Rechargeable Na‐Seawater Batteries—A Promising Battery Energy Storage Solution for Coastal Economies

ABSTRACT Battery Energy Storage Systems (BESS) are required to be safe, cost‐effective, and demonstrate long‐duration energy storage capabilities and sodium‐based rechargeable seawater batteries can be promising candidates for such demanding applications. These batteries are ideal for coastal economies where the use of abundant seawater as cathode materials and their compartmentalized and adaptable design can be redesigned to enable water desalination, CO ₂ capture, and several other applications. Moreover, variants of these systems can potentially use metallic sodium with a very high volumetric energy density of >4 kWhl ⁻¹ . Our technical assessments reveal that such configurations boast volumetric energy densities ∼5 times greater than prevalent hydrogen‐based storage systems. This comprehensive review compiles and summarizes recent research developments in rechargeable seawater batteries. Moreover, we have also evaluated the potential of prospective deployment of seawater batteries for applications such as behind the meter energy storage systems for EV charging stations. Additionally, we have also evaluated the technical feasibility of these batteries compared to other prevalent long‐duration energy storage systems as a potential storage solution for coastal economies. Overall, this review provides a detailed summary, feasibility study, and perspective on the promise of sodium‐based rechargeable seawater batteries for BESS applications.