Mechanochemical synthesis and ion transport properties of Na3OX (X = Cl, Br, I and BH4) antiperovskite solid electrolytes
Mechanochemical synthesis and ion transport properties of Na3OX (X = Cl, Br, I and BH4) antiperovskite solid electrolytes
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DOI：
10.1016/j.jpowsour.2020.228489
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发表时间：
2020-09-30
影响因子：
9.2
通讯作者：
Famprikis, Theodosios
中科院分区：
文献类型：
--
作者：
Ahiavi, Ernest;Dawson, James A.;Famprikis, Theodosios
下一代固态电池的发展推动了对新型固体电解质材料的研究。钠反钙钛矿代表作为结果出现的离子导体的结构家族，在组成调整、电化学稳定性、机械柔软性和高离子电导率方面具有预期的优点。在这里，我们报告的机械化学合成的几种材料在这个结构的家庭，包括新的混合卤化物组合物，如Na 3 OCl 0.5（BH 4）（0.5），Na 3 OBr 0.5（BH 4）（0.5），Na 3 OI 0.5（BH 4）（0.5）和Na 3 OCl 0.33Br 0.33（BH 4）（0.33）。我们通过衍射、阻抗谱和分子动力学分析了卤化物取代对这些材料的结构和离子输运性质的影响。最后，我们讨论了Na 3 OBH 4，这是最近报道的快离子导体，由于复杂的超卤阴离子BH 4-的旋转无序。我们无法重现报道的高离子电导率的Na 3 OBH 4无论是通过实验还是从头计算模拟。
The push towards the development of next-generation solid-state batteries has motivated the search for novel solid electrolyte materials. Sodium antiperovskites represent a structural family of ion conductors that has emerged as a result, with expected advantages in terms of composition tuning, electrochemical stability, mechanical softness and high ionic conductivity. Here, we report the mechanochemical synthesis of several materials in this structural family, including novel mixed-halide compositions such as Na3OCl0.5(BH4)(0.5), Na3OBr0.5(BH4)(0.5)Na3OI0.5(BH4)(0.5) and Na3OCl0.33Br0.33(BH4)(0.33). We rationalize the effect of halide substitution on the structure and ion transport properties of these materials through diffraction, impedance spectroscopy and molecular dynamics. We conclude with a discussion on Na3OBH4, which has recently been reported to be a fast ion conductor, owing to the rotational disorder of the complex superhalide anion BH4-. We are unable to reproduce the reported high ionic conductivity of Na3OBH4 neither by experiment nor ab initio simulation.