Recent Advances in Multivalent-Ion Batteries for Next-Generation Energy Storage

<div>As global demand for sustainable energy solutions increases, there is a push to develop alternatives to lithium-ion batteries, which face limitations in cost, resource availability, and safety. In particular, multivalent-ion batteries based on magnesium, calcium, zinc, and aluminum have emerged as promising candidates due to their ability to transfer multiple electrons per ion, offering higher volumetric energy density and greater material abundance. This review examines recent advances in electrode and electrolyte development for these systems, highlighting cathode innovations such as cobalt sulfides for magnesium, NASICON-type and redox-coupled materials for calcium, molybdenum trioxide frameworks for zinc, and organic and composite electrodes for aluminum. Electrolyte research has produced improved ionic transport and stability through solvation tuning, hybrid and polymer systems, and deep eutectic solvents. Interfacial engineering is identified as a key enabler for enhancing reversibility, dendrite suppression, and long-term cycling stability. A comparative analysis of the different chemistries found that zinc-ion systems are closest to commercial deployment, aluminum-ion batteries are advancing for grid and flexible devices, and magnesium and calcium-ion batteries hold long-term potential for high-energy applications. The study concludes with future research directions emphasizing solvation control, sustainable materials, and intelligent diagnostics to achieve scalable multivalent battery technologies.</div>