Converting rice husk activated carbon into active material for capacitor using three-dimensional porous current collector

• Published in: Journal of power sources 2011-12, Vol.196 (24), p.10788-10790
• Main Authors: Kuratani, Kentaro, Okuno, Kazuki, Iwaki, Tsutomu, Kato, Masahiro, Takeichi, Nobuhiko, Miyuki, Takuhiro, Awazu, Tomoyuki, Majima, Masatoshi, Sakai, Tetsuo
• Format: Article
• Language: English
• Subjects: Accumulators; Aluminum; Applied sciences; Capacitors; Capacitors. Resistors. Filters; Collectors; Discharge; Electric double layer capacitor; Electrical engineering. Electrical power engineering; Exact sciences and technology; Foils; Internal resistance; Oryza sativa; Rice; Rice husk activated carbon; Three dimensional; Three dimensional current collector; Various equipment and components
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2011.09.001

► Application of rice husk activated carbon to electric double layer capacitor. ► The discharge capacity at 50 mA g −1: 14 mAh g −1 (3D) vs. 14 mAh g −1 (Al foil). ► The discharge capacity at 1000 mA g −1: 12 mAh g −1 (3D) vs. 4.5 mAh g −1 (Al foil). ► The cycle durability after 5000 cycles: 95% (3D) vs. 30% (Al foil). We have successfully applied rice husk activated carbon (RHAC) as an active material for the electric double layer capacitor using a three-dimensional (3D) porous current collector. The capacity and cycle stability were evaluated in a 1.0 mol dm −3 tetraethylammonium tetrafluoroborate/propylene carbonate solution in the range of 0–2.5 V. The specific capacity of the RHAC was about 14 mAh g −1 at the 50 mA g −1 discharge rate, corresponding to 19 F g −1 under the present conditions. The RHAC cell using the 3D porous current collector possessed a lower internal resistance and better high-rate discharge properties than the RHAC cell using a conventional aluminum (Al) foil collector. After 5000 cycles of charging and discharging, the RHAC cell with the 3D current collector maintained 95% of its initial capacity, while the capacity of the one with the Al foil collector dropped to only 30%.