Silver-oxide battery

A silver-oxide battery uses silver(I) oxide as the positive electrode (cathode), zinc as the negative electrode (anode), plus an alkaline electrolyte, usually sodium hydroxide (NaOH) or potassium hydroxide (KOH). The silver is reduced at the cathode from Ag(I) to Ag, and the zinc is oxidized from Zn to Zn(II).

The half-cell reaction at the negative plate:

${\displaystyle {\ce {Ag2O + 2H+ + 2e- -> 2Ag (v) + H2O}}}$, ${\displaystyle (E^{\circ }=+1.17{\text{ V}})}$

The reaction in the electrolyte:

${\displaystyle {\ce {2H2O -> 2H+ + 2OH-}}}$, ${\displaystyle (E^{\circ }=-0.83{\text{ V}})}$

The half-cell reaction at the positive plate:

${\displaystyle {\ce {{Zn}+2OH^{-}->{\overset {Zinc~hydroxide}{Zn(OH)2}}+2e-}}}$ , ${\displaystyle (E^{\circ }=-1.22{\text{ V}})}$

Overall reaction:

${\displaystyle {\ce {Zn + H2O + Ag2O -> Zn(OH)2 + 2Ag(v)}}}$, ${\displaystyle (E^{\circ }=+1.56{\text{ V}})}$

Overall reaction (anhydrous form):

${\displaystyle {\ce {Zn + Ag2O ->[{\ce {KOH/NaOH}}] ZnO + 2Ag (v)}}}$

Several sizes of button and coin cells, some of which are silver-oxide

Until recently, all silver-oxide batteries contained up to 0.2% mercury. The mercury was incorporated into the zinc anode to inhibit corrosion in the alkaline environment. Sony started producing the first silver-oxide batteries without added mercury in 2004.[6]

• Battery nomenclature
• Battery recycling
• Comparison of battery types
• Fuel cell
• History of the battery
• List of battery sizes
• List of battery types

Wikimedia Commons has media related to Electric batteries.

• SR (Silver Oxide Battery) from Maxell