Aqueous Zinc-Ion Batteries: Progress, Challenges, and Pathways Towards Greener Energy Storage

Spurred by the rapid expansion of renewable and clean energy technologies, secondary batteries have become indispensable to modern energy systems. At the same time, growing demand for safer and more environmentally friendly energy-storage solutions has accelerated interest in zinc-ion batteries (ZIBs), which offer attractive advantages over lithium-ion batteries, including high theoretical capacity, intrinsic safety, and natural abundance. This review summarizes recent progress in aqueous ZIBs, with particular focus on highly reversible Zn anode, electrolyte optimization, and the development of advanced cathode materials. In addition, emerging methods designed to address the key limitations of aqueous ZIB systems are discussed. Finally, this review provides perspectives on future research directions and design principles that may guide the development of next-generation aqueous ZIBs.