Igniting Grotthuss Topochemistry in Hydrated Vanadium Pentoxide for High‐Performance Aqueous Zn‐Ion Batteries

ABSTRACT The pursuit of advanced aqueous Zn‐ion batteries (AZIBs) relies on the breakthroughs in cathode materials design. Vanadium pentoxide is considered as a promising cathode owing to the high theoretical specific capacity and open framework. However, its application is hindered by vanadium dissolution and slow Zn 2+ diffusion kinetics. Herein, we report a one‐pot hydrothermal method for the synthesis of 1,10‐phenanthroline intercalated V 2 O 5 · n H 2 O (Phen‐VOH). 1,10‐phenanthroline molecules serve as robust pillars to expand the interlayer spacing and stabilize the structure. Meanwhile, the co‐intercalated structural water creates a hydrogen‐bonding network, which can activate the ultrafast Grotthuss proton transport. Besides, this unique architecture, coupled with abundant oxygen vacancies, significantly enhances Zn 2+ ion diffusion and reaction kinetics. Consequently, the Phen‐VOH electrode delivers an exceptional cycling stability of 20 000 cycles with 75.3% capacity retention and a high capacity of 179.9 mAh g −1 at 10 A g −1 , substantially outperforming the pristine VOH counterpart. This work unlocks a promising strategy for developing high‐performance AZIBs cathodes with exceptional stability and rate capability.