Nanoporous carbons from cypress II. Application to electric double layer capacitors

• Published in: New carbon materials Vol. 22; no. 4; pp. 321 - 326
• Main Authors: Ito, Eiki, Mozia, Sylwia, Okuda, Masaharu, Nakano, Takashi, Toyoda, Masahiro, Inagaki, Michio
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-12-2007
• Subjects: Cypress charcoal; Electric double layer capacitor; NiO loading; Super-heated steam; Cypress charcoal; Electric double layer capacitor; NiO loading; Super-heated steam
• ISSN: 1872-5805; 1872-5805
• DOI: 10.1016/S1872-5805(08)60003-7

Cypress charcoals, which were prepared under super-heated steam and had a relatively large amount of mesopores, were used in electric double layer capacitors (EDLCs) in 1 mol/L H
2SO
4 electrolyte. The gravimetric capacitance of cypress charcoals was about 190 F/g at a current density of 50 mA/g (
C
50) and 140 F/g at 1000 mA/g (
C
1000) and the performance rating defined by
C
1000/
C
50 was about 0.72. The capacitance observed was explained by the contributions from the surfaces from the micropores and the larger pores. By loading minute NiO particles through a simple impregnating process, the capacitance of the loaded charcoals was enhanced by about 13% in gravimetric capacitance and by about 27% in volumetric capacitance and the performance rating was kept the same.