CN-121997496-A - Design method and preparation process of gradient structure porous transmission layer of AEM electrolytic tank

CN121997496ACN 121997496 ACN121997496 ACN 121997496ACN-121997496-A

Abstract

The invention relates to a design method of a gradient structure porous transmission layer of an AEM electrolytic tank and a preparation process thereof, wherein a set of systematic solution is provided by fusing a logic flow of pore characteristic analysis, model optimization and physical verification aiming at the core service scene problem of influence of the porous transmission layer pore structure of the AEM electrolytic tank on gas and liquid transmission efficiency; the AEM electrolytic cell porous transmission layer prepared by the technical steps is used for depositing non-noble metal on nickel felt or porous nickel, so that the porosity of the porous transmission layer is improved, the contact resistance between the porous transmission layer and a membrane electrode is reduced, the activity of the electrolytic cell is improved, and the purpose of improving the electrolytic cell performance is achieved.

Inventors

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Assignees

江苏凯辰能源有限公司

Dates

Publication Date: 20260508
Application Date: 20260129

Claims (10)

1. A design method of a gradient structure porous transmission layer of an AEM electrolytic tank is characterized by comprising the following steps: Acquiring image data of an initial uniform pore structure of a porous transmission layer by a scanning electron microscope, and analyzing pore size distribution and a porosity value by adopting an image processing algorithm to obtain an initial pore characteristic parameter set; constructing a thickness direction model from the catalytic layer to the flow field plate by adopting a finite element simulation algorithm according to the initial pore characteristic parameter set, simulating gas and liquid transmission paths, and determining the position coordinates of potential blocking areas; If the position coordinates of the potential blocking areas exceed a preset threshold, adjusting pore size parameters in the model to realize continuous gradient distribution from small to large so as to obtain an optimized pore gradient model; Acquiring data curves of gas flow speed and liquid permeability through the optimized pore gradient model, judging whether the data curves meet the ordered transmission requirement, and acquiring a verification result index; according to the verification result index, a three-dimensional printing technology is adopted to generate a porous transmission layer sample, and the porous transmission layer sample is integrated into a gradient pore structure to obtain a physical sample entity; aiming at a physical sample entity, performing electrochemical impedance spectrum test to obtain actual transmission resistance and stability data, and determining a deviation value from a simulation model; if the deviation value is lower than the preset threshold value, integrating the actual transmission resistance and stability data into a finite element simulation algorithm, and updating the pore gradient model parameters to obtain final design scheme data.
2. The method for designing the porous transport layer with the gradient structure of the AEM electrolytic tank according to claim 1, wherein if the position coordinates of the potential blocking area exceed a preset threshold value, the pore size parameter in the model is adjusted to realize continuous gradient distribution from small to large, and an optimized pore gradient model is obtained, and the method comprises the following steps: If the coordinate data of the potential blocking area exceeds a preset threshold value, classifying and sorting the coordinate data through an information processing link to obtain a classified coordinate set; extracting key points related to the pore size by adopting a data screening method according to the classified coordinate set, and determining the distribution range of the key points; Analyzing the change trend of the pore size through the distribution range of the key points, and obtaining the gradient direction of the size change; according to the gradient direction of the size change, adjusting parameter configuration in the model to form a continuous gradient distribution form, and obtaining an adjusted parameter set; constructing a preliminary framework of pore gradients aiming at the adjusted parameter set, and judging whether the distribution in the framework accords with preset gradient conditions; if the distribution in the frame accords with the preset gradient condition, combining the parameter set with the frame through an information integration link to construct an optimized pore gradient model; and generating corresponding distribution data records according to the optimized pore gradient model, and determining a final model structure.
3. The method for designing the porous transmission layer with the gradient structure of the AEM electrolytic tank according to claim 1, wherein the step of obtaining the data curves of the gas flow speed and the liquid permeability through the optimized pore gradient model, judging whether the data curves meet the ordered transmission requirement or not, and obtaining the verification result index comprises the following steps: Acquiring a data curve of gas flow speed and liquid permeability through the optimized pore gradient model, and primarily finishing the data curve to obtain a structured data set; According to the structured data set, carrying out sectional analysis on the data curve by adopting an information processing link, extracting the change characteristics of the gas flow speed and the liquid permeability in different intervals, and determining the distribution mode of the change characteristics; aiming at the distribution pattern of the change characteristics, comparing the ordered transmission standard under the preset condition, and if the distribution pattern deviates from the preset condition, correcting the data set to obtain a corrected data set; According to the corrected data set, acquiring key points related to transmission requirements, analyzing the position distribution of the key points on a data curve, and determining the regularity of the position distribution; Aiming at the regularity of position distribution, an information processing link is adopted to group and sort key points, and if the grouped points meet the transmission requirement, a corresponding matching record is generated to obtain a result set of the matching record; Constructing a verification framework related to ordered transmission by matching the recorded result set, and judging whether the data in the framework meet preset conditions or not to obtain a final verification result index; And generating transmission evaluation data related to gas flow and liquid permeation according to the final verification result index, and determining an integrity record of the transmission evaluation data.
