Type

Journal Article

Authors

Valeria Nicolosi
Beatriz Mendoza Sanchez

Subjects

Chemistry

Topics
single walled carbon nanotubes high rate cyclic voltammetry graphene electrochemical impedance spectroscopy electrochemical electrodes spray deposition high power

Scaleable ultra-thin and high power density graphene electrochemical capacitor electrodes manufactured by aqueous exfoliation and spray deposition (2013)

Abstract Graphene electrodes of high power density were manufactured by a surfactant-water based exfoliation method followed by a scaleable spray-deposition process. Cyclic voltammetry and galvanostatic charge–discharge experiments revealed a combination of electric double layer and pseudocapacitive behavior that, unlike the many graphene-oxide derived electrodes, was maintained to unusually high scan rates of 10,000 mV s−1, reaching a maximum capacitance of 543 μF cm−2 and with a capacitive retention of 57% at 10,000 mV s−1. The performance of graphene electrodes was contrasted with carboxylated single walled carbon nanotubes that showed a sharp decrease in capacitance above 200 mV s−1. Electrochemical impedance spectroscopy analysis showed a fast capacitor response of 17.4 ms for as manufactured electrodes which was further improved to 2.3 ms for surfactant-free 40 nm thick electrodes. A maximum energy density of 75.4 nW h cm−2 gradually decreased as power density increased up to 2.6 mW cm−2. Graphene electrodes showed 100% capacitance retention for 5000 cycles at the high power scan rate of 10,000 mV s−1.
Collections Ireland -> Trinity College Dublin -> Administrative Staff Authors (Scholarly Publications)
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Full list of authors on original publication

Valeria Nicolosi, Beatriz Mendoza Sanchez

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Valeria Nicolosi
Trinity College Dublin
Total Publications: 67