Engineering On The Edge

Hydrogen fuel cells may very well power the electric vehicles of the future, but right now hydrogen power has some inherent limitations. The technology is expensive, and the hydrogen in these systems has to be compressed at high pressures; current systems lose a significant amount of energy quickly, and the high pressure can lead to unsafe conditions.

Researchers at Lawrence Berkeley National Laboratory are investigating alternative storage methods for hydrogen-powered fuel cells by synthesizing novel materials with high hydrogen adsorption capacities. By improving storage capacity, the batteries could achieve longer charges, which would be a boon for hydrogen-powered electric vehicle designs.

The U.S. Department of Energy has awarded Berkeley Lab $2.1 million in funding for the three-year project (General Motors and NIST are also chipping in).

The folks at Berkeley Lab are using metal-organic frameworks (MOFs), three-dimensional constructions composed primarily of carbon atoms. By modifying the chemistry of the surfaces, the team can make the materials more attractive for hydrogen to stick to.

These sponge-like constructions can double hydrogen capacity, but only at low temperatures: -321 degrees Fahrenheit. The next step will be to develop materials that can boost capacity at room temperature.

Berkeley Lab chemist Martin Head-Gordon, who co-leads the project, will work on a theoretical understanding of MOFs in order to predict their hydrogen storage properties and help identify which types of materials to synthesize.

The DOE also awarded funding to three other hydrogen storage projects. The DOE’s Pacific Northwest Laboratory is working with Ford and several other companies looking at ways to improve carbon fiber composite materials in order to lower the cost of making high-pressure hydrogen storage tanks. HRL Laboratories in Malibu, CA, is testing engineered liquids that can absorb and release hydrogen gas, while the University of Oregon is heading up a project to test new types of materials for hydrogen storage.

The folks at Berkeley Lab, meanwhile, are also evaluating MOFs as a potential lower-energy alternative for trapping carbon dioxide gas as it emerges from power plan exhaust stacks.

Source: Lawrence Berkeley National Laboratory