Improving the performance of a non-aqueous lithium-air battery by defective titanium dioxides with oxygen vacancies

Abstract

In this work, we proposed using titanium dioxides (TiO2) with oxygen vacancies (H-TiO2) as cathode catalysts to improve the electrochemical performance of non-aqueous lithium-air batteries. Such H-TiO2 catalysts were attained by a facile heat treatment of rutile TiO2 and the existence of vacancies was confirmed by Raman spectra and X-ray photoelectron spectroscopy (XPS). It was demonstrated that due to the presence of defects which can facilitate the adsorption and dissociation of oxygen, the in-house lithium-air battery with H-TiO2 can be discharged at the current densities of 0.3 and 0.5mAcm−2 while maintaining the specific capacities of 3.2 and 2.8mAhcm−2, respectively, much higher than those of the batteries without catalysts or with pristine rutile TiO2. In addition, the cycling test showed that the battery with H-TiO2 can undergo 400 and 372 cycles, respectively, at the current densities of 0.3 and 0.5mAcm−2 with a fixed specific capacity of 0.1mAhcm−2 and a cutoff discharge voltage of 2.0V.