The kinetics of lithium transport through LiNiO2 by current transient analysis

The kinetics of lithium transport through Li1-deltaNiO2 have been investiga ted in a 1 M solution of LiClO4 in propylene carbonate using current transi ent: technique. All the cathodic and anodic current transients experimental ly measured hardly follow the Cottrell behaviour. From the linear relations hip between initial current level in current transient and applied potentia l step. 'cell-impedance' was determined as a function of the electrode pote ntial. 'Cell-impedance' with the electrode potential calculated from the cu rrent transient, is similar in value to that of internal cell resistance co mposed of solution resistance, contact resistance, and absorption resistanc e obtained from the Nyquist plot. Taking the variation of 'cell-impedance' with the electrode potential into account, the lithium transport through th e Li1-deltaNiO2 electrode was theoretically analysed by means of numerical simulation of the current transient under the assumption of the 'cell-imped ance controlled' lithium transport. The current transients theoretically ca lculated quantitatively shared well those experimentally measured. Lithium transport through the Li1-deltaNiO2 electrode being even degraded by jumpin g the electrode potential to the value higher than 4.20 VLi/Li+, proceeds u nder the 'cell-impedance controlled' constraint. (C) 2001 Elsevier Science B.V. All rights reserved.