US EPA

612488 

Journal Article 

Ru oxide supercapacitors with high loadings and high power and energy densities 

Liu, X; Pickup, PG 

2008 

Yes 

Journal of Power Sources
ISSN: 0378-7753 

176 

1 

410-416 

10.1016/j.jpowsour.2007.10.076 

WOS:000252823400059 

Abstract: Supercapacitors with very high energy and power densities have been constructed with hydrous ruthenium oxide powder prepared by a sol–gel method and annealed at 110°C. Novel features of the capacitors, which improve their performances, are the use of a carbon fibre paper support, a Nafion separator, and Nafion as a binder. 1M sulfuric acid was employed as the electrolyte. The performances of the supercapacitors were characterized by cyclic voltammetry, impedance spectroscopy and constant current discharging. The interfacial capacitance increased linearly with increasing ruthenium oxide loading to at least 50mgcm^{−2} on each electrode. The gravimetric capacitance of the Ru oxide measure by impedance reached 742Fg^{−1} (9.66Fcm^{−2}) at a loading of 13.0mgcm^{−2}, and an interfacial capacitance of 34.9Fcm^{−2} (682Fg^{−1}) was obtained at 51.2mgcm^{−2}. The average effective series resistance was 0.55Ω, the electronic resistance of the electrodes was negligible, and their ionic resistances were <0.42Ω. The average power density for full discharge at 1Acm^{−2} for supercapacitors with 10mgcm^{−2} Ru oxide increased by 39% when 5% Nafion binder was added. The maximum average power density for full discharge was 31.5Wg^{−1} while the maximum energy density was 31.2Whkg^{−1}. At a 1mA discharge rate a specific capacitance of 977Fg^{−1} of Ru oxide was obtained. [Copyright 2008 Elsevier] Copyright of Journal of Power Sources is the property of Elsevier Science Publishers B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts) 

OXIDES; ENERGY storage; IMPEDANCE spectroscopy; POWER resources