Dendritic growth mechanisms in lithium/polymer cells

Direct in situ observation of dendritic electrodeposition of lithium has be en performed in symmetrical lithium/PEO-LiTFSI cells under galvanostatic co nditions. Our experimental set-up allows us to measure simultaneously the v ariation of the cell potential, the evolution of the dendrites, and the var iation of the ionic concentration in the electrolyte around the dendrites. Depending on current density, we observe two different regimes for the dend ritic growth: at high current density, dendrites start when the ionic conce ntrations drop to zero at the negative electrode, whereas at low current de nsity, local inhomogeneities seem to play a major role. (C) 1999 Elsevier S cience S.A. All rights reserved.