Achieving Fast kinetics and enhanced Li storage capacity for Ti₃C₂O₂ by intercalation of quinone molecules

In this work, we demonstrated that high Li storage capacity and fast kinetics are achieved for Ti₃C₂O₂ by preintercalating organic molecules C₆H₄O₂ and C₆F₄O₂. As compared to Ti₃C₂O₂ bilayer without linkers, considered pillared structures facilitate a much faster transport and higher charge/discharge rate for Li. For example, while the diffusion barrier of a Li ion within pristine Ti₃C₂O₂ bilayer is around 1.0 eV, it becomes 0.3 eV in pillared structures. Although we can only intercalate one monolayer of Li within pristine Ti₃C₂O₂ bilayer, our calculations showed that at least two layers of Li can be stored between Ti₃C₂O₂ layers of pillared structures, without forming bulk Li and losing the pillared structure upon Li loading/unloading. A small change in the in-plane lattice parameters (<1%) and interatomic bond lengths, and ab-initio molecular dynamics simulations prove the stability of the pillared structures against Li intercalation and thermal effects.