Lithium titanium oxynitride thin film with enhanced lithium storage and rate capability

The lithium titanium oxynitride (LTON) thin film electrode was prepared by radio frequency (RF) magnetron sputtering deposition using a cubic spinel structure Li ₄ Ti ₅ O ₁₂ (LTO) powder target in a N ₂ atmosphere for lithium ion batteries. XRD and SEM test results showed that the thin film was composed of weak crystal or amorphous structure and that its surface was homogeneous. XPS analyses indicated that nitrogen atoms were actually incorporated into the LTO matrix framework. The substitution of nitrogen for oxygen in the thin film created more abundant cross-linking structures, which favored the higher mobility of lithium ions. The LTON had a high capacity of 290 mAh g ^-1 at 0.1C, excellent rate capability of 160 mAh g ^-1 at 5C and only ≈7% capacity loss after 100 cycles at 5C charge and discharge rate. These properties make this thin film electrode a promising candidate material for use in thin film lithium ion batteries.