DOI QR코드

DOI QR Code

Synthesis of Self-doped Poly(PEGMA-co-BF3LiMA) Electrolytes and Effect of PEGMA Molecular Weight on Ionic Conductivities

자기-도핑형 poly(PEGMA-co-BF3LiMA) 전해질의 합성과 이온전도도에 대한 PEGMA분자량의 영향

  • Kim, Kyung-Chan (Department of Engineering Chemistry, Chungbuk National University) ;
  • Ryu, Sang-Woog (Department of Engineering Chemistry, Chungbuk National University)
  • Received : 2012.10.15
  • Accepted : 2012.11.21
  • Published : 2012.11.30

Abstract

Polymer electrolytes consisted of $BF_3LiMA$ and 300 (PEGMA300) or 1100 (PEGMA1100) g $mol^{-1}$ of PEGMA were prepared and the electrochemical properties were characterized. Interestingly, the AC-impedance measurement shows $1.22{\times}10^{-5}S\;cm^{-1}$ of room temperature ionic conductivity from PEGMA1100 based solid polymer electrolytes while $8.54{\times}10^{-7}S\;cm^{-1}$ was observed in PEGMA300 based liquid polymer electrolytes. The more suitable coordination between lithium ion and ethylene oxide (EO) unit might be the reason of higher ionic conductivity which can be possible in PEGMA1100 based electrolytes since it has 23 EO units in monomer. The lithium ion transference number was found to be 0.6 due to the side reactions between $BF_3$ and lithium metal expecially for longer time but 0.9 was observed within 3000 seconds of measuring time which is strong evidence of a single-ion conductor.

분자량이 각각 300(PEGMA300) 및 1100(PEGMA1100) g $mol^{-1}$인 PEGMA와 합성된 $BF_3LiMA$ 리튬염을 이용하여 다양한 조성의 고분자전해질을 제조하고 전기화학적 특성을 평가하였다. 흥미롭게도 AC-impedance 측정법에 의한 상온 이온전도도는 분자량 $300g\;mol^{-1}$로 합성된 액체 고분자전해질에서 $8.54{\times}10^{-7}S\;cm^{-1}$의 값이 얻어진 반면, PEGMA1100으로 합성된 고체상태의 고분자전해질에서 최대 14배 이상 높은 $1.22{\times}10^{-5}S\;cm^{-1}$가 관찰되었다. 이러한 결과는 PEGMA에 ethylene oxide 단위가 5개인 $300g\;mol^{-1}$보다 23개인 $1100g\;mol^{-1}$에서 리튬이온의 배위가 쉽게 일어나기 때문으로 해석된다. 또한 양이온 수율 측정결과 리튬메탈과 $BF_3$간의 반응으로 인해 0.6의 비교적 낮은 값이 나왔지만 초기 3000초 동안에는 0.9 이상의 값이 관찰되어 단일이온 전도체의 특징을 보여주었다.

