Morphology-controlled fabrication of polypyrrole hydrogel for solid-state supercapacitor

Conducting polypyrrole (PPy) hydrogels are considered as one promising class of materials for high performance supercapacitors because they synergize the unique features of conducting polymers and hydrogels with three-dimensional porous network. PPy hydrogels are synthesized in the absence of any additional crosslinkers by using ammonium persulfate as the oxidizing agent and sodium dodecylsulfonate as the surfactant. The as-prepared hydrogels exhibit nanoparticle-based porous networks with high surface area and electrical conductivity. The effect of different oxidants on the formation and the morphology of PPy hydrogels are also studied. The facile synthesis method offers PPy hydrogels morphology-controllable nanostructures and good mechanical property, as well as scalable processability. Moreover, PPy hydrogels coated on carbon cloth as binder free electrodes are further used for the fabrication of a symmetric solid-state supercapacitor with good rate capability, cyclic stability and bendable performance. Based on the simple fabrication and electrochemical performances, this PPy hydrogel can be expected as a potential material for flexible energy storage device.