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 selfsupported 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 mu Ah cm(-2)) has been retrieved after 100 cycles with 100% coulombic efficiency attesting the excellent stability of the electrode. (C) 2019 The Authors. Published by Elsevier Ltd.