Solid-state ionics: Studies of lithium-conducting sulfide glasses and a superconducting oxide compound

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:7110202

Ahn, Byung Tae

The first part of this work studies lithium-conducting sulfide glasses for battery applications, while the second part studies the thermodynamic properties of a superconducting oxide compound by using an oxide electrolyte. Lithium conducting glasses based on the SiS{sub 2}-Li{sub 2}S system are possible solid electrolytes for high-energy-density lithium batteries. The foremost requirement for solid electrolytes is that they should have high ionic conductivities. Unfortunately, most crystalline lithium conductors have low ionic conductivities at room temperature. However, glass ionic conductors show higher ionic conductivities than do crystalline forms of the same material. In addition to higher ionic conductivities, glasses appear to have several advantages over crystalline materials. These advantages include isotropic conductivity, absence of grain boundary effects, ease of glass forming, and the potential for a wide range of stability to oxidizing and reducing conditions. Using pyrolitic graphite-coated quartz ampoules, new ternary compounds and glasses in the SiS{sub 2}-Li{sub 2}S system were prepared. Several techniques were used to characterize the materials: powder x-ray diffraction, differential thermal analysis, differential scanning calorimetry, and AC impedance spectroscopy. The measured lithium conductivity of the sulfide glasses was one of the highest among the known solid lithium conductors. Measuring the equilibrium open circuit voltages assisted in determining the electrochemical stabilities of the ternary compounds and glasses with respect to pure Li. A solid-state ionic technique called oxygen coulometric titration was used to measure the thermodynamic stability, the oxygen stoichiometry, and the effects of the oxygen stoichiometry, and the effects of the oxygen stoichiometry and the cooling rate on superconductivity of the YBa{sub 2}Cu{sub 3}O{sub 7-x} compound were investigated.

• Research Organization: Stanford Univ., CA (United States)
• OSTI ID: 7110202
• Country of Publication: United States
• Language: English

Related Subjects

25 ENERGY STORAGE
250900 -- Energy Storage-- Batteries
36 MATERIALS SCIENCE
360202 -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
360207 -- Ceramics
Cermets
& Refractories-- Superconducting Properties-- (1992-)
360602 -- Other Materials-- Structure & Phase Studies
360606* -- Other Materials-- Physical Properties-- (1992-)
ALKALI METAL COMPOUNDS
ALKALI METALS
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
CALORIMETRY
CHALCOGENIDES
CHEMICAL PREPARATION
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER OXIDES
DATA
DIFFERENTIAL THERMAL ANALYSIS
DIFFRACTION
ELECTRIC BATTERIES
ELECTRIC CONDUCTIVITY
ELECTRIC IMPEDANCE
ELECTRICAL PROPERTIES
ELECTROCHEMICAL CELLS
ELECTRODES
ELECTROLYTES
ELEMENTS
ENERGY LEVELS
EXPERIMENTAL DATA
FERMI LEVEL
GLASS
IMPEDANCE
INFORMATION
IONIC CONDUCTIVITY
LITHIUM
LITHIUM COMPOUNDS
LITHIUM SULFIDES
METALS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SCATTERING
SILICON COMPOUNDS
SILICON SULFIDES
SOLID ELECTROLYTES
STOICHIOMETRY
SULFIDES
SULFUR COMPOUNDS
SUPERCONDUCTORS
SYNTHESIS
THERMAL ANALYSIS
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION
YTTRIUM COMPOUNDS
YTTRIUM OXIDES