Engineers develop new materials for hydrogen storage
16 April 2014
Engineers at the University of California, San Diego, have created new ceramic materials that could be used to store hydrogen safely and efficiently.
The researchers have created for the first time compounds made from mixtures of calcium hexaboride, strontium and barium hexaboride. They also have demonstrated that the compounds could be manufactured using a simple, low-cost manufacturing method known as combustion synthesis.
The work is at the proof of concept stage and is part of a $1.2 million project funded by the US National Science Foundation, a collaboration between UC San Diego, Alfred University in upstate New York and the University of Nevada, Reno.
The manufacturing process for the ceramics is faster and simpler than traditional methods used to manufacture these types of materials.
"We are looking for solid materials that can store and release hydrogen easily," says UC San Diego's Professor Olivia Graeve.
Storing hydrogen has become increasingly important as hydrogen fuel cells become more popular power sources in industry and elsewhere. But hydrogen is difficult to store. It tends to diffuse through the walls of pressurised tanks. It also needs to be compressed in order to occupy manageable amounts of space when stored.
The resulting ceramics are essentially crystalline structures in a cage of boron. To store hydrogen, the researchers would swap the calcium, strontium and boron with hydrogen atoms within the cage.
Engineers mixed boron with metal nitrates and organic fuels, such as urea, in a box furnace at temperatures below 400 degrees Celsius. The nitrates and organic fuels ignite, generating heat that then drives the reaction without the need for an external source of power (combustion synthesis).
"It's a very simple, nice process," adds Professor Graeve.