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CN-122013250-A - High-performance membrane electrode for electrolyzed water and preparation method and application thereof

CN122013250ACN 122013250 ACN122013250 ACN 122013250ACN-122013250-A

Abstract

The invention relates to the field of fuel cells, in particular to a high-performance membrane electrode for electrolyzed water, a preparation method and application thereof. The membrane electrode comprises a proton exchange membrane and catalytic layers coated on two sides of the proton exchange membrane, wherein the proton exchange membrane comprises a sulfonated polyether sulfone base membrane, a reinforcing layer covering the sulfonated polyether sulfone base membrane and a sulfonated polyether sulfone top layer membrane covering the reinforcing layer, the reinforcing layer is a bulked polytetrafluoroethylene porous membrane, and the catalytic layers contain sulfonated polyether sulfone. Meanwhile, an 'integrated' thermal crosslinking strategy is adopted in the preparation method, so that the ionomer layer and the membrane matrix are crosslinked together, the proton conductivity of the bulk is remarkably improved, and the interface contact resistance is reduced.

Inventors

  • HAO JINKAI
  • WANG BAOAN
  • SHAO ZHIGANG

Assignees

  • 中国科学院大连化学物理研究所

Dates

Publication Date
20260512
Application Date
20260213

Claims (10)

  1. 1. The membrane electrode comprises a proton exchange membrane and catalytic layers coated on two sides of the proton exchange membrane, and is characterized in that the proton exchange membrane comprises a sulfonated polyether sulfone base membrane, a reinforcing layer covering the sulfonated polyether sulfone base membrane and a sulfonated polyether sulfone top layer membrane covering the reinforcing layer, the reinforcing layer is a bulked polytetrafluoroethylene porous membrane, and the catalytic layers contain sulfonated polyether sulfone.
  2. 2. The membrane electrode according to claim 1, wherein the sulfonated polyethersulfone in the proton exchange membrane has a sulfonation degree of 80-99%; the porosity of the expanded polytetrafluoroethylene porous membrane is 30-90%, and the average pore diameter is 100-200nm; the thickness of the sulfonated polyethersulfone basement membrane is 10-50 mu m, the thickness of the reinforcing layer is 3-20 mu m, and the thickness of the sulfonated polyethersulfone top layer membrane is 10-50 mu m.
  3. 3. The membrane electrode assembly of claim 1 wherein the sulfonated polyethersulfones in the catalytic layer each comprise a degree of sulfonation of 60-70%.
  4. 4. The membrane electrode according to claim 1, wherein the anode catalytic layer has a thickness of 5-12 μm and the cathode catalytic layer has a thickness of 3-8. Mu.m.
  5. 5. A method of producing a membrane electrode as claimed in any one of claims 1 to 4, comprising the steps of: S1, dissolving sulfonated polyether sulfone in an alcohol solvent to prepare a casting solution, casting the casting solution on a substrate, and drying to form a sulfonated polyether sulfone substrate film; S2, covering one side of the expanded polytetrafluoroethylene porous membrane wetted by the alcohol solvent on the sulfonated polyethersulfone base membrane obtained in the step S1, casting the casting solution obtained in the step S1 on the other side of the expanded polytetrafluoroethylene porous membrane, and drying to obtain a SPES/PTFE composite primary membrane; S3, preparing cathode catalyst slurry and anode catalyst slurry, and respectively coating the cathode catalyst slurry and the anode catalyst slurry on two sides of the SPES/PTFE composite primary membrane to obtain an initial membrane electrode; S4, performing stepwise heat crosslinking treatment on the initial membrane electrode obtained in the step S4 to obtain the membrane electrode.
  6. 6. The preparation method of claim 5, wherein in the step S1, the mass concentration of the sulfonated polyethersulfone in the casting solution is 2-20wt%; In the step S2, the temperature of the first drying step is 30-60 ℃ and the drying time is 12-15h; the second drying mode is that the drying is carried out for 12h-15h under 50-80 ℃ and then for 12h-15h under 70-120 ℃.
  7. 7. The method according to claim 5, wherein in step S3, the cathode catalyst slurry comprises Pt/C catalyst and sulfonated polyethersulfone solution; The anode catalyst slurry comprises an Ir Black catalyst sulfonated polyethersulfone solution; The mass concentration of the sulfonated polyethersulfone solution is 2-8%; in the anode catalyst slurry, the mass ratio of carbon in the Pt/C catalyst to sulfonated polyether sulfone is 1:0.5-0.8; In the anode catalyst slurry, the mass ratio of the Ir Black catalyst to the sulfonated polyether sulfone is 1:0.5-0.8.
  8. 8. The method of claim 5, wherein in step S3, both the cathode catalyst slurry and the anode catalyst slurry are sprayed on both sides of the SPES/PTFE composite primary membrane, the spraying parameters are that the spraying temperature is 40-60 ℃, the flow rate is 0.1-2mL/min, and the interval is 5-10mm.
  9. 9. The method according to claim 5, wherein in step S4, the step thermal crosslinking treatment is performed in a nitrogen-filled environment, the initial temperature is 120 ℃, the temperature is raised to 180-200 ℃ in steps of 4-8 steps, and each step is kept for 2 hours.
  10. 10. Use of a membrane electrode according to any one of claims 1 to 4 or a membrane electrode produced by a method according to any one of claims 5 to 9 in the electrolysis of medium-high temperature PEM water, said medium-high temperature being in the range of 90 to 140 ℃.

