Nano-Enhanced Hydrogen Storage Media for Fuel Cells

Many current DoD systems use battery technologies that require extended mission capabilities with reduced volumetric and gravimetric impact. OSD is interested in developing manufacturable technologies with improved volumetric and gravimetric storage densities for hydrogen. Specific design goals are man transportable hydrogen sources with gravimetric and volumetric storage densities greater than 4% and 20 g H2/L, respectively. Metal hydride storage has reached the limits of hydrogen storage capacity over the past 25 years, and large leaps in storage capacity from about 5-6 wt.% are not expected. Increases beyond this will require much lower temperatures or higher pressures, or the media needs to be modified to enhance the storage capacity as well as sorption kinetics. Current metal hydrides can also be poisoned by impurities in the hydrogen, thereby reducing their usable capacity. Nano-structures can be integrated with solid storage media (i.e., directly attached), with potential impacts on storage density, impurity tolerance, and kinetics. This effort will demonstrate the feasibility and comparable performance of innovative solid hydrogen storage media integrated with nanomaterials. Mainstream has already demonstrated the manufacturability of these storage substrates, and project that the OSD volumetric and gravimetric steerage density targets can be met.