N-Doping-Induced Amorphization for Achieving Ultrastable Aqueous Zinc-Ion Batteries

Vanadium-based oxides, known for their high capacity and low cost, have garnered significant attention as promising cathode candidates in aqueous zinc-ion batteries. Nonetheless, their poor rate performance and limited durability in aqueous electrolytes present a challenge to the realistic implementation of vanadium-based aqueous zinc-ion batteries. Here, we synthesized nitrogen-doped V₂O₃@C (N-V₂O₃@N-C) via ammonia treatment of V₂O₃@C derived from vanadium-based metal-organic framework (V-MOF), aiming to achieve outstanding rate and cycling performance. The N-V₂O₃@N-C electrode exhibits notable in situ self-transformation into an amorphous state. Density functional theory calculations reveal that the distorted N-V₂O₃ structure and uneven charge distribution result in the creation of an amorphous state. As expected, Zn/N-V₂O₃@N-C aqueous zinc-ion batteries can achieve remarkable specific capacity (349.0 mAh g^-1 at 0.1 A g^-1), along with impressive rate performance, showcasing a capacity of 253.5 mAh g^-1 at 5 A g^-1 and exceptional durability at 5 A g^-1 (96.4% after 1350 cycles). The employed induced amorphization approach offers novel perspectives for designing high-performance cathodes that exhibit both sturdy structures and extended cycling lifespans.