Sodium ionic conduction in complex hydrides with [BH_4]~- and [NH_2]~- anions

摘要

We report the experimental results of structural and sodium ionic conductive properties of the Na(BH_4)-Na(NH_2)-NaI system. Na(BH_4)_(0.5)(NH_2)_(0.5)with [BH_4]~- and[NH_2]~- complex anions formed by combining Na(BH_4) and Na(NH_2) complex hydrides shows the most superior sodium ionic conductivity of 2 × 10~(-6) S/cm at 300 K because of the specific antiperovskite-type structure with vacancies in the Na~+ site Furthermore, Na(BH_4)_(0.5)(NH_2)_(0.5) shows a high electrochemical stability of at least 6 V (vs Na~+/Na). The result suggests that Na(BH_4)_(0.5)(NH_2)_(0.5) could be a potential candidate for solid electrolyte.