DOI QR코드

DOI QR Code

활성탄/리튬티탄산화물 커패시터의 전기화학적 특성에 미치는 비닐에틸렌카보네이트의 영향

Effect of Vinyl Ethylene Carbonate on Electrochemical Characteristics for Activated Carbon/Li4Ti5O12 Capacitors

  • 권용갑 (한국과학기술원 에너지융합센터) ;
  • 최호석 (한국과학기술원 에너지융합센터) ;
  • 이중기 (한국과학기술원 에너지융합센터)
  • Kwon, Yong-Kab (Center for Energy Convergence, Korea Institute of Science and Technology) ;
  • Choi, Ho-Suk (Center for Energy Convergence, Korea Institute of Science and Technology) ;
  • Lee, Joong-Kee (Center for Energy Convergence, Korea Institute of Science and Technology)
  • 투고 : 2012.08.14
  • 심사 : 2012.08.30
  • 발행 : 2012.08.31

초록

비닐에틸렌 카보네이트(VEC: vinyl ethylene carbonate)를 전해질 첨가제로 사용했을 때 하이브리드 커패시터(hybrid capacitors) 전극에서 나타나는 전기화학적 특성변화에 대해서 고찰하였다. 하이브리드 커패시터는 양극은 활성탄(AC : activated carbon) 음극은 리튬티타늄옥사이드(LTO: $Li_4Ti_5O_{12}$)를 사용하였고, 전해질로서는 에틸렌 카보네이트(EC: ethylene carbonate): 디메틸 카보네이트 (DMC: dimethyl carbonate) : 에틸메틸 카보네이트(EMC : ethyl methyl carbonate)를 사용하였고, 염으로 육불화인산리튬($LiPF_6$: lithium hexafluoro phosphate)을 사용하였다. 전극 표면의 산소관능기 그룹을 제거하고, 표면을 환원시킴으로써 전극에 안정성을 향상시킨다고 알려진 VEC의 첨가량에 따른 전기화학적 특성을 평가하였으며, 0.7%(부피비)의 VEC첨가시, 가장 우수한 전기화학적 특성을 얻을 수 있었다. 0.7% 이상 첨가하였을 경우, 오히려 부반응 증가로 전기화학적 성능이 감소하였다. X-ray photoelectron spectrocopy (XPS) 결과로부터 LTO 전극에서 VEC가 첨가되지 않은 전해질에 비해 LiF가 감소한 것을 확인 할 수 있었다. VEC가 첨가되지 않은 전해질은 2500 사이클 후, 43.2 %의 용량 유지를 나타냈지만, 최적화된 VEC 첨가를 통하여 82.7 %의 높은 용량을 유지하는 특성을 가진 하이브리드 커패시터를 얻을 수 있었다.

We employed the vinyl ethylene carbonate (VEC) as an electrolyte additive and investigated the effect of the electrolyte additive on the electrochemical performance in hybrid capacitor. The activated carbon was adopted as cathode material, and the $Li_4Ti_5O_{12}$ oxide was used as anode material. The electrolyte was prepared with the $LiPF_6$ salt in the mixed solvent of ethylene carbonate (EC), dimethyl carbonate (DMC), and ethyl methyl carbonate(EMC). We evaluated the electrochemical performance of the hybrid capacitor with increasing the amount of the VEC electrolyte additive, which is known as the remover of oxygen functional group and the stabilizer of the electrode by reducing the surface of electrode, and obtained the superior performance data especially at the addition of the VEC electrolyte additive of around 0.7 vol%. On the contrary, the addition of the VEC more than 0.7 vol% in the electrolyte leads to the degradation in electrochemical performance of hybrid capacitor, suggesting the increase of the side reaction from the excessive VEC additive. X-ray photoelectron spectroscopy (XPS) revealed that the addition of the VEC suppressed the formation of LiF component, which is known as the insulator, on the surface of electrode. The optimized addition of VEC exhibited the improved capacity retention around 82.7% whereas the bare capacitors without VEC additive showed the 43.2% of capacity retention after 2500 cycling test.

