Membrane Journal (멤브레인)

The Membrane Society of Korea (한국막학회)
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Behaviors of Ionic Conductivity with Temperature for High-Temperature PEMFC Containing Room Temperature ionic Liquids Under Non-humidified Condition

상온 이온액을 이용한 고온 무수 PEMFC용 고정화 액막의 온도에 따른 이온전도도 거동

  • Kim, Beom-Sik (Chemical Process and Engineering Center, Korea Research Institute of Chemical Technology) ;
  • Byun, Yong-Hoon (Chemical Process and Engineering Center, Korea Research Institute of Chemical Technology) ;
  • Park, You-In (Chemical Process and Engineering Center, Korea Research Institute of Chemical Technology) ;
  • Lee, Sang-Hak (Chemical Process and Engineering Center, Korea Research Institute of Chemical Technology) ;
  • Lee, Jung-Min (Chemical Process and Engineering Center, Korea Research Institute of Chemical Technology) ;
  • Koo, Kee-Kahb (Department of Chemical and Biomolecular Engineering, Sogang University)
  • 김범식 (한국화학연구원 화학공정연구센터) ;
  • 변용훈 (한국화학연구원 화학공정연구센터) ;
  • 박유인 (한국화학연구원 화학공정연구센터) ;
  • 이상학 (한국화학연구원 화학공정연구센터) ;
  • 이정민 (한국화학연구원 화학공정연구센터) ;
  • 구기갑 (서강대학교 화공생명공학과)
  • Published : 2006.12.31
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Abstract

Novel SILEMs were prepared by multi-stage phase separation process combined by the low temperature phase separation (LTPS) and the high temperature phase separation (HTPS) using room temperature ionic liquids (RTILs) which have a high ionic conductivity. PVDF and imidazolium series ionic liquids were used as membrane material and electrolyte, respectively. To study the ion conducting properties, the SILEMs were tested using LCR meter at temperature controlled from 30 to $130^{\circ}C$. Under humid conditions, with increasing temperature from 30 to $100^{\circ}C$, the ion conductivity of the cast $Nafion^{(R)}$ membrane increased linearly, but then started to decrease after $100^{\circ}C$. However, in the case of the SILEMs, with increasing operating temperature, the ion conductivity increased. Also, the ion conductivity behaviors of the SILEMs were almost same, regardless of humidity. The ion conductivity of the SILEMs was $2.7{\times}10^{-3}S/cm$ and increased almost linearly up to $2.2{\times}10^{-2}S/cm$ with increasing temperature to $130^{\circ}C$. The effects of an inorganic filler on the physical properties of the SILEMs were studied using the $SiO_2$. The addition of $SiO_2$ could improve the mechanical strength of the SILEMs, though the ionic conductivity was decreased slightly.

이온전도도가 높은 상온 이온액을 이용하여 저온, 고온 상분리에 의한 multi-stage phase separation process로 새로운 고정화 이온액 전해질 막(supported ionic liquid electrolyte membranes, SILEMs)을 제조하였다. PVDF와 imidazolium계 이온액을 각각 분리막 소재와 전해액으로 사용하였다. 이온전도도 특성을 알아보기 위해 SILEMs을 LCR meter를 이용 해 $30^{\circ}C$부터 $130^{\circ}C$까지 실험하였다. 가습조건에서 cast Nafion 막의 이온전도도는 $30^{\circ}C$부터 $100^{\circ}C$까지는 직선적으로 증가하였으나 그 이후에는 감소하였다. 그러나 SILEMs의 경우 운전온도의 증가에 따라 이온전도도가 증가하였다. 또한 SILEMs의 이온전도도 거동은 가습과 관계없이 거의 같았다. SILEMs의 이온전도도는 $30^{\circ}C$에서 $2.7{\times}10^{-3}S/cm$이었고 온도가 $130^{\circ}C$까지 증가함에 따라 $2.2{\times}10^{-2}S/cm$까지 거의 직선적으로 증가하였다. $SiO_2$를 이용하여 SILEMs의 물리적 성질에 대한 무기첨가제의 영향에 관하여 연구하였다. SILEMs에 $SiO_2$의 첨가는 비록 약간의 이온전도도 감소는 있으나 SILEMs의 기계적 강도를 향상시킬 수 있었다.

Keywords

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