Journal of the Korean Electrochemical Society (전기화학회지)

The Korean Electrochemical Society (한국전기화학회)
권호 표지
DOI QR코드

DOI QR Code

1-Ethyl-1-Methyl Piperidinium Bis(Trifluoromethanesulfonyl)Imide as a Co-Solvent for Li-ion Battery Electrodes

혼합 용매로서의 1-Ethyl-1-Methyl Piperidinium Bis(Trifluoromethanesulfonyl)Imide의 리튬 이차 전지용 전극별 거동

  • Koh, Ah Reum (Department of Chemistry, Sangmyung University) ;
  • Kim, Ketack (Department of Chemistry, Sangmyung University)
  • Received : 2014.01.10
  • Accepted : 2014.04.20
  • Published : 2014.05.31
Download PDF
⟨ Previous Next ⟩

Abstract

In the study, a room temperature ionic liquids as a co-solvent was used to evaluate the feasibility with various electrodes in Li-ion batteries. 1-Ethyl-1-methyl piperidinium bis(trifluoromethanesulfonyl) imide(PP12 TFSI) is an ionic liquid that melts at $85^{\circ}C$. Pure PP12 TFSI is not able to be used as an electrolyte because it is a solid salt at room temperature. PP12 TFSI is mixed with EC/DEC(1/1 vol.%) to prepare mixed solvents. The electrolyte 1.5M $LiPF_6$ in a mixed solvent having 44 wt.% PP12 TFSI is prepared to evaluated the various electrodes. The electrolytes provides good cycles life of cells with $LiNi_{0.5}Mn_{1.5}O_4(LNMO)$, $LiFePO_4(LFP)$, $Li_4Ti_5O_{12}(LTO)$ and artificial graphite. Further improvement of the cell performances can be accomplished by enhancing wettability of electrolytes to electrodes.

본 연구에서는 리튬 이차 전지의 가연성이 높은 액체 전해액의 대체 또는 개선을 위하여 이온성 액체 전해액으로 전극들에서의 거동을 관찰하였다. 이온성 액체인 1-ethyl-1-methyl piperidinium bis(trifluoromethanesulfonyl)imide(PP12 TFSI)는 녹는점이 $85^{\circ}C$이므로 상온에서 고체상이다. PP12 TFSI를 단독으로 전해액에 사용할 수 없으므로 리튬 이온 전지용 용매와 혼합하여 사용한다. PP12 TFSI를 50 wt.% 이상 사용하면 난연성이 아주 좋은 반면에 점도가 높아서 전해액 함침이 어렵다. 이온성 액체의 비율을 44 wt.%(이온성 액체:용매=1:1.25 wt.%)로 맞추고, 혼합한 용매는 EC/DEC(1/1 vol.%)이며, $LiPF_6$의 농도가 1.5 M이 되도록 전해액을 준비하여 연구하였다. 준비한 전해액은 자가소화시간 25초의 준수한 난연성을 가지고 있으며, 여러 종류의 전극에서도 우수한 수명 성능을 보여주었다. 적용된 전극은 $LiNi_{0.5}Mn_{1.5}O_4(LNMO)$, $LiFePO_4(LFP)$, $Li_4Ti_5O_{12}(LTO)$, artificial graphite이며, 특히 음극으로 사용된 artificial graphite에서의 전해액 분해를 방지하기 위한 첨가제의 거동도 관찰하였다. 여전히 전극으로의 함침의 문제가 다소 관찰이 되었으며 이런 문제가 개선될 수 있는 최적화된 혼합 이온성 액체 전해액이 개발된다면 이온성 액체의 난연성 특성은 더욱 활용성이 높아질 것이다.

