Graphene Oxide-Intercalated Montmorillonite Layered Stack Incorporated into Poly(2,5-Benzimidazole) for Preparing Wide-Temperature Proton Exchange Membranes

In this study, graphene oxide-intercalated montmorillonite (GO-MMT) layered stacks were introduced into a poly(2,5-benzimidazole) (ABPBI) matrix via in situ synthesis to prepare composite membranes (GO-MMT/ABPBI) for wide-temperature range (0-180 degrees C) fuel cell applications. After the introduction of GO-MMT nanocomposites, the ABPBI membranes showed improved tensile strength, water and phosphoric acid retention ratio, and proton conductivity. The GO-MMT/ABPBI membrane was highly conductive when operated from 0 to 180 degrees C and attained proton conductivities of 50.3 mS/cm (0% RH/180 degrees C) and 38.3 mS/cm (98% RH/90 degrees C), respectively, which were about 1.6 and 1.7 times those of the pristine ABPBI membrane under the same conditions. This improved performance was because the nanolayered stacks of GO-MMT confined phosphoric acid and water within its interchannels via hydrogen bonds. This paper demonstrates the potential application of composite membranes in fuel cells with a wide operating temperature range.