Correlations between the ionic conductivity and cation size in complex borohydrides

The ionic conduction in the metal borohydrides is often linked to the energy barriers of BH4− reorientation and cation diffusion. However, the ionic conduction is a complex phenomenon, and limited reports are available to establish straightforward correlations with experimental trends in alkali metal borohydrides. This communication reported the correlations between ionic conductivity and cationic size in complex borohydrides. The ionic conductivities of LiBH4, NaBH4, and KBH4 were found to decrease monotonically with increasing cationic radius. This evidences that borohydrides follow trends observed for other ionic conductors and provide further ground toward designing better borohydride-based electrolytes.