A NOVEL DFT STUDY OF QUANTUM CAPACITY AND ELECTRONIC STRUCTURE OF 2D MATERIALS FOR LI-ION BATTERIES

BRIZUELA

MECANICA COMPUTACIONAL

AMCA

Lugar: Santa Fe; Año: 2022

2D materials have a wide surface and unique electronic properties as compared to bulkmaterials. Due to the high stability, high abundance, and the existence of an excellent compatible oxide,Si and Si-based layered materials are the leading ones for microelectronic devices and may be the mostpromising materials for realistic applications. Lithium-ion batteries (LIBs) have become the mostsuccessful type of energy-storage device for applications ranging from portable electronic devices tomodes of transport such as electric vehicles, due to their lightweight, environmental friendliness, andhigh energy density. Si-based 2D materials, unlike metals, do not have a good screening. Therefore, itis expected that their intrinsic capacitance has a prominent influence on the performance of deviceswhen these materials are used in electrodes. We performed DFT calculations of Liq adsorption (q = -1,0 or +1) on a silicene single layer. Pristine and defective silicene configurations with and without Li doping were studied: single vacancy (SV), double vacancy (DV) and Stone-Wales (STW). Quantumcapacity (QC) and charge density studies were performed on Li adsorbed in various sites of the substrate. Moreover, structural studies, adsorption energies, electronic structure and charge density differenceanalysis were performed before and after adsorption at the most stables sites, which showed the presence of a magnetic moment in the undoped SV system, the displacement of the Fermi level produced by Lidoping and a charge transfer from Li to the surface. The QC analysis showed that the generation ofdefects and doping improves the QC of silicene in positive bias, because of the existence of 3p orbitalin the zone of the defect. Consequently, the innovative calculations performed in this work of chargedlithium doping on silicene can be used for future comparison with experimental studies of this Li-ionbattery anode material candidate.