In-Situ Integration of Waste Coconut Shell Derived Activated Carbon/Polypyrrole/Rare Earth Metal Oxide (Eu2O3): A Novel Step Towards Ultrahigh Volumetric Capacitance

A facile approach to synthesize a hybrid polymeric composite with ultra-high volumetric capacitance by incorporating waste coconut shell derived activated carbon (AC) and rare-earth metal oxide (Eu2O3) into the polypyrrole (PPY) matrix has been reported in this work. The composite is synthesized via in situ oxidative polymerization. The PPY/AC/Eu2O3 composite stores energy both Faradaically and electrostatically. Further, the electrochemical performance gets augmented with the incorporation of rare earth metal oxide Eu2O3 owing to the availability of multiple valence states and development of stronger interaction with PPY which a good electron donor in turn leading to easy protonation of PPY. The asprepared composites exhibit a highest gravimetric capacitance 670 F g(-1) and an outstanding volumetric capacitance 1090 F cm(-3) at the current density of 1 A g(-1). Also, the composite with the maximum volumetric capacitance exhibits a high-power density of 4108 W L-1 with the maximum energy density of 37.85 Wh L-1 at the current density of 1 A g(-1). (C) 2017 Elsevier Ltd. All rights reserved.