Polyvinyl Alcohol Based Membrane as Separator for Alkaline Water Electrolyzer

Alkaline water electrolyzer employs nickel based electrodes and asbestos cloth diaphragm. Asbestos is considered as carcinogenic. In order to limit the usage of an asbestos diaphragm, a separator membrane was synthesized from polyvinyl alcohol, glutaraldehyde, N,N,N′N′-Tetramethyl hexane-1,6 diamine, and titanium dioxide. The role of N,N,N′N′-Tetramethyl hexane-1,6 diamine is to improve the dimensional stability of the membrane. The fabricated membranes were characterized by FT-IR, TGA, DSC, and SEM techniques. These fabricated membranes effectively improved the production of hydrogen, more so than the conventional asbestos diaphragm. A current density of 0.38 A/cm2 was achieved when operating the cell with 5 wt% KOH at 30°C at 2 V. Polyvinyl alcohol composite membranes, besides being cheap, showed good electrochemical performance at ambient temperature and pressure than most commercial separator membranes. This comparison gives some insight as to future separator membrane design objectives.