Novel CuTe monolayer as promising anode material for Na-ion batteries: A theoretical study

With the rise of graphene in 2004, two-dimensional (2D) materials with atomic thickness have drawn numerous attentions due to their novel physicochemical properties, which have been widely applied in various fields, including but not limited to catalysis, batteries and capacitors. In this work, employing theoretical analysis based on density functional theory calculations and force-field molecular dynamics simulations, we report a new 2D material, monolayer copper telluride (ML-CuTe). Results show that ML-CuTe can be obtained readily by exfoliating its bulk counterpart. Furthermore, we proved that the exfoliated ML-CuTe is demonstrated to have excellent thermodynamic, kinetic and mechanical stabilities. And more notably, similar to graphene, ML-CuTe is metallic, which should be beneficial to be used as electrode material in ion-batteries. Through systematically investigating the adsorption and diffusion of Na atoms on the surface of ML-CuTe, we revealed that ML-CuTe possess a considerable specific capacity of 290 mA h mol(-1), moderate Na diffusion energy barrier (0.31-0.72 eV) and relatively low average open-circuit voltage (0.12-0.32 V), identifying the practicability of ML-CuTe as an anode material of Na-ion batteries. Our work enriches the database of 2D materials and provides a promising candidate for anode material of Na-ion batteries.