SIMULATION OF GROWTH AND CORROSION DURING THE FORMATION OF A PASSIVE LAYER

From the analysis of experiments relative to the formation of a passiv e layer at the Li-solvent interface a model is proposed in order to de scribe the gross features concerning the growth of this layer. In this model the growth is initiated by chemical reactions partially counter balanced by a poisoning process. The model which works at a mesoscopic scale is simulated on a two-dimensional lattice. A quantitative analy sis of the results shows that this model appears as the superposition of the Eden model which describes the structure of the front and a sim ilar percolation process which determines the properties of the bulk p art of the layer as its porosity. A second model in which the corrosio n is taken into account is introduced. It is analyzed in a very simple case in which there is no poisoning. The corrosion induces a restruct uring in the layer and this gives rise to a porosity in the bulk part of the layer. Some unexpected results are interpreted. (C) 1998 Elsevi er Science S.A. All rights reserved.