Silver chloride-magnesium (AgCl-Mg)
Silver chloride-magnesium cells have a magnesium anode and a silver chloride cathode. Practical output voltage is 1.6 V
They are used in a Volta stack for underwater torpedo propulsion. Seawater acts as the electrolyte, and is only fed into the cell core when the device is fired, which means the cell is inert and thus risk-free before firing. Because all components are in solid form, prolonged storage (over ten years) is possible with no deterioration in performance. Temperature control during discharge is by renewal of the electrolyte.
AgCl-Mg batteries have high energy density and power consistent with torpedo range and speed.