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The Membrane Society of Korea (한국막학회)
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Preparation and Characterization of PVdF Microporous Membranes with PEG Additive for Rechargeble Battery

Poly(ethylene glycol)를 첨가한 이차전지용 poly(vinylidene fluoride) 미세다공성 분리막의 제조와 물성

  • Nam, Sang-Yong (School of Materials Science and Engineering, Engineering Research Institute, i-Cube Center, Gyeongsang National University) ;
  • Jeong, Mi-Ae (School of Materials Science and Engineering, Engineering Research Institute, i-Cube Center, Gyeongsang National University) ;
  • Yu, Dae-Hyun (School of Materials Science and Engineering, Engineering Research Institute, i-Cube Center, Gyeongsang National University) ;
  • Koh, Mi-Jin (School of Materials Science and Engineering, Engineering Research Institute, i-Cube Center, Gyeongsang National University) ;
  • Rhim, Ji-Won (Department of Chemical Engineering, Hannam University) ;
  • Byun, Hong-Sik (Department of Chemical System Engineering, Keimyung University) ;
  • Seo, Myung-Su (Special Battery Division Research Institute R&D Team, Bexel Corporation)
  • 남상용 (경상대학교 나노신소재공학부, 공학연구원, 아이큐브 사업단) ;
  • 정미애 (경상대학교 나노신소재공학부, 공학연구원, 아이큐브 사업단) ;
  • 유대현 (경상대학교 나노신소재공학부, 공학연구원, 아이큐브 사업단) ;
  • 고미진 (경상대학교 나노신소재공학부, 공학연구원, 아이큐브 사업단) ;
  • 임지원 (한남대학교 생명.나노 과학대학 나노생명화학공학과) ;
  • 변홍식 (계명대학교 화학시스템공학과) ;
  • 서명수 ((주)벡셀 특수전지사업부 기술연구소 연구개발팀)
  • Published : 2008.03.30
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Abstract

Poly(vinylidene fluoride) has received much attention in the last several years for the lithium secondary batteries. In this study, to enhance the porosity, PVdF was prepared by phase inversion method using as an additive, PEG (poly(ethylene glycol)), with N,N-dimethylformamid as a solvent. The pores are generated during the solvent and non-solvent exchange process in the coagulation bath filled with non-solvent (distilled water). The surface and cross-section of the membranes were observed with a scanning electron microscopy (SEM). The mechanical property of the membrane was determined by using an universal testing machine (UTM) and thermal property was verified by heat shrinkage. Uniformed sponge structure of PVdF-PEG membrane for the lithium secondary batteries was prepared with 10 wt% of PEG concentration in the PVdF-PEG solution. Porosity, elongation and tensile strengh of the membrane were 87%, 75.45%, and 275. 27 MPa respectively.

본 연구에서는 기존의 이차전지의 분리막보다 좋은 성능으로 각광받고 있는 PVdF (poly(vinylidene fluoride))에 공극률을 높여 전지의 성능을 향상시켜주는 수용성 고분자인 PEG (Poly(ethylene glycol))를 첨가하여 충전용 리튬 이차전지의 분리막을 상전이 방법으로 제조하였다. 용매인 DMF (N,N-dimethylformamide)에 PVdF-PEG를 단일상으로 녹인 후 깨끗한 유리판에 캐스팅하여 막을 얻었다. 기공은 증류수로 채워진 응고조에서 용매-빈용매 교환으로 형성되어진다. 주사전자현미경(scanning electron microscopy, SEM)을 이용하여 분리막의 단면 관찰을 통해 다공성을 확인하였고 UTM (universal testing machine)을 이용하여 기계적 물성을 확인하였다. PEG-10의 정체시간 30 s에서 균일한 스폰지 구조를 확인할 수 있었으며, 이는 87%의 뛰어난 공극률을 가지며 인장강도의 경우 PEG-10에서 3.72 MPa로 가장 크게 나타났고, 신장률과 모듈러스 부분에서도 역시 75.45%와 275.27 MPa로 뛰어난 성능을 나타냈다.

