An in situ electrochemical atomic force microscopy (EC-AFM) cell was developed to study surface and dimensional changes of individual LixCoO2 crystals during lithium cle-intercalation. Discrete Li2CO3 particles having 50-250 nm in diameter and 5-15 nm in height were observed on the surface of stoichiometric LiCoO2 crystals and they were shown to gradually dissolve into the LiPF6-containing electrolyte. The dimensional change of individual LixCoO2 crystals along the c(hex) axis was monitored in situ during lithium de-intercalation. Evidence of surface instability or structural instability was not found in LixCoO2 single crystals upon de-intercalation to 4.2 V versus Li. (c) 2007 Elsevier Ltd. All rights reserved.