Synergistic effect of nanoionic destabilization and partial dehydrogenation for enhanced ionic conductivity in MBH4-C60 (M = Li+, Na+) nanocomposites

In this work, we evaluate the electrochemical properties of MBH4-C-60 (M = Li+, Na+) nanocomposites for potential use as a solid-state electrolyte in alkali-ion batteries. The enhancement of ionic conductivity for MBH4 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 MBH4. This improvement is attributed to the nanoionic destabilization of the MBH4 salt due to the affinity of the BH4- anion for C-60 and partial dehydrogenation of the MBH4 through heating. The LiBH4-C-60 nanocomposite was successfully paired with two anodes (graphite and lithium titanate) and two cathodes (LiFePO4 and TiS2) and galvanostatically cycled. The NaBH4-C-60 nanocomposite showed nearly a 4-order-of-magnitude increase in ionic conductivity versus pure NaBH4 and demonstrated reversible sodium stripping and plating in a symmetric cell.

Automated summary

In this study, the electrochemical properties of MBH4-C-60 nanocomposites were evaluated for potential use as a solid-state electrolyte in alkali-ion batteries. The addition of C-60 and partial dehydrogenation led to a significant increase in ionic conductivity for MBH4, with the LiBH4-C-60 nanocomposite successfully paired with various anodes and cathodes while the NaBH4-C-60 nanocomposite showed a substantial increase in ionic conductivity compared to pure NaBH4.