Solid electrolytes based on theoretically identified double antiperovskite phases Li6OSI2 were successfully synthesized. Experimental characterization supported the theoretical prediction that S substitution of O leads to stabilization of the double antiperovskite structure and lattice softening to significantly enhance ionic conductivity, so that the total Li+ conductivity in Li6.5OS1.5I1.5 was two to three orders better than that of the best stoichiometric antiperovskite phase Li3OCl. However, both antiperovskite and double antiperovskite materials are fundamentally susceptible to surface reconstruction, which is behind significant boundary resistances typically known for materials based on antiperovskite hali-chalcogenides. Such a surface related problem was then effectively reduced through amorphous phase formation, thus offering a feasible route to exploit the full potential of this class of new materials as competitive candidates for solid Li-ion batteries.
Cu 2 Te-based compounds show promise for thermoelectric applications, but their synthesis typically involves ball milling or melting-annealing processes. Here, we present a surfactant-free microwave-assisted solvothermal method for the controlled synthesis of Cu 2 Te 1− x S x ( x = 0, 0.1, 0.2, 0.3, 0.4 and 0.5) nanostructures at 503 K within just 30 min. The substitution of sulfur promotes the formation of a hexagonal structure in Cu 2 Te 1− x S x with x of 0.2 – 0.5, and inhibits phase transitions during heating. Moreover, the alloying of sulfur contributes to a reduction in hole concentrations toward the optimal range, resulting in enhanced power factors ( e.g. , 910 μW m −1 K −2 at 825 K for Cu 2 Te 0.9 S 0.1 ) and reduced thermal conductivity ( e.g. , 0.53 W m −1 K −1 at 825 K for Cu 2 Te 0.5 S 0.5 ). Ultimately, Cu 2 Te 0.5 S 0.5 achieves a maximum dimensionless figure of merit of 0.80 at 825 K. This study offers a controllable solution-based strategy for synthesizing Cu 2 Te-based materials with tunable compositions and enhanced thermoelectric performance.
Rui Liao,Xiongjun Xiao,Huiling Huang,Kangjie Yu,Jianxia Tan,Yue Wang,Cong Li,Siyu Li,Yi Ma
This study investigated the potential of yeast polysaccharides (YPs) as an SO 2 substitute by adding varying concentrations (0–250 mg/L) prior to wine fermentation. The antioxidant activity and color stability were evaluated using UV–visible spectrophotometry, high-performance liquid chromatography, and colorimetric methods. Furthermore, HS-SPME-GC-MS and quantitative descriptive analysis were employed to compare the volatile compound profiles and sensory attributes between the optimal yeast polysaccharide treatment group (TS100, 100 mg/L) and the sulfur dioxide treatment group (S). Results showed that YPs addition effectively preserved phenolic compounds, with TS100 exhibiting the highest total phenols, flavonoids, and anthocyanins, where total anthocyanins reached 340.79 mg/L, a 2.52% increase over the S group. ABTS + scavenging activity showed no significant difference from the S group, confirming strong antioxidant capacity. Flavor compound content was higher in TS100 (10,458.99 μg/L) than in the S group (10,156.07 μg/L), with ethyl caprylate and ethyl decanoate being particularly prominent. These esters contributed intense fatty and fruity aromas, enhancing the overall sensory quality of the wine. In summary, 100 mg/L YPs addition yielded the best wine quality, demonstrating promising potential as an SO 2 alternative in winemaking.