Regulating Extra‐Layer Ion Channels in the Conductive V2O5 Hydrogel Cathode

Abstract High‐power energy storage devices rely on the synergistic coordination of ion and electron transport. Here, an extra‐layer channels engineering strategy is presented for developing high power and energy density cathode materials for aqueous zinc batteries (AZIBs). This approach utilizes a cation‐induced self‐assembly process to form conductive hydrogels with extra‐layer channels by adding diverse cations (Li + , Na + , K + , Mg 2+ , Zn 2+ , Al 3+ , and NH 4 + ) into the carbon nanotubes (CNTs) ink dispersed hydrated V 2 O 5 (h‐V 2 O 5 ) nanowires. The cations bridge h‐V 2 O 5 nanowires and create self‐assembly network on the CNT surfaces, providing extra‐layer ion channels beyond the intrinsic interlayer of h‐V 2 O 5 . These external channels exhibit distinct properties depending on the cations, significantly influencing the performance of V 2 O 5 hydrogel cathode for AZIBs. Larger cations reduce Zn 2+ migration resistance enhancing diffusion kinetics; smaller cations strengthen the M─O bond, improving structural stability. For instance, K‐V 2 O 5 /CNT demonstrates an initial specific capacity of up to 618 mAh g −1 at 0.2 A g −1 and retains a capacity of 248 mAh g −1 even at 20 A g −1 . In contrast, the Zn‐V 2 O 5 /CNT maintains excellent cycling stability, with 230 mAh g −1 after 700 cycles at 1 A g −1 . This offers a versatile platform for tailoring ion transport channels in hydrogel cathodes for ZIBs