Enhanced electrochemical properties of LiCo0.5Ni0.5O2 by Ti-doping: A first-principle study

Ti-doping effects on the structure stability, Li+ diffusion, and working voltage of LiCo0.5Ni0.5O2 have been studied based on first-principle total energy calculations. It is revealed that due to Ti-doping, the structure stability of LiCo0.5Ni0.5O2 is enhanced because of the decrease of both the formation energy and the lattice distortion during lithium deintercalation. The diffusion of Li+ gets improved because the introduction of Ti weakens the electrostatic attraction effect of the host on Li+. Furthermore, after Ti-doping, the relaxation energy during lithium deintercalation decreases owing to the alleviation of Jahn–Teller effects, while the contribution of oxygen atoms to the redox process increases, resulting in the increase of the working voltage. Our research gives an effective method to investigate the cathode materials’ doping effect, which benefits for the design of electrode materials in lithium-ion battery.