키워드

참고문헌

  1. E. F. Camacho, T. Samad, M. Garcia-Sanz, and I. Hiskens, 'Control for renewable energy and smart grids' The Impact of Control Technology, Control Systems Soc., 69 (2011).
  2. C. A. Nogueira and F. Delmas, 'New flowsheet for the recovery of cadmium, cobalt and nickel from spent Ni- Cd batteries by solvent extraction' Hydrometallurgy, 52, 267 (1999). https://doi.org/10.1016/S0304-386X(99)00026-2
  3. T. OHZUKU, A. Ueda, M. Nagayama, Y. Iwakcihi, and H. Komori, 'Comparative study of Li$CoO_{2}$, $LiNi_{1/2}Co_{1}/_{2}O_{2}$ and $LiNiO_{2}$ for 4 volt secondary lithium cells' Electrochimica Acta., 38, 1159 (1993). https://doi.org/10.1016/0013-4686(93)80046-3
  4. J.-M. Tarascon, A. S. Gozdz, C. Schmutz, F. Shokoohi, and P. C. Warren, 'Performance of Bellcore's plastic rechargeable Li-ion batteries' Solid State tonics, 86, 49 (1996). https://doi.org/10.1016/0167-2738(96)00330-X
  5. J. Shim, R. Kostecki, T. Richardson, X. Song, and K. A. Striebel, 'Electrochemical analysis for cycle performance and capacity fading of a lithium-ion battery cycled at elevated temperature' J. Power Sources, 112, 222 (2002). https://doi.org/10.1016/S0378-7753(02)00363-4
  6. M. Winter and R. J. Brodd, 'What are batteries, fuel cells, and supercapacitors?" Chem. Rev., 104, 4245 (2004). https://doi.org/10.1021/cr020730k
  7. A. Burke, 'R&D considerations for the performance and application of electrochemical capacitors' Electrochim. Acta, 53, 1083 (2007). https://doi.org/10.1016/j.electacta.2007.01.011
  8. G. G. Amatucci, F. Badway, A. D. Pasquier, and T. Zheng, 'An asymmetric hybrid nonaqueous energy storage cell' J. Electrochem. Soc., 148, 930 (2001). https://doi.org/10.1149/1.1383553
  9. A. D. Pasquier, I. Plitz, S. Menocal, and G. Amatucci, 'A comparative study of Li-ion battery, supercapacitor and nonaqueous asymmetric hybrid devices for automotive applications' J. Power Sources, 115, 171 (2003). https://doi.org/10.1016/S0378-7753(02)00718-8
  10. J. R. Dahn and J. A. Seel, 'Energy and capacity projections for practical dual-graphite cells' J. Electrochem. Soc., 147, 899 (2000). https://doi.org/10.1149/1.1393289
  11. A. Yoshino, T. Tsubata, M. Shimoyamada, H. Satake, Y. Okano, S. Mori, and S. Yata, 'Development of a lithium-type advanced energy storage device' J. Electrochem. Soc., 151, 2180 (2004). https://doi.org/10.1149/1.1813671
  12. T. Aida, I. Murayama, K. Yamada, M. Morita, 'Analyses of capacity loss and improvement of cycle performance for a high-voltage hybrid electrochemical capacitor' J. Electrochem. Soc., 154, 798 (2007).
  13. S.-W.Woo, K. Dokko, H. Nakano, and K. Kanamura, 'Bimodal porous carbon as a negative electrode material for lithium-ion capacitors' Electrochemistry, 75, 635 (2007). https://doi.org/10.5796/electrochemistry.75.635
  14. N. Ogihara, Y. Igarashi, A. Kamakura, K. Naoi, Y. Kusachi, and K. Utsugi, 'Disordered carbon negative electrode for electrochemical capacitors and high-rate batteries' Electrochim. Acta, 52, 1713 (2006). https://doi.org/10.1016/j.electacta.2006.01.082
  15. V. Khomenko, E. Pinero, and F. Beguin, 'High-energy density graphite/AC capacitor in organic electrolyte' J. Power Sources, 177, 643 (2008). https://doi.org/10.1016/j.jpowsour.2007.11.101
  16. K. Naoi and P. Simon, 'New materials and new configurations for advanced electrochemical capacitors' J. Electrochem. Soc., Interface 17, 34 (2008).
