Zinc-Air Fuel Cell

A zinc air fuel cell is a form of zinc air electrochemical cell built to be mechanically recharged rather than thrown away or electrically recharged: instead of replenishing its reactants through an electric current the way a rechargeable battery does, a used zinc paste or pellet anode and its electrolyte are physically removed and replaced with fresh material, in effect refurbishing the cell as a fresh primary cell each time. As in any zinc air system, zinc metal serves as the fuel and reacts with oxygen drawn from the surrounding air, and the reaction rate can be controlled simply by varying the air flow into the cell. Commercial zinc air technology dates to 1932 and the National Carbon Company, and thin electrode designs developed from fuel cell research in the 1970s later enabled small button cells for hearing aids; research into the mechanically rechargeable fuel cell form has focused mainly on electric vehicles, where a car would exchange spent zinc and electrolyte for fresh reactants at a service station, though primary lithium batteries offered higher discharge rates and easier handling and limited how far the concept has been commercialized.