model corresponding to the target gas to perform resistance value analysis and processing, and obtain the total transmission resistance set corresponding to the multiple test temperatures; Fitting the pressure-total resistance relationship curves corresponding to the multiple test temperatures to obtain a pressure-total resistance fitting curve, wherein the pressure-total resistance relationship curve is determined by the total transmission resistance set; The first target transmission resistance of the target gas in the flow channel of the target membrane electrode and the carbon paper substrate under the target pressure condition is determined based on the curve slope value of the pressure and total resistance fitting curve.

2. The method according to claim 1, characterized in that The multiple test temperatures are determined based on a preset temperature range and a preset temperature difference, the multiple test pressures are determined based on a preset pressure range and a preset pressure difference, and the method further includes: Obtaining an intake air temperature and a gas flow rate corresponding to the target gas, wherein the intake air temperature is kept at the same temperature as the test temperature; Based on the fixed test parameters, the intake temperature, the gas flow rate, each test temperature and each test pressure corresponding to each test temperature, a gas complete consumption experiment is performed on the target gas to obtain a set of limiting concentration current densities corresponding to each test temperature; The limiting concentration current density set corresponding to the multiple test temperatures is determined based on the limiting concentration current density set corresponding to each test temperature.

3. The method according to claim 1, characterized in that The method further comprises: The pressure-resistant transmission resistance corresponding to each test temperature is determined based on the intersection of the pressure-total resistance relationship curve corresponding to each test temperature and the coordinate axis Y axis. The pressure-resistant transmission resistance is used to characterize the sum of the second target transmission resistance and the third target transmission resistance. The second target transmission resistance is used to characterize the transmission resistance of the target gas in the microporous layer and the pore size of the catalytic layer of the target membrane electrode. The third target transmission resistance is used to characterize the transmission resistance of the target gas in the catalytic layer resin of the target membrane electrode.

4. The method according to claim 3, characterized in that The method further comprises: Determine a target pressure transmission resistance corresponding to a plurality of target test temperatures, wherein the target pressure transmission resistance is determined by an intersection of the pressure-total resistance relationship curve and a coordinate axis Y, and the plurality of target test temperatures are determined based on the plurality of test temperatures; Based on the multiple target test temperatures, the target pressure transmission resistance and diffusion resistance calculation models corresponding to the multiple target test temperatures, equations are solved to obtain a first constant and a second constant in the diffusion resistance calculation model, and the diffusion resistance calculation model is: R0=xT -1 / 2 +yT -1 e 17200 / RT (1) Wherein, R0 is the pressure transmission resistance, x is the first constant, y is the second constant, T is the battery temperature, the temperature unit is Fahrenheit, xT -1 / 2 is the transport resistance in the pores of the microporous layer and the catalyst layer, yT -1 e 17200 / RT is the transmission resistance in the catalyst layer resin; A resistance value analysis is performed based on the target temperature, the first constant, the second constant, and the diffusion resistance calculation model to obtain the second target transmission resistance and the third target transmission resistance under the target temperature condition.

5. The method according to claim 1, characterized in that The method further comprises: A preset total transmission resistance calculation model corresponding to the target gas is constructed, and the preset total transmission resistance calculation model is: Among them, R All is the total transmission resistance, n is the number of transferred electrons, F is the Faraday constant, P is the intake pressure, is the relative humidity, a, b, c, d, f and g are all constants, T is the battery temperature, i is the limiting concentration current density, R is the universal gas constant, and λ is the mole fraction of the target gas.

6. The method according to claim 5, characterized in that The step of constructing a preset total transmission resistance calculation model corresponding to the target gas includes: The calculation formula of the diffusion flux is determined according to the proportional relationship between the concentration gradient of the target gas in the consumption process and the reactant flux, and the formula is as follows: Where N is the diffusion flux, D is the component diffusion coefficient, C is the gas inlet concentration, C0 is the gas outlet concentration, x is the diffusion distance, and A is the active area; The calculation formula of the diffusion flux is deduced based on the equivalent relationship between the consumption rate of the target gas in a stable state and the diffusion flux, and a proportional relationship formula between the diffusion distance and the diffusion coefficient is obtained, which is as follows: Where I is the reaction current, is the consumption rate; According to the relationship between the proportional relationship and the target gas transmission time per unit distance and the proportional relationship formula between the diffusion distance and the diffusion coefficient, a calculation formula for the total transmission resistance when the gas outlet concentration of the target gas is 0 is determined. The total transmission resistance R All The formula is as follows: The calculation formula of the total transmission resistance is derived according to the relationship between the gas concentration and the gas mole fraction of the target gas and the humidity equivalence relationship to obtain the preset total transmission resistance calculation model. The humidity equivalence relationship is used to characterize the equivalence relationship between the ratio of the water partial pressure to the saturation pressure and the relative humidity.

7. The method according to claim 6, characterized in that The formula for calculating the total transmission resistance is derived based on the relationship between the gas concentration and the gas mole fraction of the target gas and the humidity equivalent relationship to obtain the preset total transmission resistance calculation model, including: The relationship between the total transmission resistance and the pressure, the water partial pressure and the gas mole fraction is determined according to the relationship between the gas concentration and the gas mole fraction. The formula is as follows: Where, P is the intake pressure; P W It is water partial pressure; The preset total transmission resistance calculation model is determined based on the relationship between the total transmission resistance and the pressure, the water partial pressure and the mole fraction and the humidity equivalence relationship.

8. A membrane electrode gas transmission resistance analysis device, characterized in that: The device comprises: A parameter acquisition module, used to obtain a set of limiting concentration current densities corresponding to multiple test temperatures of a target gas in a target membrane electrode and fixed test parameters corresponding to the set of limiting concentration current densities, wherein the set of limiting concentration current densities includes limiting concentration current densities corresponding to multiple test pressures, and the limiting concentration current density is used to characterize the current density when the target gas is completely consumed under the conditions of the test temperature and the test pressure; A total transmission resistance determination module, used for inputting each limiting concentration current density, the test temperature corresponding to each limiting concentration current density, the test pressure corresponding to each limiting concentration current density and the fixed test parameters into a preset total transmission resistance calculation model corresponding to the target gas to perform resistance value analysis and processing, and obtain a total transmission resistance set corresponding to the multiple test temperatures; A fitting module, used for fitting the pressure and total resistance relationship curves corresponding to the multiple test temperatures to obtain a pressure and total resistance fitting curve, wherein the pressure and total resistance relationship curve is determined by the total transmission resistance set; The target transmission resistance determination module is used to determine the first target transmission resistance of the target gas in the flow channel of the target membrane electrode and the carbon paper substrate under the target pressure condition based on the curve slope value of the pressure and total resistance fitting curve.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores at least one instruction or at least one program, and the at least one instruction or at least one program is loaded and executed by the processor to implement the membrane electrode gas transport resistance analysis method as described in any one of claims 1-7.

10. An electronic device, characterized in that: It includes at least one processor and a memory that is communicatively connected to the at least one processor; wherein the memory stores instructions that can be executed by the at least one processor, and the at least one processor implements the membrane electrode gas transmission resistance analysis method as described in any one of claims 1 to 7 by executing the instructions stored in the memory.

Images