The lithium transport through inter-and intra-particles in porous Li1-deltaCoO2 electrode was investigated in I M LiClO4 propylene carbonate (PC) solution by using electrochemical impedance spectroscopy (EIS) combined with cyclic voltammetry. The measured contact resistance and the lithium ion diffusivity were discussed as functions of the lithium content (1 - delta) and oxide particle size in terms of the lithium intercalation-induced stress.