Korean Chemical Engineering Research, Vol.45, No.2, 178-182, April, 2007
LiMn2O4/C 복합 양극을 이용한 비수계 슈퍼커패시터의 제조
The Preparation of Non-aqueous Supercapacitors with LiMn2O4/C Composite Positive Electrodes
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초록
LiMn2O4와 활성탄을 양극의 활물질로 사용하여 비수계 슈퍼커패시터를 제조하고 LiMn2O4의 함량에 따른 특성을 분석하였다. Cyclic voltammetry, AC impedance 분석 등을 통하여, 활성탄의 전기 이중층으로 인한 capacitive 효과에 Li+ 이온의 intercalation/deintercalation에 의한 faradaic 효과가 더해진 pseudocapacitance의 발현을 확인할 수 있었으며, LiMn2O4의 함량이 증가할수록 비정전용량 및 에너지 밀도가 증가하는 것을 확인할 수 있었다. LiMn2O4:C의 비율이 0.86:0.14인 복합 양극을 사용하여, 순수 활성탄 양극 대비 2배 이상인 23.83 F/cc의 비정전용량과 17.51 Wh/L의 에너지밀도를 얻을 수 있었다. 또한, 1,000회 충방전 후에도 60% 이상 향상된 비정전용량과 에너지 밀도를 얻을 수 있었다.
Non-aqueous supercapacitors by using activated C and LiMn2O4 as an active material in a positive electrode were prepared and characterized. From the cyclic voltammetry and AC impedance analysis, the capacitive effect by electric double layer of activated carbon and the faradic effect by intercalation/deintercalation of Li+ ion were observed. Increasing the ratio of LiMn2O4, specific capacitances and energy densities of supercapacitor were increased. At the ratio of 0.86:0.14 (LiMn2O4:C), the maximum specific capacitance of 17.51 Wh/L and energy density of 23.83 F/cc were obtained, which were more than twice of those for a conventional electric double layer capacitor. Even after 1,000 charge/discharge cycle, the supercapacitor by using the electrode containing 14% of activated carbon and 86% of LiMn2O4 showed 60% better specific capacitance and energy density than that by using the electrode containing 100% activated carbon.
Keywords:Supercapacitor;Non-aqueous;Composit Electrode;Lithium Manganese Oxide;Activated Carbon;High Energy Density;High Specific Capacitance
- Conway BE, Electrochemical Supercapacitors, Scientific Fundamentals and Technological Applications, Kluwer Academic Publishers/Plenum Publishers, New York (1999)
- Miller JM, Dunn B, Tran TD, Pekala RW, J. Electrochem. Soc., 144(12), L309 (1997)
- Sato Y, Yomogida K, Nanaumi T, Kobayakawa K, Ohsawa Y, Kawai M, Electrochem. Solid State Lett., 3, 113 (2000)
- Kim KM, Hur JW, Jung S, Kang AS, Electrochim. Acta, 50(2-3), 863 (2004)
- Frackowiak E, Beguin F, Carbon, 39, 937 (2001)
- Michio O, Makoto T, US patent, US 20020012223 (2002)
- Rarnani M, Haran BS, White RE, Popov BN, J. Electrochem. Soc., 148(4), A374 (2001)
- Srinivasan V, Weidner JW, J. Electrochem. Soc., 144(8), L210 (1997)
- Liu KC, Anderson MA, J. Electrochem. Soc., 143(1), 124 (1996)
- Pasquier AD, Du Pasquier A, Plitz I, Gural J, Badway F, Amatucci GG, J. Power Sources, 136, 161 (2004)
- Tukamoto H, West AR, J. Electrochem. Soc., 144(9), 3164 (1997)
- Wang YG, Xia YY, J. Electrochem. Soc., 153(2), A450 (2006)
- Jow TR, Zheng JP, J. Electrochem. Soc., 145(1), 49 (1998)
- Taberna PL, Simon P, Fauvarque JF, J. Electrochem. Soc., 150(3), A292 (2003)
- Michael MS, Prabaharan SRS, J. Power Sources, 136(2), 250 (2004)
- Amatucci GG, Badway F, Du Pasquier A, Zheng T, J. Electrochem. Soc., 148(8), A930 (2001)