Stability & Kinetics of the Bipolar Membrane Interface: Implications for Electrochemical Technologies

Hybrids of acidic cation exchange membrane (CEM) and alkaline anion exchange membrane (AEM) electrolytes, known as bipolar membrane (BPM), are of interest to a host of electrochemical applications that range from galvanic and electrolytic to electrosynthetic systems. Hindering a more extensive establishment of BPMs into some of these devices are the characteristics of the interface, or junction, between the CEM and AEM materials. This junction must facilitate a low-loss ionic recombination or water dissociation process while also being able to withstand swelling, hydraulic, osmotic, and Maxwell stresses. We show that kinetics and stability of the BPM junction are coupled to the underlying material properties, membrane configuration, and operating conditions. We report material design guidelines as a roadmap for producing robust BPM interfaces.