Physical and chemical modification routes leading to improved mechanical properties of perfluorosulfonic acid membranes for PEM fuel cells

Proton Exchange Membrane Fuel Cells (PEMFC) are a sustainable means of power generation through electrochemical conversion of hydrogen-containing fuels especially in portable, stationary, and automotive applications. In order to improve fuel cell performance and durability as well as reduce material cost, significant research effort has been dedicated to enhancing the mechanical properties of perfluorosulfonic acid (PFSA) membranes used in PEMFCs as this allows the use of thinner membranes, which significantly reduces area resistance and improves water management in the fuel cell. This review looks at various approaches to improve the mechanical properties of PFSA membranes, from chemical methods such as cross-linking to the use of a physical reinforcement in various forms such as porous polymer matrix, fibres, or inorganic reinforcement.