Charged Lithium adsorption and diffusion on pristine and defective silicene as electrode material: A DFT study

JUAN, JULIÁN; BECHTHOLD, PABLO; ESCUDERO FEDERICO; GASTAÑAGA FRANCISCO; JASEN, P.V.; FACCIO, R.; GONZÁLEZ, E.A.

Antofagasta

Workshop; 7th International Workshop on lithium industiral minerals and energy; 2020

Li adsorption onto silicene is still not fully understood because of the lack of reliable experimental methods to make freestanding silicene so far. First-principle modeling is a powerful tool for battery research as it can accurately study the structural and electronic properties of electrode and electrolyte materials as well as the interactions between different materials.The aim of this work is to analyze the interaction of Li0 (Li atom), Li-ion (Li+1) and charged Li (Li-1) with pristine silicene single-layer and compare the performance among them. Herein we use First-principles calculations to study the adsorption and mobility of Li adatoms on a silicene sheet, using VASP code. We analyze the changes in the electronic structure, the diffusion of the Li adatoms using the Nudged Elastic Band method (NEB) and the charge density distribution through charge density difference diagrams in all cases. In addition, we calculate the quantum capacity (QC) and the average open circuit voltages (OCV). Our results show that the single vacancy generates new states in the Fermi level, which enhances the quantum capacity in positive biases. This fact makes this a promising candidate for application as supercapacitors electrodes. When Li adsorption is considered, we found that Li +1 is the most stable case. The lowest diffusion barrier for the pristine case is Li+1.