Silver-zinc (Ag-Zn)
Silver-zinc cells provide the basis for both primary and secondary (rechargeable) batteries. In cells for primary batteries, the anode is zinc and the cathode is silver oxide. In cells for secondary batteries, the anode is zinc oxide and the cathode is silver. In both cases, the electrolyte is based on potassium hydroxide. The output voltage is 1.65 V.
The main applications for silver-zinc cells are in defence (torpedoes). Other applications include guiding systems, steering and pump activation on the Ariane launch vehicle.
In military applications, rechargeable batteries are used for exercises and primary batteries for operations. For reasons of safety and performance (shelf life over 8 years), the batteries are only activated, by electrolyte injection, at the last minute.
Silver-zinc batteries have a high energy density and power.