Mercury-oxide PowerStream Battery Chemistry FAQ

Anode: Zinc (or cadmium)

Cathode: Mercuric Oxide (HgO)

Electrolyte: Potassium hydroxide

Applications: Small electronic equipment, hearing aids, photography, alarm systems, emergency beacons, detonators, radio microphones

This is an obsolete technology. Most if not all of the manufacture of these cells has been stopped by government regulators. Mercury batteries come in two main varieties: zinc/mercuric oxide and cadmium/mercuric oxide. The zinc/mercuric oxide system has high volumetric specific energy (400 Wh/L), long storage life, and stable voltage. The cadmium/mercuric oxide system has good high temperature and good low temperature (-55 C to +80 C, some designs to +180 C) and has very low gas evolution.

Basic Cell Reaction	Voltage	Electrochemical Efficiency
Zn + HgO = ZnO + Hg	1.35 V	820 mAH/g(Zn), 250 mAH/g(Hg)
Cd + HgO + H2O = Cd(OH2) + Hg	0.91 V	480 mAH/g(Cd)