Keywords

References

  1. J. B. Goodenough and Y. Kim, 'Challenges for Rechargeable Li Batteries', Chemistry of Materials, 22, 587-603, (2010). https://doi.org/10.1021/cm901452z
  2. C. K. M. Endo, K. Nishimura, T. Fujino, and K. Miyashita, 'Recent development of carbon materials for Li ion batteries', Carbon, 38, 183-197, (2000). https://doi.org/10.1016/S0008-6223(99)00141-4
  3. M. Galinski, A. Lewandowski, and I. Stepniak, 'Ionic liquids as electrolytes', Electrochimica Acta, 51, 5567-5580, (2006). https://doi.org/10.1016/j.electacta.2006.03.016
  4. A. Lewandowski and A. OEwiderska-Mocek, 'Ionic liquids as electrolytes for Li-ion batteries-An overview of electrochemical studies', Journal of Power Sources, 194, 601-609, (2009). https://doi.org/10.1016/j.jpowsour.2009.06.089
  5. J. Xu, J. Yang, Y. NuLi, J. Wang, and Z. Zhang, 'Additive-containing ionic liquid electrolytes for secondary lithium battery', Journal of Power Sources, 160, 621-626, (2006). https://doi.org/10.1016/j.jpowsour.2006.01.054
  6. K. Kim, Y.-H. Cho, and H.-C. Shin, '1-Ethyl-1-methyl piperidinium bis(trifluoromethanesulfonyl)imide as a cosolvent in Li-ion batteries', Journal of Power Sources, 225, 113-118, (2013). https://doi.org/10.1016/j.jpowsour.2012.10.038
  7. S.-Y. Lee, H. H. Yong, S. K. Kim, J. Y. Kim, and S. Ahn, 'Performance and thermal stability of LiCoO2 cathode modified with ionic liquid', Journal of Power Sources, 146, 732-735, (2005). https://doi.org/10.1016/j.jpowsour.2005.03.165
  8. V. Borgel, E. Markevich, D. Aurbach, G. Semrau, and M. Schmidt, 'On the application of ionic liquids for rechargeable Li batteries: High voltage systems', Journal of Power Sources, 189, 331-336, (2009). https://doi.org/10.1016/j.jpowsour.2008.08.099
  9. H. Sakaebe and H. Matsumoto, 'N-Methyl-Npropylpiperidinium bis(trifluoromethanesulfonyl)imide (PP13-TFSI)-novel electrolyte base for Li battery', Electrochemistry Communications, 5, 594-598, (2003). https://doi.org/10.1016/S1388-2481(03)00137-1
  10. R. A. Di Leo, A. C. Marschilok, K. J. Takeuchi, and E. S. Takeuchi, 'Battery electrolytes based on saturated ring ionic liquids: Physical and electrochemical properties', Electrochimica Acta, 109, 27-32, (2013). https://doi.org/10.1016/j.electacta.2013.07.041
  11. M. Montanino, M. Carewska, F. Alessandrini, S. Passerini, and G. B. Appetecchi, 'The role of the cation aliphatic side chain length in piperidinium bis(trifluoromethansulfonyl) imide ionic liquids', Electrochimica Acta, 57, 153-159, (2011). https://doi.org/10.1016/j.electacta.2011.03.089
  12. Y.-H. Cho, K. Kim, S. Ahn, and H. K. Liu, 'Allylsubstituted triazines as additives for enhancing the thermal stability of Li-ion batteries', Journal of Power Sources, 196, 1483-1487, (2011). https://doi.org/10.1016/j.jpowsour.2010.08.085
  13. L. Lombardo, S. Brutti, M. A. Navarra, S. Panero, and P. Reale, 'Mixtures of ionic liquid-Alkylcarbonates as electrolytes for safe lithium-ion batteries', Journal of Power Sources, 227, 8-14, (2013). https://doi.org/10.1016/j.jpowsour.2012.11.017
  14. J. Jin, H. H. Li, J. P. Wei, X. K. Bian, Z. Zhou and J. Yan, 'Li/LiFePO4 batteries with room temperature ionic liquid as electrolyte', Electrochemistry Communications, 11, 1500-1503, (2009). https://doi.org/10.1016/j.elecom.2009.05.040
  15. X.-G. Sun and S. Dai, 'Electrochemical investigations of ionic liquids with vinylene carbonate for applications in rechargeable lithium ion batteries', Electrochimica Acta, 55, 4618-4626, (2010). https://doi.org/10.1016/j.electacta.2010.03.019
  16. L. Hu, Z. Zhang and K. Amine, 'Electrochemical investigation of carbonate-based electrolytes for high voltage lithium-ion cells', Journal of Power Sources, 236, 175-180, (2013). https://doi.org/10.1016/j.jpowsour.2013.02.064
  17. Y. Talyosef, B. Markovsky, G. Salitra, D. Aurbach, H. J. Kim and S. Choi, 'The study of LiNi0.5Mn1.5O4 5-V cathodes for Li-ion batteries', Journal of Power Sources, 146, 664-669, (2005). https://doi.org/10.1016/j.jpowsour.2005.03.064
  18. S. Brutti, G. Greco, P. Reale and S. Panero, 'Insights about the irreversible capacity of LiNi0.5Mn1.5O4 cathode materials in lithium batteries', Electrochimica Acta, 106, 483-493, (2013). https://doi.org/10.1016/j.electacta.2013.05.111
  19. A. Guerfi, M. Dontigny, P. Charest, M. Petitclerc, M. Lagac, A. Vijh and K. Zaghib, 'Improved electrolytes for Li-ion batteries: Mixtures of ionic liquid and organic electrolyte with enhanced safety and electrochemical performance', Journal of Power Sources, 195, 845-852, (2010). https://doi.org/10.1016/j.jpowsour.2009.08.056
  20. K. Zaghib, M. Dontigny, P. Perret, A. Guerfi, M. Ramanathan, J. Prakash, A. Mauger and C. M. Julien, 'Electrochemical and thermal characterization of lithium titanate spinel anode in C-LiFePO4//C-Li4Ti5O12 cells at sub-zero temperatures', Journal of Power Sources, 248, 1050-1057, (2014). https://doi.org/10.1016/j.jpowsour.2013.09.083