Effect of Temperature on Electrochemical Degradation of Membrane in PEMFC

PEMFC 고분자 막의 전기화학적 열화에 미치는 온도의 영향

  • Lee, Ho (Department of Chemical Engineering, Sunchon National University) ;
  • Kim, Taehee (Department of Chemical Engineering, Sunchon National University) ;
  • Son, Ik Jae (HMC Eco Technology Research Institute) ;
  • Lee, Jong Hyun (HMC Eco Technology Research Institute) ;
  • Lim, Tae Won (HMC Eco Technology Research Institute) ;
  • Park, Kwonpil (Department of Chemical Engineering, Sunchon National University)
  • 이호 (순천대학교 화학공학과) ;
  • 김태희 (순천대학교 화학공학과) ;
  • 손익제 (현대자동차 환경기술연구소) ;
  • 이종현 (현대자동차 환경기술연구소) ;
  • 임태원 (현대자동차 환경기술연구소) ;
  • 박권필 (순천대학교 화학공학과)
  • Received : 2009.06.04
  • Accepted : 2009.06.22
  • Published : 2009.08.31

Abstract

Effect of temperature on membrane degradation in PEMFCs was studied. After cell operation at different temperatures($60{\sim}90^{\circ}C$) under accelerating degradation conditions(OCV, anode dry, cathode RH 65%) for 144 h, cell performance decreased from 12 to 35%. The results of FER in effluent water showed that this decrease in cell performance was caused by membrane degradation by the attack of $H_2O_2$ or oxygen radicals(${\cdot}OH$, $HO_2{\cdot}$) and that resulted in increase in gas crossover for radical formation. Radical formation on the electrode was confirmed by ESR. Activation energy of 66.2 kJ/mol was obtained by Arrhenius plot used to analyze the effect of temperature on membrane degradation. Increase of cell temperature enhanced gas crossover rate, radical formation rate and membrane degradation rate.

고분자전해질 막의 전기화학적 열화에 미치는 온도의 영향에 대해 연구하였다. 가속 열화 조건(OCV, anode 무가습, cathode 65% RH)에서 셀 온도를 변화시켜 144시간 운전한 후 셀 성능은 12에서 35%까지 감소하였다. 이러한 성능 감소는 FER(Fluoride Emission Rate) 측정에서 알 수 있듯이 과산화수소 혹은 산소라디칼(${\cdot}OH$, $HO_2{\cdot}$)의 공격에 의한 막의 열화에 따른 것으로 라디칼 형성을 위한 가스 crossover의 증가를 가져왔다. 전극에서의 라디칼 생성은 ESR로 확인하였다. 고분자막 열화의 온도 의존성을 나타내는 Arrhenius plot에 얻어진 활성화 에너지 값은 66.2 kJ/mol이었다. 셀 작동온도 증가는 라디칼 형성속도와 라디칼이 막을 공격하는 반응 속도뿐 아니라 가스 crossover 속도도 증가시켜 막 열화를 가속화시켰다.

Keywords

Acknowledgement

Supported by : 산업자원부

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