Layered ion dynamics and enhanced energy storage: VS2/MXene heterostructure anodes revolutionizing Li-ion batteries

Abstract

Two-dimensional (2D) material-based anodes are pivotal for advancing next-generation ion batteries, showing remarkable ion loading capacity and mobility. In this intricate study, we employed first-principles calculations to delve into the five-layer lithium ion (Li-ion) loading on transition-metal dichalcogenide (TMD; specifically VS₂) paired with MXene (Ti₃C₂O₂ and V₃C₂O₂) heterostructures. Our investigation meticulously assessed adsorption sites, binding energies, and charge transfers. Using sophisticated first-principles calculations, we probed into the Li-ion intercalation process, meticulously determining open-circuit voltages (OCV), which intriguingly ranged from 3.14 to 1.30 V for VS₂/Ti₃C₂O₂ and 2.60 to 0.73 V for VS₂/V₃C₂O₂. The adsorption energies (E_ad) were equally fascinating, with values of −2.86 eV per Li-ion for VS₂/Ti₃C₂O₂ and −2.65 eV per Li-ion for VS₂/V₃C₂O₂. The optimized VS₂/Ti₃C₂O₂ heterostructure demonstrated a staggering Li storage capacity of 425.84 mA h g⁻¹. Not far behind, the VS₂/V₃C₂O₂ heterostructure exhibited a notable Li storage capacity of 413.19 mA h g⁻¹, surpassing previously reported 2D anode materials. Following this, ab initio molecular dynamics (AIMD) simulations exposed significant variations within the VS₂/Ti₃C₂O₂ and VS₂/V₃C₂O₂ heterostructures. These simulations suggest that both the VS₂/Ti₃C₂O₂ and VS₂/V₃C₂O₂ heterostructures are not only promising, but also highly efficient anode materials for the realization of sustainable Li-ion batteries.