Vanadium Doping Enhanced Electrochemical Performance of Molybdenum Oxide in Lithium‐Ion Batteries

Molybdenum trioxide (MoO3) suffers from poor conductivity, a low rate capability, and unsatisfactory cycling stability in lithium‐ion batteries. The aliovalent ion doping may present an effective way to improve the electrochemical performances of MoO3. Here, it is shown, by first‐principle calculations, that doping MoO3 with V by 12.5% can modulate significantly electronic structure and provide a small diffusion barrier for enhancing the electrochemical performance of MoO3. The ultralong Mo0.88V0.12O2.94 nanostructures, which retain the h‐MoO3 structure and present an exceptionally high conductivity and fast ionic diffusion due to the substitution of V, facilitating lithiation/delithiation behavior, and induce a fine nanosized structure with a reduced volume change are prepared. As a result, the stress and strain are alleviated during the Li‐ion intercalation/deintercalation processes, improving the cycling stability and rate capability. Such a large improvement in the electrochemical properties can be ascribed to the stabilizing effect of V, the small migration energy barrier, and short diffusion path, which arise from the introduction of V into MoO3. The unique engineering strategy and facile synthesis route open up a new avenue in modifying and developing other species of electrode materials. The fabrication of mixed Mo‐V oxides, according to theoretical calculations and experimental approaches, has a unique electronic structure and small diffusion barrier, leading to a more superior electrochemical performance compared to that of molybdenum oxides. In addition, the unique engineering strategy and facile synthesis route establish new avenues for the modification and construction of other electrode materials.