Untitled

Леонова, Л. С.; Tkacheva, N. S.; Bukun, N. G.

doi:10.1023/a:1016042232219

Cited by 1 publication

(1 citation statement)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The initial thermal event (I) occurs in the zone between 51 °C and 142 °C, with a dominant endothermic peak at 101 °C (rate of 0.21 μW mg −1 , enthalpy change ΔH of 74.66 μJ mg −1 ) resulting in a mass loss of 4.31%; this can be attributed to the loss of physisorbed water. Events of a lesser magnitude follow with thermal peaks at 168 °C (II: monoclinic to rhombohedral 2nd order phase transition, i.e., an A-type anomaly [40,58,61]), 282 °C (III: NH4H2PO4 decomposition [62]), and 431 °C (IV: chemisorbed water; susceptibility to hydration: NaAl5O8 (β''-alumina) > NaAl11O17 (β-alumina) > Na3Zr2Si2PO12 (NASICON) > Na3Sc2(PO4)3 (PHOSCAN) [63][64][65]) resulting in gradual losses until the residual mass was stabilized at 89.99% by the 800 °C mark. In contrast, TGA/DSC curves of the thermally treated material did not display event peaks of a significant magnitude, with minor mass losses being limited to less than 5%.…”

Section: Macro-and Microstructure Phase Investigationsmentioning

confidence: 99%

Ionic Conductivity and Dielectric Relaxation of NASICON Superionic Conductors at the Near-Cryogenic Regime

2021

View full text Add to dashboard Cite

With a crystal lattice structure first characterized in the 1970s, NASICON sodium-based superionic conductors have recently found renewed interest as solid electrolytes in sodium-ion and seawater flow batteries due to their exceptional ionic conductivity being on the same scale as liquid electrolytes. Since sodium ions in the crystal lattice move among interstitial positions through site-specific bottlenecks, the overall conductivity is strongly dependent on the NASICON composition. In this work, we report on the synthesis protocols and processing parameters of Na3Zr2Si2PO12 prepared from Na2CO3, SiO2, ZrO2, and NH4H2PO4 precursors by the conventional solid-state reaction (SSR) route. We critically evaluated important observations made in the extended literature on the topic including: (i) the importance of precursor particle size concerning the SSR synthesis, focusing on effective ball-milling protocols; and (ii) the onset of excess zirconia contamination, expanding on the effects of both thermal and pressure processing—the latter often overlooked in the available literature. In approaching the cryogenic regime, the dataset availability concerning ionic conductivity and dielectric permittivity measurements for NASICON was extended, starting from elevated temperatures at 200 °C and reaching into the very low temperature zone at −100 °C.

show abstract