September 9, 2019 – Aluminum hydride promises to make nonpolluting fuel cells far safer and more powerful.
The promise of fuel cells — add hydrogen and oxygen, get water and electricity — has long been muted by the difficulty of moving and storing the universe’s lightest element as a liquid or a gas. But researchers funded by the U.S. Army say a powdery hydrogen compound once studied as a rocket-fuel additive may be the stable, energy-dense key to unlocking a wide new range of power-hungry applications, from exoskeletons to underwater drones to electric vehicles — if the U.S. can produce enough of it.
Alternative-energy enthusiasts will recall how GM and other automakers hyped fuel cells in the 2000s, a promised revolution that never took off. Compressed-gas and liquid hydrogen were never cost-effective to produce at scale, and they can be volatile; June alone saw fires at a California plant and a Norwegian refueling facility. There are ways to reduce the danger with stronger, heavier storage tanks. But that adds cost, weight, and complexity.
Enter aluminum hydride — also AIH3 or Alane — a combination of three hydrogen atoms and one aluminum atom originally developed in the 1970s as a potential additive to rocket fuel. Looking a lot like baby powder, it’s much easier to transport and use than compressed gaseous or liquid hydrogen. The energy density is also far greater. Kristopher Lichter, CEO of San Francisco-based Ardica Technologies, which makes fuel cells that run on Alane, describes it as “four times as energy dense as gaseous hydrogen…but [with] none of the problems handling.” It doesn’t require special tanker trucks or pipelines. Instead, the powder goes into a cartridge, which when heated in a fuel cell, releases gaseous hydrogen for use in generating electricity.