Current Progression in Graphene-Based Membranes for Low Temperature Fuel Cells

Nafion membrane is a commercial type of electrolyte membrane that is widely used in low-temperature fuel cells. Nafion membrane is expensive and allows fuel to crossover from anode to cathode. Therefore, it decreases fuel utilization and results in mixed potential at the cathode. Modifying the Nafion membrane and/or replacing it with non-Nafion-based materials has shown promising results in solving these problems. Graphene is a two-dimensional material with exceptional properties that positively affect the performance of several energy conversion/storage devices. With its large surface functional groups, graphene oxide exhibits considerable ionic conductivity with low fuel crossover. This paper reviews and discusses the recent progress in utilizing graphene or its derivatives as a blend with Nafion and non-Nafion based membranes as well as a standalone membrane in low-temperature fuel cells. Graphene or its derivatives possess a high potential as a standalone membrane or a composite membrane in the various low temperature fuel cells applications in terms of high ionic conductivity at low humidity and relevant high temperature, high thermal, mechanical, and chemical stabilities. This work summarizes the recent progress in utilizing graphene and its derivatives (graphene oxide and other doped graphene) in different types of fuel cells, whether as a standalone or as a modifier of the Nafion and non-Nafion based membranes. The review covers the usage of graphene and its derivatives in PEMFCs, DMFCs, anion exchange DMFCs, and MFCs. Furthermore, it elaborates on the science and the engineering aspects of utilizing graphene and its derivatives in different fuel cells. This work demonstrates the importance of the graphene and its derivatives in improving the performance of low temperature fuel cells.