Enhancing electrochemical performance of vanadium pentoxide cathodes through Ruthenium doping: A first-principles study

The performance of orthorhombic vanadium pentoxide (V₂O₅) as a cathode material in lithium-ion batteries (LIBs) is hindered by several limitations, including low ion diffusion coefficients, poor cycling stability, and moderate electronic conductivity. In this study, a first-principles investigation is conducted on Ru-doped V₂O₅ using density functional theory (DFT) to address these challenges. The thermodynamic stability of both substitutional and interstitial doped materials is verified. An increase in unit cell volume is observed for both substitutional and interstitial doping, facilitating lithium-ion diffusion. Electronic structure calculations show a reduction in the band gap and an enhancement in electrical conductivity, improving cycling stability. Lithium diffusion pathways are identified using the nudged elastic band (NEB) method, and a lower energy barrier is observed for the doped compound compared to the undoped structure. Additionally, diffusion coefficients and ionic conductivities are found to be approximately 3.7 times higher in Ru-doped V₂O₅ than in pure V₂O₅. The intercalation voltage for Ru-doped V₂O₅ is calculated to be 4.35 V, surpassing the 3.05 V obtained for pure V₂O₅. These results highlight the potential of Ru-doped V₂O₅ as an advanced cathode material for next-generation LIBs.