TiO2 nanotubes manufactured by anodization of Ti thin films for on-chip Li-ion 2D microbatteries

The use of self-organized TiO2 nanotube arrays electrochemically grown onto Si is investigated for the fabrication of an alternative electrode dedicated to on-chip Li-ion 2D microbatteries. Discharge/charge curves and cycling performance are studied in lithium-anode electrochemical test cells for both amorphous and crystalline titania nanotubes. At 5 μA cm−2 amorphous TiO2 nanotube layers onto Si deliver a maximum areal capacity of 89 μAh cm−2 in the first reversible discharge and 56 μAh cm−2 over 50 cycles. We demonstrate that these nanostructured thin film electrodes showing such electrochemical performances are compatible with IC technology.