Hydrogen – the ever-illusive solution to our energy problems. As a society that doesn’t quite accept that you “can’t take it with you,” scientists have been on the hunt for portable energy storage solutions and can’t look away from bright, taunting hydrogen, which stores more energy per unit of weight than any other element. One group of researchers at the U.S. Department of Energy’s Savannah River National Laboratory (SRNL) believe they may have discovered the key to portable fuel cell systems – aluminum hydride (AlH3), or alane.
While hydrogen possesses many great qualities for energy storage, it also has a few flaws. While it stores an amazing amount of energy by weight, it stores four times less energy by volume than gasoline, so the trick becomes how to get enough of it onboard to supply a meaningful amount of energy. One approach – taken by SRNL researchers – is to use chemical hydrogen storage materials like alane that put hydrogen into a solid state for storage.
The beauty of alane is that it has a very high hydrogen capacity, storing twice as much hydrogen in equal volume to liquid hydrogen, and releases the hydrogen in optimum conditions. Work by one of the team leaders, Ragaiy Zidan, also created a two-step process that doubles the amount of hydrogen that can be extracted from alane when using the traditional one-step process.
A common issue for hydrogen storage (and most initial technologies) is cost. There is a limited supply of commercially available alane, and it carries a high cost to produce. But, necessity led to innovation for the team, and through producing alane to run their studies, the researchers developed a lower-cost process for production. “Our process overcomes some of the handicaps of traditional methods for producing alane,” Zidan said in a statement. “This novel method minimizes the use of solvents, and is able to produce pure, halide-free alane.”