The influence of lithium excess in the target on the properties and compositions of Li1+x Mn2O4−δ thin films prepared by PLD

Abstract

Li–Mn–O thin films were deposited by pulsed laser deposition (PLD) onto stainless steel substrates using targets containing different concentrations of added Li2O. The influence of the target composition on the stoichiometry of the resulting thin films, the surface morphology and the electrochemical properties was studied. The application of the target with added 7.5 mol% Li2O results in an almost ideal lithium content, while all films were still oxygen deficient. The thin films were applied as electrodes in Li//Li1+x Mn2O4−δ cells (i.e. model cells for a rechargeable Li-ion battery) and characterized by cyclic voltammetry and galvanostatic charge/discharge experiments. The electrochemical measurements of the thin films confirmed that the thin films can serve as good model systems and that they show a sufficient cyclability.