LiCoO2 thin films with a preferential (104) orientation were prepared on An substrates by radio frequency magnetron sputtering. The Li-ion chemical diffusion coefficients (D) over tilde (Li) were measured by cyclic voltammetry (CV), galvanostatic intermittent titration technique (GITT), potentiostatic intermittent titration technique (PITT), and electrochemical impedance spectroscopy (EIS). The (D) over tilde (Li) values depended on the content of Li in Li1-delta CoO2. The (D) over tilde (Li) values by GITT and PITT were in the range of 10(-10)-10(-12) cm(2) s(-1) and 10(-11)-10(-12) cm(2) s(-1), respectively, and those by EIS varied over a more wide rang of from 10(-9) to 10(-12) cm(2) s(-1). It was found that the (D) over tilde (Li) values from different methods showed thickness independent. The (D) over tilde (Li) values from different methods were compared with those reported previously. (c) 2007 Elsevier B.V. All rights reserved.