2015 : Nanoconfined LiBH4 as a fast lithium ion conductor

Suwarno ST., MSc., Ph.D.

Abstract

Designing new functional materials is crucial for the development of efficient energy storage and conversion devices such as all solid‐state batteries. LiBH4 is a promising solid electrolyte for Li‐ion batteries. It displays high lithium mobility, although only above 110 °C at which a transition to a high temperature hexagonal structure occurs. Herein, it is shown that confining LiBH4 in the pores of ordered mesoporous silica scaffolds leads to high Li+ conductivity (0.1 mS cm−1) at room temperature. This is a surprisingly high value, especially given that the nanocomposites comprise 42 vol% of SiO2. Solid state 7Li NMR confirmed that the high conductivity can be attributed to a very high Li+ mobility in the solid phase at room temperature. Confinement of LiBH4 in the pores leads also to a lower solid‐solid phase transition temperature than for bulk LiBH4. However, the high ionic mobility is associated with a fraction of the …