Fraunhofer researchers have presented a magnesium-based “Powerpaste” that stores hydrogen energy at 10 times the density of a lithium battery, offering hydrogen fuel cell vehicles the ability to travel further than gasoline-powered ones, and refuel in minutes.
Typically, of course, hydrogen fuel cell vehicles carry their H2 fuel in gaseous form, stored in tanks at pressures around 700 bar (10,150 psi). These tanks are fairly large and heavy, which counteracts one of hydrogen’s key advantages over today’s lithium batteries – its higher energy density. The high pressures involved also make hydrogen an impractical option for powered two-wheelers like motorcycles and scooters.
But a team based at the Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Dresden have come up with an interesting new way to store and carry hydrogen energy, in the form of a magnesium hydride-based “Powerpaste” that stores the hydrogen in a chemical form, at atmospheric pressure, ready for release when needed.
To produce the paste, magnesium is combined with hydrogen at around 350 °C (662 °F) and five to six times atmospheric pressure to form magnesium hydride. An ester and a metal salt are added to complete the process and form a viscous gray goop that can be loaded into cartridges.