Ionic conductivity, lithium insertion and extraction of lanthanum lithium titanate

Chen, CH Amine, K

Ch. Chen et K. Amine, Ionic conductivity, lithium insertion and extraction of lanthanum lithium titanate, SOL ST ION, 144(1-2), 2001, pp. 51-57

19

INGLESE

Article

Apllied Physucs/Condensed Matter/Materiales Science

SOLID STATE IONICS

0167-2738 → ACNP

144

1-2

2001

51 - 57

ISI

0167-2738(200109)144:1-2<51:ICLIAE>2.0.ZU;2-4

The lithium ionic conductivity and electrochemical stability of perovskite La2/3-xLi3xTiO3 (LLTO) have been determined with AC impedance spectroscopy, cyclic voltammetry and galvanostatic cycling. Ionic conductivity of La0.55 Li0.35TiO3 and La0.57Li0.29TiO3 pellets sintered from four different powder s was measured in the temperature range from 30 to 110 degreesC. Bulk condu ctivity was found to be closely related to the calcination temperature of t he powders. Pellets from 1100 degreesC-calcined powders had higher bulk con ductivity than from 1200 degreesC-calcined powders. The grain-boundary cond uctivity was mainly determined by the sample composition. The activation en ergies were 0.14-0.18 eV for bulk conduction and 0.41-0.43 eV for grain-bou ndary conduction. Lithium was intercalated into LLTO below about 1.8 V vs. Li. With addition of acetylene black, about 0.48 Li was reversibly inserted into and extracted out of La0.55Li0.35TiO3. A phase transition is proposed to take place during the lithium insertion. Published by Elsevier Science B.V.