Two-dimensional conjugated coordination polymer monolayer as anode material for lithium-ion batteries: A DFT study

Abstract

Nowadays, lithium-ion batteries (LIBs) play a crucial role in modern society in the aspect of portable electronic devices and large-scale smart grids. However, the current performance of lithium-ion batteries has been unable to meet the growing expectations of society and scientific community. Herein, we have synthetically investigated availability of 2D Ni-TABQ monolayer as anode based on DFT for LIBs applications. Our findings have demonstrated that 2D Ni-TABQ monolayer is a semiconductor with a small band gap of 0.2 eV, which suggest that the electronic property of 2D Ni-TABQ monolayer would take place an evident shift from semiconductor property to metallic property after Li adsorption. Furthermore, we checked the stability of 2D Ni-TABQ monolayer and investigated the viability of exfoliation from bulk multilayer Ni-TABQ to form 2D Ni-TABQ monolayer in the light of exfoliation energy and binding energy. We continuously studied electrochemical properties of 2D Ni-TABQ monolayer with respect of theoretical specific capacity, Li-ion diffusion barriers and open-circuit voltage. During the charging process, 2D Ni-TABQ monolayer can achieve a high specific capacity of 722 mAh/g with an open-circuit voltage range from 1.12 V to 0.22 V. These aforementioned results make the 2D Ni-TABQ monolayer a promising anode for LIBs.