An approach to improve the Al3+ ion intercalation in anatase TiO2 nanoparticle for aqueous aluminum-ion battery

Abstract

There have been unprecedented research activities to identify electroactive materials for room temperature rechargeable aluminum-ion battery in the last 5 years. Titanium dioxide (TiO2) is emerging as a perspective anode material for aqueous aluminum-ion battery. We address here the phenomenon of Al3+ ion intercalation-deintercalation in anatase TiO2 nanoparticles. The study reveals that graphene significantly improves the electrochemical activity of TiO2 nanoparticles. It is estimated that incorporation of graphene enhances the Al3+ ion diffusion coefficient in TiO2 by 44 times. The graphene-TiO2 nanocomposite delivers an initial discharge capacity of 52 mAh g−1 at a very high current density of 6.25 Ag−1, whereas pristine TiO2 nanoparticle shows negligible capacities at a similar or lower current density. Remarkably, the reversible crystal phase transition of TiO2 to aluminum titanate (Al2TiO5) due to Al3+ ion intercalation-deintercalation is also observed for the first time.