4. The method for designing the porous transmission layer with the gradient structure of the AEM electrolytic tank according to claim 1, wherein the step of generating the porous transmission layer sample by adopting a three-dimensional printing technology according to the verification result index, and integrating the porous transmission layer sample into the gradient pore structure to obtain a physical sample entity comprises the following steps: aiming at the verification result and index data, a data processing tool is adopted to conduct segmented arrangement on the result, a segmented data set is obtained, and the structural characteristics of the data set are determined; according to the segmented data set, classifying and mapping the structural features by adopting an information processing link to obtain classified feature groups; Aiming at the classified feature groups, if the feature groups accord with preset threshold conditions, matching the feature groups with three-dimensional printing technical parameters to obtain matched parameter configuration; generating a digital model suitable for three-dimensional printing by combining the matched parameter configuration with the design schemes of the porous structure and the gradient pore, and obtaining a digital model file; Calling a three-dimensional printing equipment interface according to the digitized model file, converting the model file into an instruction set which can be identified by equipment, and determining the execution sequence of the instruction set; And aiming at the execution sequence of the instruction set, driving the three-dimensional printing equipment to construct a sample, integrating the characteristics of gradient pores and porous structures, and generating a physical entity sample.
5. The method for designing the porous transmission layer of the gradient structure of the AEM electrolytic tank according to claim 1, wherein the step of performing an electrochemical impedance spectrum test on a physical sample entity to obtain actual transmission resistance and stability data and determining a deviation value from a simulation model comprises the steps of: Scanning physical sample entities by adopting electrochemical impedance spectrum testing equipment to obtain impedance spectrum original data; extracting real and imaginary part values aiming at the original data of the impedance spectrum, and calculating to obtain a transmission resistance value and a stability value; carrying out point-by-point subtraction operation on transmission resistance values and stability values and corresponding points of the simulation model data to obtain a deviation value set; sequencing according to the absolute values of all points in the deviation value set, and determining a deviation distribution rule to obtain a main concentrated area; If the absolute value of the deviation corresponding to the main concentrated area exceeds a preset threshold condition, extracting a frequency range corresponding to the area to obtain a frequency segment range; for the frequency range, intercepting a corresponding part from the original data of the impedance spectrum to obtain a screened impedance subset; and recalculating transmission resistance values in the range of the subset according to the screened impedance subset to obtain a local transmission resistance result.
6. The method for designing the porous transmission layer of the gradient structure of the AEM electrolytic tank according to claim 1, wherein if the deviation value is lower than a preset threshold value, integrating actual transmission resistance and stability data into a finite element simulation algorithm, updating pore gradient model parameters to obtain final design scheme data, and the method comprises the following steps: If the deviation value is lower than the preset threshold value, the transmission resistance and the stability value in the actual data are arranged into a structural format through a data importing process, and a data set after arrangement is obtained; according to the sorted data set, adopting a finite element simulation algorithm to carry out parameter adjustment on the pore gradient model, and determining the adjusted model parameter range; Re-calculating the pore gradient through the adjusted model parameter range to obtain optimized gradient distribution data; If the optimized gradient distribution data meets the preset stability condition, matching the data with an initial frame of a design scheme, and judging the scheme consistency after matching; according to the consistency result after matching, carrying out local correction on the design scheme to obtain corrected scheme data; And finally verifying the simulation algorithm through the corrected scheme data to determine the final design scheme output.
7. A preparation process of a gradient structure porous transmission layer of an AEM electrolytic tank is characterized by comprising the following steps: S1, a substrate preparation step, namely cutting a nickel substrate material according to a preset size, and preprocessing to obtain a substrate, wherein the nickel substrate material is nickel felt or porous nickel; S2, preparing an electrolyte, namely dissolving non-noble metal into pure water to obtain a non-noble metal solution, adding a stabilizer into the non-noble metal solution, and stirring to obtain the electrolyte; S3, electrodepositing, namely, taking a substrate as a working electrode, a platinum sheet as a counter electrode and a saturated calomel electrode as a reference electrode, placing the electrode into the electrolyte, depositing non-noble metal on the substrate under preset electrodepositing parameters, and cleaning and airing to obtain a blank; S4, calcining the sample in a tube furnace, and performing post-treatment to obtain an initial product of the AEM electrolytic cell porous transmission layer; And S5, gradient hole etching, namely etching the surface of the initial product of the porous transmission layer of the AEM electrolytic tank by using a focused ion beam to form an array-shaped final product of the porous transmission layer with the gradient structure.
8. The process for preparing the gradient structure porous transmission layer of the AEM electrolytic tank of claim 7, wherein the pretreatment comprises immersing the nickel substrate material in a mixed cleaning solvent of 2-propanol and acetone for 15-20 min in an ultrasonic bath, and washing with deionized water.
9. The process for preparing a gradient structure porous transport layer of an AEM electrolyzer of claim 7, wherein in the electrolyte formulation step, the non-noble metals include at least two of NiCl 2 、CeCl 3 、FeSO 4 and CoCl 2 ; the concentration ranges of NiCl 2 、CeCl 3 、FeSO 4 and CoCl 2 after being dissolved in pure water are respectively in the range of 30-40 g/L, 40-60 g/L, 35-75 g/L and 30-80 g/L.
10. The process for preparing the gradient structure porous transmission layer of the AEM electrolytic tank according to claim 7, wherein the stabilizer is a mixed solution of PUB, BPC and sodium citrate, and the concentrations of the PUB, the BPC and the sodium citrate in the stabilizer are respectively in the range of 6-8 mL/L, 1-3 mL/L and 60-80 g/L.

