Electrochemically Treated TiO(2) for Enhanced Performance in Aqueous Al-Ion Batteries

The potential for low cost, environmentally friendly and high rate energy storage has led to the study of anatase-TiO(2) as an electrode material in aqueous Al(3+) electrolytes. This paper describes the improved performance from an electrochemically treated composite TiO(2) electrode for use in aqueous Al-ion batteries. After application of the cathodic electrochemical treatment in 1 mol/dm(3) KOH, Mott–Schottky analysis showed the treated electrode as having an increased electron density and an altered open circuit potential, which remained stable throughout cycling. The cathodic treatment also resulted in a change in colour of TiO(2). Treated-TiO(2) demonstrated improved capacity, coulombic efficiency and stability when galvanostatically cycled in 1 mol·dm(−3)AlCl(3)/1 mol·dm(−3) KCl. A treated-TiO(2) electrode produced a capacity of 15.3 mA·h·g(−1) with 99.95% coulombic efficiency at the high specific current of 10 A/g. Additionally, X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy were employed to elucidate the origin of this improved performance.