A spongy polypyrrole based conductive hydrogel with chemically tunable structures and electrochemical characteristics was developed for highly flexible solid-state supercapacitors.
Electrochemically active conducting polymers are an important class of materials for applications in energy storage devices such as batteries and supercapacitors, owing to their advantageous features of unique three-dimensional (3D) porous microstructure, high capacitive energy density, scalable synthesis and light weight. Here, we synthesized a nanostructured conductive polypyrrole (PPy) hydrogel via an interfacial polymerization method. The simple synthesis chemistry offers the conductive hydrogel tunable nanostructures and electrochemical performance, as well as scalable processability. Moreover, the unique 3D porous nanostructure constructed by interconnected polymer nanospheres endows PPy hydrogels with good mechanical properties and high performance acting as supercapacitor electrodes with a specific capacitance of ∼380 F g −1, excellent rate capability, and areal capacitance as high as ∼6.4 F cm −2 at a mass loading of 20 mg cm −2.