Electrical properties of polyvinylidene fluoride-H${}_3$PO${}_2$ protonic conductor; a novel electrolyte for use in fuel cells

Polyvinylidene fluoride (PVDF) and hypophosphorous acid (H${}_3$PO${}_2$) are combined to synthesize solid polymer electrolyte membranes using the solution cast method. Electrochemical impedance spectroscopy measurements are used to find the conductivity, and those values are plotted as a function of relative humidity (% RH) to which the membranes are kept. In agreement with the modified Onsager, the results show growth in conductivity as % RH increases, which states that ionic mobility of a polar polymeric phase increases as levels of absorbed water by the polymeric membrane increase. The high values of conductivity observed at high concentrations of H${}_3$PO${}_2$ (σ = 9.83 × 10${}^{-3}$ S cm${}^{-1}$ for x = 60% wt) are attributed to the increase of charge carriers and the dissociation of ions in an aqueous phase. The synthesized membranes are tested as electrolytes in a fuel cell and the voltage and power density plotted as a function of the current density with maxim values of the power density of 2.88 mW cm${}^{-2}$ for a 30% wt membrane. (© 2023 Wiley‐VCH GmbH)