Micro-Raman spectrometry was applied to the characterization of the Li x V 2 O 5 phases (0 ≤ x ≤ 1.8) electrochemically produced from V 2 O 5 thin films prepared by atomic layer deposition (ALD). An electrochemical study showed that V 2 O 5 ALD films constitute attractive positive electrodes for rechargeable lithium microbatteries. The good homogeneity and crystallinity of the films allowed us to obtain highresolution Raman spectra and to follow their transformation as lithium insertion proceeds. Specific Raman fingerprints were obtained for the successive a, e, d and g phases, and structural reversibility was evidenced for lithium uptake >1.

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The lithium intercalation into a V 2 O 5 substrate was studied by chronopotentiometry. The samples were prepared by atomic layer chemical vapor deposition which provides homogenous and coherent layers at the surface of titanium plates. During the chargedischarge process, various phase transitions occurred in the system Li-V 2 O 5 which induced a large change in the diffusion coefficient of lithium. To obtain an accurate analysis of the intercalation mechanism, the diffusion equation with a variable diffusion coefficient was solved by digital simulation. The thermodynamic and kinetic properties of the system are represented by an analytical model based on the complementary error function. This procedure was useful for study of the electrode behavior in a large concentration range or in a large potential domain. The influence of various parameters, such as the thickness of the sample or the thermodynamic enhancement factor, were examined.