All-in-One Bipolar Membrane Electrode Assembly for Water Electrolysis

Area of Science:

• Electrochemistry
• Materials Science
• Chemical Engineering

Background:

• Water dissociation (WD) at bipolar membrane (BPM) junctions is crucial for efficient green hydrogen production in water electrolyzers.
• Current BPM-integrated membrane electrode assemblies (BPMEAs) suffer from low WD efficiency and poor stability.
• These limitations hinder the practical application of BPMEAs in energy-efficient electrolysis.

Purpose of the Study:

• To develop a novel, convenient fabrication method for all-in-one BPMEAs.
• To enhance water dissociation efficiency and mass transport in BPM electrolyzers.
• To improve the stability and energy efficiency of green hydrogen production.

Main Methods:

• A serial spraying approach was employed to fabricate all-in-one BPMEAs.
• The fabrication method created a wrinkled bipolar junction and integrated membrane/electrode interfaces.
• The performance and durability of the fabricated BPMEAs were evaluated in water electrolysis.

Main Results:

• The developed BPMEA exhibited enhanced WD efficiency and mass transport due to expanded active interfaces and a wrinkled architecture.
• Competitive electrolyzer voltages were achieved: 3.25 V for pure water and 2.69 V for asymmetric acid/alkali electrolysis at 3000 mA cm^-2.
• Significant energy savings of 32% and 23% were realized, respectively. The wrinkled structure also provided improved durability.

Conclusions:

• The serial spraying approach successfully produced all-in-one BPMEAs with enhanced performance and stability.
• The wrinkled bipolar junction architecture is key to improving WD efficiency, mass transport, and durability.
• This fabrication strategy offers a promising pathway for advancing BPM electrolyzers and other electrochemical applications.