Keywords

References

  1. Y. M. Lee, C. H. Lee, H. B. Park, J. W. Rhim, S. Y. Ha, J. S. Kang, and S. Y. Nam, 'Separation for Li-Ion Secondary Batteries', Membrane J., 14(4), 263 (2004)
  2. Y. J. Hwang, S. K. Jeong, K. S. Nahm, and A. M. Stephan, 'Electrochemical studies on poly(vinylidene fluoride-hexafluoropropylene) membranes prepared by phase inversion method', Eur. Polym. J., 43, 65 (2007) https://doi.org/10.1016/j.eurpolymj.2006.10.020
  3. J. Y. Song, Y. Y. Wang, and C. C. Wan, 'Conductivity study of porous plasticized polymer electrolytes based on poly(vinylidene fluoride), a comparison with poly propylene separators', J. Electrochem Soc., 147, 3219 (2000) https://doi.org/10.1149/1.1393886
  4. A. Magistris, P. Mustarelli, and E. Quartarone, 'Poly(vinylidene fluoride)-based porous electrolytes', Electrochim Acta., 46, 1635 (2001) https://doi.org/10.1016/S0013-4686(00)00764-7
  5. W.-H. Seol, Y. M. Lee, and J.-K. Park, 'Preparation and characterization of new microporous stretched membrane for lithium rechargeable battery', J. Power Sources, 163(1), 247 (2006) https://doi.org/10.1016/j.jpowsour.2006.02.076
  6. G. G. Kumar, P. Kim, K. S. Nahm, and R. N. Elizabeth, 'Structural characterization of PVdF-HFP/PEG/$Al_2O_3$ proton conduction membarnes for fuel cells', J. Membr. Sci., 393, 126 (2007)
  7. A. M. Stephan, K. S. Nahm, M. A. Nathan, G. Ravi, and J. Wilson, 'Nanofiller incorporated PVdF-HFP composite electrolytes for lithium batteries', J. Power Sources, 159(2), 1316 (2006) https://doi.org/10.1016/j.jpowsour.2005.11.055
  8. A. Du Pasquier, P. C. Warren, D. Culver, A. S. Gozdz, G. G. Amatucci, and J. M. Tarascon, 'Plastic PVDF-HFP electrolyte laminates prepared by a phase-inversion process', Solid State Ionics, 135, 249 (2000) https://doi.org/10.1016/S0167-2738(00)00371-4
  9. W. Pu, X. He, L. Wang, C. Jiang, and C. Wan, 'Preparation of PVdF-HFP microporous membrane for Li-ion batteries by phase inversion', J. Membr. Sci., 272, 11 (2006) https://doi.org/10.1016/j.memsci.2005.12.038
  10. A. Magistris, P. Mustarelli, F. Parazzoli, E. Quartarone, P. Piaggio, and A. Bottino, 'Structure, porosity and conductivity of PVdF films for polymer electrolytes', J. Power Sourecs, 97-98, 657 (2001) https://doi.org/10.1016/S0378-7753(01)00644-9
  11. K. Gao, X. Hu, C. Dai, and T. Yi, 'Crystal structures of electrospun PVdF membranes and its separator application for rechargeable lithium metal cells', Materials Science and Engineering B, 10840 (2006)
  12. Q. Shi, M. Yu, X. Zhou, Y. Yan, and C. Wan, 'Structure and performance of porous polymer electrolytes based on P(VdF-HFP) for lithium batteries', J. Power Sources, 103, 286 (2002) https://doi.org/10.1016/S0378-7753(01)00868-0
  13. D. H. Yu, M. A. Jeong, J. W. Rhim, H. S. Byun, C. H. Jeong, Y. M. Lee, M. S. Seo, and S. Y. Nam, 'Preparation and Characterization of Microporous PVdF Membrane for Li-ion Rechargeable battery, Membrane J., 17(3), 233 (2007)
  14. D. H. Yu, M. A. Jeong, J. W. Rhim, H. S. Byun, H. O. Yoo, J. M. Kim, M. S. Seo, and S. Y. Nam, 'Preparation and Characterization of PVdFHFP Microporous Membranes for Li-ion rechargeable Battery', Membrane J., 17(4), 359 (2007)