TITLE:
Synthesis and Conductivity Characterization of Anti-Perovskite Na3OX Solid Electrolytes for All Solid Na-Ion Batteries
AUTHORS:
Wei Shi, Masataka Ohta, Hiroaki Asakawa, Yuki Osaki, Mariko Murayama, Xinwei Zhao
KEYWORDS:
Sodium Ion Battery, Solid Electrolyte, Ionic Conductivity, Anti-Perovskite
JOURNAL NAME:
Optics and Photonics Journal,
Vol.13 No.7,
July
31,
2023
ABSTRACT: 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 Na3OBr0.6I0.4, 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.