Fabricating alveolate poly(8-hydroxyquinoline) nanosheets to achieving high energy density for pseudo-capacitor

Abstract

Pseudocapacitive organic polymers with rich faradaic-active heteroatoms in an openly accessible skeleton could achieve high energy storage performance through redox processes. Through the coupling of bis(5,7-dibromo-8-quinolinolato) zinc(II) with MgO nanosheets, and upon template removing, there is the generation of materials that are based on 8-hydroxyquinoline. The as-prepared alveolated nanosheet is high in surface area (521 m2/g) and abundant in micropores and mesopores. Attributable to the unique hierarchically porous structure and diverse faradaic-active heteroatoms, the alveolate poly(8-hydroxyquinoline) nanosheet material yields a salient specific capacitance of 280.0 F/g at 1 A/g, along with superior long cycling stability for symmetric supercapacitor system. Besides, the assembled symmetric configuration displays a high energy density of 21.9 Wh/kg at power density of 187.5 W/kg in KOH electrolyte in the voltage range of 0–1.5 V. The outcome of the present study provides guidance for the design of all-polymer electrode materials for the development of efficient pseudocapacitors.