Exploring the potential of Ti2BT2 (T = F, Cl, Br, I, O, S, Se and Te) monolayers as anode materials for lithium and sodium ion batteries

Abstract

Introducing functional groups to two-dimensional transition metal borides (MBenes) is an effective way to ameliorate the properties of MBenes as electrode materials for rechargeable lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). Herein, we investigated the electrochemical performances of Ti2BT2 (T = F, Cl, Br, I, O, S, Se and Te) as anode materials for LIBs and SIBs using first-principles calculations. Firstly, the metallic nature of Ti2BT2 endows them with excellent conductivities. Besides, the phonon dispersions and ab initio molecular dynamics simulations (AIMD) were conducted to estimate the dynamic and thermal stability of Ti2BT2. Additionally, Ti2BSe2 has slight high specific capacity of 405 mA h g−1 for LIBs and Ti2BS2 possesses ultra-high specific capacity of 942 mA h g−1 for SIBs. Furthermore, the low diffusion energy barriers endow ultra-high charge/discharge rate and suitable open circuit voltages ensure the safety of battery performance. The encouraging results indicate that Ti2BSe2 and Ti2BS2 are outstanding candidates as electrode materials for LIBs and SIBs, respectively. Our work not only screened out excellent electrode materials for metal-ion batteries, but also provided constructive suggestions for the development of next-generation high-performance electrode materials.