skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: Impact of impurities on the thermal properties of a Li 2 S–SiS 2 –LiPO 3 glass
Abstract The preparation of 0.58 Li2S + 0.315 SiS2+ 0.105 LiPO3glass, and the impacts of polysulfide and P1Pdefect structure impurities on the glass transition temperature (Tg), crystallization temperature (Tc), working range (ΔT≡ Tc‐ Tg), fragility index, and the Raman spectra were evaluated using statistical analysis. In this study, 33 samples of this glass composition were synthesized through melt‐quenching. Thermal analysis was conducted to determine the glass transition temperature, crystallization temperature, working range, and fragility index through differential scanning calorimetry. The quantity of the impurities described above was determined through Raman spectroscopy peak analysis. Elemental sulfur was doped into a glass to quantify the wt% sulfur content in the glasses. Linear regression analysis was conducted to determine the impact of polysulfide impurities and P1Pdefect impurities on the thermal properties. Polysulfide impurities were found to decrease theTgat rate of nearly 12°C per 1 wt% increase in sulfur concentration. The sulfur concentration does not have a statistically significant impact on the other properties (α = 0.05). The P1Pdefect structure appears to decrease the resistance to crystallization of the glass by measurably decreasing the working range of the glasses, but further study is necessary to fully quantify and determine this.  more » « less
Award ID(s):
1936913
PAR ID:
10591431
Author(s) / Creator(s):
;
Publisher / Repository:
Wiley and Sons
Date Published:
Journal Name:
International Journal of Applied Glass Science
Volume:
15
Issue:
3
ISSN:
2041-1286
Page Range / eLocation ID:
317 to 328
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; (, Journal of the American Ceramic Society)
    Abstract In this report, a facile wet chemical method using acetonitrile combined with thermal annealing was used to prepare Li2S‐P2S5(LPS) based glass‐ceramic electrolytes with (1 wt%, 3 wt%, and 5 wt% Ce2S3) and without Ce2S3doping. The crystal structure, ionic conductivity, and chemical stability of Li7P3S11glass‐ceramic electrolytes were examined at varying temperatures (250–350°C). The results indicated that the highest ionic conductivity of 3.15 × 10−4S cm−1for pure Li7P3S11was observed at a temperature of 325°C. By incorporating 1 wt% Ce2S3and subjecting it to a heat treatment at 250°C, the glass ceramic electrolyte attained a remarkable ionic conductivity of 7.7 × 10−4(S cm−1) at 25°C. Furthermore, it exhibited a stable and extensive electrochemical potential range, reaching up to 5 volts when compared to the Li/Li+reference electrode. By tuning the glass transition and crystallization temperature, cerium doping seems to make Li7P3S11more chemically stable, compared to its original 70Li2S‐30P2S5counterpart. According to Raman and X‐ray photoelectron spectroscopy analyses, cerium doping inhibits the decomposition of highly conductive P2S74‐(pyro‐thiophosphate) to PS43−and P2S64−. Doped LPS has a greater crystallinity and more uniform microstructure than pure LPS, according to XRD, Raman spectroscopy, and scanning electron microscopy analysis. Consequently, Li7P2.9Ce0.1S11electrolyte shows great potential as a solid‐state electrolyte for constructing high‐performance sulfide‐based all‐solid‐state batteries. 
    more » « less
  2. ; ; ; (, Advanced Materials)
    Abstract Controlling crystallization kinetics is key to overcome the temperature–time dilemma in phase change materials employed for data storage. While the amorphous phase must be preserved for more than 10 years at slightly above room temperature to ensure data integrity, it has to crystallize on a timescale of several nanoseconds following a moderate temperature increase to near 2/3Tmto compete with other memory devices such as dynamic random access memory (DRAM). Here, a calorimetric demonstration that this striking variation in kinetics involves crystallization occurring either from the glassy or from the undercooled liquid state is provided. Measurements of crystallization kinetics of Ge2Sb2Te5with heating rates spanning over six orders of magnitude reveal a fourfold decrease in Kissinger activation energy for crystallization upon the glass transition. This enables rapid crystallization above the glass transition temperatureTg. Moreover, highly unusual for glass‐forming systems, crystallization at conventional heating rates is observed more than 50 °C belowTg, where the atomic mobility should be vanishingly small. 
