KOH-doped polybenzimidazole membrane for direct hydrazine fuel cell

Alkaline direct hydrazine (N₂H₄) fuel cells (DHFCs) are considered one of the most promising liquid-fed fuel cells because of their high energy density, high theoretical voltage, and zero carbon dioxide (CO₂) emissions. However, the lack of a suitable electrolyte membrane impedes the further development of alkaline DHFC. Herein, a potassium hydroxide (KOH)-doped polybenzimidazole (PBI) membrane is applied in alkaline DHFCs, and the detailed operating conditions are investigated for the first time. With optimal KOH and N₂H₄ concentrations in the anolyte, membrane thickness, and cathode gas humidity, the DHFC gives a peak power density of 0.708 W cm^-2. The results of this study demonstrate the promising application of PBI membranes in DHFC and provide a platform to evaluate the performance of catalysts synthesized for DHFC.