Structure–property relationships in polymer electrolyte membranes for fuel cell applications: insights from molecular dynamics simulations

In line with the United Nations Sustainable Development Goals (SDG) 2030 specifically Goal 7 (Affordable and Clean Energy) and Goal 13 (Climate Action) polymer electrolyte membranes (PEMs) play a critical role in advancing clean hydrogen technologies through fuel cells. As global efforts intensify toward cleaner energy systems, the development of high-performance PEMs remains a core focus in fuel cell research. While experimental techniques have advanced our understanding of PEMs, they are often limited in probing nanoscale structural behaviours and transport mechanisms. Molecular dynamics (MD) simulations have thus emerged as a powerful computational tool, capable of elucidating critical structure–property relationships at the atomic level. However, current literature on MD simulation in this context remains fragmented, with varying methodologies, inconsistent model validation, and limited integration with experimental data highlighting a significant research gap. This review aims to critically evaluate MD simulation studies applied to PEMs, focusing on how morphology, hydration, and chemical structure affect proton conductivity, water diffusion, mechanical and thermal stability. By comparing case studies across different PEM materials, from Nafion to emerging biopolymer-based membranes, this work offers a comprehensive understanding of simulation approaches, identifies their limitations, and proposes future research directions. The contribution of this study lies in its synthesis of simulation techniques with real-world membrane performance metrics, paving the way for more predictive and design-driven PEM development. In conclusion, MD simulations are not only complementary to experimental investigations but are essential for accelerating the design of next-generation membranes for sustainable energy systems. This review serves as a timely and valuable resource for researchers and engineers seeking to leverage computational tools in advancing PEM technology.