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

초록

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 (Ead) 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.

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