Pulsed laser–deposited Li2TiO3 thin film electrodes for energy storage

Abstract

Li2TiO3 (LTO) is a promising Ti-based material showing interesting electrochemical performance, good structural stability, cost-effectiveness, and non-toxic electrode material for energy storage and conversion. In this work, thin films of LTO have been deposited by the pulsed laser deposition (PLD) technique on Au/Ti/SiO2/textured Si multilayer substrates maintained at different temperatures (Ts) in a partial pressure of 0.4 mPa, and the microstructural properties are investigated. The as-deposited films are textured and contain TiO2 impurities. The LTO thin films grown at Ts of 600 °C are observed to be phase pure with a predominant (002) orientation related to the β-Li2TiO3 phase with C2/c symmetry. As electrodes for lithium microbatteries, LTO thin films delivered a specific discharge capacity of 46 μAh cm−2 μm−1 in the voltage range 0.0–1.0 V vs. Ag/AgCl and retained 91% capacity after 30 discharge cycles; as electrodes for supercapacitors, LTO thin films displayed a specific capacitance of 283 mF cm−2 at a current density of 1 mA cm−2 and retained 94% capacitance over 1000 cycles. The dual nature of the films demonstrates that the LTO films are suitable electrodes for supercapattery application.