Thermodynamic and Mass Transport Properties of  “ LiAl ”

Abstract

The compositional variations of the thermodynamic and mass transport properties of the ~ phase "LiAr' in the lithium-aluminum system have been investigated over the temperature range from 415 ~ to 600~ At 415~ the emf of the single phase "LiAI" lies between 300 and 70 mV relative to pure Li and this corresponds to a 'Li activity increasing from 0.0063 to 0.31 over the phase stability range from 46.8 to 55.0 atomic percent Li. At the ideal stoichiometry, the standard Gibbs free energy of formation of "LiAI" is --29.2 kJ/mole at 415~ and the corresponding enthalpy and entropy are --43.3 kJ/mole and --20.6 J/mole ~ respectively. Two different electrochemical transient techniques have been used to measure the chemical diffusion coefficient in "LiAI" as a function of the stoichiometry; the experimental results obtained are in good agreement. On the lithium deficit side of the ideal stoichiometry, the chemical diffusion coefficient increases with decreasing Li concentration, becoming about 10 -4 cm2/sec near the phase boundary. On the other hand, it is composition independent on the Li excess side of "LiAI," varying with temperature from 2.4 • 10 -6 cm2/sec at 415~ to 1.8 • 10-~ * Electrochemical Society Active Member.

Bulk and Surface Properties of Liquid Al-Li and Li-Zn Alloys

“…It means that the calibration C d vs Re is developed by expressing this relation by polynomial Eq. [2]. It was done for pure aluminum because of known three determined physical properties.…”

“…[1] The attention has been paid for an even longer time to the use of lithium alloys as an alternative to elemental lithium. Especially interesting are the batteries working with molten salt electrolytes that operate above the melting point of lithium, the lithium-aluminum alloys, [2] for example. Apart from these, metallic systems: Li-Zn, Li-Sn, Li-Pb, etc.…”

Lithium/iron sulfide batteries for electric-vehicle propulsion and other applications. Progress report, October 1979-March 1980

“…Also, recent work 4 has shown that the chemical diffusion coefficient of lithium in S-LiAl at the a + S phase boundary is extraordinarily large, about 10~4 cm 2 /sec. These facts make it reasonable to suggest that Li-Al electrode agglomeration may involve sintering by processes of vacancy diffusion.…”

“…Efforts to measure E 1 were unsuccessful and E 4 and E 5 could not be measured because these transitions do not occur under equilibrium conditions in LiCl-KCl eutectic electrolyte.…”

Prediction of Lithium Diffusion Coefficient and Rate Performance by using the Discharge Curves of LiFePO4Materials

“…Electro-analytical methods such as galvanostatic intermittent titration technique (GITT), potentiostatic intermittent titration technique (PITT) and electrochemical impedance spectroscopy (EIS) were used to understand the ion transport. 7,8 The diffusion coefficient obtained by these methods was useful to understand the ion transport process.…”