For years, one of the major obstacles to the realization of the hydrogen economy is hydrogen storage. Solid-state storage, using solid materials such as metals that absorb hydrogen and release it as needed, has many safety and practicality advantages over storing hydrogen as a liquid or gas, and many storage materials have been examined trying to meet DOE's goals. Several materials have been discovered that have met or exceeded the DOE gravimetric and/or volumetric performance targets. Of those, however, the majority do not have the required thermodynamic and kinetic properties that allow them to release their hydrogen when needed, and be efficiently and economically reloaded with hydrogen when spent.
Alane possesses the desired qualities, but had been considered impractical because of the high pressures required to combine hydrogen and aluminum to reform the hydride material. Alternate methods of production using chemical synthesis have typically produced stable metal chloride byproducts that make it practically impossible to regenerate the alane. The electrochemical cycle demonstrated by Dr. Zidan and the SRNL team for production of alane avoids both of these issues.
In conjunction with this research, the SRNL team discovered novel ways to facilitate separation and formation of aluminum hydride that also apply to the formation of other complex metal hydrides and have the potential to cost-effectively regenerate other high capacity hydrogen storage materials. The SRNL results are expected to accelerate the development of a whole class of similar materials needed for hydrogen, batteries and other energy storage applications.
In addition, this work will significantly impact other fields including those of thin films, adduct based syntheses, and the recycling and regeneration of other materials.
SRNL has a long history of successful research and development in the field of hydrogen storage methods, an outgrowth of the Laboratory's decades of support for the National Nuclear Security Administration's tritium mission. Tritium is the radioactive form of hydrogen used in national defense.
SRNL is DOE's applied research and development national laboratory at the Savannah River Site (SRS). SRNL puts science to work to support DOE and the nation in the areas of environmental management, national and homeland security, and energy security. The management and operating contractor for SRS and SRNL is Savannah River Nuclear Solutions, LLC.