DFT+DMFT Study of Li-Induced Delocalized Polaron and Burstein-Moss Shift in α-V₂O₅

V₂O₅, with its highest oxidation state of +5 (d⁰), exhibits strong electronegativity and a high degree of covalency in oxide compounds. It has long been a key material for studying electronic properties in transition metal oxides, as well as for applications in photocatalysis, smart windows, and electrochemical storage. We investigate the electronic properties of V₂O₅ and LixV₂O₅ (x = 0.125, 0.25) using density functional theory (DFT)+U and dynamical mean field theory (DMFT) with a continuous-time quantum Monte Carlo impurity solver. Pristine V₂O₅, a charge-transfer insulator with strong O p–V d hybridization, has a large band gap and a nonzero conduction-band gap. Our DMFT calculations show excellent agreement with experimental results for the band gap, number of vanadium d-electron (N_d), and conduction-band gap, while DFT+U overestimates N_d and underestimates the conduction-band gap. At low Li doping, the electronic behavior is driven by polarons, with DMFT identifying both free and bound polarons, while DFT+U predicts only free polarons. As Li doping increases, electrons fill the conduction band and shift the Fermi level, consistent with the observed Burstein-Moss shift. Our findings demonstrate that the DFT+DMFT approach provides an accurate and realistic description of strongly correlated materials.