Toward a new generation of low cost, efficient, and durable metal-air flow batteries

Over the past few decades, metal-air flow batteries (MAFBs) have attracted great attention as a promising candidate for next-generation energy storage systems because of their potential to offer both high performance and scale flexibility, derived from the high energy density of metal-air batteries and the scalability of redox flow batteries. In this article, recent progress in metal-air flow batteries is overviewed, focusing on the structural design and advances in materials development. To obtain an insightful view of the battery features, different categories are introduced on the basis of flow media, working principles, and configurations. In addition, detailed discussion about metal-air flow batteries with aqueous and non-aqueous electrolytes is conducted, containing advances in the structural design and materials development of metal electrodes, air electrodes, and electrolytes. Finally, the challenges and perspectives for future development are synoptically presented.