On the Performances of CuxO-TiO2 (x=1, 2) Nanomaterials As Innovative Anodes for Thin Film Lithium Batteries

CuxO-TiO2 (x = 1, 2) nanomaterials are synthesized on polycrystalline Ti substrates by a convenient chemical vapor deposition (CVD) approach, based on the initial growth of a CuxO matrix (at 400 and 550 degrees C for x = 1 and 2, respectively) and the subsequent overdispersion of TiO2 at 400 degrees C. All CVD processes are carried out in an oxygen atmosphere saturated with water vapor. The obtained systems are investigated by means of glancing incidence X-ray diffraction (GIXRD), X-ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS), field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), and electrochemical experiments. Galvanostatic charge/discharge measurements indicate that Cu2O-TiO2 nanomaterials exhibit very attractive high rate capabilities (similar to 400 mA h g(-1) at 1 C; similar to 325 mA h g(-1) at 2 C) and good stability after 50 operating cycles, with a retention of 80% of the initial capacity. This phenomenon is mainly due to the presence of TiO2 acting as a buffer material, i.e., minimizing volume changes occurring in the electrochemical conversion. In a different way, CuO-TiO2 systems exhibit worse electrochemical performances as a consequence of their porous morphology and higher thickness. In both cases, the obtained values are among the best ever reported for CuxO-based systems, candidating, the present nanomaterials as extremely promising anodes for eventual applications in thin film lithium batteries.