Zinc–air battery

A zinc–air battery is a <a href="/facts/Metal%25E2%2580%2593air_electrochemical_cell/P19rjpyH">metal–air electrochemical cell</a> powered by the <a href="/facts/Oxidation/Pyd5RVcj">oxidation</a> of <a href="/facts/Zinc/80b1qgk3">zinc</a> with <a href="/facts/Oxygen/acyn6o8r">oxygen</a> from the air. During discharge, a mass of zinc particles forms a porous <a href="/facts/Anode/TjYt95zG">anode</a>, which is saturated with an <a href="/facts/Electrolyte/4YE8bIVa">electrolyte</a>. Oxygen from the air reacts at the <a href="/facts/Cathode/tqdlGayU">cathode</a> and forms <a href="/facts/Hydroxyl/1Hs2QAEv">hydroxyl</a> ions which migrate into the zinc paste and form <a href="/facts/Zincate/GazR5fbW">zincate</a> (Zn(OH)2−4), releasing <a href="/facts/Electron/L0KBo5cW">electrons</a> to travel to the cathode. The zincate decays into <a href="/facts/Zinc_oxide/P7sTyDez">zinc oxide</a> and water returns to the electrolyte. The water and hydroxyl from the <a href="/facts/Anode/TjYt95zG">anode</a> are recycled at the cathode, so the water is not consumed. The reactions produce a theoretical voltage of 1.65 <a href="/facts/Volts/KF18MXP2">Volts</a>, but is reduced to 1.35–1.4 V in available cells.
These batteries have high <a href="/facts/Energy_density/mwBXA7bC">energy densities</a> and are relatively inexpensive to produce. Zinc–air batteries have some properties of <a href="/facts/Fuel_cell/UcMYnCW3">fuel cells</a> as well as batteries: the zinc is the fuel, the reaction rate can be controlled by varying the air flow, and oxidized zinc/electrolyte paste can be replaced with fresh paste.
Sizes range from very small <a href="/facts/Button_cell/fUaN3p0X">button cells</a> for <a href="/facts/Hearing_aid/rPjt8MH2">hearing aids</a>, larger batteries used in film <a href="/facts/Camera/j4uqsfJQ">cameras</a> that previously used <a href="/facts/Mercury_battery/6AKCRqoP">mercury batteries</a>, to very large batteries used for <a href="/facts/Electric_vehicle/jhCbx5ur">electric vehicle</a> propulsion and <a href="/facts/Grid_energy_storage/SgYUxXkB">grid-scale energy storage</a>. Zinc–air batteries can be used to replace now discontinued 1.35 V <a href="/facts/Mercury_battery/6AKCRqoP">mercury batteries</a> (although with a significantly shorter operating life), which in the 1970s through 1980s were commonly used in photo cameras and hearing aids. Possible future applications of this battery include its deployment as an <a href="/facts/Electric_vehicle_battery/txjgvF76">electric vehicle battery</a> and as a utility-scale energy storage system.

Zinc–air battery open-in-new

Zinc–air battery