M E E T
The leading metal-air fuel cell company
Since 2001
Metal Fuels
Metal anode fuels practically used in the metal air cells are magnesium, aluminum and zinc. Magnesium and aluminum are limited in shapes, and only plates are used. Zinc is used in various forms, powder, plates, balls and deposited plates.
Magnesium anode fuel
The magnesium alloy plates are used as anodes instead of pure magnesium The current efficiency of the anodes varies from 50 -90% depending upon their compositions, current densities, temperature and electrolyte compositions. The loss is from the corrosion reaction of Mg with water and evolving hydrogen gas.
We are using AZ31 (rolled plates) and AZ91 alloys (die-casts).
There are chemical additives, called hydrogen inhibitors, to increase the current densities, however, their effects are not enough to form sealed cells.
Aluminum anode fuel
Aluminum foil or plate is used as anode. Only the high purity Al plate is acceptable in Al-air cells because there is hypercorrosion process generating hydrogen gas severely. Accordingly, very high purity 99.99+% of aluminum plates and high purity electrolyte with hydrogen inhibitor should be used to prevent the corrosion reaction.
Zinc anode fuel
Zinc fuel is in the form of powder, plate, balls(beads) and deposits on anode substrates. Battery grade zinc alloy powder may be used for primary batteries. We use pure zinc plates or deposits as fuels because the recycling cost of the impure ZnO is high.
A direct recycling to zinc oxide powder is also attractive, considering the price of ZnO powder is also high and the quality is similar to the chemical agents from hydro-metallurgical process.