The use of an electrocatalytic redox electrolyte for pushing the energy density boundary of a flexible polyaniline electrode to a new limit

Masumeh Hashemi | Mohammad S. Rahmanifar | Maher F. El-Kady | Abolhassan Noori | Mir F. Mousavi | Richard B. Kaner

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URL :   http://research.shahed.ac.ir/WSR/WebPages/Report/PaperView.aspx?PaperID=84581
Date :  2018/01/18
Publish in :    Nano Energy
DOI :  https://doi.org/10.1016/j.nanoen.2017.11.058
Link :  https://www.sciencedirect.com/science/article/pii/S2211285517307462
Keywords :redox, electrolyte, energy, boundary, electrode

Abstract :

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While the market for supercapacitors is rapidly growing due to their high power density, their low energy density compared to batteries represents a great barrier for the future of this technology. The poorly understood chemistry of electrode-electrolyte interfaces implies that there is substantial room for improvement through a careful design of the materials involved. Here we present a unique approach for improving the energy density of supercapacitors through redox additive-assisted electrocatalytic in situ regeneration of the electrode active materials. By utilizing a quinone-based redox electrolyte and a nanostructured conjugated polyaniline electrode, we continually regenerate the reactants, resulting in a redox supercapacitor having an extremely high energy density of 1091 Wh kg−1 (based on the total mass of the electrode active materials and the redox additive) and a high power density up to 196 kW kg−1. Considering the other outstanding properties of the polyaniline-naphthoquinone system, such as extreme flexibility (96 capacity retention after bending at an angle of 180° for 1000 cycles), non-flammability, and excellent cycling stability (84 capacity retention after 7000 cycles at 35 A g−1), such a well designed in situ regeneration of the electrode active materials makes this method a very promising approach towards the development of state-of-the-art energy storage devices.