Synergistic effect of nanoionic destabilization and partial dehydrogenation for enhanced ionic conductivity in MBH 4 -C 60 (M = Li + , Na + ) nanocomposites

In this work, we evaluate the electrochemical properties of MBH 4 -C 60 (M = Li + , Na + ) nanocomposites for potential use as a solid-state electrolyte in alkali-ion batteries. The enhancement of ionic conductivity for MBH 4 was achieved through the addition of C 60 and partial dehydrogenation, resulting in an electrolyte with significantly higher ionic conductivity when compared to the pure MBH 4 . This improvement is attributed to the nanoionic destabilization of the MBH 4 salt due to the affinity of the BH 4 − anion for C 60 and partial dehydrogenation of the MBH 4 through heating. The LiBH 4 -C 60 nanocomposite was successfully paired with two anodes (graphite and lithium titanate) and two cathodes (LiFePO 4 and TiS 2 ) and galvanostatically cycled. The NaBH 4 -C 60 nanocomposite showed nearly a 4-order-of-magnitude increase in ionic conductivity versus pure NaBH 4 and demonstrated reversible sodium stripping and plating in a symmetric cell.