Sol-gel fabrication and lithium insertion kinetics of the Mo-doped lithium vanadium oxide thin films Li1-xMoyV3-yO8

Thin films of molybdenum-doped vanadium oxide bronzes Li1+xMOyV3-O-y(8) (0less than or equal toyless than or equal to0.20) were synthesized by sol-gel process in metal alkoxides solution. The influence of the applied hydrolysis ratio on the particle's shape and size, their location and orientation on the substrate has been investigated. The variation of both material morphology and unit cell geometry changes the lithium galvanostatic discharge capacity significantly. There are two factors resulted in increasing of material capacity: decreasing of (100) crystallite faces contribution to the whole particle surface and increasing of Mo-doping level y. Lithium chemical diffusion coefficient and exchange current density on the interface film/aprotic Li+-conducting electrolyte were determined on materials having optimized Mo-doping level and particle morphology at various Li concentrations in the host structure by electrochemical impedance spectroscopy. (C) 2002 Elsevier Science B.V. All rights reserved.