Metal-air/seawater batteries have high gravimetric energy densities; however, open-circuit (OC) anode corrosion causes severe capacity fade when the battery is shut off. Previous technologies focus on chemical mitigation methods (i.e. changing electrode or electrolyte composition), which provide insufficient corrosion mitigation and power density. Other mechanical corrosion mitigation methods require flushing the cell, which increases the volume of tanks required for the system. The proposed technology implements a system that displaces the electrolyte with oil when the battery is off to prevent OC corrosion.