Study of Alkaline Water Electrolysis (II)

Abstract

There are four main factors in the Alkaline Water Electrolysis (AWE) for contributing to the cell performance. One is cell structure which is related to the uniform electrolyte concentration with proper internal circulation of electrolyte in the cell room or the out gassing from electrode, separator and cell chamber. Second is cathode property such as low cathode overpotential and long life. Third is anode property as cathode. Forth is the characteristic of separator which is the most significant influence for total cell performance (cell voltage, hydrogen gas purity and life). Then, various separators and several anode materials were evaluated to confirm the performance. Although, thin IEM (25μm thickness) of polyethylene base showed the lowest cell voltage 1.7V at 0.4A/cm2, the film did not have durability against continuous operation because of deterioration of base film. Raney Ni coating and Spinel type coating for anode achieved 100mV and 50mV, respectively.