Vacancy-controlled quaternary sulfide Na_3−xZn_1−xGa_1+xS₄ with improved ionic conductivity and aqueous stability

Abstract

Solid electrolyte containing mobile alkaline ions is a key component in all-solid-state rechargeable batteries. In this work, a relatively new Na+-conducting solid electrolyte, Na3ZnGaS4, is investigated for a significant increase...

Topology driven and soft phonon mode enabled Na-ion diffusion in quaternary chalcogenides, Na3ZnGaX4 (X = S, and Se)

“…The crystal structures of Na 3 ZnGaX 4 (X = S, Se) have been described in the literature adequately. 45,46,60 Therefore, we briey touch upon the salient structural features here. Both compounds are isostructural, crystallising in a tetragonal crystal system with space group I4 1 /acd 60 (Fig.…”

“…Following Balijapelly's work, Han et al also demonstrated these compounds' excellent moisture and aqueous stability. 46 Therefore, we wanted to investigate these two pristine compounds, Na 3 ZnGaX 4 (X = S, Se), 45,46 and delve much deeper into the microscopic origin of good ionic conductivity through a combination of neutron scattering experiments and molecular dynamic simulations. To understand the diffusion process of Na-ions at the microscopic level, we performed inelastic neutron scattering (INS) and quasielastic neutron scattering (QENS) experiments and ab initio molecular dynamics (AIMD) simulations.…”

“…In this regard, it must be mentioned that some recently discovered Na-based superionic conductors containing chalcogenide elements like Na 3 PS 4 , 29,39 Na 3 FCh (Ch = S, Se, and Te), 40,41 Na 11 Sn 2 PS 12 , 31 Na 3 SbS 4 (ref. 42–44) and Na 3 ZnGaX 4 (X = S, Se) 45,46 are showing great promise with high ionic conductivity and low activation barriers at room temperature. Among these, Na 3 ZnGaX 4 (X = S, Se) caught our attention because of their high air and aqueous stability and ability to further improve the ionic conductivity through compositional adjustments.…”

“…45 Alternatively, by increasing the amount of Ga and controlling the Na vacancy, Han et al decreased the activation energy ( E b = 0.30 eV) and substantially increased the ionic conductivity (0.32 mS cm −1 ) in Na 3− x Zn 1− x Ga 1+ x S 4 . 46 Balijapelly et al reported that both compounds are moisture stable, i. e., not very sensitive to air. Following Balijapelly's work, Han et al also demonstrated these compounds' excellent moisture and aqueous stability.…”

Ultra‐High Capacity and Cyclability of β‐phase Ca0.14V2O5as a Promising Cathode in Calcium‐Ion Batteries

“…For density-functional theory (DFT) calculations, we selected the top 10 most stable configurations based on coulomb energy values because it is practically impossible to calculate all configurations in most distribution types. [60,61] For instance, the total number of configurations in Ca 0.67 V 2 O 5 with Ca 2+ distribution in M1 (SOF = 0.5) and M2 (SOF = 0.5) was 3920, including symmetry-related and unstable ones. The violin plot for Ca 0.14 V 2 O 5 showed that the most stable distribution occurs when all Ca 2+ ions are in M1 (no.…”