Enhanced Hydrogen Storage Kinetics of LiBH4 in Nanoporous Carbon Scaffolds

Enhanced kinetics for hydrogen exchange in LiBH4 incorporated within nanoporous carbon scaffolds are described. Dehydrogenation rates up to 50 times faster than those in the bulk material are measured at 300 °C in a nanostructured hydride formed by filling a porous carbon aerogel host with LiBH4. Furthermore, the activation energy for hydrogen desorption, measured using the approach developed by Ozawa, is reduced from 146 kJ/mol for bulk LiBH4 to 103 kJ/mol for nanostructured LiBH4, and the faster kinetics result in desorption temperatures that are reduced by up to 75 °C. In addition, nanostructured hydrides exhibit increased cycling capacity over multiple sorption cycles. This work demonstrates that confinement within a porous scaffold host is a promising approach for enhancing hydrogen uptake and release in reversible light-metal complex hydrides.