Article
  • Thermal and Electrical Properties of Poly(vinylidenefluoride-hexafluoropropylene)-based Gel-Electrolytes
  • Kim YW, Choi BK, Ahn SH
  • Poly(vinylidenefluoride-hexafluoropropylene)계 겔-전해질의 열적, 전기적 특성
  • 김영완, 최병구, 안순호
Abstract
Polymer electrolyte films consisting of poly( vinylidenefluoride-hexanuorofluoro-propylene) (PVdF-HFP), LiClO4 and a mixture of ethylene carbonate(EC) and γ-butyrolactone(GBL) were examined in order to obtain the best compromise between high ionic conductivity, homogeniety, dimensional and electrochemical stability, Measurements of ionic conductivity, differential scanning calorimetry and linear sweep voltammetry have been carried out for various compositions. The highest conductivity of 3.8 x 10-3 Scm-1 at 30 ℃ were obtained for a film of 30 (PVdF-HFP) + 7.8LiClO4 + 62.2EC/GBL, From the DSC study, it has been found that the PVdF-HFP gels are stable up to 100 ℃, and the salt lowers the melting temperature of crystalline part of PVdF by interacting sensitively with polymer segments. When Lithium metal is in contact with the gel films, it tends to undergo corrosion and the reaction products accumulate resulting in the formation of a passive film on Li electrode. As the aging time progresses, the interfacial resistance increases continuously. Anodic stability is measured to extend up to about 4.5 V vs. Li.

이온전도도가 높으며 균일하고 또 기계적 강도와 전기화학적 안정성이 우수한 전해질막을 얻기 위하여 poly(vinylidenefluoride-hexafluoropropylene)(PVdF-HFP) 공중합체를 전해질의 지지체로 선택하고, LiClO4 염이 포함된 ethylene carbonate(EC)와 Υ-butyrolactone(GBL)의 혼합용매를 사용하여 겔-전해질을 제조하였다. 다양한 조성의 겔-전해질에 대하여 이온전도도, 열분석 및 선형주사전위 실험을 수행하였다. 이온전도도는 30PVdF-HFP＋7.8LiClO4+62.2EC/GBL 전해질막에서 3.8×10-3 Scm-1로 가장 높았다. 열분석 결과에서 대부분의 시료는 대략 100℃ 정도까지는 안정하였으며, 특히 염은 고분자 사슬과 민감하게 반응하여 PVdF 결정질의 고온용융점을 낮추는 것을 확인하였다. 리튬 금속과 전해질 사이의 부식에 의해 생성된 부동태막에 의해 계면저항이 시간에 따라 계속적으로 증가하는 것을 확인하였으며, anodic stability는 대략 4.5 V vs. Li까지 안정한 것으로 측정되었다.

Keywords: Ionic conductivity; PVdF-HFP; Polymer electrolyte; Gel electrolyte

References
  • 1. Croce F, Gerace F, Dautzemberg G, Passerini S, Appetecchi GB, Scrosati B, Electrochim. Acta, 39(14), 2187 (1994)
  •  
  • 2. Abraham KM, Choe HS, Pasquariello DM, Electrochim. Acta, 43(16-17), 2399 (1998)
  •  
  • 3. Matsuda Y, Morita M, Tsutsumi H, J. Power Sources, 43-44, 439 (1993)
  •  
  • 4. Selvaraj II, Chaklanobis S, Chandrasekhar V, J. Electrochem. Soc., 142(2), 366 (1995)
  •  
  • 5. Tunemi K, Ohno H, Tsuchida E, Electrochim. Acta, 28, 833 (1982)
  •  
  • 6. Tarascon JM, Schmutz S, Gozdz AS, Warren PC, Shokoohi FK, Mater. Res. Soc. Symp. Proc., 369, 595 (1995)
  •  
  • 7. Pistoia G, Antonini A, Wang G, J. Power Sources, 58, 139 (1996)
  •  
  • 8. Gozdz AS, Tarascon JM, Gebizlioglu OS, Schmutz CN, Warren PC, Shokoohi FKRechargrable Li and Li-ion Batteries, eds. S. Megahed, B.M. Barnett, and L. Xie, Electrochem. Soc., Pennington, 1995 (1995)
  •  
  • 9. Beeman RG, J. Polym. Sci., 9, 472 (1953)
  •  
  • 10. Thevenin JG, Muller RH, J. Electrochem. Soc., 134, 273 (1987)
  •  
  • 11. Morzilli S, Bonini F, Scrosati B, Electrochim. Acta, 32, 961 (1987)
  •  
  • 12. Aurbach D, Weissman I, Zaban A, Chusid O, Electrochim. Acta, 39(1), 51 (1994)
  •  
  • Polymer(Korea) 폴리머
  • Frequency : Bimonthly(odd)
    ISSN 0379-153X(Print)
    ISSN 2234-8077(Online)
    Abbr. Polym. Korea
  • 2022 Impact Factor : 0.4
  • Indexed in SCIE

This Article

  • 2000; 24(3): 382-388

    Published online May 25, 2000