Lithium Transport through Sputter Deposited Lithium Cobalt Dioxide Thin Film Electrode

Abstract

Lithium transport through lithium cobalt dioxide thin film electrode prepared by rf-magnetron sputtering was investigated in 1M solution of LiClO4 in propylene carbonate using cyclic voltammetry, galvanostatic intermittent titration technique (GITT) and potentiostatic current transient technique. The cathodic and anodic current transients exhibited the non-Fickian behaviour of lithium transport when the applied potential steps encountered potential plateaus near 3.91 VLi/Li+, determined from GITT. It is suggested that the occurrence of this abnormal behaviour during lithium intercalation and deintercalation is accompanied by a 'diffusion-controlled' alpha/beta phase transformation and 'cell-impedance-controlled' phase transformation, respectively. Lithium transport through the electrode comprising two phases of alpha and beta has been theoretically considered by a numerical analysis of the phase transformation.