Density functional theory (DFT) was employed to study the influence of the d-spacing on the Li + diffusion barriers in bilayered V2O5. First, a benchmark of DFT functionals was conducted using the generalized gradient approximation (GGA) with the Perdew-Burke-Ernzerhof (PBE) functional, the non-empirical strongly constrained and appropriately normed (SCAN) meta-GGA functional, and the hybrid Heyd-Scuseria-Ernzerhof (HSE) functional (α=0.25) within the projected augmented wave (PAW) method as implemented in the Vienna ab initio simulation package (VASP). The third generation (D3) semi-empirical van der Waals corrections proposed by Grimme and the revised Vydrov-van Voorhis (rVV10) nonlocal correlation functional, respectively, were integrated into the structure optimizations. In addition, the influence of including Hubbard-type correction to accurately depict the behavior of localized d-electrons on the structural parameters was tested with the datadriven Hubbard U values of UPBE=3.25 and USCAN=1.0 . The benchmarking of the DFT functional employed in this study is presented in Table of the Supporting Information. The plane-wave cutoff energy was set at 520 eV, with Monkhorst-Pack (MP) k-point meshes of 3 × 3 × 3 representing the Brillouin zone. Activation barriers and minimum energy paths for carrier hopping were determined by the climbing image nudged elastic band (cNEB) method. The diffusion path was first constructed by linear interpolation of atomic coordinates between initial and final states with five distinct images, followed by relaxation until the forces on all atoms were below 0.01 eV Å -1 . In the cNEB computations, the total energies were assessed using the SCAN+rVV10 functional, without incorporating any U corrections. Large supercells were used to ensure ion isolation from periodic images (ions separated by at least 10 Å). Initial atomic configurations were obtained from the Materials Project (MP) database.