Elaboration and characterization of crystalline RF-deposited V2O5 positive electrode for thin film batteries

Investigations were realized on the microstructural and morphological evolution of RF-sputtered vanadium pentoxide thin films during growth. V2O5 thin films at different stages of growth were studied by spectroscopic ellipsometry, X-ray diffraction, atomic force microscopy and scanning electron microscopy. Film grain orientation, roughness and density were found to have notable evolution during growth. Electrochemical tests in liquid and solid electrolyte state configuration showed non-linear relationship between discharge capacity and V2O5 film thickness (<1 μm), which could be attributed in parts to the observed morphological and microstructural changes during growth, mainly the existence of a gradient density through film thickness and the pronounced top surface roughness.