Realizing Dual-Mode Zinc-Ion Storage of Generic Vanadium-Based Cathodes via Organic Molecule Intercalation

Intercalation engineering is a promising strategy to promote zinc-ion storage of layered cathodes; however, is impeded by the complex fabrication routes and inert electrochemical behaviors of intercalators. Herein, an organic imidazole intercalation strategy is proposed, where V₂O₅ and NH₄V₃O₈ (NVO) model materials are adopted to verify the feasibility of the imidazole intercalator in improving the zinc storage capabilities of vanadium-based cathodes. The intercalated imidazole molecules could not only expand interlayer spacing and strengthen structural stability by serving as extra "pillars" but also provide extra coordination sites for zinc storage via the coordination reaction between Zn²⁺ and the C═N group. This gives rise to a dual-mode ion storage mechanism and favorable electrochemical performances. As a result, imidazole-intercalated V₂O₅ delivers a capacity of 179.9 mAh g^-1 after 5000 cycles at 20 A g^-1, while the imidazole-intercalated NVO harvests a high capacity output of 170.2 mAh g^-1 after 700 cycles at 2 A g^-1. This work is anticipated to boost the application potentials of vanadium-based cathodes in aqueous zinc-ion batteries.