Controlling the Growth of LiBH4 Nanoparticles for Hydrogen Storage

LiBH4 is a potentially promising material to store high-density hydrogen reversibly. However, its practical use is hindered by the poor reversibility and excessive temperature required for hydrogen release. Nanosizing and the core-shell approach in particular are effective strategies to enable hydrogen reversibility at low temperatures because the properties of LiBH4 highly depend upon particle size. In this context, the development of synthetic methods and understanding to tune the particle size of LiBH4 has become important. The synthesis of isolated LiBH4 nanoparticles stabilized by different surfactants by the solvent evaporation method is reported. The surfactants' chain length, their steric hindrance, and the ability of the surfactant head group to bind strongly to LiBH4 are found to control the growth and stabilization of LiBH4 nanoparticles. In particular, long linear chains with hard-type head groups are preferable for the synthesis of LiBH4 particles <20 nm.