Reinforced polyaniline/polyvinyl alcohol conducting hydrogel from a freezing–thawing method as self-supported electrode for supercapacitors

In the present work, by using the in situ polymerization of aniline in acidic aqueous solution of PVA and freezing–thawing method, the reinforced conducting polymer hydrogel of polyaniline/polyvinyl alcohol (PANI/PVA) was prepared and directly used as the self-supported electrode for supercapacitor. The chemical structure of PANI/PVA hydrogel was characterized by UV–Vis, and the three-dimensional (3D) interconnected hierarchical nanoporous structure was observed by scanning electron microscopy. The measurement of compressive strength demonstrated the high mechanical strength of the hydrogel. The electrochemical properties of PANI/PVA hydrogel electrodes were evaluated by using cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge/discharge, which indicated their good responsiveness and rate capability, low resistance, high specific capacitance (240 F/g at current density of 1 A/g) and excellent cycling stability. The easily fabricated PANI/PVA hydrogel combined hierarchical nanoporous microstructure, self-supported feature and favorable capacitive behavior and provided a new strategy for constructing high-performance electrode for supercapacitors.