Novel Mg-ion conductive oxide of μ-cordierite Mg0.6Al1.2Si1.8O6

Hayami Takeda; Koki Nakano; Naoto Tanibata; Masanobu Nakayama

doi:10.1080/14686996.2020.1730237

Novel Mg-ion conductive oxide of μ-cordierite Mg_0.6Al_1.2Si_1.8O₆

Sci Technol Adv Mater. 2020 Feb 20;21(1):131-138. doi: 10.1080/14686996.2020.1730237. eCollection 2020.

Authors

Hayami Takeda^{1

2}, Koki Nakano¹, Naoto Tanibata^{1

2}, Masanobu Nakayama^{1

2

3

4}

Affiliations

¹ Department of Advanced Ceramics, Nagoya Institute of Technology, Nagoya, Japan.
² Elements Strategy Initiative for Catalysts and Batteries (ESICB), Kyoto University, Kyoto, Japan.
³ Frontier Research Institute for Materials Science (FRIMS), Nagoya Institute of Technology, Nagoya, Japan.
⁴ Center for Materials Research by Information Integration (CMI2), Research and Services Division of Materials Data and Integrated System (Madis), National Institute for Materials Science (NIMS), Tsukuba, Japan.

Abstract

Solid electrolytes with high Mg-ion conductivity are required to develop solid-state Mg-ion batteries. The migration energies of the Mg²⁺ ions of 5,576 Mg compounds tabulated from the inorganic crystal structure database (ICSD) were evaluated via high-throughput calculations. Among the computational results, we focused on the Mg²⁺ ion diffusion in Mg_0.6Al_1.2 Si_1.8O₆, as this material showed a relatively low migration energy for Mg²⁺ and was composed solely of ubiquitous elements. Furthermore, first-principles molecular dynamics calculations confirmed a single-phase Mg²⁺ ion conductor. The bulk material with a single Mg_0.6Al_1.2Si_1.8O₆ phase was successfully prepared using the sol-gel method. The relative density of the sample was 81%. AC impedance measurements indicated an electrical conductivity of 1.6 × 10^-6 Scm^-1 at 500°C. The activation energy was 1.32 eV, which is comparable to that of monoclinic-type Mg_0.5Zr₂(PO₄)₃.

Keywords: 107 Glass and ceramic materials; 207 Fuel cells / Batteries / Super capacitors; 401 1st principle calculations; AC impedance spectra; Mg ion batteries; density functional theory; high-throughput materials search; solid electrolytes.