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Hierarchically Porous Carbon with Manganese Oxides as Highly Efficient Electrode for Asymmetric Supercapacitors
Author(s) -
Chou Tsuchin,
Doong Rueyan,
Hu Chichang,
Zhang Bingsen,
Su Dang Sheng
Publication year - 2014
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201301014
Subject(s) - supercapacitor , materials science , nanocomposite , anode , cathode , chemical engineering , capacitance , electrolyte , carbon fibers , nanotechnology , transmission electron microscopy , electrode , energy storage , composite material , composite number , chemistry , engineering , power (physics) , physics , quantum mechanics
A promising energy storage material, MnO 2 /hierarchically porous carbon (HPC) nanocomposites, with exceptional electrochemical performance and ultrahigh energy density was developed for asymmetric supercapacitor applications. The microstructures of MnO 2 /HPC nanocomposites were characterized by transmission electron microscopy, scanning transmission electron microscopy, and electron dispersive X‐ray elemental mapping analysis. The 3–5 nm MnO 2 nanocrystals at mass loadings of 7.3–10.8 wt % are homogeneously distributed onto the HPCs, and the utilization efficiency of MnO 2 on specific capacitance can be enhanced to 94–96 %. By combining the ultrahigh utilization efficiency of MnO 2 and the conductive and ion‐transport advantages of HPCs, MnO 2 /HPC electrodes can achieve higher specific capacitance values (196 F g −1 ) than those of pure carbon electrodes (60.8 F g −1 ), and maintain their superior rate capability in neutral electrolyte solutions. The asymmetric supercapacitor consisting of a MnO 2 /HPC cathode and a HPC anode shows an excellent performance with energy and power densities of 15.3 Wh kg −1 and 19.8 kW kg −1 , respectively, at a cell voltage of 2 V. Results obtained herein demonstrate the excellence of MnO 2 /HPC nanocomposites as energy storage material and open an avenue to fabricate the next generation supercapacitors with both high power and energy densities.