Lithium diffusion in cerium-vanadium mixed oxide thin films: a systematic study

Three electroanalytical techniques have been used to study the solid-state ionic diffusion of lithium into cerium-vanadium mixed oxide thin films, i.e . potentiostatic intermittent titration technique, galvanostatic intermitte nt titration technique and electrochemical impedance spectroscopy. Diffusio n coefficients measured with the above mentioned techniques show a non-mono tonic decay between 8 x 10(-12) and g x 10(-14) cm(2) s(-1). In particular, lithium diffusion coefficient drops by mon than one order of magnitude at lithium intercalation degree x = 0.6. This abrupt change seems to be relate d to a dramatic increase of the material resistance suggesting that the lim iting factor in atomic lithium diffusion may be the low electronic conducti vity. (C) 2001 Elsevier Science Ltd. All rights reserved.