Orbital and Electrical Dual Function of Polymer Intercalant for Promoting NH₄⁺ Storage in Vanadium Oxide Anode

Abstract Polymer‐intercalated metal oxides have attracted considerable attention for ammonium ions (NH₄⁺) storage due to their enhanced interlayer space, which, through the pillar effect, facilitates rapid and efficient transport of NH₄⁺. However, the understanding remains limited regarding how polymer intercalants affect the intrinsic structure of host materials, especially the variations in atomic orbital and electronic structural induced by the intercalants. Herein, a polyaniline‐intercalated vanadium oxide (P‐VO_x) is developed and, for the first time, its NH₄⁺ storage behavior is validated as an anode material. Using various spectroscopy techniques combined with theoretical simulation, the changes are analyzed in atomic orbital and electronic structure induced by the intercalant. Spectroscopy studies reveal that the insertion of polyaniline optimizes the electronic structure of V₂O₅, promoting the transition of electrons to the V 3d_xy state and increasing the occupation of the V t_2g orbital, thereby enhancing electrical conductivity. Computational results confirm that P‐VOx lowers the NH₄⁺ migration barrier, thereby enhancing electron/NH₄⁺ transfer. As a result, the P‐VO_x electrode demonstrates outstanding capacity and unprecedented long‐term cycling stability. This study provides new insights into the atomic and electronic structural changes induced by the polymer intercalant and underscores the advantages of polymer‐intercalated VO_x as a high‐performance electrode for NH₄⁺ storage.