Figure 1: Thermal Properties Test Cell

Hydrogen storage engineering has been a major focus at the Sandia California laboratory for nearly 50 years. Our original mission focused on providing engineering design for hydrogen transfer and storage systems in non-nuclear components of the nation’s nuclear weapons stockpile. The focus of this effort has expanded over time to encompass the ever-changing issues of energy and national security. Currently, we are developing safe, reliable and optimized engineering systems for storing hydrogen on automobiles.

The engineering and material properties of candidate materials directly influence the efficiency, performance, safety, and cost of the entire hydrogen storage system. Therefore, these properties must be characterized prior to the realization of efficient storage solutions based on newly discovered materials.

Capabilities at Sandia-CA include:

• Thermal properties characterization test cells (Figure 1) which were designed and built to accommodate the complex decomposition and recombination reactions of hydrogen storage materials. The fully calibrated test cells are capable of measuring thermal conductivities ranging from 0.001 W/m-K to greater than 20 W/m-K as a function of sorption cycle, material phase, gas pressure, and system temperature. These test cells were recently utilized to measure the thermal properties of NaAlH₄.
• Fully calibrated mechanical properties test cells (Figure 2) that measure the pressure exerted on a vessel wall by volumetric expansion during hydrogen absorption and desorption.

Figure 2: Mechanical Properties Test Cell

Using measured thermodynamic and chemical kinetic data, we formulate physically-based kinetics models for the absorption and/or desorption of hydrogen storage materials. These models rigorously enforce thermodynamic constraints based on the measured equilibrium (plateau) pressures of the storage material.

An online storage materials properties database was developed at Sandia and lists several hundred materials and properties related to H₂ storage. (http://hydpark.ca.sandia.gov/)

Contact:

Daniel Dedrick
Phone: 925-294-1552
Email: dededri@sandia.gov