Magnesium can also be used as a fuel for fuel cells.
A lot of laboratories are developing a metal-air battery, such as zinc, aluminium, iron, lithium and magnesium. It is a battery which uses oxidizing properties between metal and oxygen. An ordinary battery needs cathode active and anode active. On the other hand, cathode active of the metal-air battery is oxygen. If metal as anode active can be exchangeable, the metal-air battery becomes a fuel cell.
A passenger fuel cell vehicle requires 6kg of hydrogen in order to run 500km, and the same quantity of energy is produced from about 70kg of magnesium. When it is put in practical use, it is thought that a pack of magnesium cassette will be installed in the power generation compartment of fuel cells. You would replace fuel packs just like you fill up the gas tank of you car with gasoline at a gas station now.
In 2003, a research-oriented venture company for metal fuel cells, eVionyx (Hawthorne, New York State), has developed an experimental car by converting a regular passenger car, and has achieved a continuous run of 600km without replacing its fuel cells. They have also proved that there was no problem in running the vehicle by replacing its fuel cells for over 100 times.
Based on this experimental data, the efficiency of a zinc fuel cell is 500 Watt-Hour per 1kg. If you apply this experimental data to magnesium, the efficiency of a magnesium fuel cell would be 1500 Watt-hour for 1kg of magnesium, which far exceeds that of a lithium ion battery (200Wh).