Divergent Synthesis of Bipolar Membranes Combining Strong Interfacial Adhesion and High-Rate Capability

Bipolar membranes are emerging as attractive solid electrolytes for water electrolysis, electrochemical CO₂ reduction, and CO₂ capture by base from electrodialysis. The development of these technologies is currently hampered by the resistance of current commercial materials under reversed bias, as well as interfacial incompatibility between the layers that can lead to delamination. This letter reports a divergent route to a nonfluorinated TiO₂-catalyzed bipolar membrane, where the interfacial compatibility is governed by constructing the cation/anion exchange layers from the same backbone chemistry. We show that this BPM design concept has the potential to drastically enhance the adhesion strength at the interfacial junction, without compromising rate capability under bipolar membrane water electrolysis conditions.