High pseudocapacitance of MnO 2 nanoparticles in graphitic disordered mesoporous carbon at high scan rates

Mehul N. Patel, Xiqing Wang, Daniel A. Slanac, Domingo A. Ferrer, Sheng Dai, Keith P. Johnston, Keith J. Stevenson

Research output: Contribution to journalArticlepeer-review

90 Scopus citations

Abstract

Nanocomposites composed of MnO 2 and graphitic disordered mesoporous carbon (C MnO2/C) were synthesized for high total specific capacitance and redox pseudocapacitance (C MnO 2) at high scan rates up to 200 mV s -1. High resolution transmission electron microscopy (HRTEM) with energy dispersive X-ray spectroscopy (EDX) demonstrated that MnO 2 nanodomains were highly dispersed throughout the mesoporous carbon structure. According to HRTEM and X-ray diffraction (XRD), the MnO 2 domains are shown to be primarily amorphous and less than 5 nm in size. For these composites in aqueous 1 M Na 2SO 4 electrolyte, C MnO2 reached 500 F/g MnO2 at 2 mV s -1 for 8.8 wt% MnO 2. A capacitance fade of only 20% over a 100-fold change in scan rate was observed for a high loading of 35 wt% MnO 2 with a C MnO2 of 310 F/g MnO2 at the highest scan rate of 200 mV s -1. The high electronic conductivity of the graphitic 3D disordered mesoporous carbon support in conjunction with the thin MnO 2 nanodomains facilitate rapid electron and ion transport offering the potential of improved high power density energy storage pseudocapacitors.

Original languageEnglish
Pages (from-to)3160-3169
Number of pages10
JournalJournal of Materials Chemistry
Volume22
Issue number7
DOIs
StatePublished - Feb 21 2012

Fingerprint

Dive into the research topics of 'High pseudocapacitance of MnO 2 nanoparticles in graphitic disordered mesoporous carbon at high scan rates'. Together they form a unique fingerprint.

Cite this