Physical and electrochemical behaviors of AgX (X = S/I) in a GeS2–Sb2S3 chalcogenide-glass matrix

Abstract

Ion-conducting chalcogenide glasses of a AgX (X = S/I)-modified GeSbS system were triumphantly synthesized through the conventional techniques of melt quenching. The evolution of the physical and structural natures of these samples were examined through density and microhardness tests, DSC, and Raman scattering spectroscopy. The electric features of the bulk samples were studied by means of impedance spectroscopy. Room-temperature ionic conductivity dramatically increased by six orders of magnitude from 7.68 × 10-10 to 3.54 × 10-4 S/cm with increasing Ag + content. The blocking effect, a novel phenomenon caused by the presence of a small amount of I ions in the glass system, was also observed, and its corresponding mechanism was proposed. The blocking effect hindered a portion of the mobile carriers in the network. Another phenomenon, i.e., the saturation of Ag ions, resulted in a slow increase in ionic conductivity at high Ag + dopant concentrations. These results provide novel insights into structural evolution and electrochemical properties of metal-doped solid electrolytes.

EFFECT OF Ga/Ge RATIONS ON THE STRUCTURE AND ELECTRIC PROPERTIES OF Ga–Ge–Sb–S–AgI SYSTEM

“…In this study, the relative atomic mass of Ge (72.64 g/mol) was higher than that of Ga (69.72 g/mol), which directly helped decrease the sample density. On the contrary, the chemical strength of Ga-S bond energy at 294 kJ/mol was higher than that of Ge-S bond energy at 265 kJ/mol [5,6,9], indicating the increase in hardness of the materials. Moreover, all samples maintained a glass transition temperature Tg of 170 °C-180 °C with stable thermal properties.…”

“…The two shoulders at 265 and 340 cm −1 belonged to the symmetrical stretching vibrations of [GeS 4 ] units in most Ge-based glasses. The other band at 360 cm −1 named "companion peak" was attributed to the edge-shared [GeS (4−x) I x ] mixed structure, and the three-dimensional network structure was produced by bridging the sulfur connections, the vibrations of bands near 106 cm −1 and 137 cm −1 assigned to [SbI 3 ] and [SbSI] structure units, respectively [9,10,14] . Replacing Ge with Ga in the network resulted in changes in the Raman spectra with a lowered vibration band at 265 cm −1 , indicating the formation of [S 3 Ge(Ga)-(Ga)GeS 3 ] units.…”

Transition metal chalcogenides for next-generation energy storage

“…Therefore, several modication strategies including doping of cations at the P site or halogen ions at the S site, forming hybrid organic-inorganic composites like polyethylene oxide-based Na 3 PS 4 , hightemperature heat treatment for crystal transformation, and ceramization and vitrication have been effectively explored to increase the stability, electrochemical performance, and mechanical properties of these next-generation solid-state chalcogenide electrolytes. [132][133][134][135][136][137][138] SIBs contain source materials that are cost-effective, abundantly available on earth, and do not pose any safety concerns. Therefore, they provide an attractive and more sustainable alternative to the existing lithium-ion technology.…”

Effective Approaches of Improving the Performance of Chalcogenide Solid Electrolytes for All-Solid-State Sodium-Ion Batteries

“…Ceramization and vitrification is also a common approach to modify the solid electrolyte (Tanibata et al, 2014b;Park et al, 2018;Tsuji et al, 2018;Ma et al, 2020). Vitrification is the process of transforming a substance into the glassy state, in which there is no crystal structure.…”

“…In recent years, chalcogenide glass-ceramic electrolytes have made great progress, such as Na 10 GeP 2 S 12 glass ceramic (1.2 × 10 −5 S cm −1 , RT) (Tsuji et al, 2018), 94Na 3 PS 4 •6Na 4 SiS 4 glass ceramic (7.4 × 10 −4 S cm −1 , RT) (Tanibata et al, 2014b), and AgX (X = S/I)-GeS 2 -Sb 2 S 3 glass (3.53 × 10 −4 S cm −1 , RT) (Ma et al, 2020). Recently, Kim et al reported a layered chalcogenide compound of composition Na 2 (Ga 0.1 Ge 0.9 ) 2 Se 4.95 with high room-temperature ionic conductivity (>10 −5 S cm −1 ), synthesized as a glass-ceramic composite in the ternary system Na 2 Se-Ga 2 Se 3 -GeSe 2 (Kim et al, 2014), as shown in Figure 2.…”