Self-supported sulphurized TiO2 nanotube layers as positive electrodes for lithium microbatteries

Abstract

We report the synthesis and characterization of self-supported sulphurized TiO2 nanotube layers as a cathode material for Li microbatteries. Sulphurized TiO2 nanotubes were obtained by annealing of self-supported TiO2 nanotubes in sulphur atmosphere. The morphology, structure, composition and thermal stability of the TixOySz nanotube layers were studied by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and thermogravimetric analysis. The electrochemical behaviors of the chemically modified nanotubes were investigated by cyclic voltammetry and chronopotentiometry techniques. This nanostructured electrode used as a cathode material showed high rate capabilities even at very fast kinetics. Remarkably, a high discharge capacity (340 μAh cm−2) has been retrieved after 100 cycles with 100% coulombic efficiency attesting the excellent stability of the electrode.