Phase Equilibria in Lithium-Chalcogen Systems

Abstract

The equilibrium phase diagram of the lithium-tellurium phase system has been investigated. Eutectic points occur at 179.9~ and greater than 99.0 atomic per cent (a/o) lithium, 448.5~ and 35.7 a/o lithium, and 423.1~ and 10.5 a/o lithium. Two intermediate phases, Li2Te and LiTes, are present having melting points of 1204.5 ~ and 459.9~ respectively.

Self-Assembly of Bi2Te3-Nanoplate/Graphene-Nanosheet Hybrid by One-Pot Route and Its Improved Li-Storage Properties

“…During the second cathodic scan, the peak at 2.0 V almost disappears, the peak at 0.6 V is shifted to a higher value of 0.7 V (A’), while the peak at 1.2 V is divided into two peaks, B’ and C’, located at 1.35 and 1.65 V, respectively. The division of the peak means that the reaction of Te with Li occurs via a two-step mechanism by forming LiTe 3 and Li 2 Te successively, both of which are stable phases at room temperature [32]. The lower peak potential in the first cathodic scan compared with those in the subsequent scans is due to the additional energy required for the displacement reactions of Bi 2 Te 3 upon Li uptake [4].…”

On the crystal structure of LiTe3

“…This compound, first reported by Foster, Johnson, Davis, Peck & Schablaske (1969), then confirmed by Cunningham, Johnson & Cairns (1973), melts congruently at 460°C and forms simple eutectics with Te at 423°C and with Li2Te (fluorite structure, Zintl, Harder & Dauth, 1934) at 449°C. Cunningham et al (1973) stated that X-ray powder patterns of LiTe 3 were consistent with a body-centered-cubic structure with a = 6.162/k; the nature of that structure was not specified.…”

“…This compound, first reported by Foster, Johnson, Davis, Peck & Schablaske (1969), then confirmed by Cunningham, Johnson & Cairns (1973), melts congruently at 460°C and forms simple eutectics with Te at 423°C and with Li2Te (fluorite structure, Zintl, Harder & Dauth, 1934) at 449°C. Cunningham et al (1973) stated that X-ray powder patterns of LiTe 3 were consistent with a body-centered-cubic structure with a = 6.162/k; the nature of that structure was not specified. In this paper, we present a more detailed description of the X-ray diffraction data and show that applications of modulated symmetry theories to the problem yield a structure with only one variable parameter whose value may be fixed by qualitative comparisons of predicted and observed intensities.…”

“…Since [ai [= 6.1620(2) A at t = 21°C, it follows that IA,I = 8.7144(3) A and [CI = 5.3364 (2) A, with an axial ratio of 0.61237 (4) (~x/~ within experimental error). If it is assumed that the cubic pseudocell contains two formula weights of LiTe3, the X-ray density is 5.532(1) g cm-3; Cunningham et al (1973) gave a density of 5.29 (25) g em -3 measured with an aircomparison pycnometer.…”

“…Data were recorded with a relatively lowresolution powder diffractometer (HB-3) at the HighFlux Isotope Reactor at a wavelength of 1.542 A. reported by Cunningham et al (1973). Corrected for differences in multiplicity, main reflections with all cubic indices even were systematically more intense than those with two indices odd.…”