<p>Steady growth in renewable energy sources necessitates upscaling grid-level energy storage technologies. Among these, redox flow batteries (RFBs) are a promising option due to their decoupled power and energy, longer life, and improved safety for medium to large-scale applications. Membranes are one of the key components in RFBs that prevent the mixing of redox-active species from the two electrolytes. Hence, membranes play a critical role in the operation and efficiency of redox flow batteries (RFBs). This review provides an overview of the fundamental principles and components of redox flow batteries (RFBs), with a specific focus on the various types of membranes used in these systems. It explores the different methods employed for the preparation of inorganic-polymer nanocomposites and multi-composition membranes. In addition, the article highlights the advancement of membrane technology through the integration of inorganic nanoparticles into polymer matrices, aimed at enhancing the performance of both aqueous and non-aqueous redox flow batteries (RFBs). Various membrane types used in redox flow batteries are discussed in detail. The overall discussion in the article highlights the key strategies and developments in improving membrane functionality for optimized battery efficiency and longevity. The concluding section highlights present challenges, future directions, and perspectives on inorganic-polymeric membranes for RFB technology.</p> Graphical abstract <p></p>