Promoting Electrochemical Performance of Ti3C2O2 MXene-Based Electrodes of Alkali-Ion Batteries via S Doping: Theoretical Insight

• DOI: 10.1021/acsami.1c17802
• Publication Date: 2021-11-23T21:17:32Z
• Authors: Paratee Komen; Lappawat Ngamwongwan; Sirichok Jungthawan; Anchalee Junkaew; Suwit Suthirakun
• Keywords: MXenes

Ti3C2O2 MXene has been proposed as a promising electrode material for alkali-ion batteries owing to its tunable physical and chemical properties without sacrificing the excellent metallic conductivity. However, it still suffers from low specific capacity due limited interlayer spacing, especially larger ion like sodium (Na). Sulfur doping was suggested viable strategy improve electrode's storage performance. Herein, first-principles calculations kinetic Monte Carlo (kMC) simulations were carried out study role of S on Li/Na intercalation. Based experimental findings, two different sites, C (SC) O (SO), with various concentrations reported therefore used models in this study. Computations reveal that both sites improves electronic conductivity MXenes their densities states at Fermi level are increased. In addition, doped an expanded lattice parameter normal direction, which agrees observations. only SO-doped display enlarged whereas site increases layer thickness. The spacing stabilities transport kinetics intercalation indicated by significantly lower insertion energies diffusion barriers when compared those pristine system. kMC account anisotropic obtained macroscopic coefficients apparent activation system clearly confirm superior kinetics. estimated Li(Na) improved 4(8) orders magnitude upon SO doping. A fundamental understanding capacitive serves good guide developing MXene-based materials Li- Na-ion batteries.