Microstructural and electrochemical properties of lithium manganese oxide thin films grown by pulsed laser deposition

Abstract

The pulsed laser deposition (PLD) and one of its variants, the ultraviolet assisted pulsed laser deposition (UVPLD) techniques were used to deposit LiMn2O4 films on various substrate materials. The effects of processing variables on microstructural and electrochemical characteristics of the grown films were evaluated. Films possessing higher crystallinity were obtained at higher deposition temperatures while for identical deposition conditions UVPLD films possessed a higher degree of crystallinity and a smaller lattice constant than those grown by PLD. An oxygen-rich, defective spinel phase was identified for films deposited using the UVPLD method. The diffusion coefficient of Li for these films, measured using cyclic voltammetry, was found to reach much higher values, of around ∼10−8 cm2/s, for those deposited at lower temperatures compared with only ∼10−10 cm2/s values found for films deposited at higher temperatures.