Sun Yulong, Wang Yuechao, Liang Xinmiao, Xia Yuanhua, Peng Linfeng, Jia Huanhuan, Li Hanxiao, Bai Liangfei, Feng Jiwen, Jiang Hong, Xie Jia
State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering , Huazhong University of Science and Technology , Wuhan , Hubei 430074 , China.
Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering , Peking University , 100871 Beijing , China.
J Am Chem Soc. 2019 Apr 10;141(14):5640-5644. doi: 10.1021/jacs.9b01746. Epub 2019 Mar 29.
Sodium superionic conductors are keys to develop high safety and low cost all-solid-state sodium batteries. Among developed sodium ionic conductors, antiperovskite-type ionic conductors have attracted vast interest due to their high structural tolerance and good formability. Herein, we successfully synthesize NaOBH with cubic antiperovskite structure by solid-state reaction from NaO and NaBH. NaOBH exhibits ionic conductivity of 4.4 × 10 S cm at room temperature (1.1 × 10 S cm at 328 K) and activation energy of 0.25 eV. The ionic conductivity is 4 orders of magnitude higher than the existing antiperovskite NaOX (X = Cl, Br, I). It is shown that such enhancement is not only due to the specific cubic antiperovskite structure of NaOBH but also because of the rotation of BH cluster anion. This work deepens the understanding of the antiperovskite structure and the role of cluster anions for superionic conduction.
钠超离子导体是开发高安全性和低成本全固态钠电池的关键。在已开发的钠离子导体中，反钙钛矿型离子导体因其高结构容忍度和良好的可成型性而备受关注。在此，我们通过NaO和NaBH的固态反应成功合成了具有立方反钙钛矿结构的NaOBH。NaOBH在室温下表现出4.4×10 S cm的离子电导率（在328 K时为1.1×10 S cm），活化能为0.25 eV。其离子电导率比现有的反钙钛矿NaOX（X = Cl、Br、I）高4个数量级。结果表明，这种增强不仅归因于NaOBH特定的立方反钙钛矿结构，还由于BH簇阴离子的旋转。这项工作加深了对反钙钛矿结构以及簇阴离子在超离子传导中作用的理解。