Description

Design method and preparation process of gradient structure porous transmission layer of AEM electrolytic tank Technical Field The invention relates to the technical field of AEM water electrolysis hydrogen production, in particular to a design method of a gradient structure porous transmission layer of an AEM electrolytic tank and a preparation process thereof. Background AEM electrolyzer is used as a high-efficiency low-cost hydrogen production technology, and plays an important role in the large-scale utilization of renewable energy sources, and the performance of AEM electrolyzer is directly related to the economy and reliability of green hydrogen production. The porous transmission layer is positioned between the catalytic layer and the flow field plate, bears multiple transmission tasks of water, gas and electrons, and is one of core components for determining the overall efficiency and stability of the electrolytic cell. Most porous transmission layers currently employ a uniform pore structure, which design exposes significant drawbacks in practical operation. The area close to the catalytic layer needs to have enough fine pores to ensure uniform distribution of gas and liquid, avoid current non-uniformity and hot spot formation caused by local excessive concentration of reaction, and one side close to the flow field plate needs to have enough pores to quickly discharge a large amount of generated oxygen and unreacted water, so as to prevent blockage of a transmission channel and pressure accumulation. The uniform structure cannot meet the requirements of the two ends which are quite different at the same time, so that the flow paths of substances in the transmission layer are disordered, gas is easy to stay in the pore areas to form bubbles, and liquid is difficult to effectively permeate in the coarse pore areas. The opposite demands of the input and output ends on the pore characteristics form the most central contradiction in the design of the transmission layer, i.e. the pore size must be compatible with both uniform contact and low resistance transmission. Too small pores can significantly increase gas discharge resistance, cause oxygen to accumulate in the transmission layer, cause local water film thickening and reaction sites to be blocked, and too large pores can weaken water film uniformity near the catalytic layer, cause insufficient reactant supply in partial areas and serious uneven current density distribution. The conflict between the two makes the single pore size unable to realize high-efficiency cooperation in the whole thickness direction, and finally limits the long-term stable operation of the electrolytic tank under high current density. How to realize continuous gradient change of the pores from small to large from one side of the catalytic layer to one side of the flow field plate on the porous transmission layer, and simultaneously accurately control the pore diameter range and the porosity value of each position, ensure that gas and liquid can pass orderly according to an expected path without obvious blockage or unbalanced distribution, and become key problems for improving the overall performance of the AEM electrolytic tank. Disclosure of Invention The invention aims to solve the technical problem of providing a design method and a preparation process of a gradient structure porous transmission layer of an AEM electrolytic tank, which can solve the problems that the traditional porous transmission layer with uniform aperture has contradiction between liquid phase reactant and gas phase product discharge, is easy to form air blockage and increases concentration polarization. In order to solve the technical problems, the technical scheme of the invention is that the design method of the gradient structure porous transmission layer of the AEM electrolytic tank is characterized by comprising the following specific steps: Acquiring image data of an initial uniform pore structure of a porous transmission layer by a scanning electron microscope, and analyzing pore size distribution and a porosity value by adopting an image processing algorithm to obtain an initial pore characteristic parameter set; constructing a thickness direction model from the catalytic layer to the flow field plate by adopting a finite element simulation algorithm according to the initial pore characteristic parameter set, simulating gas and liquid transmission paths, and determining the position coordinates of potential blocking areas; If the position coordinates of the potential blocking areas exceed a preset threshold, adjusting pore size parameters in the model to realize continuous gradient distribution from small to large so as to obtain an optimized pore gradient model; Acquiring data curves of gas flow speed and liquid permeability through the optimized pore gradient model, judging whether the data curves meet the ordered transmission requirement, and acquiring a verification result index; accordin