  17. M. Inaba, H. Tomiyasu, A. Tasaka, S.-K. Jeong, and Z. Ogumi, 'Atomic force microscopy study on the stability of a surface film formed on a graphite negative electrode at elevated temperatures' Langmuir, 20, 1348 (2004). https://doi.org/10.1021/la035857z
  18. M. Masatoshi, U. Satoshi, Y. Eriko, K. Keiji, and I. Shinji, 'Development of long life lithium ion battery for power storage' J. Power Sources, 101, 53 (2001). https://doi.org/10.1016/S0378-7753(01)00554-7
  19. N. Kiyoshi, N. Ryosuke, M. Tomoko, and M. Hiroshi, 'Preparation of particulate $Li_{4}Ti_{5}O_{12}$ having excellent characteristics as an electrode active material for power storage cells' J. Power Sources, 117, 131 (2003). https://doi.org/10.1016/S0378-7753(03)00169-1
  20. S. S. Zhang, K. Xu, and T. R. Jow, 'EIS study on the formation of solid electrolyte interface in Li-ion battery' Electrochim. Acta, 51, 1636 (2006). https://doi.org/10.1016/j.electacta.2005.02.137
  21. H. Schranzhofer, J. Bugajski, H. J. Santner, C. Korepp, K.-C. Moller, J. O. Besenhard, M. Winter, and W. Sitte, 'Electrochemical impedance spectroscopy study of the SEI formation on graphite and metal electrodes' J. Power Soureces, 153, 391 (2006). https://doi.org/10.1016/j.jpowsour.2005.05.034
  22. S. S. Zhang, K. Xu, and T. R. Jow, 'Optimization of the forming conditions of the solid-state interface in the Liion batteries' J. Power Soureces, 130, 281 (2004). https://doi.org/10.1016/j.jpowsour.2003.12.012
  23. Y. Fu, C. Chen, C. Qiu, and X. Ma, 'Vinyl ethylene carbonate as an additive to ionic liquid electrolyte for lithium ion batteries' J. Appl Electrochem, 39, 2597 (2009). https://doi.org/10.1007/s10800-009-9949-4
  24. W. Yao, Z. Zhang, J. Gao, J. Li, J. Xu, Z. Wang, and Y. Yang, 'Vinyl ethylene sulfite as a new additive in propylene carbonate-based electrolyte for lithium ion batteries' Energy & Environ. Sci., 2, 1102 (2009). https://doi.org/10.1039/b905162g
  25. Y. Hu, W, Kong, H, Li, X, Huang, L, Chen, 'Experimental and theoretical studies on reduction mechanism of vinyl ethylene carbonate on graphite anode for lithium ion batteries' Electrochemistry Commu., 6, 126 (2004). https://doi.org/10.1016/j.elecom.2003.10.024
  26. L. Chen, K. Wang, X. Xie, and J. Xie, 'Effect of vinylene carbonate (VC) as electrolyte additive on electrochemical performance of Si film anode for lithium ion batteries' J. Power Sources, 174, 538 (2007). https://doi.org/10.1016/j.jpowsour.2007.06.149
  27. A. Schechter, D. Aurbach, and H. Cohen, 'X-ray photoelectron spectroscopy study of surface films formed on Li electrodes freshly prepared in alkyl carbonate solutions' Langmuir, 15, 3334 (1999). https://doi.org/10.1021/la981048h
  28. D. Bar-Tow, E. Peled, and L. Bursteinb, 'A study of highly oriented pyrolytic graphite as a model for the graphite anode in Li-ion batteries' J. Electrochem. Soc., 146, 824 (1999). https://doi.org/10.1149/1.1391688
  29. H. Ota, Y. Sakata, A. Inoue, and S. Yamaguchi, 'Analysis of vinylene carbonate derived SEI layers on graphite anode' J. Electrochem. Soc., 151, 1659 (2004). https://doi.org/10.1149/1.1785795
  30. A. Bismarck, R. Tahhan, J. Springer, A. Schulz, T. M. Klapijtke, H. Zell, and W. Michaeli, 'Influence of fluorination on the properties of carbon fibres' J. Fluorine Chem., 84, 127 (1997). https://doi.org/10.1016/S0022-1139(97)00029-8
  31. A. M. Andersson and K. Edstrom, 'Chemical composition and morphology of the elevated temperature SEI on graphite' J. Electrochem. Soc., 148, 1100 (2001). https://doi.org/10.1149/1.1397771