Impact of the Cation Exchange Membrane Thickness on the Alkaline Water Electrolysis

The replacement of diaphragm by ion selective membrane represents one way to intensify process of alkaline water electrolysis. This approach was chosen in present work. An important novelty represents application of cation-selective membrane Nafion® as a separator and polymer electrolyte in one. Its greatstability in alkaline environment (in comparison with currently available anion-selective membranes) is the main advantage of this process. On the other hand, it suffers also from some disadvantages. As the most important high membrane cost together with lower mobility of alkaline metals ions in the Nafion® membrane when compared to the proton in the PEM and hydroxyl ion in the alkaline process have to be mentioned at this place. Results comparable to the industrial alkaline water electrolyzers were achieved.