Flexible blend polymer electrolyte membranes with excellent conductivity for fuel cells

Abstract

Polymer electrolyte membrane with high conductivity is an indispensable need in fuel cell applications due to some major drawbacks of the commonly used polymer electrolytes. Herein, we have synthesized two thermally and chemically stable polymer electrolytes; poly(2,5-dioxo-2,5-dihydro-1H-pyrrole-1-carbonyl)sulfamoyl fluoride-co-styrene) (PDDPCSFS), and sulfonated Pmax-1200 (SPmax-1200). PDDPCSFS and SPmax-1200 showed (70.50 and 75.44) mS/cm proton conductivity (σ), (30 and 48)% water uptake (WU), and (1.35 and 1.93) meq./g ion exchange capacity (IEC) value, respectively, at 80 °C. We also prepared blend polymer electrolytes by blending PDDPCSFS and SPmax-1200 polymer with different ratios and observed that the blend polymer electrolytes exhibited enhanced performances compared to their parent's compounds by forming an excellent ion-conducting channel. The blend polymers, Blend (9:1), and Blend (8:2) exhibited excellent IEC (2.09 and 2.19) meq./g, σ (93.14 and 117.50) mS/cm at 80 °C under 80% relative humidity (RH), mechanical, and chemical stability, which are higher or comparable to Nafion 117. Moreover, the maximum power density of fuel cells with Blend (9:1) and Blend (8:2) polymer electrolytes was ca. (0.55 and 0.59) W/cm2, respectively, which are very close to the power density of fuel cell with commercial polymer electrolyte. Therefore, these blend polymer electrolytes can be used as effective proton conductive materials for fuel cell applications.