TiO2 nanopowder as a high rate, long cycle life electrode in aqueous aluminium electrolyte

Abstract TiO 2 nanopowders have been used to manufacture negative electrodes and their cycle life, efficiency and rate capability investigated for use in aqueous Al-ion cells. A high efficiency of 99% was measured when an electrode was cycled at 7.2 A g −1 (360C) in 1 mol dm −3 AlCl 3 /1 mol dm −3  KCl and a discharge capacity of 20 mA h g −1 could be maintained for nearly 4000 cycles at 100 C. Also explored is the low coulombic efficiency seen for TiO 2 in previous aqueous Al-ion publications, while mass loading and electrolyte O 2 content affect coulombic efficiency. The high coulombic efficiency and charge/discharge current make these electrodes suitable for use in charge storage devices targeted at high power/low capacity applications, such as capturing bursts of power during regenerative breaking.