Harnessing N─H···O═V Bonding Toward Stable Vanadium Cathodes in Ah‐Level Zn‐Ion Batteries

Abstract

ABSTRACT The vanadium‐based batteries deliver great potential in Ah‐level energy storage systems, ascribing to their high specific capacity. Nevertheless, the metal‐oxygen bonds are unstable in aqueous electrolytes, resulting in structural degradation and capacity attenuation. Here, inspired by the robust N─H···O═C bonding that stabilizes protein structures, we propose a bioinspired polymer‐integrated electrolyte based on poly(N‐acryloyl glycinamide) (PNAGA). The amide‐rich N‐H groups in PNAGA can anchor onto vanadium oxide units (O═V) via strong protein‐like intermolecular N─H···O═V interactions, which effectively stabilize the cathode framework by suppressing vanadium dissolution and preserving structural integrity during Zn 2+ intercalation and deintercalation. In addition, the PNAGA can establish an electron‐enriched environment on the vanadium cathode surface via N─H···O═V hydrogen bonding to accelerate redox kinetics for high rate capability and cycling stability. Consequently, the Zn/Zn 0.25 V 2 O 5 full battery delivers a high specific capacity of 286.2 mA h g −1 with 97% capacity retention over 1000 cycles at 2 A g −1 . Meanwhile, the PNAGA‐enabled pouch cell can achieve 1.35 Ah at 0.15 A g −1 , demonstrating a universal molecular design strategy for high‐performance aqueous vanadium‐based batteries.