A Semi-Interpenetrating Network of a Polycation and Crosslinked Poly(vinyl alcohol) for OH-Conducting Membranes

Applications

This technology is an improved membrane for alkaline electrolysis cells that has applications in industrial hydrogen production.

Problem Addressed

Hydrogen has a wide range of industrial uses, including fertilizer manufacturing and food processing. Currently, most of the world’s hydrogen is harvested using processes that are dependent on fossil fuels. Water electrolysis cells provide a safe, green alternative to traditional hydrogen isolation, however, electrolysis remains an inefficient process. Alkaline water electrolysis cells produce H2 and O2 using two electrodes in a liquid alkaline solution separated by a membrane. Current membrane designs require crosslinking or reinforcing materials to increase the tensile strength of the membrane, however, these reinforcement techniques greatly reduce efficiency by impeding OH- conductivity across the membrane. These inventors have engineered a novel alkaline electrolysis membrane that has both greater strength and OH- conductivity in comparison to traditional membrane materials. 

Technology

This technology is an alkaline electrolysis membrane that maximizes both tensile strength and OH- conductivity. The membrane is composed of a semi-interpenetrating network of crosslinked poly(vinyl alcohol) (PVA) and a polycation (qPPO). This PVA/qPPO membrane functions as an anion exchange polymer and closely mimics the OH- conductivity of an aqueous KOH solution by facilitating Grotthuss mechanism conduction across the membrane. The PVA/qPPO polymer is very stable, has high tensile strength, and demonstrates remarkable OH- conductivity, providing a greatly improved membrane for alkaline electrolysis. Finally, this technology could potentially be applied as a replacement to aqueous KOH in alkaline fuel cells.

Advantages

  • Improved membrane for alkaline electrolysis
  • High tensile strength while maintaining OH- conductivity