Description

High-performance membrane electrode for electrolyzed water and preparation method and application thereof Technical Field The invention relates to the field of fuel cells, in particular to a high-performance membrane electrode for electrolyzed water, a preparation method and application thereof. Background The high-temperature proton exchange membrane electrolyzed water (ET-PEMWE) can raise the running temperature of PEMWE to 100-200 ℃, can effectively improve the electrode reaction dynamics, reduce the thermodynamic decomposition voltage, reduce the electric energy consumption and the consumption of noble metal catalysts, and is an important development direction of the next-generation green hydrogen production technology. The core component of this technology is the Membrane Electrode Assembly (MEA), which is typically composed of a central proton exchange membrane and anode (oxygen evolution reaction, OER) and cathode (hydrogen evolution reaction, HER) catalyst layers coated on both sides thereof, respectively, and sometimes a current collector or gas diffusion layer. The overall electrochemical reaction process and the transfer of protons, electrons, water, and gases are highly dependent on the structural integrity and functionality of the MEA. However, the low saturated vapor pressure of water vapor under high temperature conditions causes serious water loss of the membrane electrode assembly, the internal resistance of the proton exchange membrane in the membrane electrode assembly is increased, the catalyst layer is dehydrated and contracted, and the gas selective permeability (GTR) can be unbalanced, so that the ohmic overpotential and the concentration polarization are rapidly increased, and the practical application of the technology is restricted. Studies have shown that by increasing the feed pressure to achieve liquid water supply at high temperature conditions, a sufficiently hydrated state of the membrane and catalytic layer can be maintained, thereby significantly improving the electrolytic performance. Therefore, the high temperature and high pressure liquid water condition is considered as an operation mode of the ET-PEMWE with practical application potential. Under the working condition, if a membrane electrode with better electrolysis performance is desired, on one hand, a proton exchange membrane of one of important components in the membrane electrode needs to have high proton conductivity, good thermal mechanical stability and high-pressure liquid water scouring resistance, and on the other hand, the interface between the membrane and the catalytic layer needs to realize low proton transmission resistance. In summary, how to advance the membrane electrode towards the high current density and high efficiency under the high temperature and high pressure working condition, and stable and high efficiency operation is the current research and development focus. Disclosure of Invention The invention aims to provide an electrolyzed water high-performance membrane electrode, a preparation method and application thereof, and an integrated interface structure constructed by jointly thermally crosslinking a membrane matrix and an ionomer is beneficial to improving the continuity of a proton conduction channel and reducing the interface contact resistance of the membrane/the catalyst layer by designing a proton exchange membrane and a catalyst layer, so that the membrane electrode can meet the requirements of high current density and high-efficiency operation under the working condition of high-temperature high-pressure liquid water. In order to achieve the above object, the technical scheme of the present invention is as follows: The invention provides a membrane electrode, which comprises a proton exchange membrane and catalytic layers coated on two sides of the proton exchange membrane, wherein the proton exchange membrane comprises a sulfonated polyether sulfone base membrane, a reinforcing layer covering the sulfonated polyether sulfone base membrane and a sulfonated polyether sulfone top layer membrane covering the reinforcing layer, the reinforcing layer is a bulked polytetrafluoroethylene porous membrane, and the catalytic layers contain sulfonated polyether sulfone. Further, the sulfonation degree of the sulfonated polyethersulfone in the proton exchange membrane is 80-99%; the porosity of the expanded polytetrafluoroethylene porous membrane is 30-90%, and the average pore diameter is 100-200nm; the thickness of the sulfonated polyethersulfone basement membrane is 10-50 mu m, the thickness of the reinforcing layer is 3-20 mu m, and the thickness of the sulfonated polyethersulfone top layer membrane is 10-50 mu m. Further, the sulfonation degree of the sulfonated polyether sulfone in the catalytic layer is 60-70%. Further, the thickness of the anode catalytic layer is 5-12 mu m, and the thickness of the cathode catalytic layer is 3-8 mu m. The second aspect of the present invention provid