First-principle calculations of lithium adsorption and diffusion on titanium-based monolayers

Abstract

Rechargeable lithium-ion batteries with excellent mobility and intrinsic safety have attracted great attention for energy storage applications. The performance of electrode materials greatly impacts the development of lithium-ion batteries Titanium-based. 2D materials such as TiO2, Ti2C, and TiCl2, with a high surface-to-mass ratio and excellent surface morphology exhibit a significant promising application on lithium-ion batteries. In this paper, first-principle calculations are carried out to investigate the electronic structure, Li storage capability and diffusion pathway of TiO2, Ti2C, TiCl2 monolayers. The results indicate that TiO2, Ti2C, and TiCl2 monolayers were slightly doped by lithium ions and show metallic electronic structures. According to NEB calculations, TiO2, Ti2C possessed very low diffusion energy barrier and high ion hopping rate of 7.5 × 1010 s−1 and 1.92 × 1012 s−1, respectively. The calculated capacities for the single-layer lithium ion adsorption of TiO2 and Ti2C is 670, 496 mA h g−1. We also explored the double-layer lithium-ion adsorption characteristics on TiO2 and Ti2C surfaces, which greatly enhance the theoretical lithium storage capacity of the material (1342, 995 mA h g−1). Accordingly, that TiO2 with hexagonal fluorite-like (111) morphology was promising for anode materials in new generation lithium-ion batteries.