Mechanism of Sodium-Ion Diffusion in Alluaudite-Type Na 5 Sc(MoO 4 ) 4 from NMR Experiment and Ab Initio Calculations

Nadezhda I. Medvedeva, Anton L. Buzlukov, Alexander V. Skachkov, Aleksandra A. Savina, Vladimir A. Morozov, Yana V. Baklanova, Irina E. Animitsa, Elena G. Khaikina, Tatiana A. Denisova, Sergey F. Solodovnikov

Research output: Contribution to journalArticlepeer-review

16 Citations (Scopus)

Abstract

The crystal structure, electronic properties, and sodium diffusion mechanism in Na 5 Sc(MoO 4 ) 4 were investigated using the powder X-ray diffraction, nuclear magnetic resonance, and electrical conductivity measurements, as well as ab initio calculations. Na 5 Sc(MoO 4 ) 4 belongs to the family of alluaudite-type oxides Na x M y (AO 4 ) 3 (M = In, Sc, Mg, Cd, Zn, Mn, Fe, Co, and Ni; A = Mo, W, P, As, and S), which are now considered as promising materials for sodium-ion batteries. Our results demonstrate a considerable difference in the mechanism of Na + ion transport in Na 5 Sc(MoO 4 ) 4 and in previously studied alluaudite oxides, where one-dimensional sodium diffusion was suggested to occur through channels along the c-axis. The Na + motion in Na 5 Sc(MoO 4 ) 4 is found to be rather two-dimensionally occurring along the bc-plane. We believe that filling of the M-sublattice plays a key role in the mechanism of Na + ion diffusion in alluaudite compounds. In particular, in Na 5 Sc(MoO 4 ) 4 characterized by a low Sc-occupancy of the M-sublattice, the sodium ions located far from scandium are the first to be activated with increasing temperature and the activation energy for their jumps, E a ≤ 0.3 eV, has one of the lowest values among Na-conductive materials.

Original languageEnglish
Pages (from-to)4729-4738
Number of pages10
JournalJournal of Physical Chemistry C
Volume123
Issue number8
DOIs
Publication statusPublished - 28 Feb 2019

Fingerprint

Dive into the research topics of 'Mechanism of Sodium-Ion Diffusion in Alluaudite-Type Na 5 Sc(MoO 4 ) 4 from NMR Experiment and Ab Initio Calculations'. Together they form a unique fingerprint.

Cite this