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Highly Conductive and Porous Activated Reduced Graphene Oxide Films for High-Power Supercapacitors
journal contribution
posted on 2016-02-21, 14:55 authored by Li Li Zhang, Xin Zhao, Meryl D. Stoller, Yanwu Zhu, Hengxing Ji, Shanthi Murali, Yaping Wu, Stephen Perales, Brandon Clevenger, Rodney S. RuoffWe present a novel method to prepare highly conductive,
free-standing,
and flexible porous carbon thin films by chemical activation of reduced
graphene oxide paper. These flexible carbon thin films possess a very
high specific surface area of 2400 m2 g–1 with a high in-plane electrical conductivity of 5880 S m–1. This is the highest specific surface area for a free-standing carbon
film reported to date. A two-electrode supercapacitor using these
carbon films as electrodes demonstrated an excellent high-frequency
response, an extremely low equivalent series resistance on the order
of 0.1 ohm, and a high-power delivery of about 500 kW kg–1. While higher frequency and power values for graphene materials
have been reported, these are the highest values achieved while simultaneously
maintaining excellent specific capacitances and energy densities of
120 F g–1 and 26 W h kg–1, respectively.
In addition, these free-standing thin films provide a route to simplify
the electrode-manufacturing process by eliminating conducting additives
and binders. The synthetic process is also compatible with existing
industrial level KOH activation processes and roll-to-roll thin-film
fabrication technologies.