Rotational Cluster Anion Enabling Superionic Conductivity in Sodium-Rich Antiperovskite Na3OBH4

Yulong Sun; Yuechao Wang; Xinmiao Liang; Yuanhua Xia; Linfeng Peng; Huanhuan Jia; Hanxiao Li; Liangfei Bai; Jiwen Feng; Hong Jiang; Jia Xie

doi:10.1021/jacs.9b01746

Rotational Cluster Anion Enabling Superionic Conductivity in Sodium-Rich Antiperovskite Na₃OBH₄

J Am Chem Soc. 2019 Apr 10;141(14):5640-5644. doi: 10.1021/jacs.9b01746. Epub 2019 Mar 29.

Authors

Yulong Sun¹, Yuechao Wang², Xinmiao Liang³, Yuanhua Xia⁴, Linfeng Peng¹, Huanhuan Jia¹, Hanxiao Li², Liangfei Bai⁴, Jiwen Feng³, Hong Jiang², Jia Xie¹

Affiliations

¹ 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.
² Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering , Peking University , 100871 Beijing , China.
³ State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences , Wuhan , Hubei 430071 , China.
⁴ Key Laboratory of Neutron Physics and Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics , Mianyang , Sichuan 621999 , China.

PMID: 30912936
DOI: 10.1021/jacs.9b01746

Abstract

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 Na₃OBH₄ with cubic antiperovskite structure by solid-state reaction from Na₂O and NaBH₄. Na₃OBH₄ exhibits ionic conductivity of 4.4 × 10^-3 S cm^-1 at room temperature (1.1 × 10^-2 S cm^-1 at 328 K) and activation energy of 0.25 eV. The ionic conductivity is 4 orders of magnitude higher than the existing antiperovskite Na₃OX (X = Cl, Br, I). It is shown that such enhancement is not only due to the specific cubic antiperovskite structure of Na₃OBH₄ but also because of the rotation of BH₄ cluster anion. This work deepens the understanding of the antiperovskite structure and the role of cluster anions for superionic conduction.