Investigation on Titanium-based MXenes in Li-ion batteries: Empowering future electrodes

This paper evaluates Titanium-based MXenes, namely Ti2C, Ti2N, Ti3C2, Ti3N2, Ti4C3, and Ti4N3, with general formula of Tin+1Xn (X = C and N, n = 1, 2, 3), for implication as electrodes for Li-ion batteries. Comprehensive theoretical assessments are carried out using various approaches, via GGA and GGA + U, in the framework of density functional theory (DFT). Structural, electrochemical, electrical properties, and voltage- ranges/profiles are investigated. The relaxed structures, before and after delithiation, are reported, confirming structural stability of the considered MXene electrodes. The theoretical voltage is estimated by two approaches, namely Fermi and internal energies. The calculations suggest the better anodic characteristic for the nitrides. Evaluating the electrical properties (DOS diagrams) indicates that all the considered MXenes have high electrical conductivity and rate-capability. As the final metric, voltage-range and voltage-profile of the evaluated MXene electrodes are investigated. On this basis, descending order of the appropriate materials is reported. The conclusions suggest that the nitride MXenes deserve more experimental attention. This paper delves into the significance of using MXenes as intercalation electrodes, and sheds light on the transformative journey of Ti-based MXenes.