Rechargeable magnesium batteries: System-level opportunities and challenges for battery energy storage applications
Panagiotis Herodotou, Ren Hao, George E․ Georghiou, Shunsuke Yagi
Abstract
The global transition to electric vehicles, renewable energy, and broader electrification requires energy storage technologies that are scalable, sustainable, and cost-effective. Although lithium-ion batteries (LIBs) have served as the commercial standard for three decades, concerns regarding supply chain risks and safety have intensified research into alternative chemistries. Rechargeable magnesium batteries (RMBs) have emerged as a promising candidate for grid-scale and stationary storage because of magnesium’s abundance, low cost, high volumetric energy density, and intrinsic safety features such as minimal dendrite formation. However, RMBs currently face major material and engineering obstacles hindering their practical deployment. This review provides a system-level assessment of RMB technology, including the physical and electrochemical properties of magnesium, cell-design considerations, and comparative analyses with state-of-the-art lithium-ion systems. Key technical challenges, such as sluggish Mg²⁺ diffusion in cathodes, anode passivation and interfacial instability, and the lack of commercially viable electrolytes with sufficiently wide electrochemical windows, are explored in the context of grid energy storage requirements for energy density, cyclability, rate capability, and cost. Recent advancements in materials development, including chloride-free electrolytes, artificial interphases, and novel cathode architectures are discussed, alongside emerging approaches using machine learning for materials innovation and battery management. A roadmap for RMB development is proposed toward overcoming current limitations and accelerating the translation of RMBs from laboratory prototypes to grid-ready systems. This review aims to guide interdisciplinary research toward establishing magnesium-based batteries as a viable and sustainable component of future energy systems.