    more » « less
  3. ; ; ; ; ; ; (, physica status solidi (b))
    The observation of reversibility windows (RWs) in binary GexS100−x, AsxS100−xand ternary GexAsxS100−2xglass systems permits constructing a global topological phase diagram in the GeAsS composition triangle. The RW denotes glass compositions for which the enthalpy of relaxation atTgvanishes, leading to thermally reversing glass transitions. The phase diagram permits delineating glass compositions that are in the flexible phase (FP), intermediate phase (IP), and the stressed rigid phase (SRP) for all ternary GexAsxS100−2xglass compositions. For the IP compositions examined, a general lowering of the molar volumes,Vm, is observed in relation to those for non‐IP compositions, giving rise to a volumetric window. Melt dynamics of IP compositions reveal a fragility index,m < 20, lower than that for non‐IP melts for whichm > 20 displays a fragility window, underscoring in part the reason for the delayed homogenization of melts in these sulfide glasses. The observations of the three types of window characteristics of IP compositions are feasible only when the homogeneous bulk glasses are synthesized, in which the variance ⟨Δx⟩ in As and Ge concentrations,x, across batch compositions is less than 0.01%. This is established by Fourier transform–Raman profiling of each batch of composition that is synthesized. 
    more » « less
  4. ; ; ; ; (, Journal of Polymer Science)
    ABSTRACT Brown grease (BG) is a high‐free fatty acid (FFA) waste coproduct from the food industry that remains largely unexploited. Herein, we describe a design strategy to upcycle BG into high sulfur‐content materials (HSMs) via inverse vulcanization, circumventing the need for costly transition metals or food‐grade compatibilizers. First, BG was esterified with methyl or allyl groups, yielding MeBG and aBG, respectively. This modification masked the polar carboxylic acids and enhanced miscibility with molten sulfur. Subsequent inverse vulcanization produced remeltable HSMs at 80 or 90 wt% sulfur with uniform elemental distributions by SEM–EDX. FT‐IR spectroscopy revealed the consumption of C=C moieties and the formation of C–S bonds, signifying robust cross‐linking. Thermal analysis (TGA, DSC) indicated good thermal stability (Td,5%up to 223°C) and glass transitions characteristic of polysulfide networks. Mechanical evaluations demonstrated compressive strengths up to 19.2 MPa, exceeding the minimum requirement for residential foundation‐grade cement (17 MPa) and rivaling previously reported HSMs containing similarly high sulfur content. Notably, MeBG and aBG incorporate organics comprising up to 97 wt% BG, significantly improving the upcycled mass efficiency relative to earlier BG‐based composites. This esterification‐driven approach thus offers a practical, scalable pathway to convert low‐value BG into advanced materials with tunable thermomechanical properties. 
    more » « less
  5. ; ; ; ; ; ; ; ; ; ; et al (, Advanced Materials)
    Abstract This is the first report of molybdenum carbide‐based electrocatalyst for sulfur‐based sodium‐metal batteries. MoC/Mo2C is in situ grown on nitrogen‐doped carbon nanotubes in parallel with formation of extensive nanoporosity. Sulfur impregnation (50 wt% S) results in unique triphasic architecture termed molybdenum carbide–porous carbon nanotubes host (MoC/Mo2C@PCNT–S). Quasi‐solid‐state phase transformation to Na2S is promoted in carbonate electrolyte, with in situ time‐resolved Raman, X‐ray photoelectron spectroscopy, and optical analyses demonstrating minimal soluble polysulfides. MoC/Mo2C@PCNT–S cathodes deliver among the most promising rate performance characteristics in the literature, achieving 987 mAh g−1at 1 A g−1, 818 mAh g−1at 3 A g−1, and 621 mAh g−1at 5 A g−1. The cells deliver superior cycling stability, retaining 650 mAh g−1after 1000 cycles at 1.5 A g−1, corresponding to 0.028% capacity decay per cycle. High mass loading cathodes (64 wt% S, 12.7 mg cm−2) also show cycling stability. Density functional theory demonstrates that formation energy of Na2Sx(1 ≤x ≤ 4) on surface of MoC/Mo2C is significantly lowered compared to analogous redox in liquid. Strong binding of Na2Sx(1 ≤x ≤ 4) on MoC/Mo2C surfaces results from charge transfer between the sulfur and Mo sites on carbides’ surface. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email