A review on sulfonated organic polymer based composite membranes for PEM water electrolyzers

Hydrogen is the most effective energy carrier for future applications because it produces no harmful byproducts and is highly efficient. However, numerous obstacles persist in the application of hydrogen, including production, transport, storage, and conversion. Compared with alkaline water electrolysis, which is a well-established technology for water electrolysis, polymer electrolyte membrane water electrolysers (PEMWEs) have made significant advances in terms of quick activation, sensitive to power variation, high working current density, pollution free electrolyte, and less installation space, and their installation capacity was growing in the recent year. This renders technology a promising candidate for large-scale hydrogen production, particularly for energy storage in conjunction with renewable energy sources, an application where PEMWEs offer inherent advantages over alkaline electrolysis. Increasingly high operational current densities have resulted from advancements in PEMWE technology, necessitating mass transport strategies to guarantee adequate reactant supply and product removal. Based on all of this, and for the first time, this review will provide an overview of hydrogen production technologies and discuss their corresponding structures, principles, advantages, and limitations. The current state of knowledge regarding proton exchange membranes that are based on solid polymers with sulfonated and phosphoric acid group and their characterization and diagnosis for PEMWEs, with a focus on the flow channels, liquid-gas diffusion layer, and polymer electrolyte membrane will also be discussed.