Author(s)

Wei Shi^1*, Masataka Ohta¹, Hiroaki Asakawa¹, Yuki Osaki¹, Mariko Murayama^1,2, Xinwei Zhao^1,3*

¹Department of Physics, Tokyo University of Science, Tokyo, Japan.
²Faculty of Science and Engineering, Toyo University, Saitama, Japan.
³International Institute for Urban Systems Engineering, Southeast University, Nanjing, China.

Solid electrolytes for all solid sodium-ion batteries have been attracting much attention as an alternative energy storage system, which have the advantage of being extremely safe because it can be charged quickly and is nonflammable. We have synthesized anti-perovskite type Na₃OX (X = Br, and I) electrolytes with high purity, by reactions of halogen mixtures with sodium oxides. After mixing, it was filled in an alumina crucible and heated for 6 hours at 330°C. It was confirmed that a large crystal strain was introduced by eutectication, which might reduce the activation energy of Na ion conduction and lead to an improvement of the conductivity. A relatively higher ionic conductivity of σ = 1.55 × 10^-7 S/cm at 60°C has been obtained for Na₃OBr_0.6I_0.4, which is about three orders higher than that in literature. A different ratio of X (X = Br, I) ions was added into sodium oxide to make the Na₃OX crystal. The influence of strain introduction on optimizing the bottleneck and improving the conductivity was discussed.

Sodium Ion Battery, Solid Electrolyte, Ionic Conductivity, Anti-Perovskite

Shi, W. , Ohta, M. , Asakawa, H. , Osaki, Y. , Murayama, M. and Zhao, X. (2023) Synthesis and Conductivity Characterization of Anti-Perovskite Na₃OX Solid Electrolytes for All Solid Na-Ion Batteries. Optics and Photonics Journal, 13, 189-198. doi: 10.4236/opj.2023.137017.