Membrane electrode for alkaline water electrolysis for hydrogen production and preparation method therefor, and electrolytic cell
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Solution Overview
Problem
Conventional membrane electrodes for alkaline water electrolysis face high energy consumption due to significant overpotential, and the preparation methods for proton exchange membrane electrolysis are not directly applicable to alkaline water electrolysis due to differences in membrane properties and solvent compatibility.
Innovation Solution
A direct coating and hot pressing method is used to prepare a membrane electrode for alkaline water electrolysis, employing porous membranes and alkaline anion exchange membranes with a catalyst slurry containing a perfluorosulfonic acid resin solution or ionomer dispersion, controlled at specific mass concentrations and ratios, to form uniform and firm catalyst layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a discrete membrane-electrode structure is used in conventional electrolytic cells, then the structure is simple to manufacture, but significant overpotential is generated leading to high energy consumption
Solution Approach 1:
The patent combines the membrane and electrode into an integrated membrane electrode assembly, eliminating the discrete structure. The catalyst layers are directly coated onto the membrane surface, creating a unified structure that reduces interfacial resistance and overpotential, thereby lowering energy consumption while maintaining manufacturing feasibility through direct coating and hot-pressing methods
2Adaptability or versatility
If transfer printing techniques are used for membrane electrode preparation, then the method is suitable for proton exchange membrane water electrolysis, but the solvent causes membrane swelling making direct coating impossible for alkaline water electrolysis
Solution Approach 1:
The patent changes the solvent parameters by using water or water-mixed solvents instead of organic solvents. This parameter change prevents membrane swelling in alkaline conditions while maintaining catalyst slurry coherence, enabling direct coating onto alkaline ion exchange membranes without the swelling issues that plague proton exchange membrane preparation methods
3Strength
If catalyst slurry with high binder solution concentration is used, then the catalyst layer has good adhesion, but the water electrolysis voltage increases reducing efficiency
Solution Approach 1:
The patent optimizes the binder solution concentration parameter, specifying it should be 5-30 mass%. This parameter range achieves the optimal balance where sufficient adhesion is obtained through hot-pressing while maintaining low electrolysis voltage. The controlled concentration prevents excessive binder that would block active sites and increase resistance
4Area of stationary object
If the mass ratio of binder solution to catalyst is too high, then the catalyst layer has good coverage, but the electrolysis voltage increases and energy efficiency decreases
Solution Approach 1:
The patent specifies the mass ratio of binder solution to catalyst should be 1:1 to 4:1. This parameter optimization ensures adequate catalyst layer coverage for effective electrocatalysis while preventing excessive binder content that would increase electrolysis voltage and reduce energy efficiency. The balanced ratio maintains both coverage and electrical performance
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method results in a membrane electrode with enhanced stability and lower water electrolysis voltage, facilitating efficient hydrogen production with improved energy efficiency.
Implementation Method 1
a catalyst slurry containing a perfluorosulfonic acid resin solution or ionomer dispersion, controlled at specific mass concentrations and ratios, to form uniform and firm catalyst layers
Implementation Method 2
A direct coating and hot pressing method is used to prepare a membrane electrode
Implementation Method 3
A direct coating and hot pressing method is used to prepare a membrane electrode
Implementation Method 4
Hydrogen production by water electrolysis represents the most effective approach to developing clean and pollution-free hydrogen energy
Implementation Method 5
the membrane and electrode serve as the core components of the electrolytic cell for alkaline water electrolysis
Data Source
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AI summary
The present disclosure provides a membrane electrode for hydrogen production by alkaline water electrolysis, a preparation method therefor, and an electrolytic cell. According to the method provided by the present disclosure, a membrane electrode with catalyst layers uniformly and firmly adhered to the surfaces of a membrane can be obtained via a direct coating and hot pressing. The membrane electrode is endowed with good stability, and the obtained membrane electrode exhibits a significantly reduced overpotential for water electrolysis. The method comprises the following steps: directly applying a catalyst slurry (catalyst slurries) onto both sides of a membrane, followed by drying and hot pressing the catalyst slurry (catalyst slurries) to form catalyst layers on each surface of the membrane to obtain the membrane electrode. The membrane is selected from a porous membrane or an alkaline anion exchange membrane; the catalyst slurry comprises a binder solution and a catalyst, wherein the binder solution is one or more selected from a perfluorosulfonic acid resin solution and a perfluorosulfonic acid ionomer dispersion, and the mass concentration of the binder solution is 5% to 30%; and the mass ratio of the binder solution to the catalyst is 1:1 to 4:1.