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.