DOI QR코드

DOI QR Code

Comparison between Acid and Heat Treatment for Capacity Enhancement of RuO2/MWNT Composite Electrode Materials for Ultracapacitor

울트라캐패시터용 RuO2/MWNT 복합 전극재료의 용량개선을 위한 산처리 및 열처리 효과 비교

  • 김용태 (부산대학교 기계공학부)
  • Published : 2010.01.01

Abstract

In this study, we compared two methods(an acid treatment in strong acid reflux and a heat treatment in air atmosphere) for hydrophilic surface treatment of multi-walled carbon nanotubes(MWNT) to enhance the capcity of $RuO_2$/MWNT composite electrode materials for ultracapacitor. Both treatments generated a number of defects on the surface of MWNT by the breakage of $\pi$ bond in graphene layer at which carboxyl groups were introduced. However, the degree of hydrophilicity generated by strong acid treatment was higher than that by heat treatment in air, which was revealed by the quantitative measurement of surface carboxyl groups by using Boehm titration. The increased hydrophilicity save rise to an improved dispersity of $RuO_2$ nanoparticles on MWNT. Finally, the improved dispersity resulted in the capacity enhancement of composite electrode materials for ultracapacitor.

References

  1. 전흥신, 김형택, “에너지 연소 환경”, 한티미디어, p. 27, 2006.
  2. 양민복, “미래형 자동차”, 인터비전, p. 183, 2007.
  3. B. E. Conway, "Electrochemical supercapacitor: Scientific fundamentals and technological applications", Kluwer academic, p. 259, 1999.
  4. H. Liang, F. Chen, R. Li, L. Wang, and Z. Deng, "Electrochemical study of activated carbon-semiconducting oxide composites as electrode materials of double-layer capacitors", Electrochim. Acta., Vol. 49, p. 3463, 2004. https://doi.org/10.1016/j.electacta.2004.03.016
  5. M. Ramani, B. S. Haran, R. E. White, B. N. Popov, and L. Arsov, "Studies on activated carbon capacitor materials loaded with different amounts of ruthenium oxide", J. Power Sources, Vol. 93, p. 209, 2001. https://doi.org/10.1016/S0378-7753(00)00575-9
  6. X. Qin, S. Durbach, and G. T. Wu, "Electrochemical characterization on $RuO_2.xH_2O/carbon$ nanotubes composite electrodes for high energy density supercapacitors", Carbon, Vol. 42, p. 451, 2004. https://doi.org/10.1016/j.carbon.2003.11.012
  7. J. Ko, K. Ryu, S. Kim, and K. Kim, "Supercapacitive properties of composite electrodes consisting of polyaniline, carbon nanotube, and $RuO_2$", J. Appl. Electrochem., Vol. 39, p. 1331, 2009. https://doi.org/10.1007/s10800-009-9800-y
  8. Y. Kim, K. Tadai, and T. Mitani, "Highly dispersed ruthenium oxide nanoparticles on carboxylated carbon nanotubes for supercapacitor electrode materials", J. Mater. Chem., Vol. 15, p. 4914, 2005. https://doi.org/10.1039/b511869g
  9. J. Park, J. Ko, and O. Park, "Carbon $nanotube/RuO_2$ nanocomposite electrodes for supercapacitors", J. Electrochem. Soc., Vol. 150, p. A864, 2003. https://doi.org/10.1149/1.1576222