Structural Design and Performance Optimization of Proton Exchange Membranes for Water Electrolysis: A Review

Area of Science:

• Materials Science
• Electrochemistry
• Polymer Chemistry

Background:

• Proton exchange membranes (PEMs) are critical components in PEM water electrolysis (PEMWE).
• A key challenge is the trade-off between ionic conductivity and membrane stability.
• Optimizing PEMs is essential for efficient and cost-effective hydrogen production.

Purpose of the Study:

• To review the design and fabrication of homogeneous and composite PEMs for water electrolysis.
• To establish structure-performance relationships for PEMs.
• To provide a framework for designing next-generation PEMs for PEMWE.

Main Methods:

• Systematic illustration of molecular design principles for PEM main chains, side chains, and sulfonate groups.
• Exploration of composite strategies using organic polymers and inorganic nanofillers.
• Analysis of structure-property relationships focusing on proton conductivity, hydrogen permeability, and stability.

Main Results:

• Fluorinated and non-fluorinated PEM designs offer distinct advantages at the molecular level.
• Composite membranes leverage material synergies to enhance mechanical integrity, proton conduction, and chemical resistance.
• Microstructure significantly influences the overall performance of membrane materials.

Conclusions:

• Rational design of PEMs, considering both molecular architecture and macroscopic composite strategies, is crucial.
• Composite approaches offer a promising route to overcome the conductivity-stability trade-off in PEMs.
• Advancements in PEM design are vital for the commercialization of PEM water electrolysis technology.