Emerging role of aqueous batteries in next generation energy-dense sustainable storage

Aqueous metal batteries are emerging as promising candidates for next-generation energy storage, offering safer, more sustainable, and cost-effective alternatives to lithium-ion batteries (LIBs). Leveraging earth-abundant metals such as zinc, aluminium, magnesium, and silicon, these systems benefit from non-flammable, water-based electrolytes and simplified manufacturing, making them attractive for grid-scale and off-grid applications. This review highlights recent progress in aqueous battery chemistries, including metal-ion, metal-sulfur, and metal-air systems, emphasizing advancements in electrode design, electrolyte engineering, and interface optimization to improve energy density and cycling stability. Key challenges such as dendrite formation, self-corrosion, and parasitic reactions are critically examined, along with emerging solutions like functional additives, protective coatings, and nanostructured materials. This review underscores the potential of aqueous batteries in supporting decarbonized energy infrastructures by categorizing systems according to charge-storage mechanisms and life cycle assessment (LCA) indicators. Although unlikely a universal replacement for LIBs, aqueous systems offer highly viable solutions for stationary storage, requiring further research, scalable design strategies, and targeted investment to transition from laboratory innovation to commercial deployment. Finally, this review discusses the trade-off between various aq. battery systems and concludes with key research priorities and policy recommendations to guide future development aligned with LCA principles.