Interface porosity in multilayered all‐conducting polymer electrodes

Multilayered films made with at least two different electroactive polymers, in which the least conducting one acts as a dielectric and separates the layers made with the other, behave as efficient electrodes for electrochemical supercapacitors. In this work, we present a simple strategy to develop improved multilayered electrodes with structured interfaces by enhancing the porosity of the dielectric. This has been achieved by growing sodium chloride crystals onto a conducting polymer layer and, after generation of all required layers using the layer-by-layer electrodeposition technique, salt crystals have been eliminated by water etching. Results from morphological and topographical studies on single-layered poly(3,4-ethylenedioxythiophene) (PEDOT), poly(N-methylpyrrole) (PNMPy), and poly(3,4-ethylenedioxythiophene-co-N-methylpyrrole) (COP), as well as electrochemical investigations on bi-layered films with enhanced porosity at the interface between the two layers, have been used to design new four-layered electrodes. These consist in two layers of PEDOT separated by two layers of nanosegregated COP with a porous interface in the middle. Although the properties of the new four-layered electrodes improve due to the porous interface, the highest specific capacitance corresponds to the two-layered electrode in which two PEDOT layers are separated by an ultra-porous interface.