Energy Density Comparison of the Silver-Zinc Button Cell Battery with Rechargeable Li-Ion and Li-Polymer Coin and Miniature Prismatic Cells
Silver-zinc batteries have the highest theoretical specific energy (Wh/kg) and energy density (Wh/L) of all rechargeable battery technologies available commercially today. Rechargeable silver-zinc batteries have been successfully used for decades in military and aerospace applications where high energy and power density are required. The electrochemical reaction involves the oxidation of zinc to zinc oxide and the accompanying reduction of silver(II) oxide to metallic silver. The reaction at the AgO cathode involves a two-step oxidation (1.8 V and 1.5 V) of two water molecules to form hydroxide anions that migrate to the anode where they oxidize the metallic Zn to form the soluble zincate species before precipitation of the zinc oxide.