Two-dimensional tetragonal Ti2BN: A novel potential anode material for Li-ion batteries

Abstract

In this work, we theoretically design a new class of two-dimensional (2D) ternary transition-metal compound, namely, tetragonal Ti2BN monolayer sheet. The first-principles calculations proved that this system exhibits good dynamic and thermal stability, inherent metal properties and good mechanical properties. Additionally, we investigate the suitability of 2D Ti2BN as host materials in Li-ion batteries (LIBs). Our results show that the diffusion barrier of Li on surface (24 meV) and interlayer (165 meV) of Ti2BN monolayer are extremely low. At 300 K, their corresponding diffusion coefficient of Li are 6.08 × 10−3 and 0.028 × 10−3 cm s−1, respectively. Besides, it also exhibits extremely high theoretical capacity (889 mA h g−1) and low average open circuit voltage (0.24 V). All these advanced properties indicate that Ti2BN monolayer is a promising negative electrode material for LIBs. In order to facilitate the experimental synthesis of this material, wetheoretically predicted that Ag (1 0 0), Au (1 0 0) and Sn (1 0 0) may be good growth substrates for Ti2BN sheet.