The diffusion coefficient of Li+ in the γ-lithium vanadium bronze (Li1+xV3O8) has been measured with the long-pulse galvanostatic technique. Values ranging from 1.7×10-7 cm2s-1, at x=0.3, to 2.2×10-8 cm2s-1, at x= 1.4, have been measured. The thermodynamic factors, d ln a/d ln c, determined from the OCV/x curve and from voltage relaxation after the current pulse, have a mean value of ∼15. The pseudo two-phase region observed in the OCV/x curve at high Li+ concentrations seems attributable to ordering of Li+ in specific sites and to alteration of the unit cell. This process is reversible as shown by X-ray diffractometry. Finally, from OCV/t plots at different x, the partial molar entropy of Li+ was determined. The values, on account of the large dE(x)/dt measured, are higher than those found for V6O13 or TiS2. © 1987.
Pistoia, G., DI VONA, M.l., Tagliatesta, P. (1987). Transport and equilibrium characteristics of γ-lithium vanadium bronze. SOLID STATE IONICS, 24(2), 103-109.
Transport and equilibrium characteristics of γ-lithium vanadium bronze
DI VONA, MARIA LUISA;TAGLIATESTA, PIETRO
1987-01-01
Abstract
The diffusion coefficient of Li+ in the γ-lithium vanadium bronze (Li1+xV3O8) has been measured with the long-pulse galvanostatic technique. Values ranging from 1.7×10-7 cm2s-1, at x=0.3, to 2.2×10-8 cm2s-1, at x= 1.4, have been measured. The thermodynamic factors, d ln a/d ln c, determined from the OCV/x curve and from voltage relaxation after the current pulse, have a mean value of ∼15. The pseudo two-phase region observed in the OCV/x curve at high Li+ concentrations seems attributable to ordering of Li+ in specific sites and to alteration of the unit cell. This process is reversible as shown by X-ray diffractometry. Finally, from OCV/t plots at different x, the partial molar entropy of Li+ was determined. The values, on account of the large dE(x)/dt measured, are higher than those found for V6O13 or TiS2. © 1987.Questo articolo è pubblicato sotto una Licenza Licenza Creative Commons