Conductive polymer intercalated vanadium oxide on carbon cloth for fast ammonium-ion storage in supercapacitor applications

Aqueous energy storage systems based on ammonium-ion (NH 4 + ) as charge carrier have attracted increasing interest owing to their great potential for large-scale application. Developing suitable cathodes (especially binder-free electrodes) for excellent NH 4 + storage is still in their infancy. Herein, a binder-free ACC@VPP electrode, activated carbon cloth (ACC) coated by polymer-intercalated vanadium oxide hydrate (VOH), is demonstrated to be an effective cathode to store NH 4 + for the first time. The polymer not only expands V-O interlayer space facilitating rapid ion diffusion, but also benefits VPP coated on ACC. The reversible (de)insertion of NH 4 + is along with hydrogen-bond fracture/formation between NH 4 + and V-O layers, ensuring encouraging electrochemical properties: a high superior capacitance of 511 F·g −1 (170 mAh·g −1 ) at 0.5 A·g −1 and durable lifetime over 10,000 cycles. The achieved performances exceed the state-of-the-art NH 4 + -hosting materials. Assembled flexible quasi-solid-state hybrid supercapacitor (QSS HSC) device delivers an areal capacitance of 411 mF·cm −2 and energy density of 3.2 Wh·m −2 at 1 mA·cm −2 . The performances of the QSS HSC devices in different deformation, series and parallel states show greatly potential practicability in the wearable energy supply. This contribution elucidates a new view to design binder-free electrodes for high-performance aqueous NH 4 + -SCs.