Molecular dynamics study of mechanical stability of TiC MXene subjected to chirality, temperature, strain rate, and point-vacancy for Lithium-ion batteries.

Two-dimensional TiC MXene has recently emerged as a promising electrode for Lithium-ion batteries (LIBs) because of its outstanding ion-transport abilities and high Li-absorbability. This study employed molecular dynamics simulation to explore the mechanical stability of TiC MXene subjected to various temperatures, strain rates, and vacancy concentrations. A slightly superior tensile strength and elasticity modulus have been observed along zigzag directions, measuring 148.14 GPa and 29.17 GPa, respectively. On the other hand, armchair-oriented TiC MXene shows a considerably greater fracture strain of 0.259 due to its strain-hardening tendency at lower temperatures. Elevated temperature decreases both fracture strength and fracture strain, which is opposite to the effect of strain rate. Armchair loading has been revealed to be more sensitive to strain rate than its counter direction. Unlike temperature and strain rate, point vacancy significantly deteriorates the elastic modulus of TiC MXene. Carbon vacancies are more probable than titanium vacancies, which have less formation energy. The atomistic deformation profile supports the predicted values of fracture strain from stress-strain behavior. This in-depth study offers a detailed understanding of the mechanical behavior of TiC MXene under diverse circumstances, which will aid further experimental study and be beneficial for adopting TiC as anode materials in LIBs.