Vanadium‐Iodine Co‐Regulation Enabled by Trifunctional Conjugated Organic Interface for High‐Energy and Robust Zn Batteries

Aqueous Zn batteries (AZBs) utilizing vanadium-iodine dual energy storage mechanisms hold great promise for large-scale energystorage applications. Yet, the development of such AZBs is plagued by severe vanadium dissolution and uncontrolled polyiodideshuttling during the multi-step electron transfer process. Herein, we reported a core–shell VO2 cathode wrapped in situ by aconjugated poly(phenylenediamine) (pPDA) layer, denoted VO2– pPDA, which enables highly reversible and efficient V 5+/V4+/V3+and I−/I 0 redox reactions in ZnI 2 -containing electrolytes. According to in/ex situ characterizations and theoretical calculationresults, abundant ─C═N─ moieties in poly(PDA) enabled a synergistic optimization for the stabilization of VO 2 and interfacialiodine anchoring. Meanwhile, the π-conjugated framework of poly(PDA) collaborated with VO2 to catalyze the high-efficiencyiodine conversion. Due to V-I co-regulation, Zn//VO 2 -pPDA battery exhibited a high working voltage of 1.09 V, ultrahigh capacityof 610 mAh g−1 , and outstanding lifespan over 40 000 cycles. Moreover, a practical 1.0 Ah pouch cell further demonstrated thestrong application potential of this system, highlighting the effectiveness of multifunctional interfacial organic engineering forhigh-performance Zn batteries.