N-Functionalized Ti2b Mbene as High-Performance Anode Materials for Sodium-Ion Batteries: A Dft Study

Abstract

Exploring the electrode materials for rechargeable metal-ion batteries other than lithium is a key link to the design and development of the next-generation energy storage device. Herein, the structural stabilities of B, C, and N functionalized Ti 2 B were systematically discussed and the potential of the stable structure Ti 2 BN 2 as anode materials for Li-, Na-, K-, Mg-, Ca- and Zn-ion batteries was further studied using first-principles calculations. Specifically, phonon dispersion curves and ab-initio molecular dynamics simulations identified the dynamic and thermodynamic stability of Ti 2 BN 2 . The intrinsic metallic nature and non-magnetism of Ti 2 BN 2 were then revealed by band structure and density of state. Moreover, benefit from the light weight and energetically favorable bilayer Na adsorption, Ti 2 BN 2 exhibits a high theoretical capacity of 797 mA h/g for sodium-ion batteries (SIBs), which shows great advantage than most two-dimensional anode materials. Besides, the low diffusion barrier of 0.34 eV and suitable open-circuit voltage of 0.27 V further illustrate Ti2BN 2 is a competitive candidate for anode material of SIBs. Our work not only revealed a high-capacity electrode material of SIBs but also promoted the research of N-functionalized MBenes.

Keywords: First-principles, MBenes, Sodium-ion batteries, high theoretical capacity