Core–Shell NaBH4@Na2B12H12 Nanoparticles as Fast Ionic Conductors for Sodium-Ion Batteries.

Herein, we report on a method to engineer a conductive interface to promote high Na⁺ ionic conductivity in NaBH₄. By controlled reaction with B₂H₆, the ionic conductivity of NaBH₄ is enhanced by 5 orders of magnitude at room temperature. The origin of the enhanced conductivity is believed to be the result of the formation of a Na₂B₁₂H₁₂ layer on the surface of α-NaBH₄ particles. The resultant NaBH₄@Na₂B₁₂H₁₂ heterostructure exhibits a high ionic conductivity of 10^–4 S cm^–1 at 115 °C superior to that of pristine NaBH₄ and shows the potential to act as a solid-state electrolyte for all Na solid-state batteries. [ABSTRACT FROM AUTHOR]