PEDOT/Cobalt hexacyanoferrate free-standing films for high-performance quasi-solid-state asymmetric supercapacitor

Recently, with the increasing number of electronic devices and electric vehicles, supercapacitors have been investigated as high-performance energy storage devices. However, most electrodes fabricated with inactive additives (binder and conductive agent) have a problem with dead mass in the electrodes, which limits the application of lightweight energy storage devices. Herein, poly[3,4-ethylenedioxythiophene] nanowires (PEDOT NWs)/Cobalt hexacyanoferrate nanoparticles (CoHCF NPs) free-standing films (PCF films) were prepared using a vacuum-assisted filtration process. The PEDOT NWs acted not only as active materials but also as conductive substrates and provide numerous sites for the CoHCF NPs to achieve enriched redox reactions. The as-prepared free-standing PCF-4 electrode displays a high areal capacity of 386.4 mu A h cm-2 at a current density of 1 mA cm-2 and the long-term stability in 1 M Na2SO4 electrolyte. The fabricated quasi-solid-state asymmetric capacitor (PCF-4//activated carbon) shows a high energy density of 0.126 mW h cm-2 and power density of 0.82 mW cm-2.

Automated summary

In this study, poly[3,4-ethylenedioxythiophene] nanowires/cobalt hexacyanoferrate nanoparticles free-standing films were successfully prepared as high-performance energy storage electrodes. The electrodes showed high capacity and long-term stability, indicating their potential application in lightweight energy storage devices.