Preintercalation-Enabled Highly Oriented Open Interlayer Spacing and Dual-Site Storage in Vanadium Cathodes for Robust Aqueous Zinc Batteries

Vanadium-based materials possess an open framework, rich valence state variations, and high theoretical specific capacity, making them highly promising cathodes for zinc-ion batteries. However, conventional bulk layered vanadium cathodes exhibit low intrinsic conductivity and dense stacking, leading to strong interactions between Zn²⁺ and the V-O framework, poor interlayer coupling, and structural failure during cycling. Here, we employ an organic molecular preintercalation strategy to transform randomly stacked dense bulk V₂O₅ into highly (00l)-oriented open nanobelts (VEM), enabling directional Zn²⁺ diffusion within the interlayer channels. Imidazole (EM) pillars enlarge the gallery spacing to 1.25 nm and enhance the interlayer coupling, improving structural stability. Moreover, the EM can act as additional redox-active sites, coordinating Zn²⁺ to provide extra capacity and relieve flux-induced stress during discharge. As a result, VEM cathodes deliver 358.5 mAh g⁻¹ at 0.1 A g⁻¹, achieve 205.4 mAh g⁻¹ at 5 A g⁻¹, and retain 80% of the capacity after 8000 cycles. Notably, the assembled pouch cell delivers 0.54 Ah and maintains stable operation over 50 cycles. This work provides a design direction for achieving layered vanadium cathodes with stable large interlayer spacing.