Complex Hydrides with (BH4)− and (NH2)− Anions as New Lithium Fast-Ion Conductors

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• 作者：Motoaki Matsuo ; Arndt Remhof ; Pascal Martelli ; Riccarda Caputo ; Matthias Ernst ; Yohei Miura ; Toyoto Sato ; Hiroyuki Oguchi ; Hideki Maekawa ; Hitoshi Takamura ; Andreas Borgschulte ; Andreas Zttel ; Shin-ich
• 刊名：Journal of the American Chemical Society
• 出版年：2009
• 出版时间：November 18, 2009
• 年：2009
• 卷：131
• 期：45
• 页码：16389-16391
• 全文大小：192K
• 年卷期：v.131,no.45(November 18, 2009)
• ISSN：1520-5126

文摘

Some of the authors have reported that a complex hydride, Li(BH₄), with the (BH₄)⁻ anion exhibits lithium fast-ion conduction (more than 1 × 10⁻³ S/cm) accompanied by the structural transition at 390 K for the first time in 30 years since the conduction in Li₂(NH) was reported in 1979. Here we report another conceptual study and remarkable results of Li₂(BH₄)(NH₂) and Li₄(BH₄)(NH₂)₃ combined with the (BH₄)⁻ and (NH₂)⁻ anions showing ion conductivities 4 orders of magnitude higher than that for Li(BH₄) at RT, due to being provided with new occupation sites for Li⁺ ions. Both Li₂(BH₄)(NH₂) and Li₄(BH₄)(NH₂)₃ exhibit a lithium fast-ion conductivity of 2 × 10⁻⁴ S/cm at RT, and the activation energy for conduction in Li₄(BH₄)(NH₂)₃ is evaluated to be 0.26 eV, less than half those in Li₂(BH₄)(NH₂) and Li(BH₄). This study not only demonstrates an important direction in which to search for higher ion conductivity in complex hydrides but also greatly increases the material variations of solid electrolytes.