It was shown that a combination of quasi-equilibrium (chronopotentiometric) and kinetic (electrochemical impedance) measurements could be used to extract ionic mobility data such as the jump diffusion coefficient, DJ. Results were presented on the variation, with composition, of the jump diffusion coefficients of several cations (Li+, Na+, K+) intercalated into electron-beam evaporated a-WO3 thin films. It was found that DJ exhibited its highest values for the smallest ion (Li+), and then decreased as the ion size increased. In all cases, DJ took lower values at high intercalation levels. It was noted that the type of cation influenced transport mechanisms rather than equilibrium properties (insertion thermodynamics). The energy barrier to ion hopping was analyzed in terms of available microscopic diffusion models and simulations.

Jump Diffusion Coefficient of Different Cations Intercalated into Amorphous WO3. G.Garcia-Belmonte, J.García-Cañadas, J.Bisquert, C.Person: Solid State Ionics, 2006, 177[19-25], 1635-7