Mechanisms of lithium transport through transition metal oxides studied byanalysis of current transients

Lithium transport through such transition metal oxides as Li1+delta[Ti5/3Li 1/3]O-4, Li1-deltaNiO2 and LideltaV2O5 was investigated by analysis of curr ent transients. All the experimental current transients in shape deviated m arkedly from the Cottrell character during the whole intercalation/deinterc alation, and the initial current level varied linearly with the applied pot ential step according to Ohm's law. Moreover, it was observed that the curr ent transient during phase transformation is characterised by a 'current pl ateau'. The current transient was simulated as a function of applied potent ial by numerical analysis assuming 'cell-impedance-controlled' lithium tran sport. The numerically simulated current transient featured quantitative be haviour characteristic of non-Cottrell behaviour and exhibited a 'current p lateau'. The lithium transport mechanism through the oxides is discussed in terms of 'cell-impedance-controlled' intercalation/deintercalation. (C) 20 01 Elsevier Science Ltd. All rights reserved.