Preparation and Characterization of PVdF-HFP Microporous Membranes for Li-ion Rechargeable Battery

Poly(vinylidene fluoride-hexafluoropropylene)를 이용한 이차전지용 미세다공성 분리막의 제조와 물성

  • Nam, Sang-Yong (School of Nano and Advanced Materials Engineering, i-Cube Center, Engineering Research Institute, Gyeongsang National University) ;
  • Yu, Dae-Hyun (School of Nano and Advanced Materials Engineering, i-Cube Center, Engineering Research Institute, Gyeongsang National University) ;
  • Jeong, Mi-Ae (School of Nano and Advanced Materials Engineering, i-Cube Center, Engineering Research Institute, Gyeongsang National University) ;
  • Rhim, Ji-Won (Department of Chemical Engineering, Hannam University) ;
  • Byun, Hong-Sik (Department of Chemical System Engineering, Keimyung University) ;
  • Yoo, Hyun-Oh (School of Chemical Engineering, Hanyang University) ;
  • Kim, Jong-Man (School of Chemical Engineering, Hanyang University) ;
  • Seo, Myung-Su (Special Battery Division Research Institute R&D Team, Bexel Corporation)
  • 남상용 (경상대학교 나노신소재공학과, 아이큐브 사업단) ;
  • 유대현 (경상대학교 나노신소재공학과, 아이큐브 사업단) ;
  • 정미애 (경상대학교 나노신소재공학과, 아이큐브 사업단) ;
  • 임지원 (한남대학교 생명.나노 과학대학 나노생명화학공학과) ;
  • 변홍식 (계명대학교 화학시스템공학과) ;
  • 유현오 (한양대학교 공과대학 응용화학공학부) ;
  • 김종만 (한양대학교 공과대학 응용화학공학부) ;
  • 서명수 ((주)벡셀 특수전지사업부 기술연구소 연구개발팀)
  • Published : 2007.12.30

Abstract

The copolymer membranes, poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) were prepared by phase inversion method using as an additive 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 highest porosity of the membrane was 60%. The surface and cross-section of the membranes was observed with a scanning electron microscopy (SEM). The mechanical property of the membrane was determined by using an universal testing machine (UTM). Tensile strength of measured membranes is presented the maximum 6.57 MPa at 30 wt% of PVdF-HFP.

본 연구에서는 불소계 고분자인 PVdF (poly(vinylidene fluoride))에 HFP (hexafluoropropylene)가 결합된 공중합체인 PVdF-HFP로 충전용 이차전지의 분리막으로 쓰이는 다공성 막을 상전이 방법으로 제조하였다. 용매인 DMF (N,N-dimethylformamide)에 PVdF-HFP를 단일상으로 녹인 후 깨끗한 유리판에 캐스팅하여 막을 얻었다. 기공은 증류수로 채워진 응고조에서 용매-빈용매 교환으로 형성되어진다. 얻어진 분리막에서 가장 높은 공극률은 60%로 얻어졌다. 시차주사현미경(scanning electron microscopy, SEM)을 이용하여 분리막의 단면 관찰을 통해 다공성을 확인하였고 UTM (universal testing machine)을 이용하여 측정된 분리막의 인장강도는 PVdF-HFP 30 wt%에서 최대 6.57 MPa의 값을 나타내었다.

Keywords

References

  1. 이영무, 오부근, '리튬이온 이차전지에서의 미세다공성 격리막의 역할', 한국막학회지, 7(3), 123-130 (1997)
  2. 이영무, 이창현, 박호범, 임지원, 하성용, 강종석, 남상용, '리튬이온 2차전지용 분리막', 한국막학회지, 14(4), 263-274 (2004)
  3. Y. J. Hwang, S. K. Jeong, K. S. Nahm, and A. Manuel Stephan, 'Electrochemical studies on poly(vinylidene fluoride-hexafluoropropylene) membranes prepared by phase inversion method', Eur. Polym. J., 43, 65-71 (2007) https://doi.org/10.1016/j.eurpolymj.2006.10.020
  4. 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, 3219-3225 (2000) https://doi.org/10.1149/1.1393886
  5. A. Magistris, P. Mustarelli, and E. Quartarone, 'Poly(vinylidene fluoride)-based porous electrolytes', Electrochim Acta., 46, 1635-1639 (2001) https://doi.org/10.1016/S0013-4686(00)00764-7
  6. 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, 7908 (2006)
  7. 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. Membrane Sci., 272, 11-14 (2006) https://doi.org/10.1016/j.memsci.2005.12.038
  8. 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, 657-660 (2001) https://doi.org/10.1016/S0378-7753(01)00596-1
  9. 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)
  10. 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, 286-92 (2002) https://doi.org/10.1016/S0378-7753(01)00868-0
  11. A. Manuel Stephan, 'Dale-teeters characterization of PVdF-HFP polymer membranes prepared by phase inversion technique-morphology and charge-discharge studies', Electrochim Acta., 48, 2143-2148 (2003) https://doi.org/10.1016/S0013-4686(03)00197-X
  12. A. Manuel Stephan, K. S. Nahm, M. Anbukulandai Nathan, G. Ravi, and J. Wilson, 'Inert filler incorporated PVdF-HFP composite electrolytes for lithium batteries', J. Power Sources, 159, 1316-21 (2006) https://doi.org/10.1016/j.jpowsour.2005.11.055
  13. 변홍식, 박병규, 홍병표, 여광수, 윤무홍, 강남주, 'Pore-filled PVDF 이온교환막의 제조 및 응용', 한국막학회지, 14(2), 108-116 (2004)
  14. A. Bottino, G. Camera-Roda, G. Capanelli, and S. Munari, 'The formation of microporous polyvinylidene difluoride membranes by phase separation', J. Mem. Sci., 57, 1-20 (1991) https://doi.org/10.1016/S0376-7388(00)81159-X
  15. 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, 249-257 (2000) https://doi.org/10.1016/S0167-2738(00)00371-4
  16. 유대현, 정미애, 임지원, 변홍식, 정철호, 이영무, 서명수, 남상용, '이차전지용 미세다공성 PVdF 분리막의 제조와 물성', 한국막학회지, 17(3), 233-243 (2007)