Superionic Conduction of Sodium and Lithium in Anion-Mixed Hydroborates Na3BH4B12H12 and (Li0.7Na0.3)3BH4B12H12.

Novel mixed‐anion compounds Na3BH4B12H12 and (Li0.7Na0.3)3BH4B12H12 show superionic conduction corresponding to highly disordered cations and continuous migration paths in the structure. Na‐rich Na3BH4B12H12 with a room‐temperature conductivity of 0.5 × 10−3 S cm−1 provides a light‐weight solution for the electrolyte in Na‐based, all solid‐state batteries. (Li0.7Na0.3)3BH4B12H12 favors ionic conductivity for both Li and Na cations, but only above 500 K. [ABSTRACT FROM AUTHOR]