Highly Conductive and Porous Activated Reduced Graphene Oxide Films for High-Power Supercapacitors
2012; American Chemical Society; Volume: 12; Issue: 4 Linguagem: Inglês
10.1021/nl203903z
ISSN1530-6992
AutoresLili Zhang, Xin Zhao, Meryl D. Stoller, Yanwu Zhu, Hengxing Ji, Shanthi Murali, Yaping Wu, Stephen Perales, Brandon Clevenger, Rodney S. Ruoff,
Tópico(s)Advancements in Battery Materials
ResumoWe 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 m(2) 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.
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