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Hierarchically Nanoperforated Graphene as a High Performance Electrode Material for Ultracapacitors
Author(s) -
Mhamane Dattakumar,
Suryawanshi Anil,
Unni Sreekuttan M.,
Rode Chandrashekhar,
Kurungot Sreekumar,
Ogale Satishchandra
Publication year - 2013
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201202670
Subject(s) - graphene , supercapacitor , materials science , capacitance , graphite , electrode , electrolyte , power density , current density , oxide , graphite oxide , nanotechnology , nanoparticle , chemical engineering , composite material , power (physics) , chemistry , physics , quantum mechanics , engineering , metallurgy
High performance is reported for a symmetric ultracapacitor (UC) cell made up of hierarchically perforated graphene nanosheets (HPGN) as an electrode material with excellent values of energy density (68.43 Wh kg −1 ) and power density (36.31 kW kg −1 ). Perforations are incorporated in the graphite oxide (GO) and graphene system at room temperature by using silica nanoparticles as template. The symmetric HPGN‐based UC cell exhibits excellent specific capacitance ( Cs ) of 492 F g −1 at 0.1 A g −1 and 200 F g −1 at 20 A g −1 in 1M H 2 SO 4 electrolyte. This performance is further highlighted by galvanostatic charge–discharge study at 2 A g −1 over a large number (1000) of cycles exhibiting 93% retention of the initial Cs . These property features are far superior as compared to those of symmetric UC cells made up of only graphene nanosheets (GNs), i.e. graphene sheets without perforations. The latter exhibit Cs of only 158 F g −1 at 0.1 A g −1 and the cells is not stable at high current density.