Synergistic Effects of Structural and Electronic Dual Engineering for Ultra-Stable Aqueous Zinc-Ion Batteries

Abstract

Layered vanadium-based oxides have emerged as promising cathode materials for aqueous zinc-ion batteries (AZIBs) owing to their high theoretical capacity, multivalent vanadium species, and low cost. However, their practical development has been hindered by limitations such as narrow interlayer spacing and structural instability. To address these challenges, we successfully generated oxygen vacancies by a one-step hydrothermal method, and simultaneously inserted benzyltrimethylammonium organic cations (TMBA+) into the interlayers of V2O5 to obtain a VOH-TMBA+ composite electrode material, realizing the dual-strategy modification of V2O5. In the resulting VOH-TMBA+, oxygen vacancies and TMBA+ synergistically expand the interlayer spacing from 6.84 to 13.8 Å, stabilize the layered framework, and modulate the local atomic coordination and electronic structure. This “structural-electronic” dual regulation endows VOH-TMBA+ with a high specific capacity of 417.2 mAh g−1 at 0.2 A g−1 and exceptional cycling stability (90.7% capacity retention after 7000 cycles at 10.0 A g−1). In-situ XRD/Raman and ex-situ XPS/SEM characterizations clarify that the VOH-TMBA+ electrode is an energy storage mechanism based on H+/Zn2+ co-insertion/extraction. Furthermore, density functional theory calculations demonstrated that the conductivity of VOH-TMBA+ is further enhanced, while the reduction of electrostatic interactions facilitates the transfer of Zn2+. This work provides a generalizable strategy for engineering layered metal oxides through collaborative structural and electronic modulation, offering perspectives for designing high-performance cathode materials in AZIBs. (Figure presented.).