A principle that mother nature uses since millions of years ago may just be the solution to an efficient hydrogen storage material, as hydrogen is the ultimate energy carrier, because burning it emits nothing but water.
So far, the few hydrogen-powered cars that are not even on the market yet, but merely as leased test prototypes, have been using pressurized tanks for storing liquefied hydrogen. Magnesium had been touted as a promising candidate for that purpose, but sticking the hydrogen atoms to magnesium atoms can only be done at high pressures and temperatures and that makes it an unlikely candidate so far.
Scientists at the National Institute of Standards and Technology (NIST) have developed molecular scale “veins” of iron permeating grains of magnesium like a network of capillaries. This approach may not only ease the adoption of hydrogen molecules inside magnesium, which could be done very fast, but could also be released as fast.
“Powder grains made of iron-doped magnesium can get saturated with hydrogen within 60 seconds,” says Bendersky, “and they can do so at only 150 degrees Celsius and fairly low pressure, which are key factors for safety in commercial vehicles.”
It has been established that a practical hydrogen storage material would store at least 6 percent of its own weight in hydrogen gas, and would be able to get charged as quickly as you would charge a normal gas tank. The iron-permeated magnesium invented at the NIST exceeds that target, storing about 7 percent of its own weight in hydrogen. This makes it a perfect candidate for real world applications in cars.