Enhanced Sodium-Ion Mobility and Electronic Transport of Hydrogen-Incorporated V2O5 Electrode Materials

Although alpha-V2O5 as an attractive electrode material for electrochemical energy storage devices exhibits a high theoretical capacity., its atomic structure with the confined size of channels for Na-ion transport and low electronic conductivity lead to the poor rate performance. Here we demonstrate that hydrogen incorporation in alpha-V2O5 is an effective way to improve the kinetics of ionic and electronic transports by using the density functional theory. Among various structures of hydrogen-incorporated alpha-V2O5, H2V2O5 presents enlarged diffusion channels along the [010] and [001] directions where the diffusion energy barriers decrease to 0.844 eV (-34.93%) and 1.737 eV (-41.81%), respectively. Improved electronic conductivity is also achieved for H2V2O5 due to the insulator metal transition attributed by the high concentration of hydrogen atoms. As H2V2O5 has smaller volume expansion occurring during the Na-intercalation process, H2V2O5 at the comparable specific capacity exhibits higher rate capability and cyclability than alpha-V2O5.