Nonhumidified high temperature H2/Cl2fuel cells using protic ionic liquids

Abstract

An innovative electrolyte membrane concept based on the synergetic combination of porous nanofiltration (NF) membrane 81.0% in porosity containing ionic liquid trimethylammonium phosphate ([N_1,1,1H]H₂PO₄) as an intrinsic proton conductor has been developed for H₂/Cl₂ fuel cell applications. This proton conducting composite membrane showed promise for operation in high temperature H₂/Cl₂ fuel cells under anhydrous conditions. Proton conductivity at a level of 15.0 mS cm⁻¹ was achieved at 160 °C, as high as about 50% of that of neat ionic liquid. The single cell fabricated with the NF/[N_1,1,1H]H₂PO₄ composite membrane gave the highest current density of 196.8 mA cm⁻² at the output voltage of 0.2 V under 160 °C and nonhumidification.