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

• TiO2 with oxygen vacancies was synthesized by a facile heat treatment method.
• Oxygen vacancies on TiO2 can effectively facilitate ORR in an aprotic electrolyte.
• The capacity of a Li-air battery was greatly increased by adding defective TiO2.
• Decent cycling performance was achieved with defective TiO2.

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 0.5 mA cm−2 while maintaining the specific capacities of 3.2 and 2.8 mAh cm−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 0.5 mA cm−2 with a fixed specific capacity of 0.1 mAh cm−2 and a cutoff discharge voltage of 2.0 V.