3.3-V-Rated edlc performance with an alternative conducting agent (Nc-RuO2.NH2o/kb)

Abstract

Nano-crystalline hydrous RuO2 particles that are hyper-dispersed within Ketjen Black (KB) matrix have been added as an alternative-conducting agent. In the present study, the authors succeeded in enhancing the EDLCs withstanding voltage from 2.7 to 3.3V by addition of small amount of MOx/KB (MOx = RuO2) composite. Addition of 4wt% RuO2/KB only in the positive activated carbon electrode dramatically increased the voltage limitation up to 3.3V. To date 3.3-V-rated EDLC (activated carbon based electrochemical capacitor) has never been attained. The test EDLC cell demonstrated a high energy density (18Whkg-1) with prolonged charge-discharge cycling up to 9000 times in the voltage range of 0-3.3V. In this study, the critical factors enabling such a high voltage operation have been investigated in relation to the mechanism that efficiently prevents consecutive water-induced chained failure mode reactions. © The Electrochemical Society of Japan, All rights reserved.