Keywords

References

  1. K. Matsushita, Y. Shimazaki, M. A. Mehta, and T. Fujinami, 'Synthesis and characterization of aluminate polymer electrolytes and their blends with poly(ether)s' Solid State Ionics, 133, 295 (2000). https://doi.org/10.1016/S0167-2738(00)00760-8
  2. M. Watanabe, Y. Suzuki, and A. Nishimoto, 'Single ion conduction in polyether electrolytes alloyed with lithium salt of a perfluorinated polyimide' Electrochim. Acta, 45, 1187 (2000). https://doi.org/10.1016/S0013-4686(99)00380-1
  3. X. Sun and C. Angell, 'New single ion conductors ("polyBOP" and analogs) for rechargeable lithium batteries' Solid State Ionics, 175, 743 (2004). https://doi.org/10.1016/j.ssi.2003.11.045
  4. X. Sun, J. Hou, and J. Kerr, 'Comb-shaped single ion conductors based on polyacrylate ethers and lithium alkyl sulfonate' Electrochim. Acta, 50, 1139 (2005). https://doi.org/10.1016/j.electacta.2004.08.011
  5. N. Byrne, D. MacFarlane, and M. Forsyth, 'Composition effects on ion transport in a polyelectrolyte gel with the addition of ion dissociators' Electrochim. Acta, 50, 3917 (2005). https://doi.org/10.1016/j.electacta.2005.02.068
  6. H. Allcock, D. Welna, and A. Maher, 'Single ion conductors-polyphosphazenes with sulfonimide functional groups' Solid State Ionics, 177, 741 (2006). https://doi.org/10.1016/j.ssi.2006.01.039
  7. R. Meziane, J.-P. Bonnet, M. Courty, K. Djellab, and M. Armand, 'Single-ion polymer electrolytes based on a delocalized polyanion for lithium batteries' Electrochim. Acta, 57, 14 (2011). https://doi.org/10.1016/j.electacta.2011.03.074
  8. Y. Zhu, X. Gao, X. Wang, Y. Hou, L. Liu, and Y. Wu, 'A single-ion polymer electrolyte based on boronate for lithium ion batteries' Electrochemistry Communications, 22, 29 (2012). https://doi.org/10.1016/j.elecom.2012.05.022
  9. D. Sadoway, B. Hyang, P. Trapa, P. Soo, P. Bannerjee, and A. Mayes, 'Self-doped block copolymer electrolytes for solid-state rechargeable lithium batteries' J. Power Sources, 97-98, 621 (2001). https://doi.org/10.1016/S0378-7753(01)00642-5
  10. N. Kobayashi, M. Uchiyama, and E. Tsuchida, 'Poly [lithium methacrylate-co-oligo(oxyethylene)methacrylate] as a solid electrolyte with high ionic conductivity' Solid State Ionics, 17, 307 (1985). https://doi.org/10.1016/0167-2738(85)90075-X
  11. D. Benrabah, S. Sylla, F. Alloin, J.-Y. Sanchez, and M. Armand, 'Perfluorosulfonate-polyether based single ion conductors' Electrochim. Acta, 40, 2259 (1995). https://doi.org/10.1016/0013-4686(95)00173-C
  12. T. Fujinami, A. Tokimune, M. Mehta, D. Shriver, and G. Rawsky, 'Siloxyaluminate polymers with high Li+ ion conductivity' Chem. Mater., 9, 2236 (1997). https://doi.org/10.1021/cm970399z
  13. T. Aoki, A. Konno, and T. Fujinami, 'Li-ion conductivity of aluminate and borate complex polymers containing fluoroalkane dicarboxylate' J. Electrochem. Soc., 151(6), A887 (2004). https://doi.org/10.1149/1.1710894
  14. Z. Florjanczyk, W. Bzducha, N. Langwald, J. R. Dygas, F. Krok, and B. Misztal-Faraj, 'Lithium gel polyelectrolytes based on crosslinked maleic anhydride-styrene copolymer' Electrochim. Acta, 44, 3563 (2000).
  15. J. MacCallum, and C. Vincent, 'Polymer Electrolyte Reviews-1' 69, Elsevier Applied Science, New York (1987).
  16. G.-A. Nazri and G. Pistoia, 'Lithium Batteries Science and Technology' 574, Kluwer Academic Publishers, New York (2004).
  17. S.-W. Ryu, P. Trapa, S. Olugebefola, J. Gonzalez-Leon, D. Sadoway, and A. Mayes, 'Effect of counter ion placement on condutcitity in single-ion conducting block copolymer electrolytes' J. Electrochem. Soc., 152(1), A158 (2005). https://doi.org/10.1149/1.1828244
  18. W. Kang, H. Park, K. Kim, and S. Ryu, 'Synthesis and electrochemical properties of lithium methacrylate-based self-doped gel polymer electrolytes' Electrochim. Acta, 54, 4540 (2009). https://doi.org/10.1016/j.electacta.2009.03.050
  19. K. Kim and S. Ryu, 'Synthesis and electrochemical properties of solid polymer electrolytes using BF3LiMA as monomer' J. Kor. Electrochem. Soc., 14, 208 (2011). https://doi.org/10.5229/JKES.2011.14.4.208
  20. S. Celik, and A. Bozkurt, 'Polymer electrolytes based on the doped comb-branched copolymers for Li-ion batteries' Solid State Ionics, 181, 987 (2010). https://doi.org/10.1016/j.ssi.2010.05.039
  21. V. Mauro, A. D'Aprano, F. Croce, and M. Salomon, 'Direct determination of transference numbers of LiClO4 solutions in propylene carbonate and acetonitrile' J. Power Sources, 141, 167 (2005). https://doi.org/10.1016/j.jpowsour.2004.09.015
  22. P. Brucea and C. Vincent, 'Steady state current flow in solid binary electrolyte cells' J. Electroanal. Chem., 225, 1 (1987). https://doi.org/10.1016/0022-0728(87)80001-3
  23. F. Krok, J. Dygas, B. Misztal-Faraj, Z. Florjanczyk, and W. Bzducha, 'Impedance and polarisation studies of new lithium polyelectrolyte gels' J. Power Sources, 81, 766 (1999). https://doi.org/10.1016/S0378-7753(99)00099-3

Cited by

  1. Synthesis of Poly(MMA-co-PEGMA) Electrolytes by Grafting-onto Method and Effect of Composition on Ionic Conductivities vol.16, pp.4, 2013, https://doi.org/10.5229/JKES.2013.16.4.198