MXene/PPy nanocomposite as an electrode material for high-capacity Na-ion batteries investigated from first principle calculation

Abstract

Mxene/Polypyrrole (Mxene/PPy) nanocomposite films are gaining importance for designing electrodes for energy storage applications. In this work, density functional theory (DFT) simulation is used to investigate the energy storage properties of PPy-based nanocomposite. The adsorption sites, adsorption energies, and electronic structures of Na storage abilities of Ti2CO2−MXene/PPy nanocomposite are all thoroughly investigated. The findings show that Na ion in Ti2CO2−MXene/PPy nanocomposite has high adsorption energy of −0.44 eV and a narrow energy bandgap of 0.02. The adsorption distance of the Na atom on the nanocomposite is relatively high. And according to charge transfer analysis from the electron density difference study, physisorption is the dominating adsorption mechanism for the Na-ion in the substrate. The Na-ion adsorbs onto the nanocomposite at 2.95 Å from the surface of the Ti2CO2−MXene and at a distance of 2.60 Å from the PPy. The projected density of state (PDOS) reveals the ability of the electrode to transmit electrons during the electrochemical process. This suggests that the Ti2CO2−MXene/PPy nanocomposite might be a promising Na-ion electrode material for battery use. As such, based on the nanocomposite's metallicity, chemical stability, and capacity to absorb sodium ions with low adsorption energy, which can result in effective Na release. It may be recommended for use as an anode.

Keywords

• Energy storage
• Na-ion battery
• Polypyrrole
• MXene
• Nanocomposite
• DFT