The diffusion mechanism of Li ion in a Cu thin film was investigated from first-principle calculations. The energy barriers for possible spatial hopping pathways were calculated with the adiabatic trajectory method. Theoretically, it was found that Li-ions could diffuse through a Cu thin film by successive nearest neighbour vacancy–atom exchanges at room temperature. It was found, by comparing the various mechanisms, that nearest-neighbour vacancy-assisted jumping was highly probable. It was also confirmed that more free diffusion could be observed by increasing the number of Cu vacancies in the thin film.

First-Principles Study of Li Ion Diffusion in Copper Thin Film. Z.H.Xiong, M.S.Lei: Chinese Physics, 2005, 14[6], 1199-204